Core 111

Question 1

Duncan, Dunne & Petty (1968) concerns a detailed analysis of the void index of rock materials classified by their absolute geological age. Rock materials were initially laid down as loose sands or muds, sediments have been subjected to substantial overburden pressures during the course of geological time. Which of the following is NOT true?
A. As the depositional load increased, lower layers suffered a volume reduction largely attributable to an increase of the pore volume of the rock.
B. With decreasing pore volume the deposit progressively increased in strength.
C. All through the course of geological time progressive loading results in constant changes in the texture, pore volume and strength of the materials.
D. At high overburden pressures there is a welding together of individual grains arising largely from high stresses at point contacts between grains and consequently from a pressure-solution effect.

Answer 1

A. As the depositional load increased, lower layers suffered a volume reduction largely attributable to an increase of the pore volume of the rock.

Statement A is incorrect because as the depositional load increases due to the weight of overlying sediments, the pore volume of the rock actually decreases, not increases. The increased pressure compresses the material, squeezing out water or air from the spaces between grains (the pores). This reduction in pore volume is the primary cause of the overall volume reduction of the rock layers.

Question 2

The Third Fan Law states that the fan-power input varies directly as the fan speed cubed and directly as the air density. Twice the volume requires how many times of the power?
A. 4 times
B. 6 times
C. 8 times
D. 9 times

Answer 2

C. 8 times

W2/W1=(2*N1/N1)^3
W2/W1=2^3
W2/W1=8

First Fan Law: The volume of air (Q) is directly proportional to the fan speed (N).
Q2/Q1=N2/N1

​Second Fan Law: The pressure (P) varies as the square of the fan speed.
P2/P1=(N2/N1)^2

Third Fan Law: The power input (W) varies as the cube of the fan speed.
W2/W1=(N2/N1)^3

Question 3

How many rare earth elements are there?
A. 15
B. 16
C. 17
D. 18

Answer 3

C. 17

There are 17 rare earth elements (REEs). This group includes the 15 lanthanide elements on the periodic table, plus scandium and yttrium.

Lanthanides (15): Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Lutetium (Lu).
Other Elements (2): Scandium (Sc) and Yttrium (Y).

Although they are called “rare,” many are actually quite abundant in the Earth’s crust. Their name comes from the fact that they are not often found in concentrated, economically viable deposits, making their extraction difficult and costly.

Question 4

In underground timbering, what do you call that small part that is used to tighten spaces between timber, and reduce sliding or movements between timber and tunnel walls?
A. Cap
B. Splice
C. Wedge
D. Girt

Answer 4

C. Wedge.

In underground timbering, a wedge is a small, tapered piece of wood or metal used to fill and tighten the gaps between the timber supports and the surrounding rock or soil. This action serves several crucial purposes:

A. Cap: The horizontal timber placed on top of the vertical posts. It’s the primary support for the roof of the tunnel.
B. Splice: A method of joining two pieces of timber together end-to-end to create a longer support. It’s a connection, not a filler.
D. Girt: A horizontal timber member that connects and braces the posts in a timber set. It resists lateral pressure from the tunnel walls.

Question 4

Which of the following is the revised Mines Safety Rules and Regulations of 1991?
A. MAO No. MRD 51
B. MAO No. MRD 21
C. DENR Administrative Order No. 82, Series of 1990
D. DAO 2000-98

Answer 4

A. MAO No. MRD 51.

The Mines Administrative Order No. MRD 51, also known as the Revised Mines Safety Rules and Regulations of 1991, was a key policy issued by the Department of Environment and Natural Resources (DENR) of the Philippines. It was a significant document that governed the safety, health, and welfare of workers in the mining industry. This order provided a comprehensive framework for ensuring safe mining operations and preventing accidents.

It’s important to note that these rules were later replaced and superseded by subsequent administrative orders. For example, DAO 2000-98 (Mine Safety and Health Standards) was a more recent set of regulations that further updated and expanded on the provisions of MAO No. MRD 51, aligning them with the provisions of the Philippine Mining Act of 1995 (RA 7942).

Question 4

In 2014, what was DOE’s estimate of the Potential Coal Resources of the Philippines?
A. 1,600 MMT
B. 2,100 MMT
C. 2,400 MMT
D. 3,600 MMT

Answer 4

C. 2,400 MMT.

According to the Department of Energy’s (DOE) 2014 data, the potential coal resources of the Philippines were estimated at 2.4 billion metric tons (BMT), which is equivalent to 2,400 million metric tons (MMT).

Question 5

In a typical nickel laterite profile, which of the following zones contains the highest Nickel concentration?
A. Limonite
B. Transition zone
C. Saprolite
D. Ultramafic bedrock

Answer 5

C. Saprolite

Located directly above the bedrock, this is the most important ore zone for nickel laterites. It is characterized by its soft, clay-like texture, which retains the original rock structure. During weathering, magnesium and silica are leached out, while nickel, which is not as mobile, is left behind and concentrated. This process significantly increases the nickel grade, making the saprolite zone the primary target for mining.

Question 5

The Fourth Industrial Revolution is also called?
A. Digital Era
B. Information Era
C. Automation Era
D. Technological Revolution

Answer 5

A. Digital Era.

The Fourth Industrial Revolution, or Industry 4.0, is fundamentally about the convergence of digital and physical technologies. This includes artificial intelligence, the Internet of Things (IoT), robotics, and big data. These technologies are blurring the lines between the physical, digital, and biological spheres, which is why “Digital Era” is the most accurate description.

Question 6

The interest charge on borrowing that’s calculated using an original principal amount only and an interest rate that never changes. The amount of interest earned is proportional to the principal amount.
A. Compound interest
B. Simple interest
C. Nominal interest
D. Effective interest

Answer 6

B. Simple interest.

Simple interest is calculated solely on the original principal amount. The interest rate remains constant over the life of the loan or investment, and the interest earned or charged each period is a fixed amount. This is different from compound interest, where interest is calculated on both the principal and any previously accumulated interest.
Interest=Principal+Rate+Time

A. Compound interest is calculated on the principal and the accumulated interest from previous periods.
C. Nominal interest is the stated or advertised interest rate before accounting for compounding or inflation.
D. Effective interest is the true or actual interest rate earned or paid on a loan, taking into account the effects of compounding over a year.

Question 6

Portion of a deposit overlying an excavation and left in place.
A. Sill
B. Crown
C. Rib
D. Island

Answer 6

B. Crown.

In mining, a crown pillar is a block of ore or waste rock that is left in place to provide structural support. Specifically, it’s the portion of the ore body located at the top of an excavation, often between a stope (an underground excavation where ore is removed) and the overlying ground surface or a previously mined area.

A. Sill: A sill pillar is similar to a crown pillar but is the portion of the deposit left at the bottom of an excavation to support the floor or the workings below.
C. Rib: A rib pillar is a block of ore left between two adjacent stopes or workings to support the sidewalls (or “ribs”) of the excavation.
D. Island: While “island” can be used in some mining contexts to describe an isolated body of rock, it’s not a standard term for a structural support pillar left in place to protect the area above an excavation.

Question 7

Which of the following is not a direct method of mineral prospecting?
A. Visual examination of outcrop
B. Visual examination of float
C. Aerial Photography
D. Airborne survey

Answer 7

C. Aerial Photography or D. Airborne survey

Mineral prospecting is the process of searching for mineral deposits. This can be done through direct and indirect methods. Direct methods involve physically observing and analyzing the earth’s surface and rock formations to find minerals. Indirect methods use remote sensing, geophysical, and geochemical techniques to infer the presence of minerals without direct physical contact.

Visual examination of outcrop: This is a direct method. An outcrop is a visible exposure of bedrock or rock strata on the surface of the earth.
Visual examination of float: This is also a direct method. Float refers to rock fragments or minerals that have been transported from their original source, usually by erosion.

Aerial photography: This is an indirect method. It involves taking photographs from an aircraft to create detailed images of the ground.
Airborne survey: This is an indirect method. This involves using specialized sensors on an aircraft or helicopter to measure geophysical properties of the earth, such as magnetic fields, gravity, or electrical conductivity.

Question 7

The test involves heating the coal under various conditions for variable amounts of time to determine moisture, volatile matter, fixed carbon, and ash yield. This one of the first analyses performed on coal after mining.
A. Ultimate analysis
B. Primary analysis
C. Proximate analysis
D. Heat analysis

Answer 7

C. Proximate analysis.

Proximate analysis is a fundamental and common test performed on coal and other fuels to determine their key components by heating a sample under controlled conditions. It provides a quick and valuable assessment of the coal’s quality for various commercial and industrial applications.

1. Moisture: The water content of the coal, which reduces its heating value and increases transportation costs.
2. Volatile Matter: The gaseous components (like methane, hydrogen, and hydrocarbons) that are released when the coal is heated. High volatile matter content means the coal ignites more easily and burns with a longer, more smoky flame.
3. Fixed Carbon: The solid, combustible material that remains after moisture and volatile matter are removed. It’s the primary source of heat from the coal, and a higher percentage generally indicates better quality.
4. Ash: The inorganic, non-combustible residue left after the coal is completely burned. High ash content reduces the heating value and can cause issues with equipment and waste disposal.

Question 8

What is referred to as the ratio of the weight of water absorbed to the weight of dry rock?
A. Porosity
B. Void index
C. Permeability
D. Saturation

Answer 8

D. Saturation (nearest) but not the correct answer, it should be water content or moisture content.

A. Porosity: It is the ratio of the volume of voids (empty spaces) to the total volume of the rock. It’s a measure of the rock’s capacity to hold fluids, not the actual amount of fluid it currently contains by weight.
B. Void index: This is not a standard term. The correct term is void ratio which is the ratio of the volume of voids to the volume of solid particles. It’s a different measure from porosity.
C. Permeability: It is a measure of a rock’s ability to transmit fluids. It describes how well the pores are interconnected, allowing fluids to flow through the material.
D. Saturation: It is the ratio of the volume of water to the volume of voids. It’s a measure of how full the void spaces are with water.

Question 8

Which of the following is not a product of chemical grade chromite ore?
A. Pigments
B. Wood preservatives
C. Ferrochrome
D. Leather tanning salts

Answer 8

C. Ferrochrome. This is a product of metallurgical grade chromite ore. It’s a key ingredient in making stainless steel, not a chemical product.

A&B. Pigments: These, along with wood preservatives, are also products of chemical grade chromite ore. Chromium compounds are used to create vivid, stable pigments for paints and dyes.
D. Leather Tanning Salts: These are indeed products of chemical grade chromite ore. The primary chemical used for tanning leather is chromium sulfate, which is produced from chemical-grade chromite. This process is known as chrome tanning.

Question 9

A type of contour map that displays the stratigraphic thickness between an upper and lower horizon. It is measured as the shortest distance between the two surfaces. It is a map that joins contour lines of equal thickness over an area.
A. Isopach map
B. Isochron map
C. Isochore map
D. Isobase map

Answer 9

A. Isopach map. An isopach map is a type of contour map used in geology and petroleum exploration that shows the stratigraphic thickness of a rock layer. The term is derived from the Greek words “iso” (equal) and “pachys” (thick). The thickness is measured as the true stratigraphic thickness (TST), which is the shortest distance perpendicular to the bedding planes between the upper and lower surfaces of the unit.

B. Isochron map: An isochron map shows lines of equal travel time. This is commonly used in seismic surveys to map subsurface features based on the time it takes for seismic waves to travel to a specific geological horizon and back.
C. Isochore map: An isochore map also shows the thickness of a stratigraphic unit, but the thickness is measured vertically instead of perpendicular to the bedding. This is known as true vertical thickness (TVT).
D. Isobase map: An isobase map is a geographical map that shows lines connecting points of equal uplift or subsidence since a specific geological time, such as the last glacial period.

Question 10

Those underground and surface mines/service contractor employing a total of not less than twenty five (25) employees and not more than fifty (50) employees, respectively, to not more than fifty (50) and seventy-five (75) employees, respectively.
A. Class B
B. Class A
C. Class D
D. Class C

Answer 10

D. Class C

Class “A”: Underground and surface mines/service contractors employing a total of not less than 150 and 250 employees, respectively.

Class “B”: Underground and surface mines/service contractors employing a total of not less than 50 and 75 employees, respectively, to not more than 150 and 250 employees, respectively.

Class “C”: Underground and surface mines/service contractors employing a total of not less than 25 employees and not more than 50 employees, respectively, to not more than 50 and 75 employees, respectively.

Class “D”: Underground and surface mines/service contractors employing a total of not more than 25 and 50 personnel, respectively.

Question 10

Which of the following is the simplest beneficiation used in coal?
A. Flowing film concentration
B. Hand sorting
C. Jigging
D. Gravity concentration

Answer 10

B. Hand sorting. It is a rudimentary and direct method of mineral processing. It involves manually separating valuable coal from waste rock (known as gangue) based on visual differences in color, size, and shape.

A. Flowing film concentration: This is a gravity concentration method. It uses a thin layer of flowing water over an inclined surface to separate minerals based on differences in density and particle size. Examples include sluices and shaking tables.
C. Jigging: Jigging is a mechanical gravity concentration process. It uses a pulsating fluid (usually water) to create a stratified bed of particles. Heavier particles sink, and lighter particles (the coal) rise, allowing for separation.
D. Gravity concentration: This is a broad category of beneficiation methods that includes jigging, flowing film concentration, dense-medium separation, and spirals.

Question 11

This is a comprehensive study of a range of options for the technical and economic viability of a mineral project that has advanced to a stage where a preferred mining method, underground or surface, has been selected and an effective method of mineral processing has been determined. It includes a financial analysis based on reasonable assumptions on the Modifying Factors and the evaluation of any other relevant factors which are sufficient for an ACP, acting reasonably, to determine if all or part of the Mineral Resource may be converted to a Mineral Reserve at the time of reporting.
A. Feasibility Study
B. Pre-feasibility Study
C. Definitive Feasibility Study
D. Scoping Study

Answer 11

A. Feasibility Study. Often referred to as a Definitive Feasibility Study (DFS) or Bankable Feasibility Study (BFS), is the final, most detailed, and most accurate study in the mineral project development cycle.

Question 11

What is the heat content of coal mined and used (both imported and exported) in the Philippines?
A. 8,000 BTU/lb
B. 10,000 BTU/lb
C. 12,000 BTU/lb
D. 15,000 BTU/lb

Answer 11

A. 8,000 BTU/lb

Philippine coal is primarily classified as low-rank coal, specifically sub-bituminous and lignite. A 2016 study on the Philippine coal industry from the DOE noted that the country’s coal is generally of low rank quality, with an average heating value of 8,810 BTU/lb.

A local coal supplier specifies that their local coal, sourced from Semirara, has a Gross Calorific Value (GCV) of 5000-5400 kcal/kg, which is equivalent to approximately 9,000-9,700 BTU/lb.

While the Philippines does import higher-grade coal (often from Indonesia) with a calorific value of 10,000 BTU/lb or higher for specific industrial uses, the overall average heat content of the domestically mined and consumed coal is significantly lower.

Question 12

In the engineering classification of intact rocks on the basis of modulus ratio, an intact rock having a modulus ratio of 200 is categorized as?
A. Class II High modulus ratio
B. Class III Medium modulus ratio
C. Class V Low modulus ratio
D. Class VI Very Low modulus ratio

Answer 12

B. Class III Medium modulus ratio

Class I High modulus ratio (H): Modulus Ratio > 500
Class II Medium modulus ratio (M): Modulus Ratio 200 to 500
Class III Low modulus ratio (L): Modulus Ratio < 200

Question 12

Which of the following is not one of the purposes of benches in open pit mining?
A. Control the depth of the blast holes.
B. Control the grade of the blocks.
C. Control slope of the pit walls.
D. Control the dangers of highwall faces.

Answer 12

B. Control the grade of the blocks.

A. Control the depth of the blast holes: Benches provide a level surface from which to drill blast holes. This ensures that the holes are drilled to a uniform, predetermined depth, which is critical for achieving a controlled and effective blast.
C. Control slope of the pit walls: The benches divide the high walls of the pit into smaller, manageable sections. This design allows for the overall pit slope to be controlled, ensuring the long-term stability of the mine walls and preventing large-scale failures.
D. Control the dangers of highwall faces: Benches act as safety catchments for falling rocks and debris from the wall above. They provide a safe working platform for equipment and personnel and help reduce the risk of rockfalls.

Question 12

In the engineering classification of intact rocks on the basis of strength, an intact rock having an ultimate compressive strength between 8,000 to 16,000 lbs/sq in is categorized as?
A. Class A Very high strength
B. Class B High strength
C. Class C Medium strength
D. Class D Low strength

Answer 12

C. Class C Medium strength

Class A: Very high strength: Over 2250 kg/cm² ≈ Over 32,000 lbs/sq in
Class B: High strength: 1125 to 2250 kg/cm² ≈ 16,000 to 32,000 lbs/sq in
Class C: Medium strength: 562.5 to 1125 kg/cm² ≈ 8,000 to 16,000 lbs/sq in
Class D: Low strength: 281.25 to 562.5 kg/cm² ≈ 4,000 to 8,000 lbs/sq in

Question 12

This geophysical method is used to detect heavy minerals like galena, chromite, pyrite, and chalcopyrite, as well as to locate geologic structures such as faults, anticlines, salt domes, intrusions, and buried channel which can be applied either on the ground or from an aircraft.
A. Gravimetric
B. Electromagnetic
C. Seismic
D. Resistivity

Answer 12

B. Electromagnetic

The Electromagnetic (EM) method is specifically designed to measure variations in the ground’s electrical conductivity. It works by inducing an electrical current and then measuring the resulting secondary magnetic field. This makes it highly effective at pinpointing buried conductive mineral deposits, such as massive sulfide ores containing pyrite and chalcopyrite.

A. Gravimetric: This method measures density variations, not electrical conductivity. While it can detect dense bodies like some intrusions and salt domes (which are less dense than their surroundings), it is not the primary method for directly detecting conductive sulfide minerals like pyrite or chalcopyrite.
C. Seismic: This method uses sound waves to map subsurface rock layers and structural features. It is excellent for imaging faults and anticlines but is not used to detect specific mineral types based on their density or conductivity.
D. Resistivity: This is a ground-based method that measures electrical resistance. While it can be used to locate some of the features mentioned, it is not typically performed from an aircraft, making it an incomplete fit for the description.

Question 12

The FCF Minerals of the Runruno Gold-Molybdenum Project in Nueva Vizcaya uses what mining method?
A. Block caving
B. Open Pit
C. Shrinkage stoping
D. Cut-and-Fill stoping

Answer 12

B. Open Pit. A method where ore and waste rock are extracted from a series of benches in a large, open excavation.

A. Block caving: This is a large-scale underground mining method that involves undermining a large ore body and allowing it to cave in under its own weight.
C. Shrinkage stoping: This is an underground mining method where ore is mined from a stope and a portion is left in place to provide a working platform and support the walls.
D. Cut-and-Fill stoping: This is another underground mining method where mined ore is replaced with backfill material. It is a labor-intensive method used for smaller, higher-grade deposits.

Question 12

This is comprised of the weight of the overburden and any tectonic forces acting at depth. A. Overburden pressure B. Tensile force C. Principal forces D. Superincumbent load

Answer 12

D. Superincumbent load. A superincumbent load refers to the total weight and pressure exerted on a rock mass or a geological formation at depth. This load is comprised of two primary components: 1. Overburden Pressure (or Lithostatic Stress): This is the vertical pressure caused by the gravitational weight of all the overlying rock and sediment layers. This force acts downward and increases with depth. 2. Tectonic Forces: These are the horizontal and vertical forces created by plate tectonics, such as compression from colliding plates or tension from separating plates. These forces contribute to the overall stress state at depth, alongside the weight of the overburden. B. Tensile force: This is a specific type of stress that pulls a rock apart. C. Principal forces: This is a general term in rock mechanics for the three mutually perpendicular stress components (vertical, maximum horizontal, and minimum horizontal) that act on a body.

Question 12

What is an overshot in diamond drilling? A. A tool with flat bottom tip diamond. Used to grind away material encountered. B. A drilling accessory used to help start drilling, keeps diamond drill in place and prevents it from wobbling, frequently used when drilling horizontal surface. C. A part of the diamond drill that goes into drilling machine chuck or collet. Most types used for diamond drills are a straight stem with or without hole in center. D. A fishing tool that is attached to tubing or drill pipe and lowered over the outside wall of pipe or sucker rods lost or stuck in the wellbore.

Answer 12

D. A fishing tool that is attached to tubing or drill pipe and lowered over the outside wall of pipe or sucker rods lost or stuck in the wellbore.

Question 12

A mining method that recovers coal or other minerals from under the highwall when the ultimate stripping ratio has been achieved in open cast mining operations. A. Hydraulicking B. Gloryhole mining C. Auger mining D. Solution mining

Answer 12

C. Auger mining Once the stripping ratio (the ratio of waste rock to ore) becomes too high to continue open-pit operations economically, auger mining is used as a low-cost method to extract the remaining mineral from the exposed seam. A. Hydraulicking: This method uses high-pressure jets of water to excavate material. B. Gloryhole mining: This is a method of underground mining where ore is funneled into a central raise or shaft by gravity. It is used for large, steep ore bodies. D. Solution mining: This method involves injecting a solvent into a mineral deposit to dissolve the target mineral, which is then pumped to the surface. It is used for deposits like uranium, potash, and salt.

Question 12

According to the fan laws, twice the volume develops how many times the pressure? A. 2 times the pressure B. 4 times the pressure C. 5 times the pressure D. 8 times the pressure

Answer 12

B. 4 times the pressure First Fan Law: The volume of air (Q) is directly proportional to the fan speed (N). Q2/Q1=N2/N1 ​Second Fan Law: The pressure (P) varies as the square of the fan speed. P2/P1=(N2/N1)^2 Third Fan Law: The power input (W) varies as the cube of the fan speed. W2/W1=(N2/N1)^3

Question 12

The ratio of the confining pressure to the fractional reduction of volume in response to the applied hydrostatic pressure. A. Shear modulus B. Young’s modulus C. Poisson’s ratio D. Bulk modulus

Answer 12

D. Bulk modulus. The bulk modulus (K) is a measure of a substance's resistance to uniform compression. It is defined as the ratio of the confining pressure (or hydrostatic stress) applied to a material to the resulting fractional reduction of its volume (volumetric strain). A. Shear modulus (G)/modulus of rigidity: This modulus measures a material's resistance to shearing or twisting forces, which change its shape without changing its volume. It is the ratio of shear stress to shear strain. B. Young’s modulus (E)/modulus of elasticity: This modulus measures a material's resistance to change in length under tensile or compressive stress. It is the ratio of normal stress to longitudinal strain. C. Poisson’s ratio (ν): This is a dimensionless ratio that describes the change in a material's width relative to its change in length when stretched or compressed. It is the ratio of lateral strain to axial strain.

Question 12

According to Mine Safety Rules, all underground mines shall have at least how many interconnected, properly maintained openings to the surface? A. 1 B. 2 C. 3 D. 4

Answer 12

B. 2 This is a fundamental safety rule designed to ensure that miners have a safe way to enter and exit the mine and to provide an alternative escape route in case of an emergency, such as a fire, explosion, or cave-in. ne opening serves as the primary access and ventilation path, while the second acts as a dedicated escapeway and is crucial for rescue and emergency ventilation.

Question 12

Which of the following is not used in the geophysical exploration of Petroleum? A. Gravimetric B. Seismic C. Induced Polarization D. Magnetic

Answer 12

C. Induced Polarization The Induced Polarization (IP) method measures a rock's ability to temporarily store and release an electrical charge, a property known as chargeability. This method is a powerful tool in mineral exploration because it is highly effective at detecting disseminated sulfide minerals, such as pyrite, chalcopyrite, and galena, which are often associated with valuable metal deposits like gold, copper, and silver. A. Gravimetric: This method measures variations in the Earth's gravitational field. It can detect low-density rock formations like salt domes, which often act as traps for oil and gas. B. Seismic: This is the most widely used and effective method in petroleum exploration. It involves generating sound waves and measuring their reflection and refraction off subsurface rock layers. The resulting data is used to create detailed images of geological structures like faults and anticlines that can contain hydrocarbon reservoirs. D. Magnetic: This method measures tiny variations in the Earth's magnetic field. It is often used as a reconnaissance tool to map the depth of the basement rock and to identify large geological structures or igneous intrusions that might affect the sedimentary basins where petroleum is found.

Question 12

The First Fan Law tells us that the change in air flow rate of a fan is proportional to the change in speed of the propeller. If the volume of air is doubled, what is the required speed? A. 0.5 times B. 2 times C. 4 times D. 8 times

Answer 12

B. 2 times First Fan Law: The volume of air (Q) is directly proportional to the fan speed (N). Q2/Q1=N2/N1 ​Second Fan Law: The pressure (P) varies as the square of the fan speed. P2/P1=(N2/N1)^2 Third Fan Law: The power input (W) varies as the cube of the fan speed. W2/W1=(N2/N1)^3

Question 12

An Act Strengthening Compliance with Occupational Safety and Health Standards and Providing Penalties for Violations thereof. The Occupational Safety and Health (OSH) Law of 2017 is known as what RA? A. RA 7160 B. RA 11058 C. RA 10962 D. RA 8749

Answer 12

B. RA 11058. A. RA 7160: This is the Local Government Code of the Philippines. C. RA 10962: This law is known as the "Act Expanding the Coverage of the Income Tax Holiday." D. RA 8749: This is the Philippine Clean Air Act of 1999.

Question 12

Which of the following cannot not used as a neutralizing agent for AMD treatment? A. Nickel laterite ore B. Fly Ash C. Concrete/Cement waste D. Synthetic gypsum

Answer 12

D. Synthetic gypsum. It is a product of neutralization, not the agent itself. It's essentially calcium sulfate, a neutral salt that is not a strong base. AMD's acidity comes from sulfuric acid. A. Nickel laterite ore: Some nickel laterite ores contain alkaline minerals like serpentinite, which can generate alkalinity and help neutralize AMD. B. Fly Ash: This is a very common and effective AMD treatment agent. As a byproduct of coal combustion, it is rich in calcium oxides and other alkaline compounds that readily react with and neutralize the sulfuric acid in AMD. C. Concrete/Cement waste: Similar to fly ash, concrete and cement waste are highly alkaline because they contain calcium hydroxide and calcium oxide. When crushed and added to AMD, these compounds dissolve and release hydroxide ions, which raise the pH and neutralize the acid.

Question 12

In 2014, what was DOE’s estimate of the Mineable or Proven Coal Reserves of the Philippines? A. 150 MMT B. 275 MMT C. 305 MMT D. 465 MMT

Answer 12

B. 275 MMT Global Methane Initiative (published in June 2015, but referencing 2014 data) states that the Philippines' "Estimated Proved Coal Reserves" are 315 million tonnes, with the breakdown being 41 million tonnes of Anthracite & Bituminous and 275 million tonnes of Sub-bituminous & Lignite.

Question 12

What is the melting point of Nickel? A. 1685°F B. 2109°F C. 2647°F D. 3659°F

Answer 12

C. 2647°F The melting point of nickel is approximately 1455 °C (2651 °F), though some sources provide slightly different values like 1453 °C. This high melting point makes nickel valuable for high-temperature applications, such as in jet engines and nuclear reactors, due to its thermal stability.

Question 12

In 2021, which of the following renewable energy sources has the highest installed capacity in the Philippines? A. Geothermal B. Hydropower C. Solar D. Wind

Answer 12

B. Hydropower Hydropower: 3,841 megawatts (MW) Geothermal: 1,987 MW Solar: 3,003 MW Wind: 427 MW Hydropower: This is the leading renewable energy source, making up the largest share of the country's clean energy installed capacity. Its capacity is derived from large dam projects and run-of-river systems. Geothermal: The Philippines is the third-largest producer of geothermal energy in the world and this source accounts for the second-largest share of the country's installed renewable energy. Solar and Wind: While having a smaller percentage of the overall installed capacity compared to hydropower and geothermal, these two sources are experiencing the most significant and rapid growth. Biomass: This source also contributes to the mix, though at a smaller scale.

Question 12

Which of the following is also known as the modulus of rigidity? A. Young’s modulus B. Shear modulus C. Bulk modulus D. Poisson’s ratio

Answer 12

B. Shear modulus (modulus of rigidity) A. Young’s modulus (modulus of elasticity) C. Bulk modulus (incompressibility)

Question 12

In the selection of underground mining methods, which of the following is applicable to strong ore, weak rock, fairly high grade and tabular or irregular deposits? A. Cut-and-Fill stoping B. Square-set stoping C. Sublevel stoping D. Sublevel caving

Answer 12

A. Cut-and-Fill stoping. The ore is excavated in horizontal or slightly inclined slices, starting from the bottom of the orebody and working upwards. After each slice is mined out, the void (stope) is immediately filled with a backfill material, such as waste rock or mill tailings mixed with cement. B. Square-set stoping: While also a supported method used for weak ground and irregular deposits, it is highly labor-intensive and expensive due to the use of interlocking timber frames for support. C. Sublevel stoping: This method is best suited for strong ore and strong surrounding rock. It is an unsupported method that creates large open voids. D. Sublevel caving: This is a mass mining method that relies on the controlled collapse of both the hanging wall and the ore itself. It is used for steeply dipping deposits with weak ore and a weak, easily caving host rock.

Question 13

This is a site of recognized and potentially economic mineralization that has not yet come into production as a mine, this is an encouraging anomaly that bears additional investigation. A. Mineral deposit B. Occurrence C. Mineral concentration D. Prospect

Answer 13

D. Prospect. A prospect is a site of recognized and potentially economic mineralization that has not yet come into production as a mine. It represents an encouraging geological, geochemical, or geophysical anomaly that warrants additional investigation. A. Mineral deposit: This is a broader term for a natural concentration of minerals. B. Occurrence: A mineral occurrence is the most basic term. It simply indicates the presence of a mineral in a specific area. C. Mineral concentration: This is a very general term describing an area where minerals are more abundant than in the surrounding rock.

Question 13

This is a machine in which clay or other materials are extruded in a plastic state or a similar machine for the trituration of ore. A. Pebble mill B. Autogenous mill C. Tube mill D. Pug mill

Answer 13

D. Pug mill. It is a machine with a rotating paddle or blade within a trough or cylinder used to knead and mix clay into a consistent, plastic state. It is also used in mining for the trituration (grinding or pulverizing) of ore, where it breaks up and mixes the material to prepare it for further processing. A. Pebble mill: A type of grinding mill that uses pebbles or small rocks as the grinding media to pulverize material. B. Autogenous mill: A type of mill that grinds ore by tumbling the ore itself, without using any external grinding media. It is used for grinding and comminution. C. Tube mill: A large, rotating cylinder used for grinding and mixing materials. It is similar to a ball mill or pebble mill, but it is not an extruder and is not used to push materials out in a plastic state.

Question 13

This refers to the permits that allow the owner to emit a certain amount of carbon dioxide or other greenhouse gases (GHGs). One permit allows the emission of one ton of carbon dioxide or the equivalent of other greenhouse gases. A. Carbon credit B. Carbon neutral C. Climate neutral D. Net Zero

Answer 13

A. Carbon credit. These credits are a key component of "cap-and-trade" systems and other market-based mechanisms designed to reduce greenhouse gas emissions. Companies that emit less than their allowed amount can sell their excess credits, while those that emit more can purchase credits to offset their emissions. B. Carbon neutral: This term refers to a state where the net carbon dioxide emissions are zero. It's achieved by balancing the amount of carbon emitted with an equivalent amount of carbon sequestered or offset, often by purchasing carbon credits. C. Climate neutral: This is a broader term than carbon neutral. It means achieving net-zero emissions of all greenhouse gases, not just carbon dioxide. It also includes other human activities that have a warming effect on the climate. D. Net Zero: This is an ambitious target that has become a goal for many countries and corporations. It means achieving a balance between all greenhouse gas emissions and their removal from the atmosphere, effectively reducing emissions to as close to zero as possible. It is a more comprehensive and demanding goal than carbon neutrality.

Question 13

In a typical nickel laterite profile, which of the following zones contain the highest Cobalt concentration? A. Ultramafic bedrock B. Saprolite C. Transition zone D. Limonite

Answer 13

D. Limonite. The upper, heavily weathered zone, characterized by a high iron content. During the weathering process, cobalt is leached from the upper layers and migrates downward, where it is preferentially adsorbed onto manganese-bearing minerals and iron oxyhydroxides like goethite at the base of the limonite zone. This is where the highest concentrations of cobalt are found, making the limonite zone a key target for cobalt production.

Question 13

A stage in the regional exploration which provides for a stepwise screening by geological, geophysical, and geochemical methods in which areas of little or no apparent promise are rejected and the remaining work is focused on progressively smaller and more significant areas of manageable size. A. Target selection B. Target investigation C. Reconnaissance D. Prospect evaluation

Answer 13

C. Reconnaissance A. Target selection: This is a part of the reconnaissance and prospecting phases. It's the decision-making step where the most promising anomalies identified during reconnaissance are chosen for more detailed investigation. B. Target investigation: This term is too general and could apply to any stage of exploration. D. Prospect evaluation: This is a later stage of exploration. A prospect is a more defined area of mineralization that has already passed the reconnaissance and initial prospecting phases.

Question 13

What is the most widely available fossil fuel energy resource in the world? It is widely distributed, both geographically and in terms of resource ownership. Its abundance provides energy security to many countries because its supply will last significantly longer. A. Oil B. Natural Gas C. Coal D. Nuclear

Answer 13

C. Coal Coal is the most widely available fossil fuel energy resource in the world. It's found in over 70 countries and its reserves are estimated to last for a much longer period compared to other fossil fuels like oil and natural gas. This widespread distribution and abundance make it a key source of energy security for many nations.

Question 13

A classification of joints found in igneous rock mass where they more closely spaced near the margins of the intrusion and becoming more widely spaced towards the interior of the mass and eventually disappearing. A. Shrinkage joints B. Cooling joints C. Tectonic joints D. Tension joints

Answer 13

B. Cooling joints A. Shrinkage joints: This is a more general term for joints formed by contraction, which includes cooling joints. While technically correct, cooling joints is the more specific and descriptive term for joints that form due to thermal contraction in igneous rocks. C. Tectonic joints: These joints are formed by regional tectonic forces, not by the cooling of the rock. They are related to compression, tension, or shear stresses from plate movements and are not directly linked to the thermal gradient within an igneous intrusion. D. Tension joints: This is a genetic classification of joints that form when a rock is pulled apart.

Question 13

What is the recommended pit slope for sand and clay? A. 16 degrees B. 22 degrees C. 34 degrees D. 37 degrees

Answer 13

C. 34 degrees Sand: The angle of repose for dry sand is approximately 34 degrees. This is the steepest angle at which a pile of granular material can remain stable. Clay: While clay has some cohesion, its stability can be unpredictable, especially when wet. The recommended maximum slope for "Type C" soils, which includes most sands and clays, is 1.5 horizontal to 1 vertical (1.5:1). This translates to an angle of approximately 34 degrees.

Question 13

The length of hole drilled per ton of material blasted is called: A. Drilling factor B. Powder factor C. Blasthole factor D. Burden

Answer 13

A. Drilling factor B. Powder factor: This is the ratio of the amount of explosive used to the volume or weight of rock blasted. It measures the efficiency of the explosive. D. Burden: This is a key design parameter in blasting. It is the distance from the explosive charge to the nearest free face of the rock.

Question 13

The Philippines import coal from the following countries, except for: A. Australia B. Vietnam C. China D. Malaysia

Answer 13

D. Malaysia In recent years, beginning in the 1990s, coal has come mainly from Indonesia and some from Vietnam and Australia, among others. Over time, domestic coal production has grown. In 2007, the country began to export its coal, and China has been its top export market since. Other recipients of its coal include India and Thailand.

Question 13

Sulfur is a pollutant in coal. Sulfur occurs in coal as pyrite or? A. Galena B. Native sulfur C. Chalcopyrite D. Sphalerite

Answer 13

B. Native sulfur Sulfur in coal primarily occurs in three forms: organic sulfur, sulfate sulfur, and inorganic sulfur. The most common inorganic form is pyrite (FeS2). However, another, less common, inorganic form is native sulfur (S). A. Galena: This is lead sulfide (PbS). While it is a sulfide mineral and can be a minor component in some mineral deposits, it is not a common or significant form of sulfur in coal. C. Chalcopyrite: This is copper-iron sulfide (CuFeS2). Similar to galena, it is a key mineral in copper ore but not a major form of sulfur in coal. D. Sphalerite: This is zinc sulfide (ZnS). It is a major ore mineral for zinc but not a primary or common form of sulfur in coal.

Question 13

In 2021, which of the following renewable energy sources has the highest power generated in the Philippines? A. Geothermal B. Hydropower C. Solar D. Wind

Answer 13

B. Hydropower Based on data from the Philippine Department of Energy (DOE) for 2021, the renewable energy source with the highest power generation was hydropower.

Question 14

Class “C” mines and service contractors shall have: A. At least one (1) part time safety engineer and one (1) full time safety inspector. B. At least one (1) part-time Safety Engineer, one (1) full time Safety Inspector and a deputy safety inspector C. At least one (1) full time Safety Engineer and one (1) full time Safety Inspector. D. At least one (1) part time safety engineer, one (1) full time safety inspector, and one (1) full time deputy safety inspector.

Answer 14

B. At least one (1) part-time Safety Engineer, one (1) full time Safety Inspector and a deputy safety inspector 1. Class "A" mines and service contractors shall have at least one full time Safety Engineer and one full time Safety Inspector. 2. Class "B" mines and service contractors shall have at least one (1) full time Safety Engineer and one (1) full time Safety Inspector. 4. Class "D" mines and service contractors shall have at least one (1) part time safety engineer and one (1) full time safety inspector.

Question 14

What is the melting point of Zinc? A. 300°C B. 420°C C. 485°C D. 523°C

Answer 14

B. 420°C The melting point of zinc is approximately 420°C (788°F), although some sources list it more precisely as 419.5°C (787.1°F).

Question 14

In mineral prospecting, what is the term for the characteristic red, brown, and yellow accumulations of cellular limonitic material derived from the leaching of sulfide-bearing veins and disseminated ore bodies. A. Mineralized floats B. Soans and capping C. Geoanomalies D. Brownfields

Answer 14

B. Soans and capping. This material forms from the oxidation and leaching of sulfide-bearing veins and disseminated ore bodies near the surface. The term soans is a less common but older term for this material, while capping or gossan are more widely used. They indicate the presence of a leached zone above a potential ore deposit. A. Mineralized floats: These are fragments of mineralized rock that have been transported from their original location, often by water or ice. C. Geoanomalies: This is a broad term for any geological, geochemical, or geophysical feature that stands out from the background and could indicate the presence of a mineral deposit. D. Brownfields: In mining, a brownfield is a property or site that has been previously mined or explored.

Question 14

Which of the following countries does not produce rare earth oxides? A. Myanmar B. Madagascar C. Vietnam D. Argentina

Answer 14

D. Argentina China has the world's largest rare earth element (REE) reserves, estimated at 44 million metric tons, and also dominates the global supply chain through its extensive production and processing capabilities. While countries like Vietnam, Brazil, and the United States possess significant reserves. A. Myanmar: Myanmar is a major global producer of rare earth oxides, especially heavy rare earth elements. It has become a key supplier to China and other countries. B. Madagascar: Madagascar has significant rare earth resources and has been actively involved in the development and production of rare earth minerals. C. Vietnam: Vietnam holds some of the world's largest rare earth reserves and is actively working to develop its mining sector to become a larger global producer. It already has some small-scale production and is attracting foreign investment for new projects.

Question 15

This is the oldest gold district in the Philippines with porphyry copper. A. Surigao B. Masara C. Mankayan D. Paracale

Answer 15

B. Masara. Located in Davao de Oro, is one of the oldest and most prolific gold districts in the Philippines. More importantly, it is well-documented to have both epithermal gold deposits and porphyry copper-gold deposits, making it the correct fit for the specific combination of characteristics mentioned in the question. A. Surigao: While the Surigao district is known for its gold mineralization, it is also a major host to significant porphyry copper-gold deposits, such as the Boyongan-Bayugo deposits. B. Mankayan: This is another major gold-copper district in the Philippines. It hosts a well-known epithermal gold-copper deposit (Lepanto) and a significant porphyry copper-gold deposit (Far Southeast). D. Paracale: This is the undisputed oldest gold district in the Philippines, with a history of gold mining dating back to the 15th century. However, its deposits are classic epithermal vein-type, and it is not known to host a significant porphyry copper deposit.

Question 16

What is referred to as the ratio of stress over strain of rocks? A. Poisson’s ratio B. Shear modulus C. Bulk modulus D. Young’s modulus

Answer 16

D. Young’s modulus, also known as the modulus of elasticity, is a fundamental measure of a material's stiffness. A. Poisson’s ratio: This is a dimensionless ratio that describes the lateral strain to the axial strain when a material is stretched or compressed. B. Shear modulus: This measures a material's resistance to shearing or twisting forces. C. Bulk modulus: This measures a material's resistance to uniform compression or a change in volume.

Question 16

In conventional prospecting, a guide to ore mineralization of weathered outcrops characterized by green and blue colors is from which of the following? A. Sulphides of lead and zinc B. Oxidized copper minerals C. Oxidized manganese minerals D. Silver halides

Answer 16

B. Oxidized copper minerals The characteristic green and blue colors in weathered outcrops are a classic indicator of oxidized copper minerals. When primary sulfide minerals like chalcopyrite or chalcocite are exposed to oxygen and water, they undergo oxidation, forming secondary minerals. Highest-grade ore mineral is chalcocite (Cu₂S), containing about 80% copper by weight, followed by covellite (CuS) at approximately 66.5%. Malachite: the most common green mineral. Azurite: deep blue mineral.

Question 16

An indirect measurement obtained by summing the total length of core recovered and counting only those pieces of core which are 4 inches or more in length and which are hard and sound. A. Rock Mass Rating B. Rock Quality Designation C. System D. Geological Strength Index

Answer 16

B. Rock Quality Designation A. Rock Mass Rating (RMR): This is a more comprehensive system that classifies a rock mass based on several parameters, including RQD, joint spacing, joint condition, groundwater conditions, and the strength of the intact rock. D. Geological Strength Index (GSI): This is a classification system used to estimate the rock mass strength for jointed rock masses. It is based on a visual assessment of the rock structure and the condition of the discontinuities.

Question 16

In the Philippine Energy Plan 2020–2040, what is the target percent renewable energy share in the power generation mix by 2030? A. 25% B. 35% C. 45% D. 50%

Answer 16

B. 35%. The Philippine Energy Plan (PEP) 2020–2040 sets a target for renewable energy to make up 35% of the country's power generation mix by 2030. This is an ambitious goal that aims to increase the share of clean, indigenous energy sources and reduce the country's reliance on imported fossil fuels.

Question 16

A measure of a company’s profitability which includes the earnings before interest, taxes, depreciation, and amortization. A. Net Present Value B. Payback Period C. EBITDA D. MARR

Answer 16

C. EBITDA stands for Earnings Before Interest, Taxes, Depreciation, and Amortization. It is a financial metric used to measure a company's overall profitability. By excluding non-cash expenses like depreciation and amortization, as well as interest and taxes, EBITDA provides a clearer picture of the company's operational performance and cash flow. A. Net Present Value (NPV): This is a capital budgeting tool used to determine the profitability of a project or investment. It calculates the present value of all future cash flows from an investment and subtracts the initial investment cost. It is a project valuation tool. B. Payback Period: This is a simple capital budgeting tool that calculates the time it takes for an investment to generate enough cash flow to recover its initial cost. It is a measure of risk and liquidity. D. MARR: This stands for Minimum Attractive Rate of Return. It is the minimum rate of return that a company or individual expects to earn on an investment project before they consider undertaking it.

Question 16

This is the study of the geological classification of rocks refers to the mineralogy, fabric, chemistry, crystallography, texture and including its formation. A. Petrology B. Lithology C. Stratigraphy D. Optical mineralogy

Answer 16

A. Petrology B. Lithology: This is a more descriptive term for the physical characteristics of a rock, such as its color, grain size, and composition, as seen in the field or in hand samples. C. Stratigraphy: This is the study of rock layers (strata) and layering (stratification). It is primarily used to understand the sequence, age, and correlation of sedimentary rocks, often using fossils and other features. D. Optical mineralogy: This is a specific laboratory technique that uses a petrographic microscope to study the optical properties of minerals in rock thin sections.

Question 16

A horizontal opening in or near an ore body and parallel to the course of the vein or long dimension of the ore body. A. Crosscut B. Drift C. Adit D. Ramp

Answer 16

B. Drift. A horizontal opening driven in or near an ore body that runs parallel to the vein or the longest dimension of the ore body. Its primary purpose is to provide access for mining the ore, transporting material, and for ventilation and exploration. A. Crosscut: This is a horizontal opening driven perpendicular to the ore body. Its main purpose is to connect the main shaft to the ore vein or to connect parallel drifts for ventilation and access. C. Adit: An adit is a horizontal or nearly horizontal opening that is driven from the surface into the side of a hill or mountain. Its purpose is to provide access, drainage, and ventilation for the mine. An adit can also be a drift if it is driven along the vein. D. Ramp: A ramp is a sloping or inclined tunnel that connects different levels of a mine. It is used for transporting heavy equipment and vehicles between levels.

Question 16

Which of the following is the main objective of coal beneficiation? A. To reduce the ash content B. To remove slimes C. To increase the heating capacity D. To remove impurities

Answer 16

A. To reduce the ash content. Coal beneficiation, also known as coal preparation or washing, is a process that removes impurities from run-of-mine coal. The primary goal is to produce a higher-quality product for use in power generation and other industries. The Domino Effect of Ash Reduction: 1. Increased Heating Capacity 2. Reduced Impurities 3. Removal of Slimes

Question 16

This is the maximum amount of overburden or waste that can be extracted per unit of ore at the economic pit limit. A. Overall stripping ratio B. Maximum allowable pit limit C. Breakeven stripping ratio

Answer 16

C. Breakeven stripping ratio A. Overall stripping ratio: This is the ratio of total waste to total ore over the entire life of the mine. B. Maximum allowable pit limit: This is a term that refers to the physical boundary of the pit, which is determined by the breakeven stripping ratio, not the ratio itself.

Question 16

The following are the disadvantages of longwall mining, except for one. A. It requires a substantial capital investment to purchase the highly specialized equipment to create a longwall section. B. The development time is significant because the continuous miners have to progress the main entries and develop gate roads for the longwall panel before the longwall can be installed. C. There is little selectivity or flexibility after mining commences. D. It has a very high operating costs as various mechanized equipment and characterized by unsafe mining conditions such as subsidence.

Answer 16

D. It has a very high operating costs as various mechanized equipment and characterized by unsafe mining conditions such as subsidence. In reality, longwall mining is known for having a low operating cost per tonne and is generally considered to be safer than other underground methods due to the high degree of mechanization and remote operation. A, B & C are disadvantages.

Question 16

Which of the following metals is the most vital metal used in the transition from fossil fuel to renewable energy? A. Lithium B. Platinum C. Polonium D. Nickel

Answer 16

A. Lithium Lithium is the cornerstone of the transition because it is the primary component of lithium-ion batteries. These batteries are essential for two main applications that underpin the move away from fossil fuels: 1. Electric Vehicles (EVs): Lithium-ion batteries power the electric vehicle revolution, which is a major part of global decarbonization efforts. 2. Energy Storage: They are critical for grid-scale energy storage systems that store intermittent energy from renewable sources like solar and wind. Platinum (B): Platinum is a vital catalyst for hydrogen fuel cells and electrolyzers used to produce green hydrogen. Polonium (C): Polonium is a highly radioactive element. Nickel (D): Nickel is a crucial component in some high-performance lithium-ion batteries (e.g., NMC and NCA cathodes).

Question 16

What is the price of Gold per gram today? A. Around Php1,700.00 B. Around Php2,100.00 C. Around Php4,300.00 D. Around Php6,800.00

Answer 16

D. Around Php6,800.00 The current price for 1 gram of gold is approximately ₱6,757.02 PHP as of September 14, 2025, based on the Gram Gold (GRAMG) cryptocurrency price against the Philippine Peso.

Question 17

This refers to a renewable energy policy that offers guaranteed payments on a fixed rate per Kilowatt-hour for emerging renewable energy. A. Feed-in Tariff B. Net Metering C. Green Energy Option Program D. Duty-Free Importation

Answer 17

A. Feed-in Tariff B. Net Metering: This is a different policy that allows consumers with renewable energy systems (like rooftop solar) to receive a credit on their electricity bill for the excess power they export to the grid. They only pay for their "net" energy use. C. Green Energy Option Program (GEOP): The GEOP is a policy that gives qualified consumers (with a certain energy demand) the option to choose a renewable energy supplier. It allows them to voluntarily purchase 100% of their electricity from renewable sources. D. Duty-Free Importation: This is a fiscal incentive that allows renewable energy developers to import equipment and machinery for their projects without paying tariffs.

Question 17

In conventional prospecting, a guide to ore mineralization of weathered outcrops characterized by yellow and green colors is from which of the following? A. Sulphides of lead and zinc B. Oxidized copper minerals C. Oxidized manganese minerals D. Silver halides

Answer 17

B. Oxidized copper minerals. Green is typically from malachite, a very common secondary copper mineral. Blue is from azurite and can sometimes be mixed with green. Yellow can come from minerals like jarosite and certain limonites that form from the oxidation of pyrite associated with copper deposits. A. Sulfides of lead and zinc: Oxidized lead minerals (like cerussite) are typically white, gray, or yellow. Oxidized zinc minerals (like smithsonite) are often white, gray, or brown. C. Oxidized manganese minerals: These typically form dark brown to black coatings, such as pyrolusite or wad. D. Silver halides: These are generally white, creamy, or light yellow in color and are typically found in the upper, oxidized zones of silver deposits.

Question 17

Sublevel block caving is a hybrid between sublevel caving and block caving introduced to counter which of the following? A. Drilling and blasting problems in sublevel caving. B. Draw control problems in block caving. C. Problems in sublevel caving due to dilution and mining at depth. D. Problems in block caving regarding stability, reinforcement and secondary blasting problems.

Answer 17

D. Problems in block caving regarding stability, reinforcement and secondary blasting problems. Sublevel block caving is a hybrid mining method that was developed to overcome the limitations of traditional block caving when mining in a competent (strong, hard) rock mass. Challenges in Block Caving with Competent Rock Traditional block caving is highly effective and cost-efficient in weak, easily-caving rock. However, when applied to a strong, competent rock mass, several significant problems can arise: Secondary Blasting: The competent rock does not fracture easily on its own. It may break into very large, oversized blocks that cannot pass through the drawpoints. This necessitates dangerous and expensive secondary blasting to break down the oversized material. Stability: The high-stress environment in competent rock can lead to instability and rockbursts on the extraction level. This requires extensive and costly reinforcement to ensure the safety of miners and equipment. Hang-ups: The rock may not cave reliably, leading to unpredictable ore flow or hang-ups where a large void forms above the undercut, stopping production. How Sublevel Block Caving Addresses These Issues Sublevel block caving integrates elements from sublevel caving by using pre-conditioning with drilling and blasting. This is done before the main block caving process begins. This method allows for: Improved Fragmentation: Pre-blasting fractures the competent rock mass into smaller, more manageable sizes, significantly reducing the need for secondary blasting and improving the flow of ore. Enhanced Stability: By controlling the caving process from the start, the method helps to manage ground stresses, leading to a more stable extraction level and reducing the need for extensive ground reinforcement. More Reliable Caving: The pre-blasting ensures the rock will cave more predictably and reliably, overcoming the hang-up problems often seen with competent rock.

Question 18

1 gram of gold is equivalent to how many ounces? A. 0.03527 B. 0.03215 C. 0.03110 D. 0.02835

Answer 18

B. 0.03215 To convert grams to troy ounces (the standard unit for precious metals), you use the conversion factor that 1 troy ounce is equal to 31.1035 grams.

Question 19

The Third Fan Law states that the change in horsepower required by the fan to turn the propeller will increase by the cube of the change in propeller speed of the fan. If the propeller speed is increased by 10%, the horsepower required to turn the propeller will increase to what amount? A. 3% B. 30% C. 33.10% D. 1,000%

Answer 19

C. 33.10% The new horsepower is 1.331 times the original horsepower, which represents an increase of 33.1%.

Question 20

This means that any CO2 released into the atmosphere from a company’s activities is balanced by an equivalent amount being removed. A. Carbon credit B. Carbon trade C. Carbon neutral D. Net-zero carbon emissions

Answer 20

C. Carbon neutral. Carbon neutral is the term used to describe a state where any carbon dioxide released into the atmosphere from an activity or company is balanced by an equivalent amount being removed, most often through a process called carbon offsetting. This creates a net-zero carbon footprint. A. Carbon credit: This is a quantifiable, tradable permit that represents one metric ton of CO2 removed or avoided from the atmosphere. It is a tool used to achieve carbon neutrality, not the state itself. B. Carbon trade: This is the market-based system where carbon credits are bought and sold. It's the economic mechanism that facilitates the offsetting process. Net-Zero Carbon Emissions: This term is broader and is generally seen as a more ambitious goal. While it also refers to a balance between emissions and removals, it usually includes all greenhouse gases (GHGs), not just CO2.

Question 21

A condition or practice that could reasonably be expected to cause death or serious physical injury or damage to property prior to the adoption of appropriate measures to counter the risk. A. Force majeure B. Imminent danger C. Near miss D. Incident

Answer 21

B. Imminent danger A. Force majeure: This is a legal term for an unforeseeable circumstance, like a natural disaster (e.g., an earthquake or flood), that prevents someone from fulfilling a contract. C. Near miss: This is an unplanned event that did not result in injury, illness, or damage, but had the potential to do so. D. Incident: This is a broader term that refers to a single event or series of events that results in unintended consequences, such as an accident, a near miss, or property damage. An accident is an unplanned event resulting in actual injury, damage, or harm.

Question 22

This is the speed at which the detonation wave passes through the explosive charge usually measured in meter-per-second. A. Peak particle velocity B. Velocity of Detonation C. Blast wave velocity D. Borehole pressure velocity

Answer 22

B. Velocity of Detonation. Velocity of Detonation (VoD) is the speed at which the shock wave front travels through an explosive charge. It is a fundamental property of an explosive, typically measured in meters per second (m/s). A. Peak Particle Velocity (PPV): This measures the maximum speed of rock or ground particles as they are displaced by the blast vibration. C. Blast wave velocity: This is the speed at which the shock wave expands outward from the borehole into the surrounding rock or air. This velocity is distinct from the VoD, which is the speed of the reaction within the explosive charge.

Question 22

Radioactive elements occur naturally in the Earth’s crust and their presence can be detected by radiometric surveys. Which of the following element is not detected to discover mineralization? A. Uranium B. Carbon-14 C. Thorium D. Potassium-40

Answer 22

B. Carbon-14. It is a radioactive isotope primarily used in radiocarbon dating, a method for determining the age of organic materials. It has a very short half-life of about 5,730 years, and it is almost exclusively found in living organisms and the atmosphere. Radiometric surveys in mineral exploration primarily detect naturally occurring gamma radiation emitted by the radioactive decay of potassium-40 (K-40), uranium (U-238), and thorium (Th-232).

Question 22

In geophysical prospecting, this is the appropriate term of the difference between an observed response and normal response. This changes in mineral composition and content can be used as quantitative markers to identify adverse geology. A. Indicator minerals B. Pathfinder elements C. Anomaly D. Outlier

Answer 22

C. Anomaly. In geophysical prospecting, an anomaly is the deviation from the expected or normal response of a physical field (such as magnetic, gravity, or electrical) in a given area. A. Indicator minerals: These are specific minerals found in a rock or soil sample that are not themselves the ore, but their presence indicates that a valuable ore body is likely nearby. This is a term used in geochemical prospecting, not geophysical. B. Pathfinder elements: These are chemical elements that are not the primary metal being sought but are often associated with the ore. Like indicator minerals, they are a tool used in geochemical prospecting.

Question 23

Which of the following is a supported underground method? A. Stop-and-Pillar mining B. Shrinkage stoping C. Cut-and-Fill stoping D. Sublevel stoping

Answer 23

C. Cut-and-Fill stoping. It involves excavating ore in horizontal or slightly inclined slices, after which the void is immediately filled with a backfill material (such as waste rock or mill tailings). This backfill provides continuous support to the mine's walls, ensuring stability and allowing the mining to continue safely upwards. A. Stop-and-Pillar mining: This is a semi-supported method. It relies on leaving permanent pillars of rock or ore to support the mine roof. B. Shrinkage stoping: This is also a supported method, but the support comes from the broken ore itself. After the ore is blasted, it fills the stope, and a portion is drawn off from below to provide a working space. The broken ore holds the walls in place, but it is not a deliberate backfill material. D. Sublevel stoping: This is a bulk mining method that is unsupported. It is used in strong ore and rock and creates large, open voids that are allowed to remain empty.

Question 23

This refers to that portion of organic matter which is driven off as a gas. A. Gaseous matter B. Fixed carbon C. Volatile matter D. Moisture

Answer 23

C. Volatile matter. Refers to the portion of organic matter, such as in coal or biomass, that is driven off as a gas when the material is heated to a high temperature in the absence of air. This material consists of hydrocarbons, hydrogen, carbon monoxide, and some incombustible gases like carbon dioxide and nitrogen. The volatile matter content is a key parameter in the proximate analysis of coal, as it indicates the ease of ignition and the combustion characteristics of the fuel. B. Fixed carbon: This is the solid combustible residue that remains after the volatile matter has been driven off. It is the primary heat-generating component of coal. D. Moisture: This is the water content of the organic matter. It is typically driven off at a much lower temperature than volatile matter (usually below 110°C) and is measured as a separate component in the analysis.

Question 24

An exploration method applicable to finding and following short, narrow and irregular veins to establish its lateral extension. A. Diamond Core drilling B. Auger drilling C. Trenching D. Test pitting

Answer 24

C. Trenching A. Diamond Core drilling: This is a deeper, more expensive method used to extract a cylindrical core of rock from the subsurface. It provides detailed information on the rock type and mineralization. B. Auger drilling: This method uses a rotating blade to bore a hole and bring up loose material. It is a shallow method used for soil sampling and can be used to find the general location of a vein, but it doesn't provide the continuous exposure needed to trace its course. D. Test pitting: This involves digging small pits to collect bulk samples or to examine the rock and soil in a specific location.

Question 25

What is the boiling point of Copper? A. 1,705°C B. 2,562°C C. 3,512°C D. 2,874°C

Answer 25

B. 2,562°C The boiling point of copper is approximately 2562 °C (4644 °F). This is a very high temperature, indicating that significant energy is required to overcome the strong forces holding copper atoms together in its liquid and solid forms.

Question 26

A method to address emissions of burning coal which separates CO2 from emissions sources and recovers it in a concentrated stream. A. Carbon sequestration B. Carbon neutral C. Carbon credit D. Carbon capture

Answer 26

D. Carbon capture. It's the initial and critical step in a broader process often called Carbon Capture and Storage (CCS) or Carbon Capture, Utilization, and Storage (CCUS). A. Carbon sequestration is the long-term storage of carbon dioxide that has been captured. While it is the final step of the CCS process, it is not the process of separation itself. B. Carbon neutral is a goal or state where the net carbon emissions from a company or activity are zero. C. Carbon credit is a tradable permit that allows for the emission of one ton of carbon dioxide.

Question 26

In 2020, 96% percent of the coal mined in the Philippines was exported to which of the following countries? A. China B. South Korea C. Thailand D. India

Answer 26

A. China According to data for 2024, China accounted for the vast majority of the Philippines' coal briquette exports, with a value of $457 million. This represents a significant portion of the total coal briquette exports, with other destinations including South Korea ($41 million), Brunei ($14.2 million), and Vietnam ($3.03 million). This trend shows a continuation of the strong export relationship between the Philippines and China in the coal sector.

Question 27

What REE can be found in the moon which scientists are eyeing for exploration? This silver-white metal, found in higher concentrations in moon rocks than on Earth, can be added to aluminum to make alloys that are lighter, stronger, and more malleable. a. Terbium b. Scandium c. Cerium d. Lanthanum

Answer 27

b. Scandium Scientists are eyeing the Moon for its rare earth elements (REEs) like scandium, yttrium, and the lanthanides, which are critical for modern technologies and in increasingly short supply on Earth. While the Moon contains significant amounts of other valuable resources such as Helium-3 and water ice.

Question 28

It is the underground mine gas otherwise called as “white damp.” A. Carbon dioxide B. Carbon monoxide C. Methane D. Nitrogen dioxide

Answer 28

B. Carbon monoxide A. Carbon dioxide: This gas is known as "black damp." C. Methane: Methane is called "firedamp" or "marsh gas" D. Nitrogen dioxide: This is a toxic gas that can be produced by blasting.

Question 28

What is the recommended bench slope for solid copper ore? A. 45 degrees B. 50 degrees C. 60 degrees D. 75 degrees

Answer 28

C. 60 degrees In the absence of a detailed geotechnical analysis, a 60-degree bench angle is often used as a preliminary design guideline because it represents a good balance between safety and economics.

Question 28

A process of converting coal into liquid hydrocarbons such as liquid fuels and petrochemicals. A. Coal liquefaction B. Underground Coal Gasification C. Fluidized Bed Combustion D. Frasch Process

Answer 28

A. Coal liquefaction Coal liquefaction is a chemical process that converts solid coal into liquid hydrocarbons, such as synthetic liquid fuels and various petrochemicals. This is typically done through two main methods: (1) This involves adding hydrogen to the coal directly at high temperature and pressure. (2) This involves first converting the coal into a synthesis gas (a mixture of carbon monoxide and hydrogen) and then using a catalyst to convert this gas into a liquid fuel. B. Underground Coal Gasification (UCG): This is a process that converts coal into a combustible gas, or "syngas," while it is still in the coal seam underground. The syngas can then be used to generate electricity. C. Fluidized Bed Combustion (FBC): This is a clean combustion technology used to burn solid fuels like coal. It involves suspending the fuel in a bed of hot, fluidized particles to achieve more efficient combustion and reduce pollutant emissions. FBC is a method of burning coal, not converting it to a liquid. D. Frasch Process: This is a method used to extract sulfur from underground deposits. It involves injecting superheated water to melt the sulfur, which is then forced to the surface with compressed air.

Question 28

What is the rock quality of an intact rock with an RQD of 65%? A. Poor B. Fair C. Good D. Very Poor

Answer 28

B. Fair Rock Quality Designation (RQD) is a widely used index for classifying rock mass quality based on the percentage of sound rock core pieces longer than 10 cm (4 inches). The classification system for RQD is as follows: 90–100%: Excellent 75–90%: Good 50–75%: Fair 25–50%: Poor 0–25%: Very Poor

Question 29

A document that describes the identity of a substance which includes among others company product information, composition information on ingredients, hazard identification and control and clean-up procedures in cases of accidental spill. A. User’s Manual B. Standard Chemical Information Document C. Ingredients Safety Data Manual D. Material Safety Data Sheet

Answer 29

D. Material Safety Data Sheet

Question 30

Which of the following is not one of PNOC’s coal mines’ locations? A. Cebu B. Malangas C. Cagayan D. Bislig

Answer 30

D. Bislig Cebu: PNOC-EC has previously operated or been involved in coal exploration projects in Cebu, as part of the country's energy development programs. B. Malangas, Zamboanga Sibugay: This is the site of a significant coal reservation where PNOC-EC operates and manages coal projects. C. Cagayan (Isabela and Cagayan Valley): PNOC-EC has a project here with substantial reserves, although its status has been subject to various challenges.

Question 31

This refers to a renewable energy incentive scheme that aims to encourage users to participate in the generation of renewable energy for exportation of excess electricity to a distribution utility. A. Feed-in Tariff B. Net Metering C. Green Energy Option Program D. Duty-Free Importation

Answer 31

B. Net Metering A. Feed-in Tariff (FIT): A FIT provides a guaranteed fixed payment for all renewable energy generated and fed into the grid, often at a rate higher than the retail price. C. Green Energy Option Program (GEOP): This program allows consumers with a certain energy demand to choose to purchase 100% of their electricity from certified renewable energy suppliers D. Duty-Free Importation: This is a financial incentive that exempts developers from paying taxes on imported renewable energy equipment.

Question 32

This electrical geophysical method of exploration is aimed at the tendency of certain mineral deposits such as massive sulfides, manganese ore, graphite, cobalt minerals, magnetite, and anthracite to produce a weak electric current when interacting with groundwater. The deposits in this case act like a weak battery. A. Resistivity B. Self-Potential C. Mise-a-la-masse D. Magnetotelluric

Answer 32

B. Self-Potential. Self-potential (SP), also known as spontaneous potential, is a passive electrical geophysical method that measures naturally occurring electrical currents generated in the ground. A. Resistivity: This is an active electrical method that measures the subsurface's resistance to an artificially injected electrical current. C. Mise-a-la-masse: This is an active method where an electrical current is injected directly into a known mineral body to trace its extent and shape. D. Magnetotelluric: This is a passive method that measures naturally occurring variations in the Earth's magnetic and electric fields to determine the electrical resistivity of the subsurface.

Question 33

A form of borehole geophysical logging that measures the transit time of compression (P-wave) waves travelling through the rock mass surrounding the borehole. The logs can be used for geophysical evaluation of rocks, coal, and the surrounding strata. A. Seismic velocity B. Shear wave velocity C. Sonic velocity D. Blast wave velocity

Answer 33

C. Sonic velocity A. Seismic velocity is the velocity of seismic waves through the ground, a broader term that can be measured by various methods, including both surface seismic surveys and borehole logging. B. Shear wave velocity is the speed of S-waves, another type of seismic wave. While modern acoustic logging tools can also measure S-wave velocity. D. Blast wave velocity is the speed at which a pressure wave from an explosion propagates through the rock or air.

Question 34

Herbert Hoover was the 31st US President and a mining engineer. He married his wife which was a geologist. Who was his wife? A. Mikaela Hoover B. Jennifer Aniston C. Christina Applegate D. Lou Henry

Answer 34

D. Lou Henry Herbert Hoover's wife was Lou Henry Hoover. She was a remarkable woman and the first woman to earn a degree in geology from Stanford University, where she met Herbert. They shared a passion for the field and even collaborated on a professional translation of a 16th-century Latin book on mining and metallurgy. The book they translated is "De re metallica" by Georgius Agricola.

Question 35

A multi-element technique that uses an Inductively Coupled Plasma source to dissociate the sample into its constituent atoms or ions. The ions themselves are detected, rather than the light that they emit. The ions are extracted from the plasma and passed into the mass spectrometer, where they are separated based on their atomic mass-to-charge ratio by a quadrupole or magnetic sector analyzer. A. Inductively Coupled Plasma Optical Emission spectrometry B. Inductively Coupled Plasma Mass Spectrometry C. Inductively Coupled Plasma Atomic Emission Spectrometry D. Flame Atomic Absorption Spectrometry

Answer 35

B. Inductively Coupled Plasma Mass Spectrometry A. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES): While this technique also uses an ICP source, it detects the light 💡 emitted by excited atoms and ions, not the ions themselves. D. Flame Atomic Absorption Spectrometry (FAAS): This technique uses a flame 🔥 to atomize the sample. It measures how much light is absorbed by the atoms, and it does not use a mass spectrometer to separate ions.

Question 36

Which of the following is the measure of the stiffness of a rock mass? A. Shear modulus B. Bulk modulus C. Poisson’s ratio D. Young’s modulus

Answer 36

D. Young’s modulus

Question 37

A type of map that represents geographical features of the surface of the earth, such as hills and valleys, and its elevation changes. A. Geologic map B. Physical map C. Topographic map D. Cadastral map

Answer 37

C. Topographic map A. Geologic map: This type of map shows the distribution of different rock types, faults, and other subsurface geological features. B. Physical map: This is a broad term for a map that shows natural features like mountains, rivers, and deserts.

Question 38

The Second Fan Law states that the change in total static pressure of the ventilation system will increase by the square of the change in propeller speed of the fan. If the propeller speed is increased by 10%, the total static pressure will increase to what amount? A. 20% B. 40% C. 21% D. 41%

Answer 38

C. 21% (1.10)^2

Question 39

Coal beneficiation is based on which of the coal’s following characteristics? A. Specific gravity B. Color C. BTU D. Ash content

Answer 39

A. Specific gravity. Coal beneficiation, also known as coal washing, is a process that separates clean coal from impurities based on the difference in their specific gravity (density). Clean coal is less dense (has a lower specific gravity) than the waste mineral matter, such as shale and pyrite. C. BTU and D. Ash content are measures of the quality of the coal after beneficiation, not the physical property used to separate it. B. Color is a visual characteristic, not a physical property that allows for a mass separation process.