Core 1

Question 1

The theory that assumes that each pillar carries its full share of the overburden load provided that the width of the panel is as great as or greater than the mining depth and where the mining layout is regular, i.e. where the pillars in a panel are of the same size.
a. Pressure Arch Theory
b. Tributary Area Theory
c. Voissoir Beam Theory
d. Dome Theory

Answer 1

b. Tributary Area Theory

a. Pressure Arch Theory: This theory, also known as the pressure dome or pressure arch, describes how stress is redistributed around a mine opening. It suggests that a natural arch or dome forms in the rock mass above the opening, transferring the overburden load to the solid rock or pillars on either side.
c. Voissoir Beam Theory: This theory is a specific application of the Pressure Arch Theory. It models the rock mass above a longwall panel as a series of “voussoirs” (wedge-shaped blocks) that act as a beam. The beam spans the mined-out area, and the load is transferred to the abutments (the solid coal or pillars) at the ends of the panel.
d. Dome Theory: This is another name for the Pressure Arch Theory. It refers to the dome-like shape of the pressure redistribution that occurs above a mine opening. Like the Pressure Arch Theory, it does not assume uniform load distribution among pillars but rather a transfer of stress to the abutments or pillars at the periphery of the dome.

Question 2

Why is copper orebody very close to the surface usually excluded from the computation of the ore reserves, or at best discounted, before it is added to the rest of the reserves.
a. Because it cannot be mined
b. Because of supergene enrichment
c. Because it is usually oxidized
d. All of these

Answer 2

d. All of these

a. Because it cannot be mined. Even if the ore near the surface were high-grade, it might not be economically viable to mine. The top layer of the deposit, often referred to as the overburden, is a mixture of weathered rock, soil, and the low-grade oxidized ore. The cost of stripping this material to access the higher-grade ore below can be prohibitive.
b. Because of supergene enrichment. This is a key geological process that explains the low-grade nature of surface copper. Over geologic time, surface water leaches copper from the oxidized zone and carries it downwards. The dissolved copper then precipitates just below the water table, reacting with primary sulfide minerals to form a concentrated zone of secondary sulfides (like chalcocite, Cu₂S).
c. Because it is usually oxidized. Near-surface copper orebodies are exposed to oxygen and water, which causes the primary sulfide minerals (like chalcopyrite, CuFeS₂), to oxidize. This transforms them into secondary oxide minerals (such as malachite, azurite, and chrysocolla). While these oxide minerals still contain copper, they are often more difficult and costly to process using traditional flotation methods.

Question 3

How many long tons are there in a short ton?
a. 1.10
b. 0.91
c. 1.12
d. 0.89

Answer 3

d. 0.89

Short ton = 2,000 lbs
Long ton = 2,240 lbs

Question 4

To explore a horizontally lying deposit, how will you best position your drillholes?
a. Inclined at a steep angle
b. Inclined at a shallow angle
c. Vertical and inclined
d. Vertical

Answer 4

d. Vertical

a. Inclined at a steep angle and b. Inclined at a shallow angle: Inclined drillholes are used to explore steeply dipping or vertical ore bodies. By drilling at an angle, the drillhole can intersect the deposit at or near a 90-degree angle, which provides a more accurate representation of its true width and grade.

Question 5

A truck working in an open pit mine for 480 hours during the month was under repair for 60 hours and on standby for 180 hours. What was the effective utilization of the truck?
a. 90%
b. 89%
c. 73%
d. 67%

Answer 5

d. 67%

Effective Utilization = Working Hours/Working Hours + Repair Hours + Standby Hours

Question 6

Under the Mines Safety Rules and Regulations, what is the Classifications of mines that employ not less than 150 and 250 employees in the underground and surface respectively.
a. Class A
b. Class B
c. Class C
d. Class D

Answer 6

a. Class A

Question 7

In coal mining, which of the following conditions may cause face break?
a. Coal heave
b. Stress concentration at the face
c. Heavy stripping ratio
d. None of the above

Answer 7

b. Stress concentration at the face

A face break, also known as a coal burst or face instability, is the sudden, violent failure of the coal seam at the working face. It’s a dangerous phenomenon that can result in the rapid spalling or ejection of coal, dust, and gas into the mine roadway. The primary cause of this is stress concentration at the working face.

a. Coal heave: Coal heave (or floor heave) is the upward movement or buckling of the mine floor. It is caused by pressure from underlying strata or aquifers, or a reduction in stress from excavation.

Question 8

In open pit mine planning, what do you call the factor used in converting the volume of material into weight or tonnage.
a. Powder Factor
b. Tonnage Factor
c. Swell Factor
d. Dilution Factor

Answer 8

b. Tonnage Factor

a. Powder Factor: This is a measure of blasting efficiency. It represents the amount of explosive (in kg or lbs) required to break a specific volume or weight of rock
c. Swell Factor: This describes the increase in the volume of rock after it has been blasted and moved. It’s the ratio of the broken (loose) volume to the original in-situ (bank) volume.
d. Dilution Factor: This is the ratio of waste material to ore that is mined and processed together. It measures the amount of low-grade or non-ore material that is mistakenly included with the high-grade ore, which lowers the overall grade of the processed material.

Question 9

The renewal of the permits of safety engineers and safety inspectors is?
a. Every 1 year
b. Every 2 years
c. Every 3 years
d. Every 5 years

Answer 9

c. Every 3 years

Question 10

The angle measured in degrees of deviation from horizontal at which earthy material will stand in an excavated terrace-like cut in an open pit mine or quarry.
a. Pit Slope
b. Bench Slope
c. Angle of Repose
d. Angle of Draw

Answer 10

b. Bench Slope

a. Pit Slope: The pit slope (also called the overall slope) refers to the angle from the toe of the lowest bench to the crest of the top bench. It is a much gentler angle than the individual bench slopes because it must accommodate haul roads and ensure the overall stability of the entire pit wall.
c. Angle of Repose: This term describes the steepest angle at which loose, granular material (like sand or a stockpile of crushed ore) will remain stable without slumping.
d. Angle of Draw: The angle of draw is a term used in underground mining to define the limit of subsidence on the surface. It is the angle from the edge of the mined-out area underground to the point on the surface where subsidence (sinking) can be first detected.

Question 11

Which of the following is an ideal sensitizing agent for explosives?
a. Potassium
b. Carbon
c. Aluminum
d. Copper

Answer 11

c. Aluminum

Aluminum is an ideal sensitizing agent for explosives, particularly in commercial blasting agents like slurry and emulsion explosives. It is used in powdered form to increase the explosive’s power and detonation velocity.

a. Potassium: While potassium is highly reactive, its compounds are more commonly used in explosives as oxidizers (like potassium nitrate or potassium chlorate), not as sensitizers. Its primary role is to provide oxygen for the reaction.
b. Carbon: Carbon, in the form of carbon black or charcoal, is a common fuel component in explosives (e.g., in black powder), but it does not act as a sensitizer in the same way as aluminum.
d. Copper: Copper and its alloys are generally not used in explosives and can even be dangerous to use in environments with certain explosive mixtures.

Question 12

Which of the following exploration methods is best and widely used in establishing the area, depth and thickness of mineralization? It is also used to gather data for ore reserves estimation and technical information essential in mine planning designs.
a. Geostatistical Analysis
b. Induced Polarization
c. Diamond core drilling
d. Geochemical methods

Answer 12

c. Diamond core drilling

a. Geostatistical Analysis: This is a data analysis technique, not a method for physical exploration. It is used to statistically analyze the data gathered from drilling (like grade and thickness) to create resource models and estimate reserves.
b. Induced Polarization (IP): This is a geophysical method that measures the electrical chargeability and resistivity of the ground. It is excellent for identifying potential mineralized zones, especially those with sulfide minerals, but it provides indirect data.
d. Geochemical Methods: These methods involve analyzing the chemical composition of surface materials like soil, stream sediments, or rock chips to detect a “geochemical anomaly” that might indicate a buried deposit. Geochemical surveys are effective for initial, reconnaissance-level exploration over large areas to identify targets.

Question 13

A system of bearing down coal by which compressed air, generated locally by a portable compressor at 10,000 psi, is used in releasing cylinder, which is placed in a hole drilled in the coal.
a. Hydrox
b. Chlorox
c. Airdox
d. Cardox

Answer 13

c. Airdox

a. Hydrox: This system uses a cartridge containing chemicals that react to produce high-pressure gas, often steam, to break coal. It is a variant of a non-explosive blasting method.
b. Chlorox: This is a brand name for household bleach (sodium hypochlorite) and is not related to mining or blasting methods.
d. Cardox: This is a non-explosive blasting system that uses a steel tube filled with liquid carbon dioxide. When initiated by a small heating element, the liquid CO2 vaporizes and expands rapidly, building up pressure until a bursting disc ruptures, releasing a powerful blast of gas to break the coal.

Question 14

In mine safety, which of the following refers to that potential condition that can result in an accident and interrupt the order of activities?
a. Injury
b. Near miss
c. Hazard
d. Incident

Answer 14

c. Hazard

a. Injury: An injury is the result of an accident, not the potential condition that causes it. It is the harm or damage to a person’s body.
b. Near miss: A near miss is an unplanned event that had the potential to cause injury, illness, or damage, but did not.
d. Incident: An incident is a broader term for an unplanned, undesired event that may or may not result in loss or damage. Both an accident (which causes damage) and a near miss (which does not) are types of incidents.

Question 15

Which of the following refers to the type of deposit that is formed by deposition of mineralized solution into fractures or fissures in the earth’s crust?
a. Porphyry type deposits
b. Placer type deposits
c. Kuroko type deposits
d. Vein type deposits

Answer 15

d. Vein type deposits

a. Porphyry type deposits: These are large, low-grade deposits where minerals are disseminated throughout a large volume of rock, often in a network of fine veinlets called a stockwork. They are associated with igneous intrusive rocks (porphyries), but the mineralization is widespread not confined to a single vein or fissure.
b. Placer type deposits: These deposits are formed by mechanical and gravitational processes, not by hydrothermal solutions. Valuable, heavy minerals (like gold or diamonds) are weathered from a primary source rock and then concentrated by the action of water or wind in rivers, beaches, or stream beds.
c. Kuroko type deposits: This is a specific type of volcanogenic massive sulfide (VMS) deposit. They are formed on the seafloor where mineral-rich hot springs (black smokers) vent, depositing massive layers of sulfide minerals.

Question 16

It is the portion or remainder of shothole found in a face often blast has been fired.
a. Bootleg
b. Misfire
c. Hangfire
d. Subdrill

Answer 16

a. Bootleg

b. Misfire: A misfire refers to a situation where a shot (or entire round of shots) fails to detonate at all, not just a portion of a hole. This is a complete failure of the blasting process.
c. Hangfire: A hangfire is a delayed detonation of an explosive charge. The fuse or detonator ignites, but the main charge takes a longer than expected time to detonate.
d. Subdrill: Subdrill refers to the portion of a borehole that is drilled below the planned grade or floor level to ensure that the entire rock mass breaks cleanly to the required depth.

Question 17

When the blasting in underground coal mines, which of the following explosives is recommend?
a. Slurry explosives
b. Permissible explosives
c. Semi-gelatin explosives
d. Straight dynamite explosives

Answer 17

b. Permissible explosives

a. Slurry explosives: While some slurry explosives can be formulated to be permissible, the term “slurry explosives” itself refers to a type of explosive with a high water content and does not guarantee it meets the safety standards required for coal mines.
c. Semi-gelatin explosives: This is a type of dynamite. While they are powerful, they are not inherently “permissible” and are generally not recommended for underground coal mining due to their higher risk of producing a long flame that could ignite gas or dust.
d. Straight dynamite explosives: This is a nitroglycerin-based explosive that produces a hot, prolonged flame. It is considered extremely dangerous for use in underground coal mines and is not recommended.

Question 18

Which of the following is not a sulfide mineral?
a. Chalcocite
b. Bornite
c. Malachite
d. Enargite

Answer 18

c. Malachite.

Malachite is a carbonate mineral, not a sulfide mineral. Its chemical formula is Cu2(CO3)(OH)2.

Chacocite (Cu2S)
Bornite (Cu5FeS4)
Enargite (Cu3Ass4)

Question 19

In mineral prospecting, which of the following metals exhibit an anomalous color of red?
a. Iron
b. Chromium
c. Arsenic
d. Mercury

Answer 19

d. Mercury

For mercury, the most significant anomalous color is red, often from the presence of the mineral cinnabar (HgS). Cinnabar is the primary ore of mercury and is well-known for its striking scarlet-to-red color. Its vibrant red hue makes it a very distinctive visual indicator of mercury mineralization.

b. Chromium: While chromium can cause a red color in certain gemstones like ruby, this is a result of trace amounts of chromium ions substituting for other elements in the crystal lattice. It is not the color of chromium’s primary ore mineral. The main ore of chromium is chromite (FeCr2O4), which is typically black or brownish-black.
a. Iron: Iron minerals can indeed be red, most notably hematite (Fe2O3), which is often responsible for the reddish-brown color of many soils. However, this is not considered an “anomalous” color because iron is so abundant and its reddish hues are so common and widespread.
c. Arsenic: Arsenic’s most common ore mineral, arsenopyrite (FeAsS), is a silvery-white or steel-gray color. While some arsenic-bearing minerals like realgar (AsS) can be orange-red, this is not the most common or prominent visual indicator in arsenic prospecting.

Question 20

Sinking a number of boreholes each in different horizontal or vertical direction from a single drill set-up.
a. Fan drilling
b. Auger drilling
c. Wedge drilling
d. Burn cut drilling

Answer 20

a. Fan drilling. It is a method used in mining, specifically for sublevel stoping, where multiple blastholes are drilled in a radial pattern (like an open fan) from a single drill set-up.

b. Auger drilling: This method uses a helical screw-shaped drill bit (auger) to bore holes into the ground. The screw-like action brings the excavated material to the surface. It is primarily used for soil sampling, geotechnical exploration, and creating holes for foundations.
c. Wedge drilling: This is a technique in directional drilling used to intentionally change the direction of a borehole. A wedge is a tool placed inside an existing hole to deflect the drill bit, creating a new borehole in a different direction.
d. Burn cut drilling: This is a specific blasting pattern used in tunneling and drifting. It involves drilling a series of parallel holes, with one or more central holes left uncharged. The purpose of these uncharged relief holes is to provide an empty space for the rock to expand into when the surrounding charged holes are blasted.

Question 21

In interpreting geologic maps, limestone is always characterized by which of the following?
a. High reliefs
b. Karst topography
c. Overhangs
d. Valleys

Answer 21

b. Karst topography

Karst topography is a unique landscape that forms when soluble rocks, like limestone, are dissolved by slightly acidic groundwater. This chemical weathering creates a distinctive set of features, including: sinkholes, caves and caverns, disappearing streams, underground drainage.

a. High reliefs: While some limestone formations can form high-relief features like tower karst, limestone is a relatively soft rock and can also be found in low-relief areas or flat plains.
c. Overhangs: Overhangs, or cliffs, can be found in many different types of rock, not just limestone. Their formation is related to differential erosion, where a harder, more resistant layer of rock overlies a softer, more easily eroded layer.
d. Valleys: Valleys are a common landform found in all types of geology. While limestone areas can have valleys, they are not a unique characteristic. In fact, many karst regions are characterized by a lack of surface valleys and streams due to the underground drainage system.

Question 22

The rising of the floor of the mine caused by its being too soft to resist the weight on the pillar.
a. Heave
b. Airblast
c. Slabbing
d. Spalling

Answer 22

a. Heave. The upward movement or buckling of a mine’s floor. It happens when the pressure from the surrounding rock, often under the weight of the overlying pillars, is greater than the bearing capacity of the soft floor rock. This can cause the floor to rise and can be a significant safety and operational hazard, as it can block mine passages and destabilize pillars.

b. Airblast: An airblast is a sudden, powerful rush of air caused by a large-scale rockfall or pillar collapse. It’s a rapid displacement of air.
c. Slabbing: It refers to the fracturing or detachment of large, flat pieces of rock from the sides of mine pillars or tunnels. It’s a form of pillar failure, not floor failure.
d. Spalling: Spalling is the chipping, fracturing, and fragmentation of rock, often from the sides of an opening, due to high stress. It is a surface failure mechanism of a rock mass.

Question 23

Which of the following physical properties of rocks refers to the ratio between the volume of voids or open space inside a rock mass and the total volume of said rock mass or material?
a. Permeability
b. Bond work index
c. Young’s Modulus
d. Porosity

Answer 23

d. Porosity

a. Permeability: While related to porosity, permeability refers to the ability of a rock to transmit fluids.
b. Bond work index: This is a measure of the energy required to crush or grind a material, and is used in the field of mineral processing.
c. Young’s Modulus: This is a measure of the stiffness of a solid material. It describes the relationship between stress and strain in a material and is used in engineering and rock mechanics.

Question 24

Which of the following refers to the maximum slope at which a heap of loose material can stand without sliding?
a. Angle of Draw
b. Angle of Repose
c. Angle of Friction
d. Angle of Surcharge

Answer 24

b. Angle of Repose

a. Angle of Draw: In mining, the angle of draw is the angle from the vertical that defines the extent of a surface subsidence zone caused by underground mining. It’s used to predict how far out the ground will subside from the edge of the mined-out area.
c. Angle of Friction: For a granular material at rest, the angle of repose is equal to the angle of internal friction. However, the angle of repose is the specific term for the maximum stable slope of a loose pile, while the angle of friction is a more general term.
d. Angle of Surcharge: The angle of surcharge is an engineering term, often used in conveyor belt design. It refers to the angle that a material forms on a moving conveyor belt. It’s typically smaller than the angle of repose because the material is in motion.

Question 25

In open pit bench blasting, what do you call that portion of a drill hole that is intentionally drilled beyond the bench floor in order to prevent hard toes? a. Collar grade b. Stemming height c. Subdrill d. Secondary hole grade

Answer 25

c. Subdrill: Also known as subgrade drilling, this is the extra depth of a blast hole drilled below the final desired floor elevation (the "grade"). Its purpose is to ensure that the explosive energy is sufficient to break the rock completely at the bench floor level, preventing a condition known as a "hard toe" or "toe." A hard toe is an unwanted, unbroken section of rock that remains at the base of the bench after a blast, which can hinder subsequent excavation work. a. Collar grade: This refers to the elevation of the top of the blast hole, where the drilling begins. It is not related to the portion of the hole below the floor. Stemming height: This is the length of the blast hole at the top that is filled with inert material (like drill cuttings or crushed rock) instead of explosives. Its purpose is to confine the explosive energy within the hole, maximizing its effectiveness and minimizing flyrock and air blast.

Question 26

In open pit or quarrying operations, what do you call the drill cuttings or fine rock materials that are used to backfill the remaining height of a blasthole after it is loaded with explosives? a. Drill pattern b. Total explosives charge c. Stemming height d. Burden

Answer 26

c. Stemming height This material acts as a plug to confine the explosive energy, preventing the high-pressure gases from escaping out of the top of the hole. By containing the explosive force, stemming ensures that the energy is directed into the surrounding rock, maximizing fragmentation and reducing unwanted effects like flyrock and airblast.

Question 27

Within one (1) shift of typical tunneling operation, which of the following activities as initiated last? a. Drilling b. Hauling c. Blasting d. Mucking

Answer 27

b. Hauling. In a typical tunnel-blasting cycle, the activities are performed in a specific, recurring sequence. This cycle, often called a "round," is repeated to advance the tunnel. Drilling-Blasting-Mucking-Hauling

Question 28

The ratio of the stress to the strain within the elastic limit. a. Modulus of Elasticity b. Coefficient of Elasticity c. Poisson's Ratio d. Bulk Modulus

Answer 28

a. Modulus of Elasticity. Often called Young's Modulus (E), is a measure of a material's stiffness or its resistance to elastic deformation. c. Poisson's Ratio: This is a different elastic constant. It is the ratio of lateral strain to longitudinal strain when a material is stretched or compressed. It describes how a material's width changes when its length is changed. d. Bulk Modulus: This measures a material's resistance to uniform volumetric compression. It is the ratio of a pressure increase to the resulting relative decrease in volume.

Question 29

In underground timbering, what do you call the main part of a standard timber set that directly supports the roof or back of an underground working? a. Cap b. Post c. Wedge d. Girt

Answer 29

a. Cap b. Post: The post is the vertical support member, which holds up the cap. It does not directly support the roof itself. c. Wedge: Wedges are used to tighten the set and are not a main structural member. d. Girt: A girt is a horizontal brace used to connect and stabilize two adjacent timber sets, but it does not directly support the roof.

Question 30

Which of the following branches of the Philippine National Police is responsible of regulating the sale, disposal and inventory of explosives and explosives accessories? a. NBI b. CAFGU c. FEO d. SWAT

Answer 30

c. FEO The branch of the Philippine National Police (PNP) responsible for regulating the sale, disposal, and inventory of explosives and explosive accessories is the Firearms and Explosives Office (FEO).

Question 31

According to DAI 2000-98, in massive, unbroken or unfractured igneous rocks, what is the minimum thickness of the back from the true riverbed and the roof of the mine working to the surface if a mine working or opening shall be driven or caused to be driven under rivers, sea or any known accumulation of standing or running water? a. 8 meters b. 15 meters c. 25 meters d. 50 meters

Answer 31

c. 25 meters broken and fractured: 50 meters

Question 32

Which of the following refers to the type of blasting where large rock boulders are first drilled then loaded with dynamite for blasting? a. Mudcapping b. Blockholing c. Bouldering d. Coyote Blasting

Answer 32

b. Blockholing. It is a secondary blasting method used to break up large, oversized boulders that were not sufficiently fragmented by the primary blast. This technique involves drilling a small-diameter hole into the boulder, inserting a small explosive charge (usually dynamite), and then stemming the hole before detonation. a. Mudcapping: Also known as adobe blasting, this method involves placing a small explosive charge directly on the surface of a rock and then covering it with mud, clay, or a similar material for confinement. d. Coyote Blasting: This is a large-scale primary blasting technique used in quarries or open-pit mines. It involves driving horizontal tunnels or "coyote holes" into the base of a rock face and filling them with large quantities of explosives to blast an entire section of the quarry.

Question 33

The stress above which the stress-strain relationship is not anymore directly proportional. a. Failure point b. Yield point c. Hysteresis d. Permanent set

Answer 33

b. Yield point (proportional limit) The proportional limit is the point on the stress-strain curve where the linear relationship, as described by Hooke's Law, ends. Up to this point, the stress is directly proportional to the strain, and the material behaves elastically. The slope of this linear portion is known as the Modulus of Elasticity (Young's Modulus). The yield point is the stress at which a material begins to undergo permanent plastic deformation. a. Failure point: This is the point at which the material breaks or fractures completely. It occurs much later on the stress-strain curve, long after the material has passed both the proportional and yield points. c. Hysteresis: This refers to the energy lost as heat during the loading and unloading of a material. It's a phenomenon, not a specific point on the curve. d. Permanent set: This is the permanent deformation that remains in a material after the load is removed. It's a result of exceeding the yield point.

Question 34

A horizontal opening driven across the course of a vein or in general across the direction of the main workings. a. Ramp b. Decline c. Crosscut d. Room

Answer 34

c. Crosscut. It is a horizontal passage in an underground mine that is driven at a large angle, often perpendicular, to the main workings (like a drift or a tunnel) or to the ore body (vein). Its primary purpose is to provide access to the ore from the main haulageways or to connect different parts of the mine for ventilation and transport. a. Ramp: A ramp is an inclined roadway or tunnel that connects different levels of a mine. It is used for vehicle access to move ore, waste, and equipment. b. Decline: Similar to a ramp, a decline is a downward-sloping mine opening. It provides access to lower levels of the mine and is often used as the primary access for trackless mining equipment.

Question 35

Which piece of equipment removes materials by pulling bucket toward the machine? a. Shovel b. Dragline c. Bucket Wheel Loader d. Front End Loader

Answer 35

b. Dragline. A dragline is a large piece of excavation equipment that removes material by "dragging" a bucket across the ground toward the machine. The bucket is attached to the machine by ropes and a hoist line. The operator lowers the bucket to the ground, and the dragline then pulls it horizontally, scraping and collecting the material. a. Shovel: A shovel (specifically a power shovel or face shovel) removes material by digging and pushing its bucket away from the machine and upward into the face of a bank or pile. c. Bucket Wheel Loader: This is a continuous digging machine that uses a large rotating wheel with buckets to excavate material and dump it onto a conveyor system. It's used for large-scale earthmoving. d. Front End Loader: A front-end loader uses a bucket on a hydraulic arm to scoop up material by driving forward into a pile. The bucket's motion is a combination of scooping and lifting.

Question 36

Which of the following minerals are also essential in the manufacture of cement in addition to the most basic raw materials? a. Dunite b. Bentonite c. Dacite d. Silica

Answer 36

d. Silica. In addition to the most basic raw materials (limestone and clay), silica (SiO2) is an essential component in the manufacture of cement, specifically Portland cement. It is typically provided by materials like sand, shale, or certain types of clay. Silica acts as a primary component in the formation of clinker, the main binding agent in cement. a. Dunite: Dunite is an igneous rock composed of olivine. b. Bentonite: Bentonite is an absorbent clay formed from volcanic ash. c. Dacite: Dacite is a volcanic rock.

Question 37

In open pit mine planning and design, which of the following refers to the arithmetic of searching the optimum limit of an open pit mine considering the maximum profits that can be generated given the grade of the material and tonnage of waste that can be stripped economically? a. Tonnage optimization b. Graphical Design Technique c. Lerch-Grossman Algorithm d. Rotating Cone Technique

Answer 37

c. Lerch-Grossman Algorithm The Lerch-Grossman Algorithm is a fundamental mathematical model used in open-pit mine planning to determine the optimal economic limits of a mine. It uses a three-dimensional block model of the orebody, which contains information on the grade of the material and the cost of mining each block. The algorithm's core function is to find the pit shell that yields the maximum possible profit by identifying which blocks of ore should be mined and which should be left behind, taking into account the necessary removal of overburden (waste) to access the ore. The algorithm ensures that the value of the ore extracted from the pit is greater than the total cost of mining and processing that ore and stripping the associated waste.

Question 38

Which of the following refers to a ferruginous outcrop? a. Gossan b. Paystreak c. Overburden d. Cap

Answer 38

a. Gossan. Also known as an "iron cap" or "iron hat" (from the German Eiserner Hut), is a highly oxidized, weathered, and decomposed rock outcrop that is rich in iron. It forms at the surface when sulfide minerals, particularly pyrite, are exposed to air and water. b. Paystreak: A paystreak refers to a zone or streak within a mineral deposit that is rich enough in valuable material to be profitable. It is a term for a high-grade section of an orebody. c. Overburden: Overburden is the rock, soil, and other material that lies above an orebody and must be removed to access the valuable resource in a surface mining operation.

Question 39

Those that will not prevent the injured person from reporting to his designated work on the working day following the day of injury and thereafter. a. Lost-time accident, non-fatal b. Non-lost time accident c. Near miss d. Lost-time accident, fatal

Answer 39

b. Non-lost time accident a. Lost-time accident, non-fatal: This refers to an injury that requires the employee to miss work (i.e., lost time) but does not result in death. c. Near miss: A near miss is an unplanned event that had the potential to cause injury, illness, or damage but did not. There is no injury involved in a near miss. d. Lost-time accident, fatal: This is the most severe type of accident, resulting in a fatality. By definition, a fatal accident results in lost time.

Question 40

The rock in which the ore body is enclosed. a. Host rock b. Seal c. Country rock d. Outcrop

Answer 40

a. Host rock. A host rock is the rock mass in which an orebody, mineral deposit, or other valuable material is found. The term implies a genetic relationship: the valuable minerals were formed within or introduced into this specific rock type. c. Country rock: This term refers to the rock that is native to an area and surrounds or is intruded by another geologic body, such as a magma intrusion or a mineral deposit. While a host rock can be a type of country rock, the key distinction is that the host rock contains the ore, while the country rock is simply the surrounding or pre-existing rock. b. Seal: In geology, a seal or caprock is a low-permeability rock layer that prevents the migration of fluids, such as oil, gas, or groundwater. It does not contain the ore itself but helps trap it in a reservoir rock. d. Outcrop: An outcrop is a visible exposure of bedrock on the Earth's surface.

Question 41

Technique to reduce stress concentration at the longwall face. a. Making the face slightly concave b. Making the face slightly convex c. Making the face straight d. Making the face jagged

Answer 41

b. Making the face slightly convex In longwall mining, the area around the working face experiences a significant redistribution of stress from the overburden, leading to high stress concentrations. A slightly convex shape for the longwall face is a recognized geomechanical technique to manage this stress. A convex face curvature helps to distribute the stress more evenly across the face, reducing the peak stress concentration that would occur at the corners or ends of a straight face.

Question 42

A gold vein dipping 60 degrees (from the horizontal) needs to be drilled to measure the true thickness. What should be the inclination (from the vertical) of the drill hole? a. 30 degrees b. 45 degrees c. 60 degrees d. None of these

Answer 42

a. 30 degrees A dip angle value should be between 0° and 90°, inclusive. A 0° dip indicates a horizontal plane, while a 90° dip indicates a vertical plane. 90 deg - dip angle = drill hole inclination 90 deg - 60 deg = 30 deg

Question 43

A rock mass parameter that quantifies discontinuity by the ratio of the lengths of the individual pieces of core recovered in a drill run, having lengths of 10 cm or greater, and the total length of drill run. a. Rock Quality Designation b. Core Recovery c. Fracture Spacing d. Rock Mass Rating

Answer 43

a. Rock Quality Designation b. Core Recovery: It's the ratio of the total length of the core retrieved from the drill hole to the total length of the core run. It's a measure of the drilling efficiency, not the quality of the rock mass. c. Fracture Spacing: Fracture spacing is a measure of the distance between individual fractures or discontinuities in a rock mass. d. Rock Mass Rating (RMR): The Rock Mass Rating (RMR) system is a comprehensive classification system that uses RQD as one of its key input parameters. However, RMR also considers other factors like the strength of the intact rock, the condition of discontinuities, groundwater conditions, and the orientation of the discontinuities.

Question 44

The item to consider in designing shafts for ore hoisting is: a. Availability of skilled shaft sinkers b. Adequate ventilation c. Proper mine drainage d. Tonnage to be hoisted

Answer 44

d. Tonnage to be hoisted

Question 45

It is the perpendicular distance between adjacent discontinuities. a. Aperture b. Persistence c. Spacing d. Strike

Answer 45

c. Spacing a. Aperture: This is the perpendicular distance between the two opposing faces of a single discontinuity, like a joint or fracture. It measures the opening or width of the fracture itself. b. Persistence: This refers to the areal extent or length of a single discontinuity. A highly persistent discontinuity is one that extends for a long distance and may be a major geological feature like a fault, while a non-persistent discontinuity is limited in its extent. d. Strike: This is a geological term that describes the compass direction of the line formed by the intersection of a planar feature (like a discontinuity or bedding plane) and a horizontal plane.

Question 46

It is similar to but uniquely different from the room-and-pillar method and is most widely used in underground hard-rock mining. It is the unsupported version which the openings are driven horizontally in a mineral deposit in regular or random pattern to form pillars for ground support. a. Stope and Pillar mining b. Block Caving c. Longwall mining d. Pillar robbing

Answer 46

a. Stope and Pillar mining b. Block Caving: This is a large-scale bulk mining method that relies on gravity and a naturally occurring fracture network to break up the ore. c. Longwall mining: This is a highly mechanized underground coal mining method that uses a rotating shearer to cut a long face of coal. d. Pillar robbing: This is a secondary mining operation where the support pillars left behind in a room-and-pillar mine are systematically removed to recover additional ore.

Question 47

A bird used by the past miners to detect the methane content in a coal mine. a. Woodpecker b. Owl c. Parrot d. Canary

Answer 47

d. Canary

Question 48

In blasting operations, "powder factor" refers to: a. The amount of explosives that can be handled by one person per manshift. b. Weight of explosives needed to sufficiently break a unit of weight of volume of rock. c. Optimum amount of powder present in any given weight of explosives. d. The amount of explosives powder that is used in the calibration of ballistic pendulum to test other explosives.

Answer 48

b. Weight of explosives needed to sufficiently break a unit of weight of volume of rock.

Question 49

Wood preservatives are end products of which of the following? a. Chemical grade chromite b. Refractory grade chromite c. Metallurgical chromite d. Copper ingots

Answer 49

a. Chemical grade chromite. It is used as a raw material in the chemical industry to produce a wide range of chromium compounds, including sodium dichromate. Sodium dichromate is a key precursor for manufacturing many products, including chromic acid, chromium pigments, and various chromium salts. These chromium salts, such as chromated copper arsenate (CCA), are a major component of wood preservatives, which are used to protect timber from rot, fungi, and insects. b. Refractory grade chromite: This type of chromite is used to produce refractory materials, which are substances that are highly resistant to heat and are used in furnace linings. c. Metallurgical grade chromite: This is the most common type of chromite, used primarily in the production of ferrochromium, an alloy essential for making stainless steel. d. Copper ingots: Copper ingots are a form of pure copper used in the manufacturing of many products, including electrical wires and pipes.

Question 50

Limestone formations, whether folded or heavily faulted, are what type of rocks? a. Igneous rocks b. Volcanic rocks c. Vein type deposits d. Sedimentary rocks

Answer 50

d. Sedimentary rocks

Question 51

The air reticulation system of an underground mine has the following daily compressed air data for its pneumatic equipment: Tank 1 12,0000 cu.m. 60 psi Tank 2 12,0000 cu.m. 50 psi Tank 3 15,0000 cu.m. 70 psi Tank 4 15,0000 cu.m. 77 psi Tank 5 10,0000 cu.m. 75 psi What average pneumatic pressure is available assuming there are no leaks along the full length of the underground pipe lines? Express your answer in the nearest rounded bars pressure. a. 4 bars b. 5 bars c. 6 bars d. 7 bars

Answer 51

b. 5 bars

Question 52

Under 7076, the development and management of the country's mineral resources has been devolved from the DENR to which government agency? a. Bangko Sentral ng Pilipinas b. Philippine Mining Development Corporation c. Local Government Unit d. None of these

Answer 52

c. Local Government Unit (LGU). Under Republic Act 7076, the development and management of the country's small-scale mineral resources has been partially devolved from the Department of Environment and Natural Resources (DENR) to the Provincial/City Mining Regulatory Board, which includes representation from the Local Government Unit (LGU).

Question 53

The term used to describe the intact rock between discontinuities is called? a. Rock mass b. Rock material c. Infill material d. Rock specimen

Answer 53

b. Rock material. Also known as intact rock, refers to the solid, unfractured rock between discontinuities like joints, fractures, bedding planes, and faults. It is the fundamental building block of a rock mass. a. Rock mass: This term refers to the entire in-situ volume of rock, including both the intact rock material and all of its discontinuities. It's the whole. c. Infill material: This is the material (like clay, sand, or calcite) that fills the space within a discontinuity. d. Rock specimen: This is a small sample of rock that is removed from the ground, typically for laboratory testing.

Question 54

A mineral that has either blue or green outcrop, and exist as carbonates, silicates, sulphates, oxides, and in native form is? a. Iron b. Nickel c. Mercury d. Copper

Answer 54

d. Copper a. Iron: Iron minerals are typically associated with rusty red, brown, or black colors (e.g., hematite, magnetite). b. Nickel: Nickel minerals are usually a greenish color (e.g., garnierite), but they are not known for the wide range of blue and green. c. Mercury: Mercury's primary ore mineral, cinnabar (HgS), is a striking red. Native mercury is a silvery liquid. It is not associated with blue or green outcrops.

Question 55

An underground water derived from rain, water courses or other bodies of water. This water passes down into the earth and part of it becomes stores in the pores and cracks in the rocks and part of it circulate. a. Magmatic water b. Juvenile water c. Connate water d. Meteoric water

Answer 55

d. Meteoric water a. Magmatic water: Also known as juvenile water, this is water that originates from magma or molten rock. It is "new" water that has never been part of the Earth's atmosphere or surface. c. Connate water: This is water that was trapped in the pores of sedimentary rock when the rock was formed.

Question 56

It is the distance between rows of blastholes parallel to the major free face. a. Burden b. Spacing c. Sub-drill d. Collar distance

Answer 56

a. Burden b. Spacing: Spacing is the distance between individual blastholes within the same row. It is perpendicular to the burden. c. Sub-drill: This is the portion of a blasthole that is drilled below the intended bench floor to ensure complete breakage at the toe of the bench.

Question 57

The measure of coal quality is expressed as: a. Carbon content b. Chlorine content b. Sulfur content d. BTU

Answer 57

d. BTU. While other factors like carbon, sulfur, and moisture content are important, the BTU or calorific value is the primary measure of coal quality because it directly quantifies the amount of heat energy the coal will produce when burned. a. Carbon content: Higher carbon content generally correlates with higher quality (e.g., anthracite has a higher carbon content than lignite), but it is a measure of composition, not the final energy output. b. Sulfur content: This is a measure of an undesirable impurity. High sulfur content leads to environmental issues like acid rain and can corrode equipment.

Question 58

Any known body of mineral occurrence with a potential to become an orebody worthwhile mining. a. Prospecting b. Ore reserve c. Mineral deposit d. Mineral property

Answer 58

c. Mineral deposit. A mineral deposit is any concentration of valuable minerals or materials in the Earth's crust that has the potential for economic development. It is the initial stage of a mineral occurrence that is deemed significant enough to warrant further exploration. a. Prospecting: This is the activity of searching for mineral deposits. It is a process, not a body of mineral occurrence. b. Ore reserve: This is a more specific term. An ore reserve is the portion of a mineral deposit that has been fully evaluated and determined to be economically and legally mineable under current conditions. d. Mineral property: This refers to the land area on which a mineral deposit or occurrence is located. It is a legal term for the property rights.

Question 59

In a typical nickel profile, which of the following occurs immediately above the ultramafic? a. Laterite b. Saprolite c. Bedrock d. None of these

Answer 59

b. Saprolite Saprolite Layer: Located immediately below the laterite, the saprolite is a weathered rock zone where the original ultramafic rock has been chemically altered but its original rock structure is still recognizable. This layer is often the most economically important part of the deposit, as the nickel and other metals have been enriched here through the weathering and leaching process. a. Laterite Layer (Limonite Zone): This is the uppermost layer, rich in iron oxides, which gives it a reddish-brown color. It contains relatively low concentrations of nickel and other valuable metals. c. Ultramafic Bedrock: This is the unweathered parent rock at the base of the profile. It is a dense, primary igneous rock (like peridotite or serpentinite) from which the laterite and saprolite layers were formed.

Question 60

It is a horizontal excavation to expose a mineral outcrop. a. Shaft sinking b. Adit c. Test pit d. Trench

Answer 60

d. Trench a. Shaft sinking: This is a vertical excavation used to create a mine shaft, providing access to deeper orebodies. b. Adit: An adit is a horizontal or nearly horizontal tunnel driven from the surface into the side of a hill or mountain. Its primary purpose is to provide access to an underground mine. c. Test pit: A test pit is a small, vertical excavation dug to evaluate soil or rock conditions.

Question 61

The stress which governs the gross mechanical response of a porous material. a. Shear stress b. Thermal stress c. Normal stress d. Effective stress

Answer 61

d. Effective stress. In a porous material like rock or soil, the total stress (σ) applied by an external load is shared between the solid mineral grains and the fluid (like water or oil) in the pore spaces. Effective stress (σ′) is the portion of the total stress that is supported by the solid grain skeleton. The concept, formulated by Karl von Terzaghi. a. Shear stress: This is a stress component that acts parallel to a surface, causing a material to deform by sliding. b. Thermal stress: This is stress caused by a change in temperature or temperature gradients. c. Normal stress: This is the stress component that acts perpendicular to a surface.

Question 62

What law recognizes the rights of the indigenous peoples such as their ancestral, cultural integrity, and human rights? a. RA 8713 b. RA 8371 c. RA 1738 d. RA 3781

Answer 62

b. RA 8371 Republic Act No. 8371, also known as "The Indigenous Peoples' Rights Act of 1997" (IPRA), is the landmark law in the Philippines that formally recognizes, protects, and promotes the rights of Indigenous Cultural Communities/Indigenous Peoples (ICCs/IPs). This law specifically addresses: ancestral domain and lands, cultural integrity, and human rights.

Question 63

Which of the following local terms refers to the waste materials in a mine? a. Nava b. Muck c. Mulok d. Oversize

Answer 63

c. Mulok (old term) Nava (old term) - vein

Question 64

In diamond drilling, which of the following has the smallest diameter? a. NQ b. HQ c. BQ d. AQ

Answer 64

d. AQ AQ series: The hole diameter is approximately 48 mm. BQ series: The hole diameter is approximately 60 mm. NQ series: The hole diameter is approximately 75.7 mm. HQ series: The hole diameter is approximately 96 mm.

Question 65

A copper mine in Compostela Valley Province, Mindanao is proven to contain about 456,250,000 tons of chalcocite ores with an average grade of 0.8% Cu. The mine has an estimated operational life of 25 years. The processing technology has a recovery rate of 88%. The operating cost (mining & milling) of the mine is $15.00/ton; administrative cost of $10.00/ton; and the capital cost of equipment of $5.00/ton. The price of Cu metal in the world market is at $ 3.60/lb. Determine the daily production of the mine. a. 40,000 tons/day b. 48,000 tons/day c. 50,000 tons/day d. 52,000 tons/day

Answer 65

c. 50,000 tons/day. Total Days = Operational Life (years) × 365days/year Total Days = 25years × 365 days/year = 9,125days Daily Prod = Total Tonnage/Total Days Daily Prod = 456,250,000tons/9,125days Daily Prod = 50,000 tons/day.

Question 66

A solid petroleum that occurs as a component of shale. a. Tar b. Kerogene c. Bitumen d. Coke

Answer 66

b. Kerogene Kerogen is a solid, insoluble mixture of complex organic compounds found in sedimentary rocks, most notably shale. It is the precursor to liquid petroleum (oil) and natural gas. Over millions of years, as layers of rock are buried and subjected to heat and pressure, the organic matter from ancient plants and algae matures into kerogen. If the heating continues, the kerogen will eventually crack and transform into conventional crude oil and natural gas. Oil shales are a type of sedimentary rock that contains a high concentration of kerogen. a. Tar: Tar is a black, highly viscous liquid or semi-solid form of petroleum. While it's a hydrocarbon, it is not a solid component of shale in its raw, unrefined state. c. Bitumen: Bitumen is a black, sticky, and highly viscous form of petroleum. It is soluble in carbon disulfide and is often found in oil sands. It is a product of geological processes, not a raw component of shale. d. Coke: Petroleum coke, or coke, is a solid carbon material that is a by-product of oil refining and other industrial processes.

Question 67

What is the mining method where high pressure stream of water is directed against a bank of placer deposit to undercut and cave it? a. Hydraulicking b. Placer mining c. Sluicing d. Solution mining

Answer 67

a. Hydraulicking b. Placer mining is the broader category of mining that extracts heavy minerals from alluvial or placer deposits. Hydraulicking is a specific technique within placer mining. c. Sluicing refers to the process of using a sluice box to separate heavy minerals from the lighter gravel and sand. d. Solution mining is a different process entirely. It involves injecting a solvent solution into an underground ore body to dissolve the valuable minerals, which are then pumped to the surface for processing.

Question 68

A smooth blasting method in which cracks for the final contour are created by blasting prior to the drilling of the rest of the holes for the blast pattern. a. Perimeter blasting b. Pre-splitting c. Bouldering d. Blockholing

Answer 68

b. Pre-splitting a. Perimeter blasting: This is a general term that includes all controlled blasting methods used to define the final excavation boundary, with pre-splitting being a specific technique within this category. d. Blockholing: This is a secondary blasting method used to break up large, oversized boulders by drilling a hole and placing a small charge inside.

Question 69

The study of the properties, mechanical behavior of rock, and the nature of stresses underground. a. Engineering Geology b. Rock Mechanics c. Soil Mechanics d. Geotechnics

Answer 69

b. Rock Mechanics a. Engineering Geology: This is the application of geological principles to engineering projects. While it includes the study of rock properties, it is a broader field that also covers hydrogeology, geohazards, and site investigation. c. Soil Mechanics: This field deals with the mechanical behavior of soils, which are unconsolidated materials. It is distinct from rock mechanics, which deals with solid, consolidated rock. d. Geotechnics: This is an umbrella term that includes both rock mechanics and soil mechanics. It is the application of scientific methods and engineering principles to the acquisition, interpretation, and use of knowledge of materials of the Earth's crust.

Question 70

A mineral exploration method that utilizes a high altitude-radar equipment installed in an aircraft that maps earth's topography using satellite images to detect bedrock and mineralized zones. a. Magnetic b. Gravimetric c. Remote Sensing d. Radiometric

Answer 70

c. Remote Sensing The method described, which uses high-altitude radar from an aircraft to map topography and detect mineralized zones, is a specific application of remote sensing. Technologies like Synthetic Aperture Radar (SAR) can penetrate clouds and foliage, making them highly effective for mapping terrain and identifying geological structures, faults, and alterations that may indicate the presence of a mineral deposit.

Question 71

What mineral/metal is characterized by the following description: crystal system (isometric); color (black to brown); resinous luster; streak (brown to yellow); specific gravity (3.9 to 4.2); hardness (3.5 to 4)? a. Galena b. Rutile c. Cassiterite d. Sphalerite

Answer 71

d. Sphalerite a. Galena: Galena is also isometric but has a metallic luster, a lead-gray color and streak, a much higher specific gravity (7.4 to 7.6), and a lower hardness (2.5). b. Rutile: Rutile has a tetragonal crystal system, not isometric. It has a high specific gravity (4.2), but a hardness of 6 to 6.5 and an adamantine to submetallic luster. c. Cassiterite: Cassiterite has a tetragonal crystal system, not isometric. It has a high specific gravity (6.9 to 7.1) and a much higher hardness (6 to 7).

Question 72

Which of the following is not a rare earth element? a. Scandium b. Lanthanum c. Cerium d. Osmium

Answer 72

d. Osmium Osmium is a very dense, hard, and brittle precious metal. It is a member of the platinum group metals and is not classified as a rare earth element.

Question 73

Braggite is a mineral that contains which of the following? a. Platinum b. Copper c. Chromium d. Silver

Answer 73

a. Platinum Braggite is a rare sulfide mineral with the chemical formula (Pt,Pd,Ni)S. It is a member of the platinum-group minerals and is a major source of platinum and palladium. It is typically found in ultramafic rocks and is a key ore mineral in the Bushveld Igneous Complex in South Africa, one of the world's largest platinum deposits.

Question 74

The Chromite concentrate of Heritage Resources showed the following screen analysis: SIEVE FRACTION WEIGHT ASSAY +1.00 mm 20 MT 2% Cr2O3 -1.00 mm=0.75 mm 45 MT 24% Cr2O3 -0.75 mm+0.50mm 60MT 35% Cr2O3 -0.50mm+0.25mm 120MT 15% Cr2O3 -0.25mm+0.10mm 10MT 2% Cr2O3 -0.10mm 10MT 1% Cr2O3 A particular export market requires only the size fraction -1.00 mm + 0.25 mm inclusive. If the concentrate is re-screened to meet market specifications, what is the resulting grade assuming 100% screen recovery? a. 22.13% b. 20.13% c. 35.13% d. 32.13%

Answer 74

a. 22.13% Selected size fractions = between -1.00 mm and +0.25 mm inclusive → include: -1.00 +0.75 mm: 45 MT @ 24% -0.75 +0.50 mm: 60 MT @ 35% -0.50 +0.25 mm: 120 MT @ 15% Total weight = 45 + 60 + 120 = 225 MT Total Cr₂O₃ mass = 45×24 + 60×35 + 120×15 = 1080 + 2100 + 1800 = 4980 (MT·% units) Resulting grade = 4980 ÷ 225 = 22.133…% ≈ 22.13%.

Question 75

It is a study conducted to assess the engineering/technical and economic appraisal of the commercial viability of the project. a. Mine Valuation b. Mine Assessment c. Pre-Feasibility Study d. Feasibility

Answer 75

d. Feasibility A feasibility study is a comprehensive analysis that examines all aspects of a project to determine its commercial viability. In the context of a mining project, this study assesses the technical, engineering, economic, legal, and environmental factors to decide whether the project is financially sound and should proceed. a. Mine Valuation: This is the process of determining the monetary value of a mine or mineral property. It is a part of a feasibility study but is not the study itself. b. Mine Assessment: This is a general term that refers to evaluating a mine's condition or potential. It is not a formal study with a specific scope. c. Pre-Feasibility Study: This is an earlier-stage study that provides a preliminary evaluation of a project's potential. It is less detailed and has a lower level of accuracy than a full feasibility study.

Question 76

In mine ventilation, which of the following diseases result from excessive inhalation of coal dust? a. Asbestosis b. Silicosis c. Anthracosis d. Tuberculosis

Answer 76

c. Anthracosis Anthracosis, also known as "black lung disease" or "coal worker's pneumoconiosis (CWP)," is a lung disease that results from the long-term inhalation of large amounts of coal dust. The dust particles accumulate in the lungs and lymph nodes, causing inflammation, fibrosis, and scarring. a. Asbestosis: This is a lung disease caused by the inhalation of asbestos fibers. b. Silicosis: This is a lung disease caused by the inhalation of crystalline silica dust, which is common in hard rock mining, quarrying, and construction. d. Tuberculosis: This is a contagious bacterial infection that primarily affects the lungs. While mine workers may have an increased risk of contracting tuberculosis due to poor working conditions and weakened respiratory systems, it is not caused directly by the inhalation of mineral dust.

Question 77

The common host rocks of disseminated porphyry copper deposits usually have 30% swell factors when blasted. If the specific gravity of these host rocks is 3.0, what would be their resulting material density in loose per cubic meter? a. 0.75 b. 2.3 c. 2.8 d. 8.33

Answer 77

b. 2.3 Loose volume=(1+0.30)×In situ volume Loose density = Mass ÷ Loose volume Loose density = 3.0/1.3 = 2.3077≈2.3t/m³

Question 78

In surface excavations, where is phreatic water usually found? a. Zone of saturation b. Zone of underground river c. Zone of capillary deposition d. Zone of run-off water

Answer 78

a. Zone of saturation Phreatic water is another term for groundwater. It refers to the water that is located in the zone of saturation, which is the area below the water table where all of the pores, fractures, and voids in the rock or soil are completely filled with water. b. Zone of underground river: While phreatic water can contribute to or be part of an underground river, this is a specific type of geological feature, not the general term for where groundwater is found. c. Zone of capillary deposition: This refers to the capillary fringe, which is a saturated or nearly-saturated zone located directly above the water table. Water in this zone is held by capillary action and is not under pressure, unlike phreatic water. d. Zone of run-off water: This refers to surface water that flows over the land and does not infiltrate into the ground.

Question 79

In a typical laterite/saprolite profile, which of the following has the highest concentration of nickel? a. Laterite b. Saprolite c. Ultramafics d. None of these

Answer 79

b. Saprolite

Question 80

A mining method that reminds of a sublevel stoping and is based on the principle of spherical charge and cratering concepts. a. Resuing mining b. Sublevel retreat with backfill c. Vertical Crater Retreat d. Gloryhole mining

Answer 80

c. Vertical Crater Retreat (VCR). Vertical Crater Retreat (VCR) is an underground bulk mining method that uses principles of spherical charge and cratering to break ore in horizontal slices. This method is often considered a variant of sublevel stoping. Sublevel Stoping: In traditional sublevel stoping, long holes are drilled in a pattern, typically in a fan shape, and blasted to break ore into an open stope below. Miners work from sublevels within the ore body. a. Resuing is a selective underground mining method used for narrow, high-grade veins. It involves first mining the waste rock on one side of the vein, which is then used as backfill. The high-grade ore is then mined and extracted separately. This method is used for precision and grade control b. Sublevel Retreat with Backfill b. Sublevel retreat is a bulk mining method that is a variant of sublevel stoping. It involves mining successive horizontal slices of ore from the top down, with the broken ore drawn from a central opening. Backfilling may be used to provide ground support and allow for the recovery of pillars, but the primary breaking mechanism. d. Gloryhole Mining is an older, gravity-based surface mining method. It involves a funnel-shaped excavation that is dug from the surface, with a central shaft or tunnel at the bottom. Material is blasted or dislodged into the funnel and then falls into the shaft to be loaded and transported.

Question 81

Deposits whose minerals formed at the same time and therefore, under the same physicochemical conditions. a. Epigenetic b. Paragenetic c. Aphanitic d. Syngenetic

Answer 81

d. Syngenetic a. Epigenetic: This term describes deposits where the ore minerals were introduced into the host rock after the host rock itself had been formed. This is the opposite of syngenetic. The term comes from the Greek epi (meaning "on" or "upon"). Porphyry copper deposits and many hydrothermal vein deposits are epigenetic. b. Paragenetic: This is a term used to describe the sequence or association of minerals formed together in a deposit. It refers to the order in which minerals crystallize from a fluid, not to the overall timing of the deposit relative to the host rock. c. Aphanitic: This is a geological term used to describe the texture of an igneous rock where the crystals are so fine-grained that they are not visible to the naked eye.

Question 82

One of these minerals is exhibiting a combination of pink, violet, and black outcrop. a. Zinc b. Lead c. Mercury d. Cobalt

Answer 82

d. Cobalt. Its primary ore minerals are typically a metallic grey, but when they are exposed to the elements and oxidize, they form secondary minerals that are highly recognizable to prospectors. A key indicator for a cobalt deposit is the presence of erythrite. This mineral, often called "cobalt bloom," is a conspicuous and vivid pink to crimson color. It forms as a crust or coating on other minerals. Asbolane: A black, earthy, or sooty cobalt-bearing mineral. Cobaltite: A primary cobalt mineral with a silvery-white to steel-gray color that can tarnish to a violet or reddish color on exposure. a. Zinc's primary ore mineral, sphalerite, is typically a yellowish-brown to black color. b. Lead's primary ore mineral, galena (PbS), is a silvery-gray with a metallic luster. When exposed to the elements, it oxidizes to form secondary minerals, most commonly cerussite (PbCO3) and anglesite (PbSO4). These minerals are typically white, gray, or colorless. c. Mercury. The primary ore of mercury is cinnabar (HgS). It is a striking and unmistakable bright red to reddish-brown color, which is its most defining characteristic.

Question 83

Secondary enrichment zone is a porphyry copper mineralization is called: a. Hypogene b. Supergene c. Mesothermal d. Epithermal

Answer 83

b. Supergene These are secondary, near-surface processes that occur after the hypogene deposit has been uplifted and exposed to the surface. Meteoric water (from rain) infiltrates the deposit, dissolving copper from the upper oxidized zone and carrying it downward. When this copper-rich water hits the water table, it encounters a reducing environment. The dissolved copper then precipitates as new, high-grade sulfide minerals (like chalcocite), forming a secondary enrichment zone or "supergene blanket." This zone is often the most economically viable part of the deposit because the copper is highly concentrated. a. Hypogene Processes: These are the primary, deep-seated processes where hot, ascending hydrothermal fluids from a magma chamber deposit the initial, lower-grade ore minerals (like chalcopyrite and pyrite). The term hypogene means "originating from below." c. Mesothermal: This is a classification for a type of hydrothermal deposit that forms at intermediate depths and temperatures. d. Epithermal: This is a classification for a type of hydrothermal deposit that forms at shallow depths and relatively low temperatures.

Question 84

The recommended pit slope for gravel is: a. 16° b. 22° c. 35° d. 37°

Answer 84

d. 37° The angle of repose for gravel is typically in the range of 30° to 45°. This is the steepest angle a slope can maintain without collapsing. 35° is a widely accepted, conservative value that balances stability and efficiency in mine design. 37° is also a valid angle, but 35° is a more common and slightly more conservative choice, especially when specific geotechnical data for the site is unavailable.

Question 85

Barite is an ideal mineral used in the manufacture of which of the following? a. Cement b. Plaster of Paris c. Drilling mud d. Gypsum board

Answer 85

c. Drilling mud Barite (BaSO4), also known as baryte, is a dense mineral that is critical in the oil and gas industry. Its high specific gravity (usually 4.2-4.5) makes it an excellent weighting agent for drilling mud. a. Cement: Cement is made primarily from limestone and clay. While barite can be added to special cements, it is not a primary ingredient. b. Plaster of Paris: Plaster of Paris is made by heating gypsum, a hydrated calcium sulfate mineral. d. Gypsum board: Gypsum board (drywall) is made from gypsum, a different mineral from barite.

Question 86

The concentrates bought by Philippine Phosphate Corp for the manufacture of fertilizers contained 37% chalcopyrite. Assuming no other sulfides are contained, what is the sulfur content of the concentrate? a. 11.43% b. 12.82% c. 13.43% d. 14.82%

Answer 86

b. 12.82% The sulfur content of the concentrate is approximately 12.93%. Cu = 63.55 Fe = 55.85 S = 32.06 × 2 = 64.12 Total = 63.55 + 55.85 + 64.12 = 183.52 g/mol 64.12/183.52=0.3494≈34.94% 0.3494≈34.94% 12.93% ≈ 12.82%

Question 87

One meridional block is equal to? a. 10,000 hectares b. 5 hectares c. 20 hectares d. 81 hectares

Answer 87

d. 81 hectares

Question 88

Which of the following is one of the essential ingredients in the manufacturing of nitroglycerine? a. Titanium oxide b. Acetic acid c. Phosphatic acid d. Gelatin

Answer 88

d. Gelatin In explosive manufacturing, gelatin is mixed with nitroglycerin to create gelatin dynamite (or gelignite). The gelatin acts as a gelling agent and binder, making the final product more stable, less sensitive to shock, and easier to handle and package. The gelatin absorbs the highly unstable liquid nitroglycerin, creating a solid or semi-solid explosive mass.

Question 89

A drilling technique in mineral exploration that uses either air or water as flushing medium where cutting is siphoned/sucked from bottom of hole passing through the inner opening of the series of drill strings. a. Percussion drilling b. Rotary drilling c. Conventional drilling d. Reverse Circulation drilling

Answer 89

d. Reverse Circulation drilling a. Percussion drilling uses a heavy, sharp bit that is repeatedly raised and dropped to crush the rock at the bottom of the hole. The cuttings are typically removed by pumping water or air down the outside of the drill rod and back up the annulus, or by using a bailer. b. Rotary drilling involves a rotating drill bit that grinds or cuts rock. The cuttings are typically flushed to the surface by pumping a fluid (like mud or water) down the inside of the drill pipe and then up the annulus (the space between the drill pipe and the borehole wall). This is a forward circulation system, the opposite of the reverse circulation described in the question. c. Conventional drilling is a broad term that often refers to standard coring methods. In conventional coring, a drill bit with an inner core barrel cuts a cylindrical rock sample (a core). Drilling fluid is pumped down the outside of the drill rod, and the cuttings are carried up to the surface in the annulus. The core is retrieved from the inner barrel.

Question 90

Slender crystals arranged in a lattice-like array: a. Banded b. Columnar c. Reticulated d. Concentric

Answer 90

c. Reticulated Reticulated is a mineral habit, or crystal form, that describes slender, interlocking crystals that form a criss-crossing, net-like, or lattice-like pattern. The term comes from the Latin word reticulum, meaning "little net." a. Banded: This term describes a mineral's texture where different layers or colors are arranged in parallel bands. b. Columnar: This describes crystals that are long, slender, and prismatic, often arranged in parallel columns, but they do not typically form a net-like pattern. d. Concentric: This describes a pattern of minerals arranged in layers or shells around a central point, like an onion.

Question 91

In demolition of manmade structure such as condemned buildings, what do you call the blasting technique where the direction of blast is towards the source of explosion? This is mostly used to minimize flyaway debris especially in busy and populated areas. a. centralized blasting b. implosion c. explosion d. demolition

Answer 91

b. Implosion It is a specialized blasting technique used for demolishing structures, particularly in urban areas. The term "implosion" means to burst inward. In this technique, explosives are strategically placed to detonate in a sequence that causes the structure to collapse inward upon itself. This method is used to minimize flyaway debris, control the direction of the collapse, and contain the rubble within a small footprint, which is crucial for safety in populated areas. c. Explosion: This is a general term for a rapid expansion of volume in an explosive manner. It is the opposite of an implosion, which is an inward collapse.

Question 91

What is the mining method where high pressure stream of water is directed against a bank of placer deposit in order to undercut and cave it? a. Solution mining b. Sluicing c. Placer mining d. Hydraulicking

Answer 91

d. Hydraulicking

Question 91

What year was RA 7942 enacted into law? a. 1993 b. 1994 c. 1995 d. 1996

Answer 91

c. 1995

Question 91

Which of the following Mineral Resources Development Laws gave birth to the designation of mineral claims by meridional blocks? a. RA 8981 b. RA 7942 c. PD 463 d. RA 7076

Answer 91

c. PD 463 Presidential Decree No. 463 was a landmark law that modernized the administration of mineral lands in the Philippines. It introduced the concept of a meridional block as the fundamental unit for locating and recording a mining claim.

Question 92

In making a feasibility study to develop as mineral deposit, which of the following is considered most important? a. Availability of ore reserve b. Availability of cheap power supply c. Equipment availability d. Availability of skilled manpower

Answer 92

a. Availability of ore reserve

Question 93

An overhand method in which the ore is mined in horizontal slices and remains in the slope as temporary supper for the walls and to provide a working platform. a. Cut-and-fill stoping b. Block caving c. Top slicing d. Shrinkage stoping

Answer 93

d. Shrinkage stoping Shrinkage stoping is an underground hard rock mining method that operates in an overhand manner, meaning it progresses upwards from the bottom of the stope. After blasting a horizontal slice, only about 30-40% of the broken ore is removed through chutes at the bottom. The remaining 60-70% is left in place. The broken ore fills the stope and provides a working platform for miners to drill the next slice above. It also provides temporary support for the walls of the stope. Once mining reaches the top of the stope, all of the broken ore is drawn out. a. Cut-and-fill stoping: This method also mines in slices, but the void created is filled with backfill material (like waste rock or cemented tailings), not with the broken ore itself. b. Block caving: This is a large-scale bulk mining method that relies on the natural caving of the ore body under its own weight. c. Top slicing: This method mines from the top of the ore body downwards. It involves mining horizontal slices, but the roof is allowed to collapse in a controlled manner into the mined-out area, and the miners work under a mat of timber and broken ground.

Question 93

The recommended pit slope for the solid country rock is: a. 45° b. 50° c. 60-80° d. 63-72°

Answer 93

d. 63-72°

Question 94

This is also called a coking coal? a. Metallurgical coal b. Steam coal c. Brown coal d. Hard coal

Answer 94

a. Metallurgical coal Coking coal is a type of coal with specific properties that make it suitable for producing coke, a porous and highly concentrated form of carbon. This coke is an essential ingredient in the steel-making process, where it's used as both a fuel and a reducing agent in blast furnaces. b. Steam coal (or thermal coal) is used primarily to generate electricity. c. Brown coal is a low-rank coal with high moisture content. d. Hard coal is a general term for high-rank coals, but it is not a direct synonym for the specific type of coal used to make coke.

Question 95

In mine ventilation, hydrogen sulfide is more commonly known as: a. Black damp b. Fire damp c. Stink damp d. After damp

Answer 95

c. Stink damp a. Black damp is a term for an atmosphere deficient in oxygen and rich in inert gases like nitrogen and carbon dioxide. It can extinguish a flame and cause asphyxiation. b. Fire damp is the name for methane (CH4) in mines, which is highly explosive when mixed with air, but is odorless. d. After damp is the toxic mixture of gases, primarily carbon monoxide, left in a mine after an explosion or fire.

Question 96

A copper mine delivers 1,800 dry short tons of ore with a grade of 1% to the concentrator, which in turn mills and processes it at a concentration ratio of 30 to 1 producing concentrate at a grade of 25%. What is the mill recovery? a. 80% b. 83.3% c. 85% d. 90.3%

Answer 96

b. 83.3% Ore delivered = 1,800 short tons (st) Grade = 1% Cu Cu in feed=1800×0.01=18st Cu Concentration ratio (CR) = 30:1 That means: Concentrate tons=1800/30=60 st concentrate Concentrate grade = 25% Cu Cu in concentrate=60×0.25=15 st Cu Recovery=Cu in concentrate​/Cu in feed × 100 =15/18 × 100 =0.8333×100=83.3%