← Controller of Mines
Past Questions
As per the Mineral Concession Rules 1960, the Reconnaissance Permit to be executed within __________ months of the date of the communication of the order:
A)
12
B)
9
C)
3
D)
6
According to the Mineral Concession (MC) Rules, 1960, specifically under the provisions governing the grant of Reconnaissance Permits (RP), the permit must be executed within a specified timeframe after the order of grant has been communicated to the applicant. The rule stipulates that the Reconnaissance Permit shall be executed within 6 months from the date of the communication of the order. If the permit is not executed within this period, the grant may be liable for cancellation. Therefore, option (d) is the correct answer. Options (a) 12, (b) 9, and (c) 3 are incorrect as they do not align with the statutory timeline prescribed in the MC Rules 1960 for the execution of an RP.
How many years of practical experience of below ground mines is mandatory for getting appointment of Rescue Superintendent?
A)
10 years
B)
6 years
C)
15 years
D)
5 years
According to the Mines Rescue Rules (and the guidelines governing the appointment of rescue personnel in mining law), the qualification for the post of Rescue Superintendent requires a specific amount of practical experience in underground mining to ensure the safety and leadership of rescue teams during emergencies. The mandatory requirement for the appointment of a Rescue Superintendent is 5 years of practical experience in below-ground mines. This ensures that the individual has sufficient operational knowledge of mine environments, ventilation, and potential hazards before overseeing critical rescue operations. Options a, b, and c (10, 6, and 15 years) exceed the minimum statutory requirement set for this specific role.
According to Coal Mine Regulation 2017, “competent person” in relation to any work or any machinery, plant or equipment means a person who has attained the age of:
A)
18 Yrs
B)
20 Yrs.
C)
25 Yrs.
D)
None of the above
Under the Coal Mines Regulations (CMR) 2017, the term 'competent person' is defined based on the person's qualifications, experience, and the specific nature of the work or equipment involved, rather than a specific minimum age requirement. While general labor laws (like the Mines Act) specify minimum ages for employment (usually 18 years for underground work), the definition of a 'competent person' for the purpose of inspecting or certifying machinery, plants, or equipment focuses on professional competence, certification, and authorization by the Chief Inspector or the Central Government. Since the CMR 2017 does not stipulate a specific age (such as 18, 20, or 25) as the defining criterion for being a 'competent person', none of the provided age-based options are correct.
According to CMR, 2017 every travelling roadway shall be not less than __________ high for the entire stretch.
A)
1.8 m
B)
1.2 m
C)
1.5 m
D)
0.5 m
According to the Coal Mines Regulations (CMR), 2017, specific standards are set for the dimensions of roadways to ensure the safety and ease of movement of personnel and equipment. Under the regulations pertaining to the maintenance and dimensions of roadways, it is mandated that every travelling roadway (a roadway used for the movement of persons or materials) must maintain a minimum height to prevent hazards and ensure ergonomic passage. The prescribed minimum height for the entire stretch of a travelling roadway is 1.8 meters. Options b (1.2 m), c (1.5 m), and d (0.5 m) are incorrect as they do not meet the statutory safety requirement defined in the CMR 2017 for travelling roadways.
Who has the power to make rules and regulations?
A)
Committee
B)
Central Government
C)
Either of the above
D)
Chief Inspector
In the context of Mining Law (specifically the Mines Act, 1952), the power to make rules is vested in the Central Government. Under Section 56 of the Mines Act, 1952, the Central Government is empowered to make rules to carry out the purposes of the Act. While the Chief Inspector (Option d) has the authority to make 'Regulations' (under Section 57) for the purpose of regulating the management, control, working, plant, machinery, and supervision of mines, the overarching power to create 'Rules' (which have higher legal standing and are framed under the delegated legislation of the Parliament) resides with the Central Government. In most competitive examinations for Mining Law, when asked who has the general power to make rules and regulations (especially in a broad sense), the Central Government is the primary authority. However, it is important to note that 'Rules' are made by the Government and 'Regulations' are made by the Chief Inspector; since the question asks for the power to make rules and regulations collectively, the Central Government is the superior authority that enables the framework for both.
Coal washing is accomplished by:
A)
Jigging
B)
Float flotation
C)
Heavy liquid separation
D)
None of the above
Coal washing (or coal cleaning) is the process of removing impurities (gangue) such as shale, clay, and sulfur from raw coal to increase its heating value and reduce ash content. This is primarily achieved through gravity separation because there is a significant difference in density between clean coal (approx. 1.3 to 1.5 g/cm³) and the mineral impurities (approx. 2.0 to 2.6 g/cm³).
1. Jigging (Option a): This is a classic gravity separation method where a bed of particles is pulsed vertically with water. The heavier impurities settle to the bottom while the lighter coal floats to the top. It is one of the most widely used industrial methods for coal washing.
2. Float Flotation (Option b): This is a physico-chemical separation method based on surface hydrophobicity. While it can be used for very fine coal (coal slime), it is not the primary or general method for 'coal washing' in the context of bulk processing.
3. Heavy Liquid Separation (Option c): This is primarily a laboratory technique used to determine the ash content or the density distribution of a coal sample. It is not an industrial process for large-scale coal washing due to the cost and toxicity of the heavy liquids used.
Therefore, among the given options, Jigging is the standard industrial process for coal washing.
The three major steps involved in mineral processing are:
A)
Extraction, processing and screening
B)
Exploration, extraction and comminution
C)
Crushing, grinding and floatation
D)
Mining, transportation and marketing
Mineral processing (also known as ore dressing or mineral beneficiation) refers to the process of separating valuable minerals from the waste rock (gangue) to produce a concentrate. The general sequence of mineral processing involves: 1. Comminution (Size Reduction), which consists of Crushing (primary/secondary) and Grinding (fine reduction to liberate the mineral grains). 2. Concentration (Separation), where methods like Floatation, Gravity Separation, or Magnetic Separation are used to isolate the valuable mineral. Option (c) lists three core technical steps of this process: Crushing and Grinding (the two stages of comminution) and Floatation (a primary concentration method).
Why other options are incorrect:
- Option (a): 'Extraction' is part of mining, not mineral processing.
- Option (b): 'Exploration' and 'Extraction' are pre-processing stages (Mining cycle).
- Option (d): 'Mining', 'Transportation', and 'Marketing' are part of the overall mining business cycle, not the technical process of mineral processing.
Which of the following is naturally floatable mineral?
A)
Coal
B)
Gypsum
C)
Talk
D)
Pyrite
In mineral processing, 'floatability' refers to the inherent ability of a mineral surface to attach to air bubbles and rise to the surface of a flotation cell without the need for chemical collectors. This is determined by the hydrophobicity (water-repelling nature) of the mineral surface.
1. **Coal (Option a):** Coal is composed primarily of carbon and organic matter, which are naturally hydrophobic. Therefore, coal is a naturally floatable mineral and can be recovered using 'natural flotation' or 'froth flotation' without the addition of collectors.
2. **Gypsum (Option b):** Gypsum is a hydrophilic (water-attracting) mineral. It requires specific chemical collectors to be made floatable.
3. **Talk (Talc) (Option c):** While Talc is also naturally hydrophobic due to its layered silicate structure, in the context of standard mineral processing examinations for mining/mineral processing, Coal is the primary example of a naturally floatable organic mineral. However, if the question allows for multiple, Talc is also hydrophobic; but Coal is the most definitive answer for general 'natural floatability' in this specific exam context.
4. **Pyrite (Option d):** Pyrite is a sulfide mineral. While it can be floated, it typically requires the addition of xanthates or other collectors to achieve efficient recovery; it is not considered 'naturally floatable' in the same sense as organic carbonaceous materials.
The ore obtain from run of mine (ROM) initially goes to:
A)
Primary crusher
B)
Secondary crusher
C)
Tertiary crusher
D)
None of the above
In mineral processing, 'Run of Mine' (ROM) refers to the raw ore as it comes directly from the mining face, containing a wide range of particle sizes, including very large boulders. The goal of the comminution circuit is to reduce this material to a size suitable for downstream processing (like grinding or flotation).
1. **Primary Crusher**: This is the first stage of size reduction. It is designed to handle the largest lumps of ROM ore and reduce them to a manageable size (typically < 200mm). Common examples include Jaw Crushers or Gyratory Crushers.
2. **Secondary Crusher**: This stage receives the product from the primary crusher. It further reduces the size of the material. It cannot handle ROM ore directly because the feed size would exceed the physical dimensions of the crusher opening.
3. **Tertiary Crusher**: This is a final stage of crushing (often using cone crushers) to produce a fine feed for the grinding mills. It requires an even smaller feed size than the secondary crusher.
Therefore, the ROM ore must always enter the primary crusher first to initiate the size reduction sequence.
The lighter material from the top layer of a jig which continuously discharge from the jig box during jigging process is called:
A)
Jig hutch
B)
Jig flow
C)
Jig tails
D)
Jig bed
In the jigging process, mineral separation is based on the difference in density of the particles. The process involves the vertical pulsation of a water column through a bed of material. During this process, the bed stratifies: the heavier particles settle to the bottom (concentrates), and the lighter particles rise to the top layer. These lighter, unwanted materials are continuously washed over the weir or discharged from the top of the jig box; these are referred to as 'tails' or 'tailings' (Jig tails).
Why other options are incorrect:
- a. Jig hutch: The hutch is the bottom compartment of the jig where the heavy concentrate is collected.
- b. Jig flow: This is a general term referring to the movement of water and material, not a specific name for the discharged waste material.
- d. Jig bed: The jig bed is the entire mass of stratified particles currently undergoing the jigging process, not the material being discharged.
Choose the correct one:
A)
The hindered-settling ratio is always equal to the free-settling ratio
B)
The hindered-settling ratio is always less than the free-settling ratio
C)
The hindered-settling ratio is always greater than the free-settling ratio
D)
None of the above
In mineral processing and fluid mechanics, settling refers to the movement of particles through a fluid under gravity.
1. **Free Settling**: This occurs when the concentration of particles in the fluid is very low. Each particle settles independently without interacting with other particles. The settling velocity is determined by the balance of gravitational, buoyancy, and drag forces (governed by Stokes' Law for laminar flow).
2. **Hindered Settling**: This occurs when the concentration of particles is high. In this regime, particles are so close together that their velocity fields overlap. This leads to several effects:
- Increased effective viscosity of the suspension.
- Increased buoyancy because the particle 'sees' a fluid with a density equal to the average density of the suspension (fluid + particles).
- Upward displacement of fluid as particles settle, creating an opposing current.
3. **Settling Ratio**: The settling ratio is the ratio of the settling velocity of a particle in a suspension to the settling velocity of a single particle in a pure fluid. Because the factors mentioned above (increased viscosity and upward fluid flow) significantly increase the drag and resistance, the settling velocity in a hindered environment ($v_h$) is always lower than the free settling velocity ($v_f$).
Therefore, the ratio $v_h / v_f$ is always less than 1, making the hindered-settling ratio always less than the free-settling ratio.
The term Representative factor (RF) is associated with.
A)
Mine drainage
B)
Mine plan
C)
Mine air sampling
D)
Mine ventilation
The Representative Factor (RF) is a critical parameter used in mine air sampling, specifically when using the 'spot sampling' method to determine the average concentration of dust or contaminants in a mine atmosphere. Because dust concentrations vary significantly across different locations and heights in a mine roadway, a single sample is not representative. The Representative Factor is a multiplier used to convert a specific sample measurement into a representative average for the entire area or volume being sampled, accounting for the spatial distribution and variability of the airborne particles.
- Option (a) Mine drainage deals with water management and pumping.
- Option (b) Mine plan refers to the cartographic representation of the mine layout.
- Option (d) Mine ventilation refers to the overall system of moving air through the mine, while air sampling (option c) is the specific process of measuring the quality of that air where RF is applied.
As per National Mineral Policy 2019, ffforts shall be made by the Government to establish MTS which would primarily involve automating the entire concession life-cycle using state-of-the-art IT systems. What does MTS stand for?
A)
Mineral Tenement System
B)
Mineral Tender System
C)
Mining Tenement System
D)
None of the above
According to the National Mineral Policy (NMP) 2019, the Government of India aimed to modernize the administration of mineral concessions. To achieve this, the policy proposes the establishment of a 'Mineral Tenement System' (MTS). An MTS is a comprehensive IT-based system used globally (e.g., in Australia and Canada) to manage the entire life-cycle of a mining lease—from application and granting to renewal and relinquishment—ensuring transparency, efficiency, and the elimination of manual delays.
- Option (b) 'Mineral Tender System' is incorrect because while tendering is a part of the allocation process, the MTS covers the entire life-cycle, not just the tender phase.
- Option (c) 'Mining Tenement System' is incorrect as the official terminology used in the NMP 2019 document is 'Mineral Tenement System'.
Jaws of the crushers are made of:
A)
Copper
B)
Aluminium
C)
Alloy cast steel
D)
PVC Material
In mineral processing, a jaw crusher is used for primary crushing of hard, abrasive ores. The jaws (the fixed and moving plates) are subjected to extreme compressive forces and high abrasive wear. Therefore, they must be made of materials with high hardness, high toughness, and excellent wear resistance. Alloy cast steel (specifically manganese steel or Hadfield steel) is used because it possesses the property of 'work-hardening,' where the surface becomes harder as it is impacted by the ore, thereby extending the life of the equipment.
Why other options are incorrect:
- Copper (a) and Aluminium (b) are soft, ductile metals that would deform immediately under the pressure of crushing rock.
- PVC Material (d) is a plastic/polymer that lacks the structural strength and hardness required for industrial crushing operations.
Jigging method is mainly used to concentrate:
A)
Fine materials
B)
Relatively coarser materials
C)
Heavy materials
D)
Light materials
Jigging is a gravity concentration process that separates minerals based on their difference in specific gravity. It involves the vertical pulsation of a bed of particles in water. During the pulsation cycle (expansion and compaction), particles rearrange themselves; heavier particles settle faster and move to the bottom, while lighter particles remain on top.
1. Why 'Relatively coarser materials' is correct: Jigging is most effective for coarse particles because the settling velocity of a particle in a fluid is proportional to the square of its diameter (according to Stokes' Law and Newton's Law of settling). Coarser particles respond more rapidly to the pulsating current, allowing for efficient stratification.
2. Why 'Fine materials' is incorrect: Very fine particles (slimes) have low settling velocities and are often carried away by the water flow regardless of their density, making jigging inefficient for them. Fine materials are typically processed using shaking tables, spirals, or flotation.
3. Why 'Heavy' or 'Light' materials are incorrect: While jigging separates heavy from light materials, it is not used to concentrate 'heavy materials' exclusively or 'light materials' exclusively; rather, it is a method to separate a mixture of the two. The defining constraint for the application of a jig is the particle size (coarseness) rather than the absolute density of the material.
What is the laboratory test defined for heavy medium separation?
A)
Weight test
B)
Bubble test
C)
Strength test
D)
Float and sink test
Heavy Medium Separation (HMS) is a gravity-based concentration process where minerals are separated based on their specific gravity (density) using a medium with a density between that of the valuable mineral and the gangue.
1. **Float and Sink Test**: This is the standard laboratory procedure used to determine the feasibility of HMS. A sample of the ore is placed in a medium of a known, controlled density. Particles with a density lower than the medium will 'float', while particles with a density higher than the medium will 'sink'. By repeating this with different medium densities, a 'washability curve' is generated to determine the optimal separation density for industrial application.
2. **Why other options are incorrect**:
- **Weight test**: This is a general measurement and not a specific diagnostic test for medium separation.
- **Bubble test**: This is typically associated with flotation processes (froth flotation) to study bubble-particle attachment, not heavy medium separation.
- **Strength test**: This refers to mechanical properties (like compressive or tensile strength) of the mineral or rock, which is irrelevant to density-based separation.
Selection of crusher is mainly done on the basis of particle:
A)
Specific gravity
B)
Shape
C)
Tensile strength
D)
size
In mineral processing, the selection of a crusher is primarily determined by the size of the feed material and the desired size of the final product (reduction ratio). Crushers are categorized based on the size of the particles they can handle:
1. Primary Crushers (e.g., Jaw Crushers, Gyratory Crushers) are used for large run-of-mine ore.
2. Secondary Crushers (e.g., Cone Crushers) are used for medium-sized particles.
3. Tertiary/Quaternary Crushers (e.g., Roll Crushers, Impactors) are used for fine crushing.
While properties like hardness (related to strength) and shape can influence the specific type of crusher chosen (e.g., impactors for softer materials), the fundamental criterion for selecting which stage of crushing is required is the particle size.
- Specific gravity (a) affects the energy required for transport and separation but not the primary selection of the crusher type.
- Shape (b) may affect the efficiency of the crush, but is not the primary selection criterion.
- Tensile strength (c) relates to the material's hardness/toughness, which determines the liner material or the mechanism (compression vs. impact), but the 'selection' of the crusher in a circuit is driven by the size reduction requirements.
For well dispersed pulps, free settling dominates when the percentage by weight of solid is:
A)
Less than about 15%
B)
Less than about 50%.
C)
Less than about 75%
D)
Less than about 80%
In mineral processing and sedimentation science, the settling behavior of a pulp (a mixture of solids and liquid) is categorized into two primary regimes: free settling (hindered settling) and zone settling.
1. Free Settling: This occurs in dilute suspensions where the particles are far enough apart that they do not interfere with each other's movement. In this regime, each particle settles independently according to Stokes' Law or Newton's Law. For well-dispersed pulps, this behavior typically dominates when the concentration of solids is low, generally below 15% by weight.
2. Hindered Settling: As the concentration of solids increases (typically above 15%), the particles begin to interact. The displaced fluid moving upward creates a drag force that slows down the settling velocity of the particles.
3. Zone Settling: At even higher concentrations, the particles settle as a collective 'blanket' or zone, where the interface between the clear liquid and the suspension moves downward.
Therefore, for well-dispersed pulps, the transition from free settling to hindered settling occurs around the 15% solids by weight threshold. Options b, c, and d represent concentrations that are far too high for free settling to occur, as they would be firmly in the hindered or zone settling regimes.
Coal washing is carried out in order to:
A)
Reduce ash percentage
B)
Reduce spontaneous heating
C)
Increase oxygen percentage
D)
Easy transportation
Coal washing, also known as coal beneficiation or cleaning, is a mineral processing technique used to remove non-combustible mineral matter (gangue) from the raw coal.
1. Why 'a' is correct: Raw coal contains impurities such as shale, clay, and other minerals which constitute the 'ash' content. Since these minerals have a higher specific gravity than the organic coal matter, they can be separated using gravity-based methods (like jigs or cyclones). Reducing the ash percentage increases the heating value (calorific value) of the coal and reduces the amount of waste produced during combustion.
2. Why 'b' is incorrect: While removing certain catalytic minerals might marginally affect stability, spontaneous heating is primarily managed through proper ventilation, sealing, and stockpile management, not through washing.
3. Why 'c' is incorrect: Increasing oxygen percentage is not a goal of coal washing; in fact, high oxygen content is often associated with lower-rank coals or oxidation, which is generally undesirable.
4. Why 'd' is incorrect: While removing waste reduces the total mass to be transported, the primary technical objective of the washing process is the improvement of the fuel quality (ash reduction), not the logistics of transportation.
The simple relation between mean, median and mode is:
A)
Mean = 3(Mode) - 2(Median)
B)
Mode = 3(Median) - 2(Mean)
C)
Median = 3(Mean) - 2(Mode)
D)
Mode = 3(Mean) - 2(Median)
In statistics, for a moderately skewed distribution, there exists an empirical relationship between the three measures of central tendency: the mean, the median, and the mode. This relationship is known as the Empirical Formula. The formula states that the distance between the mean and the median is approximately one-third of the distance between the mean and the mode. Mathematically, this is expressed as: Mean - Mode = 3(Mean - Median). Rearranging this equation to solve for the Mode:
1. Mean - Mode = 3(Mean) - 3(Median)
2. -Mode = 3(Mean) - 3(Median) - Mean
3. -Mode = 2(Mean) - 3(Median)
4. Mode = 3(Median) - 2(Mean).
Therefore, option (b) is the correct mathematical representation of this relationship. Options (a), (c), and (d) are incorrect rearrangements of this formula.
According to which section of Mines Act, 1952 the provision on occupational health survey is done?
A)
9
B)
9A
C)
10
D)
11
Under the Mines Act, 1952, Section 9A specifically deals with the 'Occupational Health Survey'. This section empowers the Central Government to make rules regarding the conduct of occupational health surveys to monitor the health of workers exposed to specific hazards in mines.
Breakdown of other options:
- Section 9: Generally relates to the notice of accidents and dangerous occurrences.
- Section 10: Relates to the appointment of inspectors and their powers.
- Section 11: Relates to the powers of inspectors to enter mines and examine plants/machinery.
Therefore, Section 9A is the correct provision for occupational health surveys.
In future worth/value analysis the revenue is assigned with:
A)
Negative sign
B)
Positive sign
C)
Division sign
D)
Multiple sign
In financial analysis, specifically in Future Worth (FW) or Present Worth (PW) analysis, the 'Cash Flow Convention' is used to track the movement of money. Under this convention: 1. Cash Inflows (Revenue, savings, salvage value, or income) are assigned a positive sign (+) because they increase the wealth or value of the project. 2. Cash Outflows (Costs, initial investments, maintenance expenses, or taxes) are assigned a negative sign (-) because they represent a decrease in wealth. Since 'revenue' is a cash inflow, it is assigned a positive sign. Options c and d are mathematically incorrect as division and multiplication signs are operators, not signs used to denote the direction of cash flow.
The depreciation remains constant according to which method?
A)
Declining balance method
B)
Universal method
C)
Written down value method
D)
Straight line method
Depreciation is the systematic allocation of the cost of a tangible asset over its useful life.
1. **Straight Line Method (SLM):** In this method, the depreciation charge is spread evenly over the useful life of the asset. The formula is: (Original Cost - Salvage Value) / Useful Life. Because the base cost and the life remain constant, the annual depreciation expense remains constant every year. This is why it is the correct answer.
2. **Written Down Value (WDV) Method / Declining Balance Method:** These two terms refer to the same concept (accelerated depreciation). In these methods, depreciation is calculated as a fixed percentage of the asset's current book value (carrying amount) at the start of the year. Since the book value decreases every year, the amount of depreciation also decreases over time. Therefore, it is not constant.
3. **Universal Method:** This is not a standard accounting term for a specific depreciation method.
Conclusion: Only the Straight Line Method results in a constant depreciation amount throughout the asset's life.
What is the formula for the median of grouped data if L = lower limit of median class; cf= cumulative frequency of the class prior to median class; f = frequency of median class; h = class size and n = total frequency?
A)
Median = L + [(n/2 – cf/f)] × h
B)
Median = L + [(n/2 + cf/f)] × h
C)
Median = L + [(n/2 – cf/f)] ÷ h
D)
Median = L × [(n/2 – cf/f)] × h
The median for grouped data is calculated using a linear interpolation formula. The logic is to find the value within the median class that divides the total frequency (n) into two equal halves.
1. First, the median class is identified as the class where the cumulative frequency first reaches or exceeds n/2.
2. The formula is: Median = L + [((n/2) - cf) / f] * h.
3. Let's analyze the provided options. Option (a) is written as 'Median = L + [(n/2 – cf/f)] × h'. While the notation in the option is slightly ambiguous regarding the placement of the parentheses (it should be (n/2 - cf) divided by f), in the context of standard competitive exam multiple-choice questions, this is the intended representation of the standard formula: Median = L + ((n/2 - cf)/f) * h.
Comparing the options:
- Option (a) follows the correct structure: Lower limit + (Adjustment factor) * class size.
- Option (b) is incorrect because it adds the cumulative frequency (cf) instead of subtracting it.
- Option (c) is incorrect because it divides by the class size (h) instead of multiplying.
- Option (d) is incorrect because it multiplies the lower limit (L) by the adjustment factor instead of adding it.
As per Mizoram Minor Mineral Concession Rules 2000, no mining operation should be carried out within:
A)
50 metres of public work
B)
100 metres of public work
C)
300 metres of public work
D)
500 metres of public work
According to the Mizoram Minor Mineral Concession Rules, 2000, specific restrictions are placed on the location of mining operations to ensure the safety and integrity of public infrastructure. The rules stipulate that no mining operation shall be carried out within a distance of 100 metres of any public work (such as roads, bridges, or government buildings) to prevent structural damage or instability caused by excavation and blasting. Therefore, option (b) is the correct regulatory distance.