What is the main objective of sampling in mining?
B
To analyze the quality and quantity of mineral content
D
To identify rock type only
Analysis & Theory
Sampling helps determine the value, grade, and extent of mineralization in an ore body.
Which of the following is a primary classification of sampling?
A
Chemical and Physical sampling
B
Underground and open cast sampling
C
Random and fixed sampling
D
Grab, chip, channel, and bulk sampling
Analysis & Theory
Sampling methods are classified as grab, chip, channel, bulk, drill core, etc.
What is 'grab sampling'?
A
Collecting a small, random amount of material
B
Sampling only high-grade zones
D
Taking samples from a concentrate
Analysis & Theory
Grab sampling is the random collection of small samples, not necessarily representative.
Which sampling method is most suitable for vein deposits?
Analysis & Theory
Channel sampling provides continuous samples across veins and layered deposits.
What is bulk sampling used for?
B
High-grade vein confirmation
C
Large-scale metallurgical testing
Analysis & Theory
Bulk sampling is used to test large volumes of ore for processing and recovery studies.
Which sampling method is typically used during exploration drilling?
Analysis & Theory
Drill core sampling involves retrieving cylindrical rock samples from boreholes.
What is the main purpose of assaying?
B
Analyzing ore for its valuable metal content
Analysis & Theory
Assaying determines the metal content (grade) of a mineral sample.
Which method is commonly used in gold assaying?
Analysis & Theory
Fire assay is a standard and highly accurate method for determining precious metals like gold.
Which term refers to deliberate addition of metal to increase sample grade falsely?
Analysis & Theory
Salting is a fraudulent practice where metal is added to increase assay results artificially.
Which of the following is a precaution in avoiding sample contamination?
A
Mixing tools after every sample
C
Cleaning tools after each use
D
Combining samples for average
Analysis & Theory
Cleaning tools between samples avoids cross-contamination.
Which factor affects the reliability of a sample?
Analysis & Theory
Sample representativeness and accuracy depend on method and size.
In channel sampling, samples are collected:
A
Randomly from loose material
B
Along a fixed line of exposure
C
From the bottom of shafts
Analysis & Theory
Channel sampling collects samples along a defined, continuous section of ore.
In chip sampling, chips are collected from:
C
A narrow width of the face
Analysis & Theory
Chip sampling collects small chips over a defined width of ore face.
What is the result of salting a mine’s samples?
A
Underestimation of value
Analysis & Theory
Salting leads to overestimation of ore value, which is fraudulent.
Which of the following indicates a red flag for salting?
A
Consistently high assay results without visible ore
Analysis & Theory
Abnormally high assay results without visible minerals may indicate salting.
What is the standard way to prevent sample tampering?
B
Locking the sample room
C
Chain of custody procedures
D
Transporting in open bags
Analysis & Theory
A formal chain of custody ensures integrity and traceability of samples.
What is the purpose of duplicate sampling?
C
To verify results by reanalysis
D
To replace original samples
Analysis & Theory
Duplicate samples are used to check reproducibility and accuracy of assay results.
Assaying is most commonly done in which type of facility?
C
Assay office/laboratory
Analysis & Theory
Assaying is conducted in laboratories using standardized chemical methods.
Which of the following helps to maintain representative sampling?
A
Sampling only from ore bins
C
Systematic and unbiased collection
D
Using only visual inspection
Analysis & Theory
Systematic and unbiased methods reduce sampling error and improve reliability.
In drilling, how are core samples typically preserved?
C
Storing in core boxes with labels
Analysis & Theory
Core boxes with labels preserve orientation and continuity of drilled core samples.