100+ Free Mining Engineering Practice Questions

Explanation: Induced Polarization (IP) is highly effective for identifying disseminated and massive metallic sulfides because it measures the ground's chargeability. Sulfide mineral grains polarize under an applied current, creating a measurable voltage decay after the current is switched off. Resistivity is simultaneously measured to map host rock structures.

Explanation: In geochemical exploration, the anomaly threshold is statistically defined as the mean background concentration plus two standard deviations (Mean + 2SD). Values above this threshold represent geochemical anomalies that warrant further exploration. Anything below is considered normal background variation.

Explanation: Diamond core drilling utilizes an annular diamond-impregnated drill bit to cut a cylindrical rock core, preserving the geological and structural characteristics of the rock mass. This intact core is crucial for RQD measurement, joint orientation analysis, and precise assay sampling in hard rock.

Explanation: The nugget effect in geostatistics represents the random, short-range variability observed in samples separated by very small distances (even zero distance, theoretically). It is characterized by the non-zero intercept of the variogram model at lag distance zero, reflecting both micro-scale geological variability and sampling/assaying errors.

Explanation: A Mineral Resource is a concentration of minerals of economic interest in such form and quantity that there are reasonable prospects for eventual economic extraction. An Ore Reserve is the economically mineable part of a Measured and/or Indicated Mineral Resource, demonstrated by at least a Pre-Feasibility Study incorporating realistic Modifying Factors (mining, metallurgical, economic, marketing, legal, environmental, social, and governmental).

Explanation: To obtain a representative sample of a tabular deposit like a vein, the channel must be cut perpendicular (across) the strike of the mineralization. Sampling parallel to the strike would bias the sample by testing only a single portion of the vein thickness, resulting in an unrepresentative grade determination.

Explanation: The Lerchs-Grossmann (LG) algorithm is a 3D graph theory algorithm used in mine planning to determine the ultimate pit limit. It maximizes the total economic net value of the pit by evaluating block values and slope constraints, identifying which blocks of ore should be extracted and which waste blocks must be removed to access them.

Explanation: A raise is a vertical or inclined underground opening driven upward from a lower level to a higher level. Conversely, if it is driven downward from an upper level to a lower level, it is called a winze.

Explanation: The shaft collar is the concrete structure at the top of a shaft. It anchors the shaft lining to the surface rock/soil, prevents loose surficial material from falling in, and provides the load-bearing foundation for the headframe structure and hoisting equipment.

Explanation: The stripping ratio expresses the amount of waste material that must be removed per unit of ore mined. It is typically expressed in cubic meters of waste per metric ton of ore (m3/t) or tons of waste per ton of ore (t/t). It is a vital economic threshold in open-pit design.