JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV Year MINE ECONOMICS Previous Question Paper (October/November - 2020 - R16)

Mineral resources are classified based on the level of geological confidence and economic feasibility. These classifications are critical for mine planning and investment decisions.

Inferred Mineral Resource: This is the part of a mineral resource for which quantity and grade are estimated on the basis of limited geological evidence and sampling. The confidence level is low, and it is not sufficient to assume geological or grade continuity. These estimates are based on limited information gathered from outcrops, trenches, pits, or sparse drill holes, and they cannot be converted into mineral reserves.

Indicated Mineral Resource: This is the part of a mineral resource for which quantity, grade, density, shape, and physical characteristics can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters to support mine planning and evaluation. The geological evidence is derived from detailed and reliable exploration, sampling, and testing, gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings, and drill holes that are spaced closely enough to confirm geological and grade continuity.

Mineable Reserve (Probable and Proven): A mineable reserve is the economically mineable part of an Indicated or Measured mineral resource. It includes diluting materials and allowances for losses which may occur when the material is mined. Appropriate assessments, which may include feasibility studies, must be carried out to ensure that extraction is reasonably justified. Mineable reserves are categorized as:

• Probable Reserves: The economically mineable part of an Indicated (and in some circumstances, a Measured) mineral resource. Confidence is lower than that of Proven reserves due to uncertainties in modifying factors such as mining, processing, metallurgical, economic, marketing, legal, environmental, social, and governmental factors.
• Proven Reserves: The economically mineable part of a Measured mineral resource. These represent the highest level of confidence, where all modifying factors have been demonstrated to be technically achievable and economically viable.

Mineral reserves are classified based on the level of geological confidence and the feasibility of economic extraction. These categories are defined as follows:

Inferred Reserve: This represents the lowest level of confidence. The existence of the mineral deposit is based on limited geological evidence, such as outcrops, trenches, or widely spaced drill holes. Because the continuity of the deposit is assumed rather than verified, the quantity and grade are estimated with a high degree of uncertainty, making it insufficient for detailed mine planning or economic feasibility studies.

Indicated Reserve: This represents a moderate level of confidence. The geological evidence is sufficient to assume the continuity of the deposit between points of observation, such as drill holes or sample locations. The data obtained from detailed and reliable exploration is adequate to estimate the tonnage, density, shape, and physical characteristics of the ore body with reasonable confidence, allowing for the development of preliminary mine plans.

Proved (Measured) Reserve: This represents the highest level of confidence. The geological evidence is derived from detailed and reliable exploration, sampling, and testing, confirming the geometry, grade, and quality of the deposit with high precision. Proved reserves are supported by comprehensive technical and economic studies, confirming that the deposit can be extracted profitably under current market conditions. This category provides the necessary certainty for final investment decisions and detailed production scheduling.