Geological Exploration for Lithium
- February 14, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Geological Exploration for Lithium
Subject: Geography
Section: Economic Geography
Concept:
- The Geological Survey of India (GSI) has categorized the recent discovery of lithium resources in preliminary exploration, called the G3 stage.
- According to The United Nations Framework Classification for Resources (UNFC), there are four stages of exploration for any mineral deposit: reconnaissance (G4), preliminary exploration (G3), general exploration (G2), and detailed exploration (G1).
United Nations Framework Classification (UNFC):
- The United Nations Framework Classification for Resources (UNFC) is a resource project-based and principles-based classification system for defining the environmental-socio-economic viability and technical feasibility of projects to develop resources.
- UNFC provides a consistent framework to describe the level of confidence of the future quantities produced by the project.
- It is a universally applicable scheme for classifying/evaluating energy and mineral reserves/resources.
- It was adopted in 2004 by the United Nations Economic Commission of Europe (UNECE).
- The UNFC consists of a 3-dimensional system with the following three axes:
- The UNFC is a three-digit code-based system wherein:
- First digit represents economic viability axis,
- Second digit represent feasibility axis
- Third digit represent geologic axis
- Each of these axes has further codes in decreasing order.
E Axis:
- The degree of economic viability (economic or potentially economic or intrinsically economic) is assessed in the course of prefeasibility and feasibility studies.
- A prefeasibility study provides a preliminary assessment with a lower level of accuracy than that of a feasibility study, by which economic viability is assessed in detail.
- The Economic viability has codes 1, 2 and 3 in decreasing order.
F Axis:
- Feasibility assessment studies form an essential part of the process of assessing a mining project.
- The typical successive stages of feasibility assessment i.e., geological study as initial stage followed by prefeasibility study and feasibility study/mining report are well defined.
- The feasibility assessment has codes 1, 2 and 3.
G Axis:
- Geological Assessment, which is more or less like the classification as per ISP adopted by GSI and other agencies in India.
- The process of geological assessment is generally conducted in stages of increasing details.
- The typical successive stages of geological investigation i. reconnaissance, prospecting, general exploration and detailed exploration, generate resource data with clearly defined degrees of geological assurance.
- The mineral extraction process typically begins with the G4 stage.
- These four stages are therefore used as geological assessment categories in the classification.
- The geological assessment has 4 codes i.e.
- Detailed Exploration (G1)
- General Exploration (G3)
- Preliminary Exploration (G3)
- Reconnaissance (G4)
- The G3 stage is further categorised into a six-step process to extract Lithium from Salt-flat brines or Mineral ores.
- Stage 1: Geological Surveys: Mapping on a more extensive scale and linking prepared maps with a top grid. Assessment of lithology, structure, surface mineralisation, analysis of old workings etc.
- Stage 2: Perform Geochemical sampling rock type wise, soil survey.
- Stage 3: Detailed ground geophysical work and borehole logging.
- Stage 4: Check the technicality of pits/trench to explore the mineralised zone and drill borehole spacing
- Stage 5: Sampling for litho geochemical from a well-known section, pit/trench and core sample
- Stage 6: Petrographic and mineralogical studies: the combined study of rocks in thin sections and the chemistry, crystal structure and physical properties of the mineral constituents of rocks.
- According to the Indian Bureau of Mines (IBM), apart from the thorough examination of the above-mentioned geological axis, the proposal to mine minerals also needs to be assessed from a feasibility point of view along with the prospects of economic viability.