Details

UNFC CLASSIFICATION OF MINERALS

The UNFC consists of a three dimensional system with the following three axis: Geological assessment, Feasibility assessment and Economic viability. The process of geological assessment is generally conducted in stages of increasing details. The typical successive stages of geological investigation i.e. reconnaissance, prospecting, general exploration and detailed exploration, generate resource data with a clearly defined degrees of geological assurance. These four stages are therefore used as geological assessment categories in the classification. Feasibility assessment studies from 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 degree of economic viability (economic or subeconomic) 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.

It is a three digit code based system, the economic viability axis representing the first digit, the feasibility axis the second digit and the geologic axis the third digit. The three categories of economic viability have code 1,2 and 3 in decreasing order, similarly the three categories of feasibility study have also codes 1,2 and 3 while the four stages of geological assessment are represented by 4 codes i.e. 1 (detailed exploration), 2 (general exploration), 3 (prospecting) and 4 (reconnaissance). Thus the highest category of resources under UNFC system will have the code (111) and lowest category the code (334).
・Proved Reserves

These are reserves estimated from geological evidences by outcrop, trenches, borehole etc. and continuity of these evidences distance upto 200 m from the point of observation.
・Indicated Reserve

These are determined by taking an area of 1000 m*1000m for each point of observation.
・Inferred Reserve
This is estimate of reserve based on broad knowledge about geological character and their is no measurement.

 As per economy point of view minerable and non-minerable reserves are classified as.
International UNFC Classification System
It is mainly divided into three part, they are

E :- Economic Axis
F :- Feasibility Axis
G:- Geological Axis

Why order is in EFG ?
 ãƒ»EFG
- Easy to memory
- Economy : Primary interest to invest
Economic Axis Consist of
(1) Economic
(2) Potentially Economic
(3) Intrinsically Economic
Feasibility Axis Consist of
(1) Feasibility Study and Mining Report
(2) Prefeasibility Study
(3) Geological Study
Geological Axis Consist of
(1) Detailed Exploration
(2) General Exploration
(3) Prospecting
(4) Reconnaissance

Q What does code 111 means
Ans i.e: By using EFG rule
           EFG:111
First 1 represent:- Economic axis i.e Economic
Second 1 represent:- Feasibility axis i.e Feasibility Study and Mining Report
Third 1 represent:- Geological axis i.e Detailed Exploration
Types of Reserves as per UNFC
・Proved Mineral Reserve ...................111
・Probable Mineral Reserve.................121 and 122
・Feasibility Mineral Reserve...............221
・Prefeasibility Mineral Reserve...........222 and 223
・Measured Mineral Reserve................331
・Indicated Mineral Reserve.................332
・Inferred Mineral Reserve...................333
・Recoinnassance Mineral Reserve.......334
Total  Mineral  Resource
・Total mineral resource: Reserves + Additional or Remaining Resources.
・A concentration (or occurrence) of material of intrinsic economic interest.
・Reasonable prospects for eventual economic extraction.
・Location, grade, quantity, geological characteristic known, estimated or interpreted from specific geological evidence and knowledge.
(a) Proved Mineral Reserve  (111)
・Economically mineable part of measured and /or indicated mineral resource.
(b) Probable Mineral Reserve (121 & 122)
・Economically mineable part of Measured Mineral Resource.
・Economically mineable part of indicated or in some cases a measured mineral resource.
(c) Feasibility Mineral Resource (221)
・That part of measured mineral resource, which after feasibility study has been found to be economically not mineable.
・Possibly economically viable subject to changes in technological, economic, environmental and /or other relevant condition.
(d) Prefeasibility Mineral Resource (222 and 223)
・That part of an indicated and in some circumstances measured mineral resource that has been shown by prefeasibility study to be not economically mineable.
・Possibly economically viable subject to change in technological, economic, environmental and / or other relevant condition.
(e) Measured Mineral Resource (331)
・That part of mineral resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a high level of confidence i.e. based on detailed exploration.
(f) Indicated Mineral Resource (332)
・Tonnage, densities, shape, physical characteristic, grade and mineral content can be estimated with reasonable levelof confidence based on exploration, sampling and testing information, location of borehole, pit etc. too widely spaced.
(g) Inferred Mineral Resource (333)
・Tonnage, grade and mineral content can be estimated with low level of confidence.
・Inferred from geological evidence.
(h) Reconnaissance Mineral Resource (334)
・Estimates based on regional geological studies and mapping, airborne and indirect methods, preliminary field inspections as well as geological inference and extrapolation.
Uneconomic Occurrence
Materials of estimated quantity, that are too low in grade or for other reasons are not considered potentially economic. Thus, Uneconomic Occurrence is not part of a Mineral Resource. If quantity and quality are considered worthy of reporting, it should be recognized that an Uneconomic Occurrence cannot be exploited without major technological and/or economic changes, which are not currently predictable.
Mineral Occurrence
A Mineral Occurrence is an indication of mineralisation, that is worthy of further investigation. The term Mineral Occurrence does not imply any measure of volume/tonnage or grade/quality and is thus not part of a Mineral Resource.
Conclusion
・In UNFC 36 classifications are available in total, 8 of them are used often.
・UNFC in not rigid system.
・Solves thr previously existing semantic problems.
・Simplify comparison of the different coal and mineral commodities.
・Provide short, unambiguous identification of reserves/resources classes which facilitate computer processing of  data as well as exchange of information.

GATE Mining Exam Previous Year Questions
Q  The code for the lowest category of mineral resources under United Nations Framework Classification (UNFC) system is

(a)  444
(b)  123
(c)  334
(d)  111         

Q   The three axis comprising the numerical codification of resources, as per the UNFC, are

(a) Economic Viability, Geological Assessment, Geotechnical Assessment
(b) Geological Assessment, Environmental Assessment, Feasibility Assessment
(c) Feasibility Assessment, Geological Assessment, Mining Assessment
(d) Economic Viability, Geological Assessment, Feasibility Assessmen