GUIDELINE TO ASSESSING JORC COMPLIANCE REPORT (ORE RESERVE AND MINERAL RESOURCES) - ESTIMATION AND REPORTING OF MINERAL RESOURCES

(Adapted from The JORC Code 2012 Edition, Australasian Code of Reporting Exploration Results, Mineral Resources and Ore Reserve; download JORC Code Template)

The Joint Ore Reserve Committee (JORC) in their description of reporting exploration results recommend these generic assessment criteria that investors can use to determine the integrity of a JORC Compliance report.
There are four key areas highlighted in the assessment criteria that investors should observe. These are:

  1. Sampling Technique and data
  2. Reporting of Exploration Data
  3. Estimation and reporting of Mineral Resources
  4. Estimation and reporting of Ore Reserve

3. Estimation and reporting of Mineral Resources


  • Database integrity
It is important to note the integrity of the data presented and the necessary measures taken to ensure that data has not been corrupted. For instance handling errors, keying errors, and any error between collection and usage. In addition data validation procedures should be known.


  • Site visits
Competent person can not only/blindly prepare technical report of such nature only through the information fed. It is vital that site visits are undertaken by the competent person and the outcome of those visits highlighted. If none then its should be justified with credible evidence.


  • Geological interpretation
The technical report should indicate the level of geological confidence/uncertainty in the interpretation of deposit. It is also practical to state any assumptions made and given such shortfalls indicate clearly the limitations as to how and why and how they correlate to the nature of the data used.


  • Dimensions
The extent of the mineral resource must be explicitly defined on plan and cross sections detailing general outline of the orebody together with upper and lower limits.


  • Estimation and Modelling Techniques
This area boils down to the estimation and modelling technique. The nature and appropriateness and practicability of the estimation technique(s) applied and key assumptions applied. This includes but not limited the treatment of outliers (extreme grade values), mean values, and extent parameter and interpolation parameters. If modelling has been done using computer softwares, it is necessary to note the software product and input parameters. The model and estimate should capture mining production forecast and related and balanced scenario analysis. 


  • Moisture
It may be necessary to note the natural moisture content of the orebody and the methods in which it was determined.


  • Cut-off Parameters
An important aspect to note is the basis on which cut off grades and how quality parameters has been adopted. They should be reasonable and current.


  • Mining Factor or Assumptions
It is important to note the assumptions made regarding possible mining methods, pit layouts and where necessary indicate possible mining dilution.


  • Metallurgical factor of Assumptions

It is necessary to note assumptions regarding metallurgical amenability, for instance, plant layout, process flows, tailing and recovery.



  • Environmental Factors or Assumptions
Environmental management is always a challenge in mining and it is important to note assumptions made regarding possible waste and process residue disposal options. From mining and processing (above) mine tailing product may be known and such waste management programs/proposals should be noted.


  • Bulk density
Note the bulk density of the materials to be mine. It is important to note as to whether these values has been assumed or determined. The basis of assumption is provided (if assumed) or the method and procedure used to determine the bulk density is to be outlined. It is always practical to note the bulk density used (whether assumed/determined).


  • Classification
The main exercise of this step is the classification of the mineral resources into their different categories depending on the geological confidence level and the reliability of the classification.


  • Audits or Reviews
Note audits and reviews done on the Mineral Resource estimates.


  • Discussion of relative Accuracy/confidence
It is appropriate to include a statement declaring the relative accuracy of the classification. This adds confidence to the mineral resources and at the same time making key notes on assumptions, procedures, the manner in which data was obtained, analysed, compiled, presented and interpreted.

Read on: 
GUIDELINE TO ASSESSING JORC COMPLIANCE REPORT (ORE RESERVE AND MINERAL RESOURCES) - ESTIMATION AND REPORTING OF MINERAL RESOURCES GUIDELINE TO ASSESSING JORC COMPLIANCE REPORT (ORE RESERVE AND MINERAL RESOURCES) - ESTIMATION AND REPORTING OF MINERAL RESOURCES Reviewed by CEDRICK KAU on January 17, 2018 Rating: 5

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