Mineral Resource Classification

Natural variability, sample spacing and analytical imprecision influence the confidence we have in production plans derived from an orebody model. The quality of estimate should be considered alongside likely extraction methods in order to assess the reliability of production schedules and dependent business plans. SRK has a large team of ‘Competent Persons’ experienced in judging such uncertainty and applying Mineral Resource classification in accordance with international reporting codes, such as JORC, SAMREC and CIM (NI 43-101).

Services

• Independent Estimation and classification of Mineral Resources
• Reclassification of existing estimates in line with International Reporting Codes
• Advising on sampling programmes to improve deposit confidence classification

Approach

Whilst there are several rules of thumb used in classification, each deposit needs to be considered on its own merits. The underlying data is assessed for sampling representativeness, quality control on sample preparation and laboratory accuracy and databasing errors.

The deposit model comprises geologically and statistically robust estimation domains whose geometrical continuity and internal grade distributions can be specifically investigated.  Understanding sample spacing in relation to domain size geostatistical assessment of grade predictability and of scale mining selectivity is key to the reliability of resultant mine plans. All these influence the choice of an appropriate classification category. The potential for economical extraction is given consideration as part of the Mineral Resource classification process.

Experience

The international reporting codes require that classification of Mineral Resources is undertaken by ‘Competent or Qualified Persons’. SRK employs several appropriately experienced geologists full time.

SRK has classified Mineral Resource estimates in accordance with international reporting codes, for hundreds of deposits and our technical experts have presented to international workshops and conferences on Mineral Resource Classification.
SRK has developed particular expertise in reviewing Soviet system estimates and re-classifying these in line with international reporting codes.