The role of Certified Reference Materials
in mining and exploration projects

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OREAS® Certified Reference Materials

As an official distributor of OREAS® Australia, our products cover the entire range of certified reference materials (CRMs) used in mining and exploration projects across West Africa.

What are Certified Reference Materials?

Certified Reference Materials (CRMs) are stipulated by the legal requirements in mining and exploration worldwide. In essence, a CRM represents a known grade composition control sample and is used to test and validate mineral samples extracted in mining and exploration projects during an assay process.

The actual application of CRMs in the industry is divided into two core categories. Geologists use them for grassroots exploration, mine site exploration, resource definition, and grade control. On the other hand, chemists use them to calibrate analytical equipment, validate various analytical methods and QA/QC processes.

What defines quality Certified Reference Materials
for mining and exploration in West Africa

Proven Homogeneity

A standards CRM must demonstrate a high level of homogeneity for it to be considered of high quality. While no CRM offers 100% accuracy, an official laboratory must evaluate and certify the sampling error of each individual CRM.

Robust Characterisation

According to the ISO recommendations, each CRM must be characterized by a round-robin evaluation at 10 recognized mineral laboratories. The only exception is XRF-certified CRMs which require only 6 laboratory tests.

Supplier Reputation

Equally important is the reputation of the manufacturer who supplies the CRMs. It is imperative to monitor the source of any occurred errors observed during the analysis and re-assess your supplier if attributed to the provided CRM.

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What is the application of Certified Reference Materials

The core application of CRMs in mining and exploration is to estimate and monitor the level of bias in the analysis of various geological samples. In practice, a CRM would be inserted in the sample stream at a frequency of 1 in 20/30 and then used to compare the laboratory test results against the certified values of the inserted CRM.

Put simply; a quality Certified Reference Material could significantly and proactively improve the quality of the assumptions and decisions made at various stages of drilling operations.

Control Limits

When using CRMs in mining and exploration, there is non 100% certainty in the accuracy of the analysis results. However, it is a standard industry practice to tolerate a certain margin of error and deviation on either side of the certified value.

Confidence Interval

In practice, every CRM is accompanied by a relevant Certificate of Analysis. These certificates should include a Confidence Interval value as a percentage. This value should then be used to estimate the reliability of the certified values of the specific CRM.

Tolerance Interval

A tolerance interval of a particular CRM is used for measuring homogeneity. All OREAS® and custom gold CRMs undergo this stringent testing and, without exception exhibit a very high level of repeatability consistent with excellent homogeneity.

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our CRMs in mining & exploration?

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