The importance of sampling
Sampling forms the foundation on which you build all your future decisions. It is important to do it correctly.
What is the point of a sample?
A sample must be a representative subset of the whole. To make your sample an unbiased, representative sample attention must be given to all the steps in the process. A well designed sampling programme is necessary.
In truth the whole mining empire is built on the sampling foundation.
Minimising sampling error
A certain amount of error will always be introduced, by selecting suitable sampling methods it is possible to limit the bias and return results with an acceptable precision.
Sampling methods include diamond core drilling, reverse circulation drilling, auger drilling, channel sampling, trench sampling, water sampling, run of mine ore feed, crusher product sampling.
Submission of your samples to an analytical laboratory for analysis must also contain samples for quality control (qc) purposes. This would entail submitting duplicate samples, sample blanks and standardised samples. Quality control provides the data on which to carry out statistical analysis to determine whether analytical results are precise, reproducible and whether there is no bias. To put it plainly (simply) to determine if the results are any good.
Chain of custody is one of the cogs in the sampling wheel.
It is important to keep a log of the samples journey from sampling to analysis to ensure that the sample results are credible. Let us not forget Bre-X.
Quality assurance and quality control processes are a requirement for companies listed on the ASX and other stock exchanges, when reporting on exploration results or using the results in resource estimation and ore reserves, for example Table 1 of the JORC code. These processes provide the client with an assessment of the quality of their data.
JORC Code Table 1, relevant criteria
Quality of assay data and laboratory tests
Reporting on laboratory processes
Sample security
Database integrity
How WAZO can assist
WAZO has the skills to help you design your QC programme including the selection of certified reference materials.
QA is the next step once you have received your analytical results and WAZO is qualified to produce a statistical analysis of your data and provide you with a comprehensive QA report. This will include whether errors have been detected in field sampling.
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