Sampling Guidelines

To expedite projects and ensure data quality, the following guidelines are presented for consideration:

 

Background Information on project objectives and samples is key to successful outcomes. The types of information useful in this regard can be categorized as follows:
 

• Objectives and Analysis Request - A simple request might be to detail the minerals in a sample and measure their proportions in a semi-quantitative context. A more detailed request might be to provide an accurate determination of mineral proportions (95% confidence) and the relative distribution of an element between host minerals.
 

• Hazards & Safety - Cautionary information on levels of radioactivity, arsenic and/or other potentially harmful or toxic elements or minerals(e.g. asbestos) is always helpful.
 

• Grade of target element/mineral – When the objective of work is to locate and characterize low-grade minerals (e.g. Au, PGM, U, Ag, Ta), an idea of the grade is preferable, as several replicate sub-samples may need to be prepared and analysed. The grade therefore governs the time allotted and hence the analysis cost. If work is performed and low statistics are achieved for a given number of sub-samples and cost, results will be presented with higher detection limits and recommendations made to improve detection levels by examining more sub-samples and/or suggestions for alternative analysis.

 

Sample Submission Guidelines 
 

Samples can be submitted in various forms, ranging from solid bore-core, drill-chips, ground materials or metallurgical pulp samples. Unless only XRD is requested (or an exception made), we do not accept pulverized materials for mineralogical analysis.

 

• Solid samples – If thin sections or smaller area format samples are required or acceptable, solid samples can be submitted for analysis. These ‘grab-style’ samples are usually not considered representative even if agreement between calculated and direct assays is found. This work is, however, often ideal and useful for umpire/settlement and/or scoping style work as it is considerably faster than optical analysis.

• Particulate samples - The preferred method of presenting samples to MLA is as ground products set in a polished section. It is customary to prepare several different size fractions generated from a milled product for accurate and detailed mineralogy. For exploration purposes, and to reduce time and costs, fewer fractions of coarsely crushed material are preferable. A universal starting product for Geometallurgy is an assay reject re-ground to a passing size of under 850 microns. The choice of measuring the sample in this state or fractionating it into sub-samples depends on budgetary and accuracy constraints and are typically established in consultation with the client prior to routine analysis.