MinAnalytical offers a range of analytical options for accurate precious metals analysis including lead collection fire assay and aqua regia digestion. These options are dependent on the nature of the sample and application required – whether low level greenfields exploration or accurate resource development.
Lead collection fire assay using specially formulated flux to accommodate a variety of sample matrices. Some reduction in sample charge weight may be required to fuse difficult sample matrices.
The screen fire assay method is typically used to analyse samples containing coarse Gold. A nominal 1kg of sample is split from the bulk pulp and re-pulverized to ensure the oversize portion is not excessive. The sub-sample is then screened through the nominated screen cloth. The entire coarse fraction (including the screen cloth) is fired. The fine fraction is analysed in duplicate by fire assay. A weighted average is then calculated to determine the total Gold content for the sample.
Allowance for one coarse fraction fire has been included in the standard pricing, extra costs are incurred for each additional coarse fraction fire.
Aqua regia is generally used for low level Au analysis for exploration programs. A range of multi-elements are also available when using this digest which make this a very cost effective option. Aqua regia can digest many different mineral types including most oxides, sulphides and carbonates but will not totally digest refractory or silicate minerals. Aqua regia is ideal for exploration applications but should not be used for resource estimations.
Photon Assay is a fully automated technique designed for the analysis of ores. It uses high energy x-rays to excite the atoms so liberation from the surrounding material is not required. The 500g single-use jars allows for bulk analysis with no chance of cross contamination between samples.
*Lower detection limit may increase in the presence of Th, U or Ba.