Michael Koch, Analytical Services Manager, reports that The Perth Mint Refinery is investing in sophisticated new instrumentation for analysing the purity of precious metals.
The Refinery is eagerly awaiting the arrival and commissioning of a Panalytical wavelength dispersive X-Ray Fluorescence (XRF) instrument. Due for delivery in June, and at a cost of $470,000, this represents a significant investment in new technology for the Assay laboratory.
The instrument was purchased initially to supplement the analysis of fine gold bar samples, but will be expanded to include silver in mines, dore and other sample types once suitable methods are developed. The technique measures the fluorescent emissions produced when a sample is irradiated by an x-ray source to determine its elemental composition.
Currently, fine gold analysis is carried out by gravimetric fire assay which has been used for well over 100 years, but is still the recognised method of analysis by the industry.
For this reason, the XRF will not replace fire assay, but will be used in conjunction with the technique to reduce analysis times. It is estimated that the XRF will reduce fire assay analysis of fine gold bar samples by 75%.
The initial commissioning of the instrument for fine gold analysis is expected to be completed within three months of delivery.