Fire Assay

Fire Assay Solutions

Fire assay is a vital aspect of determining the precious metal content of samples. There are a number of stages in the process from original sample to isolated precious materials which can be tested using other techniques. Samples are placed in crucibles and heated to more that 1800 Degrees Celsius with other compounds including lead oxide. The sample separate into metals mixed with the lead and covered molten glass (slag), which contains base materials and other contaminants. This is separated from the lead ‘button’ by cupellation. The lead ‘button’ is placed on a cupel and heated to more than 1700 Degrees Celcius.

The cupel absorbs the lead leaving a small amount of precious metal which can then analysed in a variety of ways – through chemical means, through gravimetric testing or by spectrometer. Inspectorate provides fire assays through its centre of operations at Witham as well as Reno; Nevada and Shanghai; China sites.or use the Contact Us area to speak to a fire assay professional.