X-ray spectral determination of gold in geological samples after its concentration by low-temperature fire assay

Resumo

The technology of gold extraction to lead from its mixture with the sample powder during lowtemperature alkaline fusion is developed. The optimal ratios of masses for the sample, lead, and alkali, as well as heating conditions, temperature, and fusion duration, are determined for satisfactory gold recovery. A low temperature of fusion makes it possible to lighten the structure of furnaces, to decrease energy consumption, and to shorten the duration of the entire cycle from the beginning of fusion until the next set of crucibles is loaded. Using the modular approach, a furnace can be assembled in a small area for the simultaneous fusion of a great number of samples. The results of determining gold by the X-ray fluorescence method obtained by using the proposed concentration technology satisfy the regulatory requirements with respect to accuracy.