A sample of pyritic gold concentrate was investigated by wet chemical and electron optical techniques. Sub-samples were roasted in a laboratory scale fluidized bed roaster in the temperature range 400-700C. The calcine was characterised, and cyanide-leached using a standard bottle rolling test. Gold extraction efficiencies varied with roasting temperature._x000D_
At temperatures of 400 and 450C gold ex- tractions of less than 40% were achieved, but between 500-700C the extraction had increased to 93--98Z. The surface area of the calcine varied with roasting temperature, reaching a maximum at 500C. There was no correlation between the surface area of the calcine and the efficiency of gold extraction.