Experimental research on the determination of Au and Ag content in crude lead by fire assay method

In general, the standard method YS/T 248.6-2007 is used to analyze the content of silver and gold in crude lead. This method includes some key processes such as compounding, melting, assaying two key links, and ash blowing test. As the operation is tedious, it will take about 14 hours to analyze a sample, during which we have to work in high temperature, and high costs of analysis and severe environmental pollution will be produced. In order to respond to the call for energy saving, emission and consumption reduction, and on the basis of the fact that the lead content in crude lead is more than 96 %, we reach the goal of saving energy, reducing emission and consumption and saving time by improving the experimental study in which the crude lead sample is directly cupellated at 900 ℃, breaking the standard method in traditional industry and reflecting the new concept of environmental protection. Experiments show that the improved method has a good repeatability and a high accuracy so that it could guide production accurately and quickly. The method is applicable to the determination of gold 1~50 g/t and silver 50~5 000 g/t. If the proportion of silver and gold in the sample is less than 4, then pure silver should be added during cupellation.