火试金富集测定粗铅中金、银含量的改进试验研究

通常粗铅中金、银含量的分析采用标准方法YS/T 248.6-2007，而该方法分析时要进行配料、熔融、二次试金、灰吹等关键试验环节，操作过程繁琐，一个样品的分析时间大约需要14 h，不但要进行高温作业，而且分析成本高，环境污染相对较大.响应国家节能、减排、降耗的号召，根据粗铅中铅含量在96 %以上的特性，对分析方法进行了改进试验研究，将粗铅试样直接在900 ℃下进行灰吹，突破了传统行业标准方法，体现了环保新理念，达到了节能、减排、降耗、省时的效果.经过验证，改进后的方法分析结果重现性好、准确度高，能够准确、快速指导生产.该方法适用于粗铅中金量为1~50 g/t，银量为50~5 000 g/t的测定.在样品中出现银量与金量的比例小于4时，在灰吹过程应补加纯银. 

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.