铅试金-重量法测定银钨合金中的银

Determination of Silver in Silver Tungsten by Fire Assay Gravimetric Method

摘要:

银钨合金因其优良的机械加工、导电等物理性能而被广泛应用于电子信息、航天航空等领域中，但其制作工艺难以保证银均匀分布，从而导致测定结果不准确、不稳定，不利于银钨合金中银含量的控制及回收。采用铅试金-重量法测定银钨合金中的银含量，通过铅试金法去除试样中的Al、Cr、Cu及Fe等杂质元素，将试样中银富集成合粒，用醋酸将合粒洗净后称重。同时，另取纯银采用相同方法处理得到银粒，通过试金过程中银的损失比例计算得到补正系数，根据合粒重量和补正系数计算得到试样中银的含量。结果表明，该测定方法的相对标准偏差为0.12%~0.33%，银的回收率为99.4%~100.0%。由于该法称样量大，可以避免银钨合金中银分布不均匀造成的结果偏差，有效提高银钨合金中银含量测定结果的稳定性和准确度。铅试金-重量法可满足银钨合金中银的常规测定需求。

Abstract:

Silver-tungsten alloy is widely used in electronic information， aerospace and other fields because of its excellent physical properties such as machinability and electrical conductivity. However， its manufacturing process is difficult to ensure the uniform distribution of silver， which leads to inaccurate and unstable determination results， which is not conducive to the control and recovery of silver content in silver-tungsten alloy. In this paper， the silver content in the silver-tungsten alloy was determined by the fire assay-gravimetric method， and the impurity elements such as Al， Cr， Cu， Fe ， etc. in the sample were removed by the lead assay method， while the silver in the sample was enriched into silver grains. The silver grains were washed by acetic acid and weighed. At the same time， another pure silver was taken and treated by the same method to obtain silver grains. The correction coefficient was obtained by calculating the loss ratio of silver in the process of gold testing. The silver content in the sample was calculated according to the weight of silver grains and the correction coefficient. The results showed that the determination method had a large sample size， the relative standard deviation was 0.12%-0.33%， and the silver recovery was 99.4%-100.0%. It can avoid the deviation caused by the uneven distribution of silver in the silver-tungsten alloy， effectively improve the stability and accuracy of the determination of silver content， and meet the needs of conventional determination of silver in the silver-tungsten alloy.