非常规元素及气体元素对金银纯度的影响
Effect of non‑conventional and gaseous elements on the purity of gold and silver
-
摘要:
通常采用X射线荧光光谱法、火焰原子吸收光谱法、电感耦合等离子体发射光谱法及火试金重量法等国行标方法对金、银原料及制品纯度进行检测。这些检测手段仅能对常规主量和杂质元素共计20余种进行检测,而气体元素和一些非常规元素则没有相关检测标准,也没有相关文献报道。利用多种检测手段,火试金重量法、辉光放电质谱法、电感耦合等离子体发射光谱法、电感耦合等离子体质谱法、惰性气体熔融-红外吸收热导法、燃烧红外法、热重分析法对影响金、银纯度的非常规元素和气体元素进行检测。结果表明:对于常规纯度的同一金、银样品,采用不同国行标方法检测时,其纯度测量结果存在差异。对于金主量样品的检测优先采用火试金重量法;对于含金大于99.95%的金原料及制品,应先使用火试金重量法测定主量,主量满足要求,可结合其他测定杂质元素标准方法进行差减;使用差减法过程中应充分考虑原料及生产过程中可能引入的一些非常规元素。
Abstract:National and industry standard methods such as X-ray Huorescence spectrometry, Hlame atomic absorp-tion spectrometry, inductively coupled plasma emission spectrometry, and fire assay gravimetry are commonly used to detect the purity of gold and silver raw materials and products. However, these methods only cover around 20 conven-tional major and impurity elements, while there are no standard methods or literature reports available for gaseous or certain non-conventional elements. This study employed a combination of detection techniques, including fire assay gravimetry, glow discharge mass spectrometry, inductively coupled plasma emission spectrometry, inductively coupled plasma mass spectrometry, inert gas fusion-infrared absorptien thermal conductivity method, comb stion infrared method, and thermogravimetric analysis to detect non-conventional and gaseous elements that affect the purity of gold and silver. Results show that different national and industry standard methods yield varying purity results for the same gold and silver samples of conventional purity. Fire assay gravimetry is preferred for determining the gold content. For gold materials and products with gold content greater than 99.95 %, the main content should first be determined by fire assay gravimetry; if it meets the required standard, conventional methods for detecting impurities can be used to calculate the final purity by subtraction. During the subtraction process, possible introduction of non-conventional elements during raw material sourcing and production must be fully considered.
下载: