火试金法测定高品位含金样品中的金  

Determination of gold in high grade gold-bearing samples by fire assay method

作　　者：赵凯 芦新根 马丽军 刘金东 刘朝阳 ZHAO kai;LU Xin'gen;MA Lijun;LIU Jindong;LIU Zhaoyang(Changchun Gold Research Institute Co.,Ltd.,Changchun 130012,China)

机构地区：[1]长春黄金研究院有限公司,长春130012

出　　处：《化学分析计量》2023年第3期39-44,共6页Chemical Analysis And Meterage

摘　　要：建立了火试金法测定高品位含金样品中金的方法,采用随同带金标准补银与含金样品补银同时进行熔融、灰吹、分金,金标准分金后金卷的增量可代表含金样品分金后金卷的增量,通过这种方法可以消除含金样品在熔融、灰吹过程中金的损失和分金后金卷中残留银对测定结果的影响,提高高品位含金样品测定结果的准确性和稳定性。实验结果表明:称样质量以分金后得到金卷质量在0.2~0.5 g为宜、银的加入量为样品中纯金质量的2~3倍,第一次分金选择硝酸溶液(1+2),分金温度为85℃,分金时间为反应停止后继续加热10~15 min为宜;第二次分金选择硝酸溶液(2+1),分金温度为100℃,分金时间为30~60 min为宜。该方法测定结果的相对标准偏差为1.82%~2.75%(n=7),样品加标回收率为98.6%~100.3%。该方法适用于高品位含金样品中金的准确测定。A fire assay method was established to determine the amount of gold in high grade gold-bearing samples.Melting,ash blowing and gold separation were carried out at the same time along with the standard silver supplement with gold and the silver supplement with gold-bearing samples.The increment of gold roll after gold standard separation could represent the increment of gold roll after gold material separation.This method could eliminate the loss of gold in the process of melting and ash blowing and the influence of residual silver in the gold roll after gold separation,and improve the accuracy and stability of the determination results of high grade gold samples.The experimental results showed that:it was appropriate to weigh the sample mass to obtain the gold roll mass in 0.2-0.5 g after gold separation,the amount of silver added was 2-3 times of the pure gold mass in the sample,nitric acid solution(1+2)was selected for the first gold separation,the gold separation temperature was 85℃,and the gold separation time was appropriate to continue heating for 10-15 min after the reaction stops.Nitric acid solution(2+1)was selected for the second gold separation.The gold separation temperature was 100℃and the gold separation time was 30-60 min.The relative standard deviation of this method was 1.82%-2.75%(n=7),and the recovery of standard material was 98.6%-100.3%.This method is suitable for the accurate determination of gold content in high grade gold samples.

关 键 词：火试金法 高品位含金样品 纯金 增量 

分 类 号：O567.3[理学—原子与分子物理]