材料期刊网

称取一定量的载金炭进行火试金配料,经过熔炼、灰吹得到金银合粒,使用硝酸分金得到金粒,再通过计算得到载金炭中银含量,从而建立了火试金重量法测定载金炭中银含量的方法.经过试验,确定了火试金配料中试样量、氧化铅加入量、灰吹温度等最佳试验条件.根据目前国内载金炭的生产水平,在载金炭国家标准物质加入一定量的共存元素,进行了银量测定的干扰试验,结果表明载金炭中共存元素(Cu、Fe、Pb、Cd、Zn、Bi、Cr、Ca、Mg、As)对银测定无影响.将方法用于3个载金炭国家标准物质中银的测定,测定值与认定值基本吻合,相对标准偏差(RSD,n=11)为0.82%~4.2%.

Certain amount of gold-loaded carbon was sampled for fire assay tests .The gold-silver composite particles were obtained after smelting and cupellation .The gold particles were then obtained by decomposi-tion with nitric acid .Thus the content of silver in gold-loaded carbon could be calculated .The determina-tion method of silver in gold-loaded carbon by fire assay gravimetry was established .The optimum experi-mental conditions were investigated ,including the sample amount in fire assay ,the dosage of lead oxide and the cupellation temperature .According to the current situation of domestic gold-loaded carbon produc-tion ,some coexisting elements w ere added into certified reference materials of gold-loaded carbon for the interference tests .T he results show ed that the coexisting elements (Cu ,Fe ,Pb ,Cd ,Zn ,Bi ,Cr ,Ca ,M g and As) in gold-loaded carbon had no influence on the determination of silver .The proposed method was applied to the determination of silver in three certified reference materials of gold-loaded carbon .The found results were basically consistent with the certified values .The relative standard deviations (RSD ,n=11) were between 0 .82% and 4 .2% .