硼氢化钾分离-铅试金重量法测定高锑铋物料中金  

Determination of gold in high antimony and bismuth material by lead fire assay gravimetric method after separation with potassium borohydride

作　　者：王啸 李荣华 甘黎明 门倩妮 魏欣 何涛 WANG Xiao;LI Ronghua;GAN Liming;MEN Qianni;WEI Xin;HE Tao(Xi'an Center of Mineral Resources Survey,China Geological Survey,Xi'an 710100,China)

机构地区：[1]中国地质调查局西安矿产资源调查中心,陕西西安710100

出　　处：《冶金分析》2024年第8期72-77,共6页Metallurgical Analysis

摘　　要：高锑铋物料是有色金属冶炼过程中的一种中间产物,准确测定其中金的含量对于指导冶炼生产和市场交易具有十分重要意义。采用铅试金重量法分析高锑铋物料中金,锑、铋易进入铅扣,严重影响铅扣成型,不利于灰吹,导致金的测定结果误差较大。实验利用锑氢化物、铋氢化物易挥发的特性,以亚硫酸钠将高价态锑、铋分别还原至低价态,加入硼氢化钾使其与锑、铋分别反应生成对应的氢化物挥发分离,剩下残渣直接配料进行铅试金,无需过滤及焙烧即可实现锑、铋与金的分离,建立了铅试金重量法测定高锑铋物料中金的方法。对亚硫酸钠用量、硼氢化钾用量进行了优化,结果表明称取10.00 g样品于500 mL三角瓶中,加入50 mL王水(1+1)于电热板上微沸消解至近干,加入20 mL盐酸(1+1)、10 mL亚硫酸钠溶液、50 mL饱和硼氢化钾溶液,搅拌均匀,于电热板上加热蒸干后取下,可将样品中的锑、铋挥发除去。将配料中氧化铅、二氧化硅的质量进行了优化,确定二者质量分别为80、5 g。按照实验方法测定高锑铋物料中金,结果的相对标准偏差(RSD,n=7)在0.49%~3.1%之间,测定值与铋试金-电感耦合等离子体原子发射光谱法基本一致。按照实验方法分别在不同金含量水平的高锑铋物料中加入高纯金进行加标回收试验,加标回收率在96%~103%之间。High antimony and bismuth material is an intermediate product in the smelting process of non-ferrous metals.The accurate determination of gold content in high antimony and bismuth material has great significance to guide the smelting production and market transaction.When the content of gold in high antimony and bismuth material is analyzed by lead fire assay gravimetric method,antimony and bis-muth easily enter the lead buckle,which will seriously influence on the forming of lead buckle.It is not conducive to the cupellation,leading to great determination error of gold.In experiments,based on the characteristic that antimony hydride and bismuth hydride were easily volatile,the high-valence antimony and bismuth were reduced to low valence with sodium sulfite.Then potassium borohydride was added to react with antimony and bismuth to form the corresponding hydrides,which could be volatilized and sepa-rated.The residue was directly used for lead fire assay.The separation of antimony and bismuth from gold could be realized without filtration and roasting.The method for the determination of gold in high antimo-ny and bismuth materials by lead fire assay gravimetric method was established.The dosages of sodium sulfite and potassium borohydride were optimized.The results showed that the antimony and bismuth in sample could be removed by volatilization under the following experimental conditions:1o.oo g of sample was transferred into 500 mL triangular flask;after adding 50 mL of aqua regia(1+1),the solution was heated on electric hot plate to almost dryness;then 20 mL of hydrochloric acid(1+1),10 mL of sodium sulfite solution,and 50 mL of saturated potassium borohydride solution were added;after stirring,the so-lution was heated on electric hot plate to dryness.The mass of lead oxide and silicon dioxide in the ingredi-ents was optimized,and the optimal mass was 80 g and 5 g,respectively.The content of gold in high anti-mony and bismuth material was determined according to the experimental method.The relative standard dev

关 键 词：铅试金 高锑铋物料 亚硫酸钠 硼氢化钾 重量法 金 锑 铋 

分 类 号：O655.1[理学—分析化学] TF031[理学—化学]