DOC《电解法从铅阳极泥提取铋的研究》

电解法从铅阳极泥提取铋的研究 陈汉森,2,徐瑞东1,2*,朱云1,2,何世伟1,2,华宏全3,李英伟3 (1.

昆明理工大学冶金与能源工程学院,云南昆明 650093;

2.云南省复杂有色金属资源清洁利用国家重点实验室(培育),云南昆明 650093;

3.云南铜业股份有限公司冶炼加工总厂,昆明 650102) 摘要:从铅阳极泥中提取铋并富集金银等有价金属元素,对提高冶金二次资源的综合利用具有重要意义.本文将脱砷后铅阳极泥熔铸成粗铋作为BiCl3-HCl-NaCl电解体系的阳极,重点研究了温度、电流密度、酸度、Bi3+浓度、NaCl添加量对电解过程的影响.考察了电流效率、电能消耗及阴极产物纯度.结果表明:在电解液温度30℃、电流密度150A/m

2、游离HCl浓度80g/L、Bi3+浓度120g/L、NaCl添加量80g/L条件下,得到了致密的薄板状阴极铋,电流效率达到98%,电能消耗约为136kW・h/tBi,阴极铋纯度达到99.8%. 关键词:脱砷;

铅阳极泥;

电解;

回收 Recovery of Bismuth from Lead Anode Slime by Electrolysis CHEN Hansen1,2, XU Ruidong1,2*,ZHU Yu1,2, HE Shiwei1,2, HUA Hongquan3, Li Yingwei3 (1.Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093;

2.State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Cleaning Utilization in Yunnan Province, Kunming 650093;

3.Metallurgical Processing Plant, Yunnan Copper Co Ltd, Kunming 650102) Abstract: The extraction of bismuth and enrichment of other valuable metals such as gold and silver elements from lead anode slime that was important to improve the comprehensive utilization of metallurgical secondary resources. In this paper, lead anode slime of arsenic removal was cast into the crude bismuth which as anode on BiCl3-HCl-NaCl electrolyte system. The influences of temperature, current density, acidity, Bi3+ concentration, the addition level of NaCl on the electrolysis process were discussed. The current efficiency, power consumption and purity of cathode product were investigated. Optimum process parameters, namely, temperature of 30℃, current density of 150A/m2, acidity of 80g/L, Bi3+ concentration of 120g/L, the addition level of NaCl of 80g/L, were ascertained. The result show that under optimum conditions, dense sheet-shaped cathode bismuth was obtained, current efficiency reached 98%, the power consumption was about 136kW・h/tBi and purity of cathode bismuth reached 99.8%. Key words: arsenic removal;

lead anode slime;

electrolysis;

recovery

0 前言 铅阳极泥是粗铅电解精炼过程中产出的一种副产品,由于富集了铋、锑、银等有价金属,所以是回收铋的重要原料[1,2].某厂经粗铅电解精炼产生的铅阳极泥其铋、银含量分别达到43.86%、0.34%,具有很高的回收价值.铅阳极泥回收铋的方法有火法工艺和湿法工艺[3-5].火法工艺具有处理量大、原料适应性强、工艺成熟等优点,主要是将铅阳极泥经还原熔炼,然后经贵铅连续氧化吹炼并加熔剂造渣最后得到含铋约28%的氧化铋渣,最后经还原熔炼和火法精炼得到精铋产品[6,7].目前该法仍为回收铋的主要方法,但存在着铋银分离不彻底、铋的回收工艺复杂、烟尘污染严重等不足.鉴于此,80年代以来,针对铅阳极泥的湿法处理工艺的研究日益增多[8]. 目前,国内湿法处理铅阳极泥回收铋的方法主要采用盐酸浸出或者混酸浸出[9-12],在浸出过程加入FeCl

3、NaClO

3、Cl

2、H2O2等氧化剂强化铅阳极泥的氧化以提高铋的浸出率,浸出液通常采用水解沉淀法[9]、铁粉置换法[13]、电积法[14]等方法来产出氯氧化铋、海绵铋等产品.这些方法避免了火法过程中的烟尘污染、改善了劳动条件,但仍存在工序复杂、氧化浸出过程中金银易分散、试剂消耗量大、分离困难等缺点.因此,寻找一种流程短、工序简单、金银富集程度高的铅阳极泥回收铋的工艺具有重要意义. 本研究采用BiCl3-HCl-NaCl电解液体系,将脱砷后的铅阳极泥熔铸成粗铋阳极,进行了粗铋合金的电解提铋试验.重点研究了温度、电流密度、酸度、Bi3+浓度、NaCl添加量对电解过程的影响.