用na2so3与nh3分银实验研究-有色金属科学与工程.doc

用Na2SO3与NH3分银实验研究 张小林,李伟,宁瑞( 1.大冶有色金属有限公司稀贵金属厂，黄石 435005 ） 摘要：介绍了阳极泥处理过程中，氯化分金渣Na2SO3分银与NH3分银的工艺过程Na2SO3分银Na2SO3用量、pH、时间NH3分银NH3、时间，以及还原、结果表明，Na2SO3分银-甲醛还原，Na2SO3的用量为理论量1.3倍，pH为9.2浸出时间4h，银浸出率可达97.39%，甲醛用量（甲醛：银=1：2.5），pH10.5，反应4h，温度30℃～40℃银还原率可达96.33%；用NH3分银-水合肼还原，NH3浓度为8%～10%，温度为室温，反应时间为4h银浸出率可达96.23%，水合肼用量为理论量2倍，60℃，还原，银还原率可达98.1%关键词：亚硫酸钠；甲醛；氨；水合肼；分银； Experiments study on silver separated by using Na2SO3 and NH3 ZHANG Xiao-lin，LI Wei，NIN Rui (Daye Nonferrous Metals Group Holding Co., Ltd, Huangshi 435005 ） Abstract: tudy describes the process of gold dregs that separated by Chlorine separating silver by using Na2SO3 and NH3 in the anode slime treatment process; Studied amount of silver Na2SO3, pH, time on the effects of separating silver by using Na2SO3, as well as temperature, pH effects on the rate of reduction of silver reducted by using formaldehyde; studied concentration of NH3, time on the effects of separating silver by using NH3, as well as the amount of hydrazine hydrate, time and temperature on the rate of reduction of silver by using hydrazine hydrate . The results show that separating silver of Na2SO3 – reducted by using formaldehyde, when the amount of Na2SO3 is 1.3 times of the theoretical amount, pH is 9.2, and the leaching time is 4h, the silver recovery rate can be up to 97.39%, while the amount of formaldehyde (formaldehyde: Ag = 1:2.5 ), pH is 10.5, the temperature is 30 ℃ ~ 40 ℃, reacted 4h, the silver reduction rate can be up to 96.33%; Separating silver of NH3 – reducted by using hydrazine hydrate, when the concentration of NH3 between 8% to 10%,and temperature is at room temperature, the reaction time is 4h, the silver leaching rate can be up to 96.23%, when the amount of hydrazine hydrate is 2 times of the theoretical amount, temperature is 60 ℃, restored 0.5h, silver reduction rate can be up to 98.1%. Key words: sodium sulfite；formaldehyde；ammonia；hydrazine hydrate；eparating silver 0 前 言 通常情况下，铜矿、铅锌矿伴生一定的金银，铜矿含金较多，铅锌矿含银较高。国内大部分的铜冶炼铜阳极泥含银高