New Technology Of Lead Anode Slime Treatment And Preparation Of Ag Ultrafine Particles

It's significant for integrated resource recycling and improving economics to synthetically dispose anodic slimes.In this paper, techniques of comprehensively using lead anodic slimes in and out of the country are analyzed and summarized. As far as conventional pyro-metallurgical processes are concerned, a new techniques and flowsheet to treat lead anodic slimes is put forward. That is "potential-controlled chlorination-leaching in hydrochloric acid medium - lixivium deoxidization-distillation wipe off As".During the reduction of Lixivium solution, Te, part of Au and Ag have been reclaimed and also As and Sb have been converted into As (III), Sb (III) . Process of distillation can not only wipe off As, reclaim most hydrochloric acid but also greatly decrease consumption of alkali which is used to neutralize Bi and Cu. Thereby cost is reduced, liquor has been condensed, hydrolyze recovery of Sb is significantly increased. The new process ensures recovery of Au and Ag, and increase integrated recovery effect. Although the loss in liquor of Au, Ag reach to 2.4%, 1.4%, the ration relegate below 1.0% after deoxidize by sulfur dioxide. After lixivium of lead anodic that is rich in As has been treated by this new techniques, the recovery rate of Sb and Bi in concentrate are above 96%, and the ration of forming Cu to concentrate is 98%. This paper summarizes some problems encountered in design and on which importance shall be attached to production in hydrometallurgical treatment of lead anode slime, and emphasizes factors affecting process, selection of equipment and process arrangement. The result shows that in the same condition: same component, same pyrometallurgical equipment, the cost of new process relegate 4000RMB.The recovery of silver is 8% more than that by pyrometallurgical process. All these show that hydrometallurgy has its prominence both in technology and economics.The factors affecting granularity of ultra-fine sliver powders are investigated, and ultra-fine sliver powders are prepared. The result shows that the reaction of silver preparation by hydrazine hydrate deoxidizesilver ion is automatic catalyse homogeneous nucleation in liquid phase. Such conditions as low ion concentration, low hydrazine hydrate concentration, Low ammonia concentration(namely low pH), low reduction temperature and good agitation are advantageous to the preparation of ultra-fine sliver power.Adding Tween-80 makes the granularity of silver power notably minimize. In the reactor surface modified by lining, if control such conditions as 0.5M [Ag(NH3)2], 10.5 pH, 0.5M hydrazine hydrate, the ratio of AgNO3/N2H2 . H2O 2: 1, 1.5~2mL/min the drop speed, 250~300r/min agitating speed at 298K, the particle sizes may be controlled between the range of 0.015 to 0.065 u .