碲阳极泥的控制及处理方法

碲电积精炼过程产生碲阳极泥,其碲含量占到总碲量的3％ ～ 20％,导致碲的直收率降低.碲阳极泥的主要成分是高碲酸钠,由阳极产生的氧气将部分亚碲酸钠氧化形成的难溶疏松颗粒状或片状结晶,大部分沉降到槽底,少量粘附在阴极板面.高价碲盐在结晶长大、沉降、粘附过程中会夹带低价态碲盐,加大碲的损耗.采取改变阳极结构、在阳极套涤纶布...

Control and treatment method of tellurium anode slime

Tellurium anode slime was produced in the tellurium electrowinning refining process,whose tellurium content accounts for 3%to 20%of the total tellurium content,which leads to a decrease in the direct yield of tellurium.The main component of tellurium anode slime is high sodium tellurite,which is insoluble loose granular or flaky crystals generated by the Oxygen at anode reacting with sodium tellurite,most of which settle to the bottom of the tank,and a small amount adhere to the cathode plate surface.The high valence tellurium salt will contain low valence tellurium salt in the process of crystal growth,sedimentation and adhesion,which will increase the loss of tellurium.The tellurium content in the anode slime can be controlled below 3%,the optimal index can reach 1.5%,by changing the anode structure,setting polyester bags on the anode,adding an appropriate amount of reducing agent in the electrolyte,increasing the oxygen removal facilities and stirring and washing the anode slime with hot alkaline solution.The main treatment methods of tellurium anode slime include acid leaching self-reduction method,mixed acid solution replacement method and sulfide reduction method,which method has its’advantages and disadvantages,and can be selected according to the actual process.