Research Of Selenium-free Additive For Electrolytic Manganese And Exploitation Of The Electrolytic Technique

Selenium dioxide( SeO₂ )was commonly used as additive in manganese electrowinning from aqueous solutions of MnSO4 because of some advantages: high electricity efficiency, good anti-impurity character, and wide range technologic parameters. However, it also has some fetal drawbacks. SeO₂ is virulent inorganic agent. It will imperil workers' health, and destroy the environment. Especially high Se content of manganese product was confined to be used in stainless steel and electronics. So the research of new additive to substitute SeO₂ will be a significant work for electrolytic manganese industry.In this study, a new selenium-free additive called PTL-4 which can substitute for SeO₂ was successfully invented beyond the abundant study. The mechanism of SeO₂ and PTL-4 additive was investigated. Technical optimizations were obtained in detail by using PTL-4 in manganese factory. And the high pure electrolytic manganese were obtained, which can fit for the national standard (YB/T051-2003). The main content of the dissertation are as follows:1. Electrochemical measurements including Linear Sweep Voltammetry (LSV) and Cyclic Voltammetry (CV) techniques have been carried out to investigate the working process of SeO₂ during manganese electrolysis. The results indicated that SeO₂ was reduced into Sex^2n- at cathode. The suggestion of the formation of a kind of ion cluster, Se_x^2n-, was put forward and used successfully to explain some phenomena such as restraint of hydrogen evolution reaction (h.e.r.) effect of SeO₂. The detailed mechanism was further reported in this paper.2. Choose plenty of additives from relative literatures. Elementary selecting the additive by simulating the industry process in organic glass electrobathes. The main component of PTL-4 containing (TJA+TJB) which two worked as the dominating influence factors as well as (TJC+TJD) worked as the assistant ones. The proportion of these 4 ingredients was optimized with orthogonal test. The results prove that the ideal stoichiometry of new-type composite...