镍电解除铜后液氯气氧化沉淀法除铁钴

Removal of Iron and Cobalt from Copper-removal Nickel Electrolyte by Chlorine Oxidization-Precipitation Method

以氯气(Cl_(2))为Fe^(2+)和Co^(2+)氧化的氧化剂、Na_(2)CO_(3)为沉淀剂,对镍电解阳极液—硫化氢除铜后液深度除铁钴、Cl_(2)利用率和除铁钴渣成分进行了系统研究,用正交试验和单因素条件试验确立了最佳的Cl_(2)氧化沉淀法除铁钴的最佳工艺条件,阐明了除铁钴渣中镍、铁、钴的存在形态。结果表明:Cl_(2)氧化沉淀铁、镍和钴的反应均属于放热反应,能够自发进行,且热力学反应优先顺序为Fe^(2+)>Co^(2+)>Ni^(2+);正交试验和单因素条件试验结果一致,最佳的除铁钴工艺条件为:通Cl_(2)前pH=5.0、通Cl_(2)终点ORP=1050 mV、反应终点pH≥4.5。在此条件下,Fe^(2+)和Co^(2+)去除率分别为99.8%和97%,Cl_(2)利用率大于97%,除铁钴渣的Ni(Fe+Co)=0.88。除铁钴渣主要由Ni、Fe、Co、O、S等元素组成;Ni以+2价为主,Fe和Co则以+3价为主。

With chlorine(Cl_(2))as oxidant of Fe^(2+)and Co^(2+)oxidation and Na_(2)CO_(3)as precipitant,the depth removal of iron and cobalt,the utilization rate of Cl_(2)and the composition of iron-cobalt removal residue after copper removal from nickel electrolytic anodic solution by hydrogen sulfide were systematically studied.The optimum process conditions for removing iron and cobalt by Cl_(2)oxidation precipitation method were established through orthogonal experiment and single factor experiment,and the existing forms of nickel,iron and cobalt in iron and cobalt removing residue were clarified.The results show that the oxidation and precipitation of Fe,Ni and Co by Cl_(2)are exothermic reactions,which can be spontaneous,and the thermodynamic reaction order is Fe^(2+)>Co^(2+)>Ni^(2+).The results of orthogonal test and single factor test are consistent.The removal rate of Fe^(2+)and Co^(2+)is 99.8%and 97%respectively,the utilization rate of Cl_(2)is 97%above,and the Ni(Fe+Co)of iron and cobalt slag is 0.88 under the optimum conditions for removal of iron and cobalt including pH value of 5.0 before Cl_(2)inlet,ORP=1050 mV at the end point of Cl_(2)inlet,and pH≥4.5 at the end point of reaction.Fe-Co removal residue is mainly composed of Ni,Fe,Co,O,S and other elements.Ni is dominated by+2 valence,while Fe and Co are dominated by+3 valence.