Production Of Refined Nickel Sulfate From Crude Nickel Sulfate Produced By Copper Smelting

Crude nickel sulfate,a by-product of copper sulfide smelting from an enterprise in Shanxi,contains copper,nickel,cobalt,iron and zinc and other elements.In order to realize the efficient utilization of resources,it is necessary to purify and remove impurities to prepare refined nickel sulfate,and recover valuable metals such as copper and zinc at the same time.For crude nickel sulfate with many kinds of impurities,the common purification methods have long process flow and complicated operation.In order to consider a simpler and more efficient purification process,Taking crude nickel sulfate as raw material,this paper puts forward the process of"Copper sulfide precipitation-HBL110nickel extraction-P507 deep purification-Concentrated crystallization".The research results are as follows:(1)Na HS was used to selectively precipitate copper from crude nickel sulfate leaching solution.The optimum experimental conditions of copper deposition are as follows:the dosage of Na HS is 2.8 times of the theoretical dosage,reaction time of 90 min and reaction temperature of70℃.The precipitation efficiency of copper and nickel under the optimum conditions is 99.74%and 2.10%.The main phase of Na HS precipitated slag is Cu S and S with the copper,sulfate,nickel content of26.70%,50.31%and 1.02%.(2)The optimum experimental conditions of nickel extraction by HBL110 are as follows:the saponification ratio of the extractant is 60%,the initial p H of 2.2,the phase ratio(V_O:V_A)of 2:1 and the extraction time of 5 min.Under these conditions,50%volume fraction HBL110 was used for 5-stage countercurrent extraction,the extraction efficiency of nickel reached 98.63%.The removal efficiency of Fe,Co,Zn,Ca and Mg were89.59%,77.14%,91.58%,98.25%and 98.62%.The optimum experimental conditions of nickel stripping are as follows:the concentration of the stripping agent is 1.0mol/L,the phase ratio(V_O:V_A)of 4:1 and the stripping time of 5 min.Under these conditions,after4-stage countercurrent stripping,the stripping efficiency of nickel reached 98.85%.The stripping organic phase was washed and regenerated with 5mol/L Na OH solution.Under optimum conditions,the 5-stage countercurrent extraction efficiency of the regenerated HBL110 extractant was 98.02%.(3)P507 was used to purify the stripping solution.The optimum experimental conditions of extraction are as follows:the saponification ratio of the extractant is 65%,the initial p H of 3.2 and the phase ratio(V_O:V_A)of 2:1.Under these conditions,35%volume fraction P507 was used for 4-stage countercurrent extraction,the extraction efficiency of nickel was 5.68%and the removal efficiency of Fe,Zn,Co were 99.99%,99.99%and 85.87%.The organic phase can be regenerated after saponification.P507 purified nickel sulfate solution was evaporated and crystallized to obtain industrial nickel sulfate products which superior to the national industrial standard GB/T 26524-2011 classⅠ.According to the optimum conditions obtained from the purification experiment of crude nickel sulfate,a complete process flow was designed.The process has the advantages of easy operation,good impurity separation effect and high utilization efficiency of the extractant.Provide a new method for preparing refined nickel sulfate from high impurity crude nickel sulfate.