The Preparation Of Superfine Nickel Oxide From Crude Nickel Sulfate

With the increasing exhaustion of copper and nickel resources,the separationand recovery of copper and nickel is very important in the modernization construction.In this paper,nickel sulfate is used as a by-product in the process of electrolyticcopper production.The pure nickel sulfuric acid was purified by purification,and the superfine nickel oxide was further prepared.The optimum technological conditions for the removal of copper ions in nickel sulphate solution by solvent extraction are as follows:The initial pH of the solution was 2,the extraction ratio was 2:1,the volume fraction of the extraction solvent Lix984 was 20%,the extraction series was level 2,and the extraction time was 5min.At this time,the extraction rate of copper and nickel reached 99.17%and 1.94% respectively,which achieved the purpose of purifying and removing copper in the crude sulfate solution.The optimum technological parameters of iron and arsenic in the extractive liquid are:100 ml extraction liquid,the addition of 20%hydrogen peroxide solution for 3 ml,20%of polymeric ferric sulfate addition amount of 2 ml,reaction end point pH is 4,reaction temperature is 70?.Under this condition,the precipitation rate of iron and arsenic is above 98%.With sodium fluoride as the precipitant and sodium carbonate as the neutralizing agent,calcium and magnesium ions can be removed effectively.Through the study on the influence of reaction temperature,reaction time,pH value of solution endpoint and sodium fluoride overdose on calcium and magnesium precipitation rate,the optimum technological parameters for removing calcium and magnesium were determined as follows:Reaction temperature 70?,reaction time of 60 minutes,end point of solution pH value is 5,sodium fluoride,excessive coefficient of 1.5.Under this condition,the precipitation rate of calcium and magnesium was over 98%.Based on the thermodynamic analysis of the Ni²⁺-CO₃^2--OH^--H₂O system,the distribution curves of each component in the carbonic acid solution were obtained.And the relationship curve was analyzed,and the precipitation end range of nickel oxide precursor powder was determined by using sodium carbonate as precipitator.The thermal weight and differential thermal curve of the co-precipitation precursor were analyzed,and the reaction process of alkali-type nickel carbonate powder in each calcined temperature segment was obtained,and the appropriate calcination temperature was obtained above 550K.In order to purify the nickel sulfuric acid solution and add the precipitant sodium carbonate to it,a coprecipitation method can be used to prepare the nickel carbonate precursor.The results of X-ray diffraction analysis showed that the lower the pressure,the better the crystallinity of the pyrolysis products.Under normal pressure,the higher the temperature,the better the crystallinity of pyrolysis products;At the same temperature,the longer the thermal decomposition time,the higher the crystallinity of the product.The results of SEM scanning for nickel oxide are shown as follows:Increasing the calcination temperature will lead to the increase of grain size of nickel oxide.Under normal pressure,the particle size of the powder particle size is slightly less than that under 1KPa.This topic make full use of nickel resources,not only improve the product high added value,increase the economic benefits of enterprises,but also change enterprise product single situation,has both increased economic benefits and environmental benefits.