Research On The Extraction Process Of Cobalt From Copper Extraction Raffinate Of Congo Copper-cobalt Oxide

China is a country with a serious shortage of cobalt resources,Due to the continuous consumption of cobalt resources,high-grade cobalt resources are increasingly exhausted,and low-grade copper cobalt ore has become the main raw material for the production of cobalt and cobalt products.In this paper,the coppercobaltite raffinate containing impurities Fe,Al,Cu,Ca,Mg,Mn and Zn was treated,in view of the characteristics of the solution with many impurities and complex components,the long process and short process methods are used to remove impurities in the solution,and the high-quality cobalt oxide is prepared by calcining the cobalt precipitated by oxalic acid.In addition,the process of selective extraction of cobalt from copper raffinate containing various impurity ions was also carried out,the main conclusions are as follows:(1)Using CaO to remove impurities-MgO to remove impurities-NaF to remove impurities-P204 extraction to remove impurities,the effects of the main process parameters on the removal rate of impurities and the retention rate of cobalt were studied.Under this condition,Fe,Al,Cu,Ca,Mg,Mn,Zn in the raffinate of coppercobalt ore from Congo gold oxide decreased from 0.87,1.50,0.56,0.44,1.24,1.00,0.62 g/L to 0,0,0,0,0.025,0.006,0.021 g/L,and the impurity removal rate was 100%,100%,100%,100%,98%,99.4%,96.6%,respectively.The concentration of cobalt ion decreased from 1.07 g/L to 0.943 g/L,and the retention rate was 88.1%.(2)The short process of CaO-MgO one-step impurity remove-P204 extraction was used to study the influence of the main process parameters on the impurity removal rate and cobalt retention rate,and the suitable conditions for impurity removal were obtained.The optimum conditions of CaO-MgO one-step impurity removal are CaO/MgO=2:1,room temperature,30min,P204 is pH=2.0-2.5,extractant concentration is 10%,saponification rate is 60%,compared with O/A=1:1,room temperature,time is 10min.Under this condition,Fe,Al,Cu,Ca,Mg,Mn,Zn in the raffinate of Copco extraction from the DRC were reduced to 0,0,0,0.03,0.351,0.006,0.017 g/L respectively,and the impurity removal rates were 100%,100%,100%,93.2%,71.7%,99.4%,97.3%respectively.The concentration of cobalt ion decreased from 1.07 g/L to 0.954,and the retention rate was 89.2%.(3)Magnesium oxide and oxalic acid were used to study the process of liquid cobalt deposition after long flow path impurity removal.Under the condition of adding 2.0 times the mass of cobalt,reaction temperature 40℃,stirring time 5 hours,the precipitation rate of cobalt is more than 99%,and the main products are magnesium oxide and cobalt hydroxide.The optimum conditions for cobalt precipitation by oxalic acid were pH 1.5,reaction temperature 50℃,stirring time 5 h.Under this condition,the precipitation rate of cobalt is over 99%,and the product is cobalt oxalate.(4)The results of XRD and XRF show that the products of cobalt precipitation from MgO are mainly MgO and Co(OH)2 with little other impurities.Due to the limitation of cobalt precipitation process,there are too many MgO inclusions and the purity of cobalt is not high.The purity of cobalt oxalate is 94.3%.The impurity Mg content of cobalt oxalate is 27%by using oxalic acid precipitation short process,and the other impurity content is close to that of long process.(5)Cobalt oxide was prepared from the solution after long process impurity removal by high temperature calcination after cobalt precipitation with oxalic acid.XRD and XRF characterization show that the product phase composition is Co3O4 with high purity,and its content is about 95%.SEM shows that the micro morphology is spherical chain particles,EDS shows that the product mainly contains Co and O elements,which is basically consistent with the results of XRF and XRD.Cobalt oxide was prepared by calcining the cobalt precipitated by oxalic acid in a short process.XRD and XRF characterization showed that the main phases of the product were Co3O4 and MgO,with the contents of 74%and 25%,respectively.SEM showed that the micro morphology of the product was rod-shaped particles.EDS showed that the product mainly contained Co,O and Mg,which was basically consistent with the XRD and XRF results.(6)HBL110 and P204 were used to explore the selective extraction of cobalt from the copper and cobalt ore of Congo gold.It was concluded that P204 was better than cobalt in the extraction of copper and cobalt,and it was not suitable for the selective extraction of cobalt from the copper and cobalt residue or the one-step extraction of cobalt.Due to the interference of impurity ions,the extraction rate and reverse extraction of cobalt ions from HBL110 were lower.Using CaO-MgO one-step impurity removal liquid as raw material,the HBL110 extraction process was studied.The suitable extraction conditions were obtained as follows:saponification rate of extractant 40%,concentration of extractant 10%,O/A=1:2,extraction time 10 minutes.The condition of the stripping process is that the concentration of sulfuric acid solution is 60 g/L,compared with O/A=1:2,room temperature,stripping time is 5 minutes.The extraction rate of cobalt is 92.5%and the reverse extraction rate is 79.2%under the suitable conditions.After extraction and stripping,the total separation coefficients of calcium and magnesium to cobalt are infinite,and manganese and zinc to cobalt are 5.2 and 2.8.