Simultaneous Removal Of Iron And Cobalt From Nickel Electrolytic Anode Copper Removal Solution And Comprehensive Utilization Of Precipitated Slag

Under the background of the vigorous development of green energy and electronic equipment,nickel can be used to produce ternary lithium-ion batteries.Therefore,its economic value and strategic position are becoming more and more important.Aiming at the problems of long process and difficult treatment of precipitated slag in the purification and removal of iron and cobalt from nickel electrolytic anode solution and resource utilization,this paper adopts chlorine synchronous oxidation to remove iron and cobalt,and uses nickel containing iron and cobalt slag to design and prepare microwave absorbing materials with good performance.The main research contents are as follows:（1）Simultaneous removal of iron and cobalt in the liquid after nickel electrolytic copper removal:the iron and cobalt are removed by chlorine synchronous oxidation precipitation.Combined with thermodynamic analysis,the best potential range of chlorine synchronous removal of iron and cobalt is obtained.It was found that the change of temperature had little effect on the removal of iron and cobalt,and the change of pH had a great effect on the precipitation of iron,cobalt and nickel.Under the optimum conditions（the temperature is 50℃,the maximum pH is between 4～4.5,the potential control of iron removal section is 0.6～0.64V and the potential control of cobalt removal section is 1.08V）,the iron and cobalt in the liquid after copper removal are removed below 0.4 mg/L and1 mg/L respectively,which can fully meet the production requirements.（2）Preparation and performance characterization of nickel cobalt ferrite:the iron cobalt slag is roasted to obtain nickel cobalt ferrite(Ni_0.34Co_0.66Fe₂O₄),which has poor microwave absorption performance（reflection loss of-6 dB）.Considering the impurities like lead and zinc in the solution after copper removal,nickel cobalt ferrite(Me_（m+n）Ni_（0.34-m）Co_（0.66-n）Fe₂O₄)doped with Pb or Zn was prepared.It is found that when the stoichiometry of Pb or Zn≤0.01,no impurity phase will be produced;Doping lead will reduce the magnetic properties,but it has little effect on the microwave absorption performance.With the increase of stoichiometric of doped zinc from x=m+n=0.001 to 0.01,the magnetic properties of the samples first increase and then decrease,reaching the maximum at x=0.005.Similarly,the microwave absorption performance of the samples is also the best at x=0.005,with a minimum reflection loss of-19.5 dB and an effective absorption bandwidth of 2.2GHz.（3）Preparation and characterization of carbon coated nickel cobalt ferrite(C@Ni_0.34Co_0.66Fe₂O₄):in order to optimize the microwave absorption performance of nickel cobalt ferrite,glucose hydrothermal carbon coating was used to improve the dielectric loss performance of the material.The effects of different raw material ratios on the properties of the final composites were investigated.The results show that when the mass ratio of nickel cobalt ferrite to glucose is 1:2,the composite has the highest dielectric constant,and the thickness of carbon coating is about1.5 nm.When the sample thickness is 2.6 mm,there is a minimum reflection loss of-33 dB.When the sample thickness is 3.0 mm,it has the maximum effective absorption bandwidth of 6.6 GHz and shows excellent absorption performance.In this paper,nickel and cobalt are removed by synchronous oxidation,and the precipitated slag is prepared into nickel cobalt ferrite material.It has a certain guiding effect on the combination of nickel metallurgy even the whole traditional metallurgical production process with the preparation of functional materials.