Purification And Impurity Removal Of Atmospheric Acid Leaching Solution Of Laterite Nickel Ore And Preparation Of Nickel And Cobalt Products

Nickel laterite ores atmospheric acid leaching process with the advantages of less investment,small technological risk,and widely applicable for minerals,has become a very attractive technology.Base on the liquor of nickel laterite atmosphere hydrochloric acid leaching new process,which has developed and patented by Institute of Process Engineering,Chinese Academy of Sciences as raw materials in the paper.The separation and purification of the liquor and the preparation of nickel and cobalt products are studied.The main contents in the paper contain:1.With the primary separation of nickel laterite ores atmospheric acid leaching liquor of by MgO slurry,Fe,Cr,Al were removed,left Mn2+ and Mg2+ behind in the Ni-Co liquor(Hereinafter referred to as nickel and cobalt pregnant liquor,the same below).They are difficult to separate.Due to the oxidation of H2O2 in alkaline conditions,Mn2+ can be oxidized to MnO2 and it is not soluble in dilute acid liquor,as a result,the purposes of Mn and Mg isolate from Ni-Co liquor and preparation of MnO2by-product are realized.The results show that the leaching rate values of Ni and Co are approximately 100%,93.07%,the removal rate values are 93.76%,and 99.07%under the conditions of NaOH concentration of 5 wt.%,H2O2 concentration of 10wt.%,oxidation pH of 9,and HCl concentration of 10 wt.%,respectively;The Ni-Co hydroxyl residues contain over 58.62%Ni and 3.67%Co.The purity of MnO2 can reach 92.5wt.%,which can meet the industrial application.2.After the solvent extraction separation of Ni2+ and Co2+ in the Ni-Co mother liquor,the nickel liquor with anion membrane electrolysis for the preparation of Ni.The results show that the cathode current efficiency,energy consumption,and cell voltage are 98.47%,3470kW·h/t,and 3.74V under the conditions of 64g/L Ni,40g/L H3BO4 and 0.1mol/L H2SO4 at temperature of 40? and pH of 5.2 with a cathode current density of 200A/m2,respectively.The purity of the Ni can achieve more than 99.9%,which can meet the industrial requirements.3.Co2(OH)2CO3 precursor is prepared by liquid phase precipitation method from the cobalt liquor,which is calcinated for the Co3O4 particles,and then to optimize the conditions and characterize.The results indicate that the additive of sodium dodecyl benzene sulfonic acid(SDS)on the Co3O4 particle dispersion effect is obvious and the BET is bigger.With the increasing of calcination temperature,the particles morphology is more inerratic,the distribution is more homogeneous,and the granules dispersion effect is much better.By the electro-chemical performance characterization,the Co3O4 electrode has a good stability,good charge-discharge property and rate property under the condition of high current.