| With the increasing depletion of high-grade and easily exploitable nickel sulfide ore resources,laterite nickel ore has gradually become the main raw material for nickel smelting.In Indonesia,the pyrometallurgy process has many problems,such as high energy consumption and serious environmental pollution.Because of the economic and environmental factors,it has become a trend to use hydrometallurgical process with HPAL technology to extract nickel from laterite nickel ore to prepare battery-grade nickel sulfate,in which the efficient removal of impurities and the enrichment of low-concentration nickel are the key to the preparation of battery-grade nickel sulfate solution.In response to these problems,this paper proposes to realize the removal of impurities and enrichment of nickel-based extraction methods.The extractant Cyanex 272 separates cobalt,magnesium,and nickel,and P507 is used to extract and enrich low-concentration nickel to prepare highconcentration battery-grade nickel sulfate.The main contents and conclusions of this paper are as follows:(1)The extraction efficiency of Cyanex 272 for the separation of cobalt and magnesium from nickel sulfate solution was studied.The effects of p H,saponification ratio,organic to the aqueous phase(O/A),stirring time,and temperature on the extraction process were investigated under the condition that the concentration of the organic solution was 25% and kerosene was used as diluent.The experimental results of extraction show that when the saponification ratio of the extractant is 50%,the optimum p H of the aqueous solution is 5.5,the O/A is 2/1,and the stirring time is 10 min.The highest extraction(%)was achieved at 50℃,and the maximum Mg/Ni separation coefficient was obtained at 60℃.However,the Co/Ni separation factor was the highest at 40°C.The optimum extraction(%)was achieved when O/A was 8/1,and the separation factor of Mg/Ni and Co/Ni reached the highest value when O/A was 3/2.According to Mc CabeThiele’s diagram calculation of extraction stages,the results show that pure nickel sulfate solution can be obtained by two-stage extraction.(2)The effect of using P507 to enrich nickel from low-concentration nickel sulfate solution was studied.The experimental results show that the highest separation coefficient and extraction(%)can be obtained under the conditions of temperature 40℃,p H 5.5,and saponification ratio is 70%.In the O/A experiment,11 different O/A extractions were analyzed,and the results showed that the best extraction was obtained when the O/A was 1/3.The Mc Cabe-Thiele diagram method is used to simulate the extraction stages,and the complete extraction of nickel can be achieved by two-stage extraction.(3)The process of preparing high-concentration nickel sulfate by stripping with loaded extractant was studied.The experimental results show that nickel enrichment can be achieved using 3 mol/L sulfuric acid under O/A of 11,controlling the final p H value to 3.42,and performing 4-stage countercurrent stripping.After stripping,the nickel concentration was enriched from 5 g/L to 117.39 g/L.This paper has 24 figures,49 tables,and 62 references. |
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