Oxygen Pressure Leaching Characteristic Of Saprolite Laterite Nickel Ore

The consumption of a large amount of fossil energy will lead to global warming,prompting most countries in the world to switch from traditional fossil energy to green energy.Nickel is an important component of advanced electrochemical energy storage devices,therefore,the global demand for nickel will continue to increase.Indonesia has rich nickel reserves.The main ones that have been identified are limonite and saprolite-type laterite nickel ore.Among them,saprolite has a higher nickel content(about 1.5-3wt.%).In this thesis,the saprolite type laterite nickel ore is taken as the research object,and the valuable metal elements of nickel and cobalt are extracted by oxygen pressure acid leaching technology.The oxygen pressure acid leaching process of saprolite-type laterite nickel ore was carried out,and the phase composition of the leaching residue was analyzed.XRD results show that the main ore phase of saprolite-type laterite-nickel ore is lizardite,and contains a small amount of goethite and quartz ore-phase;XRF results confirm that the saprolite-type laterite-nickel ore contains high impurities of magnesium and iron,respectively.26.6 wt.% and 10.7 wt.% were reached.Thermodynamic analysis shows that high temperature sulfuric acid leaching process can be used to extract nickel and cobalt in saprolite laterite nickel ore.Although the impurity element iron is also easily leached,the ferrous ions are easily oxidized by oxygen,and finally converted into ferric oxide(i.e.,hematite),thereby being separated from the leaching solution.The effects of oxygen pressure acid leaching process parameters in sulfuric acid system on the leaching rate of valuable metal elements and impurity elements were systematically studied.The optimal parameters are known for time reaction was 2 hours,the solid-liquid ratio was 1:3,the oxygen partial pressure was 2.726 MPa,and the stirring speed was 400 r/min.Under the optimized leaching conditions,the leaching rates of Ni,Co,Fe,and Mg were 98.44 wt.%,92.27 wt.%,42.65 wt.%,and 80.23 wt.%,respectively.The color of solid residue under the optimized leaching conditions is reddish-brown.The phase and content analysis results show that at temperature 220 ℃ is mainly composed of quartz,hematite,and antigorite.24 pictures,5 tables,76 references...