Study on the Feasibility of Treating Laterite Nickel Ore with Citric Acid-oxalic Acid System
A new process of low temperature and green extraction of laterite nickel ore was studied in this paper.The main pressures faced by the traditional metallurgical industry are energy and environmental issues.This study uses citric acid and oxalic acid,two organic acids present in nature,as extraction reagents to achieve effective extraction of laterite nickel ore at low temperatures.The study uses low-grade laterite nickel ore as raw material,and adopts a process of mixed roasting with citric acid,water leaching,and oxalic acid precipitation.The effects of roasting and leaching conditions on the leaching rate of various metals in laterite nickel ore were investigated,and the feasibility of using oxalic acid to directly precipitate nickel ions from the leaching solution was also ex-plored.The results indicate thatthe roasting temperature is 120℃,the leaching rates of nickel,cobalt,and iron are(89.47%,96.83%,62.17%),respectively.When the roasting temperature is 100℃,the leaching rates of nickel and cobalt can be maintained above 87%,while the leaching rate of iron decreases to(42.83%).This indicates that roasting at lower temperatures has a certain se-lectivity for the leaching of valuable metals in laterite nickel ore;the use of ultrasonic leaching can effectively improve the leaching efficiency;controlling the leaching temperature at a lower temperature,and the metal leaching in the calcined products remains selec-tive,that is,nickel cobalt leaching is not affected,while the iron leaching rate decreases significantly;using oxalic acid as a precipi-tant,metals can be precipitated from the citric acid leaching liquid system without adjusting the pH value.The resulting oxalate pre-cipitate is a mixture of nickel oxalate and magnesium oxalate,with almost no iron precipitation.
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维普
