高浓度NaOH浸出红土镍矿中SiO_2的研究

Study on Extraction of SiO_2 from Nickel Laterite Ore Through Leaching by High Concentration NaOH Solution

研究了红土镍矿高浓度NaOH浸出的条件.探讨了搅拌强度、温度、NaOH初始质量分数、浸出时间和碱矿质量比对SiO2浸出率的影响.结果表明:搅拌强度600 r/min、浸出温度225℃、初始NaOH质量分数85%、浸出时间90 min、碱矿比5∶1时,SiO2的浸出率可达82.77%.碱浸渣中的铁、镁、镍被富集,其中氧化镍的质量分数由1.29%提高到2.15%.

A new leaching process for nickel laterite ore with high concentration NaOH solution was investigated, to which the effects of stirring speed, leaching temperature, initial NaOH concentration, leaching time and mass ratio of alkali to ore on the leaching rate of SiO2 were discussed. T,he results showed that when the stirring speed is 600 r/min at 225 ℃ for 90 min with initial NaOH concentration 85%, and the mass ratio of alkali to ore is 5：1 in leaching process, the leaching rate of SiO2 can be up to 82.77 %. In the residues the iron, magnesium and nickel are enriched, among which the NiO content increases from 1.29wt% to 2.85wt%.