红土镍矿高浓度碱浸提硅的研究

Study on Extracting of Silicon from Laterite-nickel Ore by High Concentration Alkali Leaching

通过正交试验,研究了红土镍矿高浓度碱浸脱硅过程中浸出温度、碱初始浓度、浸出时间、碱矿质量比对SiO2提取率的影响。结果表明,影响SiO2提取率的主次顺序为浸出温度>碱初始浓度>浸出时间>碱矿质量比;并得到优化的浸出条件为:浸出温度220℃,碱初始浓度85%,浸出时间90min,碱矿质量比5∶1。在溶出过程探讨了加水量、时间和洗涤次数对SiO2提取率的影响,并确定了一次溶出两次洗涤的工艺。

The effects of leaching temperature, initial alkali concentration, leaching time and mass ratio of alkali to ore on the extracting rate of SiO2 during high concentration alkali leaching are investigated by means of an orthogonal experiment. The results show that the primary and secondary sequence affecting the extracting rate of SiO2 is.. leaching temperature〉initial alkali concentration〉leaching time〉mass ratio of alkali to ore. Through orthogonal experiments an optimum condition is established： leaching temperature of 220℃, initial alkali concentration of 85%, leaching time of 90 min and mass ratio of alkali to ore of 5 ： 1. The influnces of water volume, time and washing times on the extracting rate of SiO2 during dissolving are discussed, and the process of once dissolving twice washing is proposed.