红土镍矿两段加压提镍新工艺

New Technology of Two-stage Pressure Leaching of Nickel Extraction from Nickel Laterite Ore

采用两段加压新工艺联合处理褐铁矿型红土镍矿和蛇纹石型红土镍矿。推荐一段高压酸浸工艺条件为:酸矿比330 kg/t、温度250℃、矿浆浓度30%、反应时间1 h;推荐二段加压浸出工艺条件为:温度230℃、时间1 h、矿浆浓度35%。一段高压酸浸镍浸出率97.58%,二段蛇纹石镍浸出率83.96%,镍总浸出率93.81%,极大提高了镍资源的利用率;二段加压浸出液铁、铝可降至1 g/L以下,可以减少后续中和工序的用碱量。

Two-stage pressure leaching process is proposed to extract Ni from limonite-type and saprolite-type nickel laterite ore.The recommended conditions for the first stage high pressure acid leaching include acid ore ratio of 330 kg/t,temperature of 250℃,slurry solid content of 30%and reaction time of one hour.The recommended conditions for the second stage pressure leaching include temperature of 230℃,reaction time of one hour and slurry solid content of 35%.The nickel extraction rate of first stage high pressure acid leaching and second stage pressure leaching is 97.58%and 83.96%respectively,and the total nickel leaching rate is 93.81%,which greatly improves the utilization rate of nickel laterite ore resources.The Fe and Al concentration in solution can be reduced to below 1 g/L,which can reduce the amount of alkali used in subsequent neutralization processes.