离子交换吸附富集红土镍矿浸出液中的镍

Enrichment of nickel ions by ion-exchange adsorption from leaching solution of nickel-bearing laterite

研究高镁铁质红土镍矿硫酸浸出液中镍的高效提取方法。通过在d 150 mm×1800 mm PVC柱中填充12 L CN27离子交换树脂,对高镁铁质红土镍矿硫酸浸出液进行动态吸附。研究初始液pH、Ni2+和Fe2+的质量浓度、流速、吸附时间等参数对树脂有效吸附量和吸附效率的影响。结果表明:初始液中Ni2+质量浓度2.5 g/L、pH 3~5、流速1.0 L/min、树脂饱和吸附时的有效利用率达85%~93%,树脂吸附Ni2+的最高有效吸附量可达58.0 g/kg;初始液中Ni2+质量浓度2.5 g/L、pH 4.5、流速1.0 L/min时,吸附后液Ni2+质量浓度1.0 mg/L时,树脂吸附Ni2+的有效吸附量可达41.8~42.0 g/kg,富集液中Ni2+的富集倍数达到25以上,镍离子的质量浓度提高到54 g/L以上;初始液中Fe2+的质量浓度增加,树脂对镍的吸附量降低,不仅会导致富集液中Ni2+的质量浓度降低,富集液中Fe2+的质量浓度也会增加。离子交换吸附不但能使低浓度含镍溶液富集到满足镍电积工艺的要求,且能对杂质进行有效分离。

An efficient method for extracting nickel from leaching solution of nickel-bearing laterite was carried out. A PVC column (d 150 mm×1800 mm) filled with 12 L CN27 ion exchange resins was employed to enrich nickel ions from the sulfuric acid leaching solution of nickel-bearing laterite coexisting with high concentration of magnesium and iron ions. The effects of operational parameters on the valid adsorption quantity and efficiency of resin were studied, such as pH in initial solution, mass concentrations of Ni2+and Fe2+and flow velocity, as well as contact time. The results indicate that effective utilization efficiency and adsorption capacity are 85%-93% and 58.0 g/kg, respectively, while the resin becomes saturated under the conditions of Ni2+initial mass concentration of 2.5 g/L, pH of 4.5, and flow velocity of 1.0 L/min. Moreover, the valid adsorption capacity can reach 41.8-42.0 g/kg when controlling Ni mass concentration of drainage under 1.0 mg/L under the conditions of Ni2+initial mass concentration of 2.5 g/L, pH of 4.5, and flow velocity of 1.0 L/min, and the obtained solution contains more than 54 g/L Ni2+, which is 25 times more than that in the initial solution. Finally, the nickel adsorption on the resin will decrease when the content of Fe in the initial solution increases, resulting in the lower Ni2+concentration in the rich solution as well as the Fe concentration increases in the rich solution. The dilute nickel solution can be effectively enriched by ion-exchange adsorption to a much higher concentration that meets the electrowinning process, and also effectively removes the impurities.