金属黑色页岩在过硫酸盐酸性溶液的氧化浸出行为

摘要

The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, stirring speed, initial concentration of sodium persulfate and sulfuric acid and particle size on the leaching rate were studied as well. The leaching kinetics of molybdenum, nickel and iron from metalliferous black shale shows that the leaching rate is controlled by a chemical reaction through a layer on the unreacted shrinking core. The leaching process follows the kinetics model 1−(1−a)1/3=kt with apparent activation energies of 34.50, 43.14 and 71.79 kJ/mol for Mo, Ni and Fe, respectively. The reaction orders in sodium persulfate are 0.80, 1.01 and 0.75 for molybdenum, nickel and iron, respectively, while in sulfuric acid, these orders are 0.45, 0.75 and 0.50 for molybdenum, nickel and iron, respectively. In addition, the reaction mechanism for the dissolution of the metalliferous black shale was discussed.%研究金属黑色页岩在过硫酸钠酸性溶液中的氧化浸出行为。考察了反应温度、浸出时间、搅拌速度、过硫酸钠和硫酸的浓度、矿物颗料的尺寸等因素对氧化浸出速度的影响。结果表明：黑色页岩中钼、镍和铁的浸出行为受化学反应速度控制，浸出过程的动力学模型为1−(1−a)1/3=kt，且钼、镍及铁的表观活化能分别为34.50,43.14和71.79 kJ/mol；对于过硫酸钠，钼、镍和铁的反应级数分别为0.80,1.01和0.75；对于硫酸，钼、镍和铁反应级数分别为0.45,0.75和0.50。此外，对金属黑色页岩的溶解反应机理进行了探讨。