低品位软锰矿高压低浓度碱浸预脱硅

Leaching of Silica from Low-grade Pyrolusite by Low Concentration of NaOH Solution under High Pressure

针对低品位软锰矿中含有大量硅质脉石的特点,采用高压低浓度NaOH浸出可在有效脱除SiO_2的同时获得较高模数水玻璃。通过正交实验和单因素实验,考察了浸出温度、NaOH初始浓度、液固比、反应时间对SiO_2浸出率及浸液中水玻璃模数的影响。结果表明:在170℃,NaOH初始浓度15%,液固比2.5∶1条件下浸出4 h,SiO_2浸出率达81.4%,同时可得模数为1.95的水玻璃。

High modulus of sodium silicate and desiliconization rate could be got by high pressure leaching in low concentration of NaOH solution.The effects of temperature,initial NaOH concentration of solution,liquid-to-solid ratio and leaching time have been studied by orthogonal tests and single factor experiments.The results show that the leaching rate of SiO2 can be attained by 81.4% and the modulus of sodium silicate can reach 1.95 under the condition that the leaching temperature is 170℃ with the initial NaOH concentration 15% and the liquid-to-solid ratio 2.5∶1 leaching 4 hours.