Preparation of metal zinc from hemimorphite by vacuum carbothermic reduction with CaF_2 as catalyst

CaF_2催化真空碳热还原异极矿制备金属锌(英文)

Zn reduction was investigated by the vacuum carbothermic reduction of hemimorphite with or without CaF2 as catalyst.Results indicate that CaF2 can catalyze the carbothermic reduction of zinc silicate,decrease the reaction temperature and time.The lower the reaction temperature and the more the amount of CaF2,the better the catalytic effect.The optimal process condition is obtained as follows：the addition of about 10% CaF2,the reaction temperature of 1373 K,the molar ratio of C to ZnTotal of 2.5,the pressure of system lower than 20 kPa,the reaction time of about 40 min.Under the optimal process condition,the zinc reduction rate is about 93% from hemimorphite.

通过异极矿真空碳热还原试验,研究添加CaF2和对碳热还原硅酸锌的的影响。结果表明:CaF2能催化硅酸锌的碳热还原,降低还原温度,缩短反应时间;温度越低,催化效果越好;CaF2的添加量越多,催化效果越明显。CaF2催化真空碳热还原异极矿的较佳工艺条件是:CaF2的添加量约10%,还原蒸馏温度1373K,C/Zn总的物质的量比2.5,系统压强低于20kPa,反应时间约40min。在较佳工艺条件下,异极矿中约93%的锌被还原蒸馏出来。