废镀锌板炼钢粉尘加压硫酸浸出试验研究

对废镀锌板炼钢粉尘加压硫酸浸出工艺进行了研究,并与常压酸浸进行了对比。探讨了初始硫酸浓度、浸出时间、液固比、浸出温度对浸出率的影响。结果表明,采用加压浸出技术可使常温弱酸下不溶的铁酸锌和难处理的硅酸锌高效浸出。在釜内压力0.6MPa、浸出温度140℃、液固比6∶1、搅拌速度500 r/min、硫酸浓度120 g/L、浸出时间1.5 h条件下,浸出矿浆无胶体形成、过滤性能良好,锌、铁浸出率分别为98.35%和3.51%,铅几乎全部进入渣相,浸出液中硅含量仅为0.06 g/L,实现了粉尘中锌与杂质的有效分离。

Experimental Study on Pressure Acid Leaching of Steelmaking Dust from Galvanized Sheet Scrap

Experiments were conducted on the process of pressure acid leaching of steelmaking dust from galvanized sheet scrap, which were compared with normal pressure acid leaching process for investigating the effects of initial concentration of sulfuric acid, leaching time, liquid to solid ratio, as well as temperature on the leaching rate. Results showed that the pressure leaching technique can result in both zinc ferrite that is insoluble in weak acid at the normal temperature and refractory zinc silicate effectively leached. It is found that the leaching process at temperature of 140℃for 1.5 h in the reactor with pressure kept at 0. 6 MPa, with liquid to solid ratio at 6∶1, rotating at 500 r/min, concentration of sulfuric acid at 120 g/L, resulted in the leaching rate of zinc and iron at 98. 35% and 3. 51%, respectively, with almost all lead into the slag phase. The silicon content in the leaching liquid is only 0. 06 g/L, indicating an effective separation between zinc and impurities in the dust.