烧结电除尘灰中钾盐的回收及其浸出动力学

摘要

Surface morphology and inner structure of the dust were observed by ICP-AES, SEM-EDS and XRD to examine the strengthening measures of leaching potassium salt from the sintering dust by water. The results showed that the main component of the sintering dust was iron-oxygen compound, with KCl adsorbed on its surface. Leaching experiments showed that the KCl in the ESP dust could be separated and recovered by water leaching and fractional crystallization. The yield of K-Na vaporized crystalline salt was 18.56%, in which the mass fractions of KCl, NaCl, CaSO4 and K2SO4 were about 61.21%, 13.40%, 14.62%and 10.86%, respectively. The leaching kinetics of potassium salt from the sintering dust fits the external diffusion model well. The leaching speed and the leaching rate of the potassium salt can be increased by increasing the leaching temperature, strengthening the stirring speed and increasing the liquid-solid ratio.%为了研究烧结电除尘灰中回收钾盐的强化浸出措施，使用ICP-AES、SEM-EDS和XRD分析技术对除尘灰的表面和内部形态，特别是钾盐的赋存形式进行分析。结果表明，该电除尘灰的主要成分是铁氧化合物，在其表面裸露吸附着一定含量的KCl晶体。水浸实验表明，该粉尘中的KCl可以通过水浸出、蒸发结晶的方式回收，其收率为18.56%。结晶产物的分析结果表明，KCl占61.21%，NaCl占13.40%，CaSO4占14.62%，K2SO4占10.86%。其水浸出动力学符合外扩散控制模型控制。强化浸出实验表明，提高浸出温度、加强搅拌、增加液固比等措施可以提高钾盐的浸出率和浸出速率。