Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, And College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China.
Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, And College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China.
J Environ Manage. 2023 Jan 15;326(Pt A):116676. doi: 10.1016/j.jenvman.2022.116676. Epub 2022 Nov 9.
Sintering dust from the steelmaking industry is a hazardous waste that is rich in valuable metals. The purpose with the present study has been to design an efficient process for the preparation of KSO and NHCl fertilizers by using sintering dust as raw material. The K, S, and Cl in the sintering dust were selectively and efficiently leached using water. The leaching of Ca impurities was then greatly reduced and the appearance of Zn and Mg was avoided. The Cl ions in the leachate were, thereafter, adsorbed by a 201 × 7 resin to form a KSO solution. Finally, the loaded Cl on the resin was desorbed to form a NHCl solution, and the resin was regenerated and recycled. The purified solutions were crystallized to prepare KSO(s) and NHCl(s) products, which met the national standard of China for superior potassium sulfate and ammonium chloride, to be used for agricultural use. The recoveries of K, Cl, and S from the sintering dust were 80.78%, 92.63%, and 93.92%, respectively. Notably, the Mn content in the leaching residue increased from 9.08% to 14.19%. This could be used for the conversion of Mn impurities into recyclable manganese-rich raw materials. This green process enables an effective extraction of important impurities in hazardous sintering dust, thereby providing a new potassium source for potash fertilizer manufacturing with notable economic and environmental benefits.
炼钢工业的烧结粉尘是一种富含有价金属的危险废物。本研究旨在设计一种利用烧结粉尘为原料制备 KSO 和 NHCl 肥料的高效工艺。采用水选择性、高效浸出烧结粉尘中的 K、S 和 Cl。然后大大降低了 Ca 杂质的浸出率，并避免了 Zn 和 Mg 的出现。此后，浸出液中的 Cl 离子被 201×7 树脂吸附形成 KSO 溶液。最后，将树脂上的 Cl 脱附形成 NHCl 溶液，树脂再生并回收。净化后的溶液结晶制备 KSO(s)和 NHCl(s)产品，符合中国优等硫酸钾和氯化铵的国家标准，可用于农业用途。从烧结粉尘中回收的 K、Cl 和 S 分别为 80.78%、92.63%和 93.92%。值得注意的是，浸出残渣中的 Mn 含量从 9.08%增加到 14.19%。这可用于将 Mn 杂质转化为可回收的富锰原料。该绿色工艺可有效提取危险烧结粉尘中的重要杂质，为制造钾肥提供了新的钾源，具有显著的经济效益和环境效益。
