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 K 2 SO 4 and NH 4 Cl 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 K 2 SO 4 solution. Finally, the loaded Cl − on the resin was desorbed to form a NH 4 Cl solution, and the resin was regenerated and recycled. The purified solutions were crystallized to prepare K 2 SO 4 (s) and NH 4 Cl(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.
To clarify the effect of coking dust, sintering dust and fly ash on the activity of activated carbon for various industrial flue gas desulfurization and denitrification, the coupling mechanism of the mixed activated carbon and dust was investigated to provide theoretical reference for the stable operation. The results show that coking dust had 34% desulfurization efficiency and 10% denitrification efficiency; correspondingly, sintering dust and fly ash had no obvious desulfurization and denitrification activities. For the mixture of activated carbon and dust, the coking dust reduced the desulfurization and denitrification efficiencies by blocking the pores of activated carbon, and its inhibiting effect on activated carbon was larger than its own desulfurization and denitrification activity. The sintering dust also reduced the desulfurization efficiency on the activated carbon while enhancing the denitrification efficiency. Fly ash blocked the pores of activated carbon and reduced its reaction activity. The reaction activity of coking dust mainly came from the surface functional groups, similar to that of activated carbon. The reaction activity of sintering dust mainly came from the oxidative property of Fe 2 O 3 , which oxidized NO to NO 2 and promoted the fast selectively catalytic reduction (SCR) of NO to form N 2 . Sintering dust was activated by the joint action of activated carbon, and both had a coupling function. Sintering dust enhanced the adsorption and oxidation of NO, and activated carbon further promoted the reduction of NO x by NH 3 ; thus, the denitrification efficiency increased by 5%-7% on the activated carbon.
危险品化学品经营许可证（带存储）