METHOD FOR PYROMETALLURGICAL EXTRACTION OF ZINC FROM DUST OF ARC STEEL-MAKING FURNACES Russian patent published in 2024 - IPC C22B7/02 C22B19/38 C22B5/16 

FIELD: metallurgy.

SUBSTANCE: invention relates to processing of technogenic formations of ferrous metallurgy and can be used for extraction of zinc from dust of arc steel-making furnaces. Method includes chemical analysis of dust of arc steel-making furnaces, mixing of dust of arc steel-making furnaces, solid carbonaceous reducing agent and flux, combined grinding of the mixture, its agglomeration by way of pressing in the form of briquettes, Waelz process of briquettes in a rotary furnace with supply of blast in the form of a steam-air mixture with steam content in mixture of 14–25%. Composition of the flux is determined from the data of chemical analysis of the processed dust with the addition of acidic or basic oxides before mixing the raw mixture to a level which ensures the fulfillment of the ratio (SO₃+Cl+F)/(Na₂O+K₂O)≥1. Steam-air mixture is introduced into the temperature zone of 1,000 °C, the temperature is increased to 1,100 °C and part of the sublimate containing easily sublimable compounds is removed from the furnace. After that, furnace temperature is raised to 1,350 °C and sublimate is extracted.

EFFECT: method provides higher quality of zinc sublimate at the stage of pyrometallurgical treatment without application of hydrometallurgical processing.

1 cl, 3 tbl