Method for normal-pressure distillation of zinc direct-dipping residue to extract sulfur

Abstract

The invention discloses a method for normal-pressure distillation of zinc direct-dipping residue to extract sulfur. The method includes six processes such as blending, neutralizing and drying of sulfur residue, melting of sulfur, normal-pressure distillation of sulfur, cooling and humidifying of residue and condensing of sulfur steam, and specifically includes: enabling lime and wet sulfur residue after being blended through a belt to fall into a rotary kiln for neutralizing and drying of the sulfur residue to form neutral dry sulfur residue; enabling the dry sulfur residue to fall into a sulfur melting furnace of 130-160 DEG C to form sulfur residue slurry; feeding the sulfur residue slurry into a normal-pressure distillation tank with temperature higher than 500 DEG C; allowing the surface of the sulfur residue slurry to be fully spread in the normal-pressure distillation tank, separating sulfur out, and enabling residue to fall into a residue collection tank; allowing indirect cooling and mist humidifying of the residue in the residue collection tank, discharging the residue, and allowing a condensing tank to continuously spray to condense and cool sulfur steam to room temperature; feeding water steam below 130 DEG C into the rotary kiln, and laying a heat insulating layer in high-temperature equipment pipelines and connectors without air seeping. The method can be used for extracting sulfur from zinc high-pressure oxygen direct-dipping hot filter residue and normal-pressure oxygen direct-dipping sulfur residue. By the method, recovery rate of lead, zinc, silver and indium is 99.5%, and sulfur extraction rate is 95%; the method is supportive of high-yield continuous running and free of oxygen seepage explosion potential.

Description

technical field [0001] The invention belongs to the hydrometallurgy zinc smelting industry, and in particular relates to a zinc direct leaching slag suitable for the high-pressure oxygen direct leaching hot filter residue and atmospheric pressure oxygen direct leaching sulfur slag for efficient, economical and safe recovery of zinc concentrate and atmospheric pressure distillation to extract sulfur. method. Background technique [0002] At present, more than 80% of zinc is produced by fire-wet combined smelting process, that is, roasting-leaching-purification-electrowinning process. The process has the advantages of simple process control, convenient operation, high metal recovery rate, and low equipment requirements, but there are also roasting flue gas SO 2 Pollution issues, flue gas requires acid production, and this leads to difficult sales of sulfuric acid and uneconomical production in areas where sulfuric acid consumption is underdeveloped. Moreover, it is inevitabl...

AI Technical Summary

Problems solved by technology

[0008] In view of the low recovery rate of lead, zinc, silver and indium valuable metals in the thermal filtration method, and the high sulfur content in the residue, it still needs to be returned to the roaster for processing. The vacuum distillation method has high requirements on the sealing of the equipment and can only be operated intermittently, which cannot meet the continuous and efficient smelting of large production capacity. Pro...