Process for recovering lead, zinc and cadmium in soot on recovery section in process of treating waste acid generated in lead smelting

Abstract

The invention relates to the field of nonferrous metal smelting and particularly relates to a process for recovering lead, zinc and cadmium in soot on a recovery section in the process of treating waste acid generated in lead smelting. The soot of a reduction furnace is subjected to a leaching reaction by using arsenic sulfide removal waste acid in the lead smelting industry to generate lead slag to be recovered, and then, the leaching agent is continued to be neutralized by using sodium sulphide and sodium hydroxide to generate high-grade zinc and cadmium slag to be recovered. According to the invention, the waste acid is used for separating the lead, zinc and cadmium in the soot of the reduction furnace for lead smelting, so that the operation cost is low; the problem of production operation damage caused by circulated accumulation of the zinc and cadmium in lead smelting is solved and the pressure of a lead smelting system is relieved under the condition of low cost; and the lead slag which is low in arsenic content and suitable for being treated by a lead system and the zinc and cadmium slag which is suitable for being treated by a zinc system can be generated, and meanwhile, the waste acid is also treated, so that not only is the treatment cost of the waste acid reduced, but also the treatment difficulty is lowered.

Description

technical field [0001] The invention belongs to the field of non-ferrous metal smelting, and in particular relates to a process for recovering lead, zinc and cadmium in the soot in the reduction section in the treatment process of lead smelting sewage. Background technique [0002] More and more domestic lead smelting adopts oxygen-enriched molten pool enhanced smelting process. This process has high efficiency and good environmental protection, but there is generally a problem of large amount of soot, and the content of impurities in the soot is high, especially the soot in the reduction stage contains a large amount of zinc. Impurities such as cadmium, the current treatment methods for this part of soot are as follows: [0003] 1. The soot enters the zinc smelting system for leaching, and the lead slag returns to the lead smelting system. Due to the high lead content in the soot, the processing cost of the zinc system is high, and the recovery rate of lead smelting is redu...

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Problems solved by technology

[0003] 1. The soot enters the zinc smelting system for leaching, and the lead slag is returned to the lead smelting system. Due to the high lead content in the soot, the processing cost of the zinc system is high, and the recovery rate of lead smelting is reduced

[0004] 2. The soot is returned to lead smelting for cyclic enrichment, and after enrichment to a certain extent, it is sold to zinc smelting enterprises for recycling. This process of soot cyclic smelting will increase the cost of lead smelting, increase the difficulty of lead smelting operations, and the degree of enrichment Not high, poor separation effect, low metal recovery rate

[0005] 201010187763 A treatment method for waste acid water discharged from the flue gas acid production system of lead-zinc smelting, although it is mentioned to use soot to neutralize the waste acid, but the patent does not mention that the sulfuration method should be used to remove the pollution before the soot neutralization If the arsenic in the acid is directly neutralized in this way, the arsenic in the sewage will enter the next step of lead, zinc and cadmium recovery slag, which will affect the treatment of the slag, and the patent only produces the filtrate as the raw material for zinc recovery, and does not mention the recovery of zinc The method is only suitable for enterprises whose lead system and zinc system are relatively close and do not need long-distance transportation

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