Chlorination-extraction process of gold in arsenic-containing sulphuric acid slag and comprehensive utilization method of gas heat

Abstract

The invention relates to a method for chlorinating and extracting gold in arsenic-containing sulphuric acid slag and comprehensively utilizing gas heat. The method comprises the following specific steps of (1) acid leaching and arsenic sulfide precipitation; (2) drying, wet-grinding, pelletizing, drying and chloridizing volatilization; (3) primary quench cooling, heat exchanging, secondary quenching and electrostatic precipitation; and (4) dust scrubbing, chloride leaching of gold, gold reducing, silver extraction by ammonia leaching and silver reducing. An acid leaching and arsenic precipitation technology is adopted, and arsenic is first separated from raw materials, so that the influence of arsenic on a follow-up system is eliminated. The arsenic sulfide precipitation technology realizes enrichment of arsenic in water and recycling of water. The primary quench cooling technology is adopted, so that the temperature of dust-laden gas is higher than that of a softening point of dust, and relatively high liquidity is obtained. An iron powder replacement technology is adopted, so that gold and silver enriched in recycling process water are recycled. Lead and zinc in the process water are recycled through alkaline lead and zinc precipitation, so that the problem that a pipeline is blocked with soluble salt is solved.

Description

technical field [0001] The invention belongs to the field of comprehensive utilization of solid waste, and in particular relates to a process for extracting gold by chlorination of arsenic-containing sulfuric acid slag and a method for comprehensive utilization of flue gas heat. Background technique [0002] Sulfuric acid slag is the waste residue produced during the production of sulfuric acid by roasting pyrite in the sulfuric acid plant. The main component is iron oxide, and it also contains valuable metals such as gold and silver. In order to recover valuable metals such as gold and silver, the production process of chlorination and roasting is often used at present, which can realize the comprehensive utilization of arsenic-free or low-arsenic slag. [0003] In recent years, with the continuous consumption of resources, high-quality sulfuric acid slag is increasingly scarce. In the past, the arsenic content of sulfuric acid slag was usually 0.05%-0.15%, but now the arse...

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Problems solved by technology

[0004] In order to solve the difficulties faced by the existing chlorination gold extraction process in the process of processing arsenic-containing sulfuric acid slag, the present invention discloses a chlorination gold extraction process of arsenic-containing sulfuric acid slag and a method for comprehensive utilization of flue gas heat. The specific steps as follows:

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