Treatment process of high-concentration arsenic-containing waste acid

Abstract

The invention discloses a treatment process of high-concentration arsenic-containing waste acid. The treatment process comprises the following steps: filtering the high-concentration waste acid by a filter, and introducing the filtered high-concentration waste acid into a waste acid storage tank; adding sodium hydrosulfide into a hydrogen sulfide gas generator, and adding a dilute sulfuric acid solution to obtain hydrogen sulfide gas; after sedimentation and solid-liquid separation, liquid in a waste acid storage tank is introduced into a vulcanization reactor through a centrifugal pump, then hydrogen sulfide gas is added, and high-concentration arsenic-containing waste acid is subjected to internal circulation through an internal circulation pump of the reactor, so that the hydrogen sulfide gas reacts with heavy metals in the liquid, and precipitates are produced; the precipitates are pumped into a thickening tank through a liquid discharge pump and is treated by a filter press, so that solid-liquid separation is realized, and standard discharge of the waste acid is realized. According to the process, comprehensive contrastive analysis is carried out from the aspects of a medicament adding mode and vulcanizing agent selection, the operation cost of a high-concentration waste acid treatment system is greatly reduced by upgrading and transforming vulcanizing agent dissolution and completing process system optimization, and meanwhile, the copper and arsenic removal efficiency is improved to reach the highest level of the copper smelting waste acid treatment process.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a treatment process for high-concentration arsenic-containing sewage acid. Background technique [0002] Various impurities in smelting flue gas (SO 3 , As, F, etc.) are washed and removed in the purification process, and collected into the circulating liquid of the DWI tower. In order to prevent the H in the circulating liquid of the DWI tower 2 AsO 2 Crystallization, the concentration of sulfuric acid and arsenic should be kept below the specified values ​​in the solubility table during operation, otherwise it is easy to cause crystallization in the circulating acid, resulting in blockage of equipment and pipelines, especially the dilute acid plate heat exchanger, which is forced to stop, so Water needs to be added to adjust its concentration, so that the liquid level of the DWI tower rises, and the raised part is pumped out as waste acid. The acidic wastewater prod...

AI Technical Summary

Problems solved by technology

However, the treatment cost of the sulfuration method for removing heavy metals is increasing year by year. The primary reasons are as follows: First, the arsenic index in the copper concentrate processed by copper smelting is increasing year by year, which inevitably leads to an increase in the arsenic index in the acid plant. ; Second, the production capacity of hazardous chemicals has been tightened, showing a situation in which demand exceeds supply; Third, the concentration of heavy metals in sewage acid has increased, and the vulcanization process control method cannot fully meet the changes in working conditions, and at the same time must ensure that the treatment meets the standards, so the chemical consumption is at a high level level

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