Treatment method of high-concentration salt-containing waste sulfuric acid

Abstract

The invention provides a treatment method of high-concentration salt-containing waste sulfuric acid. The treatment method comprises: (1) preparing a material slurry with a certain concentration from quicklime or limestone and water; (2) adding a proper amount of an inducer into a reaction tank containing high-concentration salt-containing waste sulfuric acid; (3) adding the material slurry into the reaction tank, stirring, measuring the pH value, stopping the adding of the material slurry when the pH value is increased to 3-5, and continuously stirring for a certain time; (4) adding a proper amount of calcium chloride into the reaction tank, and stirring for a certain time; and (5) filtering the solution in the reaction tank, carrying out evaporative crystallization on the filtrate, and drying the filter residue to obtain calcium sulfate dihydrate. With the treatment method of the invention, the salt content of the wastewater entering the evaporator can be greatly reduced, the evaporation energy consumption can be reduced, the yield of salty mud can be greatly reduced, the calcium sulfate dihydrate can be obtained, and the resource utilization of the high-concentration salt-containing waste sulfuric acid can be achieved.

Description

technical field [0001] The invention relates to the technical field of waste sulfuric acid treatment, in particular to a treatment method for high-concentration salt-containing waste sulfuric acid. Background technique [0002] Salt-containing waste sulfuric acid mainly comes from the production process of industrial enterprises engaged in metal surface treatment and electronic component manufacturing. For example, in the manufacturing process of electronic components, it is necessary to use acid for electrolytic degreasing, acid etching, sensitization before activation, catalysis, and brightening. Or in the production process of integrated circuit boards, it is necessary to use an acid etchant for oxide etching, and a large amount of high-salt waste acid solution will also be produced. For example, in metal surface treatment and other industries, it is necessary to use acid for surface cleaning, use sulfuric acid for acid etching, electrolytic degreasing, surface sensitiza...

AI Technical Summary

Problems solved by technology

Due to the complex composition and many impurities, the salt mud produced cannot be effectively utilized

Considering that salt leaching leads to excessive salinity in leachate, which affects the normal operation of the leachate treatment system, landfills are unwilling to accept salt mud for landfill

Therefore, the use of evaporation and crystallization after neutralization to deal with salt-containing waste acid leads to the problem that the salt mud cannot be disposed of and piled up in the warehouse

Images