Treatment method of sulfur-containing waste salt and solution thereof

Abstract

The invention provides a treatment method of sulfur-containing waste salt and a solution thereof. The treatment method comprises the steps of (1) preparing a saturated solution of the sulfur-containing waste salt; (2) mixing the sulfur-containing waste salt with the saturated solution obtained in the step (1), carrying out high-temperature salting-out, and carrying out solid-liquid separation to obtain salting-out mother liquor and sodium sulfate; (3) carrying out cooling crystallization on the salting-out mother liquor obtained in the step (2), and carrying out solid-liquid separation to obtain ammonium sulfate mother liquor and mixed salt; the mixed salt being reused in the step (2); and (4) evaporating and concentrating the ammonium sulfate mother liquor obtained in the step (3), and carrying out solid-liquid separation to obtain evaporated mother liquor and ammonium sulfate; the evaporation mother liquor being reused in the step (3). The treatment method is suitable for the sulfur-containing waste salt and a solution of the sulfur-containing waste salt, efficient separation of sodium sulfate and ammonium sulfate is achieved, meanwhile, the operation process is simplified, the production cost is reduced, and no three wastes are generated.

Description

technical field [0001] The invention belongs to the technical field of waste treatment, and relates to a treatment method for industrial waste salt, in particular to a treatment method for sulfur-containing waste salt and its solution. Background technique [0002] In many industrial productions, such as petroleum smelting catalytic process, sodium bicarbonate desulfurization and regeneration process, vanadium precipitation process, H acid production process and alkali production process using sodium sulfate as raw material, a large amount of by-product wastewater will be generated. These by-product wastewater are mainly composed of sodium sulfate and ammonium sulfate, and some also contain a small amount of heavy metals. If they are directly discharged into the environment, they will not only pollute the water body and soil, but also seriously harm aquatic organisms, and even enter the human body through the food chain. Significantly increase the risk of human disease. How...

AI Technical Summary

Problems solved by technology

According to the phase diagram of the water-salt system of sodium sulfate and ammonium sulfate, double salts will appear in the three cooling processes of the method, so that the purity of sodium sulfate and ammonium sulfate products is relatively low, and the energy consumption in the repeated cooling and heating process is high, which is extremely high. greatly increased operating costs