Wastewater treatment process for wet-process chromium metallurgy

Abstract

The invention discloses a wastewater treatment process for wet-process chromium metallurgy. The wastewater treatment process includes steps that wastewater enters a deaminizing reactor for extracting chromium hydroxide, with vanadium ions and chromium ions adsorbed by anion resin, and is connected with a denitriding reactor; sodion containing waste liquid enters a triple-effect multistage evaporator through a pipeline, is connected to a high-temperature evaporation crystallizer, and enters a low-temperature crystallizer to be frozen and crystallized in it; then the waste liquid enters an electrodialysis device, a sodium filter film to filter, and a reverse osmosis film. The wastewater treatment process for wet-process chromium metallurgy can reduce high-price chromium ions and realize preparation of sodium sulfate salt. In addition, sewage discharge can reach the standard.

Description

technical field [0001] The invention relates to the field of chemical environmental protection, in particular to a wastewater treatment process for hydrochrome metallurgy. Background technique [0002] Chromium-containing ores mainly include more than 30 kinds of chromite, chrome chlorite, chrome garnet, chrome mica, chrome diopside, chrome rutile, etc. Among them, chromite is of industrial value, which is extracted from chromite Chromium salts are widely used in the national economy, mainly in electroplating, leather tanning, printing and dyeing, medicine, pigments, catalysts, organic synthesis oxidants and metal corrosion inhibition. Metal chromium is mainly used in the production of superalloys, electric heating alloys, precision alloys, etc. Chromium alloys are used in aviation, aerospace, electrical appliances, instruments and other industrial sectors. In addition, they are also widely used in cast iron production. [0003] The production process of chromium salt is ma...

AI Technical Summary

Problems solved by technology

[0003] The production process of chromium salt is mainly chromite with oxidation roasting and sulfuric acid acidification method. During the chromium metallurgy process, a large amount of wastewater will be generated. The chemical composition of the wastewater is complex. The main components are ammonia, vanadium, chromium, and sodium sulfate. Environmentally friendly treatment It is very difficult. Most of the traditional methods use the reduction method to reduce hexavalent Cr to trivalent Cr and discharge it directly. However, there are still some hexavalent Cr in the wastewater, and the ammonia and sodium sulfate in the wastewater have not been treated, which still pollutes the environment and water bodies.