Process for preparing basic chromium sulfate by using waste chromium material

Abstract

The invention relates to a process for treatment of heavy metal and recovery of an inorganic salt and especially to a process for preparing basic chromium sulfate by using a waste chromium material. In the process, a waste chromium liquid storage tank, an acidifying device, a reduction device, a reaction vessel, a condensation kettle, a press filtration device, a spray drying device and a gas purifying device are utilized; the process comprises the following steps: collecting electroplating and other chromium-containing waste liquid and waste residue, adding the collected waste liquid and waste residue into an acidifying reaction vessel, optimizing a formula for reagents, removing other impurity components except chromium components through addition and reaction of the reagents and press filtration, carrying out further dehydration by adjusting the condensation kettle for further reaction and preparing the product of basic chromium sulfate by using a centrifugal spray drier. The process provided in the invention is optimized, reasonable, simple and easy, makes the most of natural resources and natural conditions, has the advantages of low production cost, small investment and high yield and enables the problem of waste chromium pollution to be effectively overcome and the waste chromium material to be processed into inorganic chemical products, thereby producing remarkable environmental and economic benefits.

Description

technical field [0001] The invention relates to a process for treating heavy metals and recovering inorganic salts, in particular to a process for preparing basic chromium sulfate by utilizing waste chrome materials. Background technique [0002] Hexavalent chromium compounds are ubiquitous environmental pollutants and are carcinogenic. They are mostly produced in printing and dyeing, electroplating, leather processing, wood preservation, organic synthesis and certain catalyst manufacturing industries. In the process of industrial production, how to control the production of hexavalent chromium compounds and their subsequent treatment is a major environmental protection problem facing the world today. At present, chromium-containing wastewater mainly comes from electroplating chromium and rinsing wastewater, in which the concentration of hexavalent chromium is about 20~300mg / L. As a solid waste with leaching toxicity, chromium slag is numbered HW21 in the "National Hazardou...

AI Technical Summary

Problems solved by technology

[0017] In the existing technology, some theoretical research has made some progress, but there is still a certain distance from the actual application, and it needs to be continuously improved, optimized and developed; some process methods are relatively mature, but the biggest problem is that the investment is large and the effect is slow. , the process is complicated, and the processing and production costs are relatively high