Treatment and recovery process of acid wastewater in titanium dioxide production process

Abstract

The invention discloses a treatment and recovery process of an acid wastewater in a titanium dioxide production process. The treatment and recovery process mainly comprises the following steps: A, pumping the acid wastewater into a membrane filtration unit, filtering by using a filtering membrane, wherein a membrane intercept object is titanium dioxide particle concentrate, and is fed to the system to be reused, and membrane permeate is a crude sulphuric acid, and enters the next step to be treated; B, pumping the crude sulphuric acid obtained in the step A into a sulphuric acid purification unit, decontaminating and purifying the crude sulphuric acid to obtain pure dilute sulphuric acid, wherein a part of pure dilute sulphuric acid is directly reused, and the other part enters the next step to be treated; C, pumping the dilute sulphuric acid obtained in the step B into a reverse osmosis unit, filtering by a reverse osmosis membrane, wherein the intercept object is concentrated sulfuric acid and is fed to a titanium dioxide production system to be used, the permeate is water and can be directly reused as process water, and 99.9% of titanium dioxide particles, 80-90% of sulfuric acid and 60-80% of water can be recovered after the titanium dioxide acid wastewater is processed by the process disclosed by the invention, so that the production cost of an enterprise can be reduced, and the discharge amount of the wastewater and the sludge waste emission are greatly reduced.

Description

technical field [0001] The invention relates to chemical production, in particular to a treatment and recovery process of acid waste water in the production process of titanium dioxide. Background technique [0002] Titanium dioxide has excellent physical, chemical, optical and pigment properties, has been widely used, and is an important daily and chemical raw material. The production methods of titanium dioxide mainly include sulfuric acid method and chlorination method. The sulfuric acid method has low requirements on raw materials and mature technology, which is in line with China's national conditions. At present, the production of domestic titanium dioxide is mainly based on the sulfuric acid method. [0003] The sulfuric acid method is used to produce titanium dioxide, the process route is long, the discharge of three wastes is large, and the pollution is serious, which are the main problems faced by the production enterprises at present. At the same time, the yield...

AI Technical Summary

Problems solved by technology

Only 10,000 tons of waste acid are directly sent to the acid hydrolysis leaching process and acid preparation for reuse, most of which cannot be effectively used, and are sent to the wastewater treatment station for neutralization and treatment before being discharged

Lime is usually used for neutralization, although the discharge can meet the standard, but a large amount of gypsum slag is produced, forming secondary pollution

Images