Method for recovering and utilizing three wastes during titanium white production through sulfuric acid process

Abstract

The invention discloses a method for recovering and utilizing three wastes during titanium white production through a sulfuric acid process, which is characterized in that crystal water is removed from titanium white waste slag copperas, anhydrous titanium white waste slag is reduced and decomposed into ferrous oxide residue and sulfur dioxide gas by reducing agents in weak oxidization mixing atmosphere at high temperature, sulfuric acid prepared by sulfur dioxide gas returns the acidolysis work procedure in the titanium white production process, the decomposed ferrous oxide residue is directly used for neutralizing the 10 to 25 weight percent waste sulfuric acid generated in the titanium white production process, excessive ferrous oxide residues can be used as raw materials for producingferric oxide series pigments and for steel plants, crystal water is removed from titanium white waste slag red gypsum, semihydrated gypsum is obtained, the semihydrated gypsum is reduced and decomposed into calcium oxide residue and sulfur dioxide gas by reducing agents in weak oxidization mixing atmosphere at high temperature, the sulfur dioxide gas can be used for preparing sulfuric acid, ferrous waste water and 0.1 to 10 percent waste sulfuric acid are neutralized by calcium oxide residues or quick lime, ferrous red gypsum is obtained through filtering, and the filter liquid can be reused.

Description

technical field [0001] The invention relates to a three-waste recycling method for producing titanium dioxide by a sulfuric acid method, and belongs to the technical field of three-waste treatment and comprehensive utilization. Background technique [0002] Titanium dioxide is a high-grade high-quality white pigment and an important inorganic chemical product. It is chemically stable with high refractive index and ideal particle size distribution. Therefore, with its good hiding power and tinting power, it is widely used in industries such as coatings, inks, materials, rubber, paper, ceramics and synthetic fibers. With the continuous development of the economy, the demand for titanium dioxide continues to increase. Since 2000, my country has completed the localization of large-scale titanium dioxide devices and equipment in China, and the titanium dioxide industry is developing rapidly towards large-scale and large-scale production. The output of titanium dioxide increase...

AI Technical Summary

Problems solved by technology

Although this method can reduce waste acid pollution, it also brings the following problems: (1) because the neutralization slag mainly contains CaSO 4 , Fe(OH) 3 , Mg(OH) 2 Wait, at present, we can only discard the pile for processing

After being washed by rainwater, it seeps into the land and farmland, pollutes groundwater resources and surface vegetation, and causes serious irreversible secondary pollution to the ecological environment

(2) Equipment investment and operating costs are high, which can only be passed on to consumers by increasing product prices in the end, thereby affecting the competitiveness of enterprises; the resulting secondary pollution will inevitably cause bitter results that go against the original intention and threaten the company's reputation Survive

(3) The sulfur resources in the waste acid are not utilized, so that the sulfur is harmful to the environment in the form of waste residue

Due to the high content of impurities in the waste acid, easy scaling and other reasons during the concentration process, some titanium dioxide factories have established concentration devices, but it is difficult to operate normally, and the equipment investment and operation costs of the devices are large, and the waste acid The cost of enrichment is significantly higher than that of new acid

At present, almost no enterprises really use the method of concentration and recycling to deal with waste acid