Reductive calcining process of ferrous sulfate as byproduct of titanium dioxide

Abstract

The invention relates to a reductive calcining process of ferrous sulfate as a byproduct of titanium dioxide. The reductive calcining process comprises the following steps of: adding reductive substances, namely coke powder, sulphur and pyrite concentrate according to a certain proportion in a process of calcining ferrous sulfate to obtain solid substances, namely iron oxide red, wherein sulfur dioxide as a main component in waste gases can be used for producing concentrated sulfuric acid and anhydrous sodium sulfite after being purified, converted and absorbed, so that sulphur and iron resources in ferrous sulfate can be comprehensively recovered; and meanwhile the pollution to environment caused by long-term stockpiling of the ferrous sulfate as the byproduct in the titanium dioxide industry is eliminated, the ferrous sulfate residues can be recycled, valuable resources, such as sulphur and iron can be comprehensively recycled, the clean production requirement is achieved and the difficulties in the titanium dioxide industry are solved.

Description

technical field [0001] The invention belongs to the field of comprehensive recovery and utilization of industrial by-product pollutants, and in particular relates to a process technology for comprehensive recovery and utilization of ferrous sulfate, a by-product of the titanium dioxide industry. Background technique [0002] There are two manufacturing methods of titanium dioxide: Sulfuric Acid Process and Chloride Process. The sulfuric acid method is to produce titanous sulfate by acidolysis reaction of ferrotitanium powder and concentrated sulfuric acid, which is hydrolyzed to generate metatitanic acid, and then calcined and pulverized to obtain titanium dioxide products. This method can produce anatase and rutile titanium dioxide. The advantage of the sulfuric acid method is that it can use ilmenite and sulfuric acid which are cheap and easy to get as raw materials, the technology is relatively mature, the equipment is simple, and the anti-corrosion materials are easy to...

AI Technical Summary

Problems solved by technology

Ferrous sulfate heptahydrate is one of the waste by-products produced in a large amount in the production of sulfuric acid titanium dioxide. It has high water content and high impurity content. It is very difficult to directly sell it as a product, and it is basically not accepted. Accepted by the market, resulting in a large accumulation of ferrous sulfate heptahydrate in the sulfuric acid titanium dioxide industry, directly affecting the normal production of titanium dioxide equipment

[0004] At present, domestic attempts have been made to use ferrous sulfate heptahydrate for the production of iron-based pigments or to simply mix and burn ferrous sulfate for the production of industrial sulfuric acid. It is difficult to achieve the standard of acid mist, which restricts the process of recovering valuable resources from industrial calcined ferrous sulfate