Method for preparing high-strength α-titanium gypsum from industrial waste titanium dioxide waste residue

Abstract

The invention discloses a method for preparing high-strength α-titanium gypsum by utilizing industrial waste titanium dioxide waste residue, specifically: adding water to finely ground titanium dioxide waste residue to prepare slurry, adding a composite nucleating agent to the slurry and adjusting pH value to 1.0 to 5.5, then add it to the reaction kettle, stir and continue to feed oxygen, heat to a slight boiling state, constant temperature dehydration and crystallization, after the reaction is completed, the prepared solution is filtered under reduced pressure, and successively use boiling water and ethanol Wash and dry to obtain short hexagonal α-titanium gypsum crystals, sieve the obtained crystals and make 15-30% of 10-30 μm, 50-75% of 30-80 μm, and 10-20% of 80-200 μm. The high-strength α-titanium gypsum with an average particle size of 20-60 μm, a compressive strength of more than 70 MPa, regular shape and uniform size can be obtained. The method has the advantages of simple process, low cost and high efficiency.

Description

technical field [0001] The invention belongs to the technical field of industrial solid waste recycling, and in particular relates to a method for preparing high-strength α-titanium gypsum by using industrial waste titanium dioxide residue. Background technique [0002] When producing titanium dioxide by the acid method, a large amount of industrial waste acid will be produced as a by-product. These waste acids cannot be discharged directly. They are usually neutralized with calcium hydroxide and converted into industrial waste residue whose main component is calcium sulfate dihydrate. These titanium dioxide waste residues are piled up or landfilled, but this backward and primitive treatment method not only occupies a large amount of land, but also poses a serious threat to the environment, and brings a huge economic burden to titanium dioxide enterprises, seriously restricting the titanium dioxide industry. benign development. How to digest and convert titanium dioxide was...

AI Technical Summary

Problems solved by technology

However, the conventional hydrothermal method has obstacles in the preparation of high-strength α-titanium gypsum from titanium dioxide waste slag. The main reason is that the purity of dihydrate gypsum in titanium dioxide waste slag is low, and the impurities, especially iron and titanium, are high in content, which greatly affects the high-strength α-titanium gypsum. The crystallization process of gypsum leads to small crystal size, imperfect shape and poor product quality of products produced by conventional hydrothermal method

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