Method for hydrolyzing low-concentration self-generating crystal seed in process of preparing titanium dioxide by sulfuric acid method

Abstract

The invention discloses a method for hydrolyzing a low-concentration self-generating crystal seed in a process of preparing titanium dioxide by a sulfuric acid method. The method comprises the step as follows: taking a hot alkali solution (comprising the concentration of 3-7% and the boiling point) accounting for 4-7.7% of titanyl sulfate solution by volume as bottom water to be added into a hydrolyzing pot, adding the titanyl sulfate solution of 88-98 DEG C into the hydrolyzing pot at a uniform speed within 12-25 minutes, controlling the concentration of the titanyl sulfate solution to be 190-210 g / L based on TiO2, controlling the heating rate at the same time, and carrying out conventional hydrolyzing steps. Due to the adoption of the scheme, the self-generating crystal seed can be hydrolyzed under the lower concentration (190-210 g / L) to obtain titanium dioxide with good particle shape and particle size distribution and excellent pigment and optical performances; and meanwhile, the method has the advantage of reducing the production energy consumption of titanium dioxide.

Description

technical field [0001] The invention relates to a method for hydrolyzing self-generated seed crystals in the production process of sulfuric acid titanium dioxide, belonging to the field of titanium dioxide production. Background technique [0002] Titanium dioxide is widely used in many fields, such as coatings, inks, plastics, rubber, paper, ceramics and synthetic fibers, for its non-toxicity, best opacity, best whiteness and brightness, and good hiding power and coloring power. . At present, my country's titanium dioxide factories mainly use sulfuric acid production process. [0003] The hydrolysis process is one of the core processes of the sulfuric acid titanium dioxide production process. The hydrolysis process is the process in which the titanium sulfate salt solution is hydrolyzed to form hydrated titanium dioxide. There are many patents and reports on the hydrolysis method of titanium liquid, but two methods are widely used at present: external seed crystal hydroly...

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Problems solved by technology

However, the concentration of titanium solution required by the self-generated seed crystal hydrolysis method is higher, and more bottom water is required, which puts forward higher requirements for the concentration process of the titanyl sulfate solution in the previous process. Therefore, it is different from the external seed crystal hydrolysis method. Compared with that, the autogenous seed crystal hydrolysis method increases the difficulty and energy consumption of the concentration process