Method for producing high-purity electronic titanium dioxide

Abstract

The invention discloses a method for producing high-purity electronic titanium dioxide. Panzhihua titanium concentrate with the concentration larger than or equal to 80% is selected as a raw material,sulfuric acid is used for acidolysis of the titanium concentrate, a flocculating agent composed of a maleic anhydride-styrene sulfonic acid copolymer, sodium lignin sulfonate and polyaluminum chloride is added for impurity removal treatment, standing and filter pressing are conducted for solid-liquid separation, filter-pressed liquid enters a vacuum crystallization system, secondary filter pressing is conducted, and refined titaniferous solution is obtained; water is added into the refined titaniferous solution to adjust the concentration to 95-200g / L, heating and stirring are performed, anda crystal form control agent is added to react to obtain a hydrolysate; the hydrolysate is washed until the iron ion content is below 150ppm, then sulfuric acid is added for bleaching and washed for the second time until the iron ion content is below 50ppm to obtain slurry; squeezing is performed by a filter press, a filter cake is calcined in a rotary kiln and crushed to obtain the electronic titanium dioxide. The purity of the titanium dioxide product prepared by the method reaches 99.5% or above, the particle size distribution is 200-400 nm, the particle size distribution is narrow, the particle size distribution is uniform, the powder whiteness reaches 90% or above, and the requirements of middle-high-end electronic-grade titanium dioxide can be met.

Description

technical field [0001] The invention belongs to the technical field of producing titanium dioxide, in particular to a method for producing high-purity electronic titanium dioxide. Background technique [0002] Titanium dioxide, namely titanium dioxide, is an important inorganic chemical raw material. Because of its non-toxic, stable physical and chemical properties, excellent optical and electrical properties and excellent pigment performance, it is widely used in coatings, inks, plastics, rubber, paper, chemical fibers, art pigments, daily cosmetics, enamel, ceramics, electronics, etc. and other fields. Electronic grade special titanium dioxide (high-purity titanium dioxide) is one of the main crystal phase raw materials for new electronic components. [0003] Used in PTC thermistors, MLCCs, semiconductor capacitors, semiconductor ceramics and piezoelectric ceramics and other fields. As one of the main raw materials for the manufacture of such electronic materials, high-...

AI Technical Summary

Problems solved by technology

[0004] Most of the existing high-purity electronic grade titanium dioxide is produced by the chlorination process, but the cost of this method is high

At present, most of the sulfuric acid method is used to prepare titanium dioxide, but this process can only produce low-end electronic grade titanium dioxide, with large particle size and low purity, which cannot meet the requirements of high-end electronic grade titanium dioxide.