Material feeding method of calcination rotary kiln for preparing titanium dioxide by sulfuric acid method

Abstract

The invention provides a material feeding method of a calcination rotary kiln for preparing titanium dioxide by a sulfuric acid method, and belongs to the field of material feeding methods. The material feeding method comprises the following steps: putting titanium dioxide slurry into a diaphragm filter press for filtration, thus obtaining slurry with the moisture content of 85 to 90 percent; putting the slurry into a diaphragm bag, and putting the bag into a centrifugal machine for separation to obtain slurry with the moisture content of 65 to 70 percent; compressing the slurry through a drying press to obtain slurry with the moisture content of 45 to 50 percent; putting the slurry into a drying machine for drying treatment to obtain a material with the moisture content of 15 to 20 percent; and crushing the material, and pumping the crushed material into the rotary kiln through a material pumping machine. Calcination in the rotary kiln is divided into three stages; crystal water in metatitanic acid is removed again at high temperature, and sulfur is removed at the high temperature; products subjected to crystal type transformation, particle size growth and qualified calcination flows out from the low end of the rotary kiln into a cooling rotary drum. According to the material feeding method provided by the invention, the material is dried in the early stage, so that the moisture content of the fed material is low, and the calcination time is shortened; and therefore, the utilization rate of calcination equipment is increased, and the productivity of a single rotary kiln isincreased by 70 to 90 percent; and the calcination energy consumption is also reduced.

Description

technical field [0001] The invention relates to the field of titanium dioxide production, in particular to a method for preparing titanium dioxide by sulfuric acid and calcining a rotary kiln. Background technique [0002] In the sulfuric acid titanium dioxide production process, calcination is one of the three most critical processes that determine the quality of titanium dioxide. The calcination process of titanium dioxide is roughly as follows: after the hydrolyzed product metatitanic acid is deprived of most of the water by a diaphragm filter press, it is input by a screw conveyor into a titanium dioxide rotary kiln with a certain inclination (generally 3-5%) and slow rotation. The kiln tail (also known as the feed end or high end) and the combustion chamber of the kiln head (ie the discharge end or low end) blow clean flames and hot air into the kiln to dehydrate, desulfurize and transform the materials. The materials calcined at high temperature come out from the disc...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for preparing titanium dioxide by sulfuric acid and calcining the rotary kiln, so as to solve the technical problem of high production cost of titanium dioxide produced by the existing acid hydrolysis method