Feeding method and feeding equipment for titanium dioxide calcination rotary kiln

Abstract

The invention relates to a feeding method and feeding equipment for a titanium dioxide calcination rotary kiln. The equipment comprises a membrane filter press (1), a belt conveyor (2), a first screw conveyor (3), a flash evaporation drying main machine (4), a second screw conveyor (5), a cyclone dust collector (6), the rotary kiln (7), a high pressure induced draft fan (14), an alkali liquor adsorption tower (10), an alkali liquor spraying pump (13), an alkali liquor storage tank (15) and a bag filter (12); a rotary blade (11) is arranged at the bottom of the flash evaporation drying main machine (4); and a first star-shaped discharge valve (8) and a second star-shaped discharge valve are respectively arranged at the bottoms of the flash evaporation drying main machine and the cyclone dust collector. The method adopting the feeding equipment comprises the steps of conveying, flash evaporation drying, recovery, collection and tail gas treatment. Metatitanic acid materials entering the flash evaporation drying main machine are in contact with high-temperature flue gas from the kiln tail of the rotary kiln; under the action of high speed rotation of the rotating blade at the bottom, the materials are crushed, dispersed and dried; and after flash evaporation drying, the materials with the moisture content of 10 to 15 percent enter the rotary kiln. Through the adoption of the feeding method and the feeding equipment disclosed by the invention, the productivity can be improved, energy consumption can be reduced and the calcination quality of products can also be improved.

Description

technical field [0001] The invention relates to a rotary kiln feeding method and equipment, in particular to a rotary kiln feeding method and equipment for calcining titanium dioxide, and belongs to the field of titanium dioxide production. Background technique [0002] In the production process of titanium dioxide by sulfuric acid method, 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 hydrolysate metatitanic acid is removed most of the water through the diaphragm filter press, the titanium dioxide rotary kiln with a certain slope (usually 3-5%) and slow rotation is fed by the screw conveyor. At the end of the kiln (also known as the feed end or high end), the combustion chamber at the kiln head (ie the discharge end or low end) blows clean flame and hot air into the kiln to dehydrate, desulfurize and transform the material. The materials cal...

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Problems solved by technology

[0003] The existing titanium dioxide calcination process has the following problems: 1. When the metatitanic acid material enters the rotary kiln, the moisture content is 50-55%, and the moisture content is high, resulting in high energy consumption and low output in the calcination process. Generally, energy consumption per ton of titanium dioxide is required 2.8-3 million kcal, The annual output of the rotary kiln is only about 20,000 tons; 2. The calcination of titanium dioxide is gradient calcination, the temperature difference is large, and the product quality is unstable; 3. The temperature of the kiln tail gas is as high as 350-450 ° C. After dust removal, it needs to be sprayed to cool down and discharged to the atmosphere. The heat of high temperature flue gas is not fully utilized

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