Titanium dioxide production process calcining tail gas processing method

Abstract

The present invention discloses a titanium dioxide production process calcining tail gas processing method comprising the following steps: 1) dust removal; 2) preliminary heat exchange, to be more specific, calcining tail gas after the dust removal is discharged into a waste heat boiler system for heat exchange with process water, and the calcining tail gas is preliminarily calcined; 3) further heat exchange, to be more specific, the preliminarily-calcined calcining tail gas enters a venturi system and further cooled by spraying with spent sulfuric acid; and 4) desulfurization. According to the titanium dioxide production process calcining tail gas processing method, waste heat boiler system with high heat recovery utilization rate is used, and by step-by-step heat exchange, heat can be efficiently recovered from the calcining tail gas, and can be used for other processes in a titanium dioxide production line, energy and water consumption can be greatly saved, and by the desulfurization, desulfurization rate of the calcining tail gas is significantly increased.

Description

Technical field [0001] The invention belongs to the field of titanium dioxide production, and specifically relates to a method for treating calcined tail gas in the titanium dioxide production process. Background technique [0002] Titanium Dioxide (TiO 2 ) Is the most important white pigment widely used at present. It is widely used in coatings, papermaking, ink and other fields, and its demand is proportional to GDP. At present, the global annual production capacity of titanium dioxide is more than 5 million tons, and the domestic annual production capacity of titanium dioxide is more than 2 million tons, and the price is about 15,000-22,000 yuan / ton. In terms of production methods, in China, except for Jinzhou Titanium Dioxide Plant which adopts the chlorination method, the rest are all produced by the sulfuric acid method. One of the more prominent problems in the current sulfuric acid titanium dioxide production process is environmental protection and energy saving. [0003]...

AI Technical Summary

Problems solved by technology

The problem with this method is that the waste heat utilization efficiency is low, and it is necessary to build a waste acid concentration device, and the pre-concentrated sulfuric acid needs to be kept warm.

The problem with this method is that the factory must be equipped with a set of graphite towers for concentrating sulfuric acid, and it is prone to equipment failure

The problem with this method is that the utilization of thermal efficiency is low, non-electric air conditioning equipment needs to be configured separately, and it is repeated with existing refrigeration equipment, which increases investment

The problem with this method is that there is no heat recovery

The problem with this method is that the heat loss of the hot waste gas is large during the waste acid spraying process, the waste heat utilization efficiency is low, and the harmful and useless gases in the calcination tail gas return to the kiln, which will adversely affect the calcination process.

[0014] To sum up, in the prior art, the waste heat of the calcination tail gas of the titanium dioxide rotary kiln is not utilized or the waste heat utilization efficiency is low, and the sulfide discharged from the calcination tail gas is difficult to control, and the calcination tail gas often fails to meet the standard.