Waste acid double-effect concentration and recycling method for titanium dioxide production enterprises

Abstract

The invention belongs to the technical field of green chemical engineering, and particularly relates to a waste acid double-effect concentration recycling method for titanium dioxide production enterprises. The method is capable of solving the problem that in recycling process of waste acid generated in titanium dioxide production enterprises in the prior art, effective utilization is difficult torealize because of too low waste acid concentration. The technical scheme comprises the following steps: (1) feeding the waste acid from titanium dioxide production process into a storage tank, and then pumping the waste acid into a primary evaporator for negative-pressure low-temperature evaporation and concentration; [2] pumping primary concentrated acid obtained after evaporation and concentration in the primary evaporator into a preheater for preheating through a pump, and then pumping the acid into a secondary evaporator to be subjected to negative-pressure medium-temperature evaporationand concentration; and (3) enabling secondary concentrated acid obtained after concentration in secondary evaporator to automatically flow into a curing tank, and then pumping the acid to a next process. The method is used for recycling the waste acid obtained in the titanium dioxide production process.

Description

technical field [0001] The invention belongs to the technical field of green chemical industry, and in particular relates to a double-effect concentration recycling method for waste acid used in titanium dioxide production enterprises. Background technique [0002] Titanium dioxide production enterprises usually need to use a large amount of sulfuric acid with a concentration of 55%, and also produce a large amount of waste sulfuric acid. If the waste acid can be used to prepare sulfuric acid with a concentration of 55% required by the process, the sulfuric acid resource can be effectively utilized and the environmental protection pressure brought about by waste acid treatment can be reduced. [0003] However, the concentration of waste acid is usually low, so that it is still necessary to use a large amount of sulfuric acid with a concentration of 98% to adjust the concentration during preparation, and a large amount of waste acid cannot be effectively utilized and can only...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem that the waste acid concentration produced by titanium dioxide production enterprises in the prior art is too dilute to be effectively utilized, the present invention provides a double-effect concentration recycling method for waste acid used in titanium dioxide production enterprises. The purpose is to: in order to save energy and reduce consumption, make full use of this part of the waste acid, add a waste acid double-effect concentration project to concentrate the waste acid, thereby increasing the proportion of waste acid used, reducing the consumption of sulfuric acid with a concentration of 98% and the load of the sewage station