Comprehensive utilization method for chlorination-process titanium dioxide post-treatment wastewater

Abstract

The invention relates to a treatment method for byproducts in a chlorination-process titanium dioxide process, and specifically discloses a comprehensive utilization method for chlorination-process titanium dioxide post-treatment wastewater. The comprehensive utilization method is characterized in that the post-treatment wastewater is treated by adopting membrane treatment technologies for many times so as to finally obtain a sodium chloride solution with solute content greater than 12% (mass concentration); the obtained sodium chloride solution is used as a production raw material of a chlorine alkali production process. The comprehensive utilization method has the advantages that firstly, the treatment rate is high; secondly, evaporative crystallization is not needed to be carried out on the post-treatment wastewater, so that a large number of energy resources are saved; thirdly, the obtained sodium chloride solution is used as the production raw material of the chlorine alkali production process, so that a chlorination-process titanium dioxide process and the chlorine alkali process are organically combined.

Description

technical field [0001] The invention relates to a production process of chlorination titanium dioxide, in particular to a treatment method for by-products produced in the production of chlorination titanium dioxide. Background technique [0002] At present, the methods for producing titanium dioxide mainly include sulfuric acid method and chloride method. Due to the long process of the sulfuric acid method, serious pollution and poor product quality, it was gradually replaced by the chlorination method. [0003] In the current production of titanium dioxide by chloride method, its main process is: [0004] a. Mix the titanium raw material (such as: high titanium slag) and the reducing agent (such as: petroleum coke) evenly and send it into the chlorination furnace, inject chlorine gas to carry out boiling chlorination at the temperature of 800℃~1000℃; [0005] b. Separating and purifying the crude titanium tetrachloride obtained after chlorination to remove impurities such...

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Problems solved by technology

However, there are certain defects in both methods. For method 1, the open-air sedimentation tank occupies a very large area and has high requirements for the site, so this method has great limitations; and because the natural evaporation rate is very slow, making this method The method is essentially to pile up a large amount of post-treatment wastewater in the sedimentation tank for a long time. In the rainy season, a large amount of rainwater may even cause the wastewater to overflow out of the sedimentation tank, causing pollution to the surrounding environment

For method 2, although rapid evaporation and crystallization can quickly treat wastewater, it consumes a lot of energy and the cost of wastewater treatment is high; and neither method 1 nor method 2 makes full use of post-treatment wastewater resources.

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