Method for treating titanium dioxide wastewater

Abstract

The invention belongs to the technical field of wastewater treatment and particularly relates to a method for treating titanium dioxide wastewater. The method includes the steps of firstly, preparingwhite gypsum; secondly, preparing red gypsum active seed crystal; thirdly, performing two-stage neutralization; fourthly, performing aeration and sedimentation. The method has the advantages that by reaction end point control, TiSO4 with the stability being not smaller than 100 in active-stage filtrate is hydrolyzed completely to finally generate TiO(OH)2 seed crystal particles which are small anduniform in size so as to obtain the red gypsum active seed crystal; by the end point control, the produced white gypsum is low in water content and can be directly used by a cement factory, red gypsum whose water content is low and SO3 content meets cement production requirements, the calcining and drying procedure of the white gypsum is omitted, the calcining and drying cost of titanium gypsum is lowered greatly, and the water content and the SO3 content of the red gypsum can meet the cement production requirements of the cement factory when the water content is 34-37% and the SO3 content is33-35%; meanwhile, discharged wastewater meets the emission standards of GB8978-1996.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, in particular to a method for treating titanium dioxide wastewater. Background technique [0002] At present, most titanium dioxide factories in China use the sulfuric acid method for production, and the treatment of their titanium dioxide wastewater is basically to prepare titanium gypsum. However, due to the preparation process, the moisture content of the titanium gypsum directly filtered through the filter press is too high. , must be dried before it can be used as a retarder in cement plants. [0003] At present, there are three types of titanium gypsum prepared by titanium dioxide wastewater in domestic sulfuric acid titanium dioxide factories: [0004] The first method: use milk of lime to directly neutralize the titanium white waste acid to pH=8-9, and obtain red gypsum by pressure filtration with a diaphragm filter press, the water content of which is controlled at 39-42%, ...

AI Technical Summary

Problems solved by technology

Its production has only one kind of red gypsum, and its water content is only 37.62% at the lowest, and the operation is complicated. The seed crystal component is gypsum, and the ratio is difficult to measure, so it is not suitable for large-scale industrial production

[0012] In view of the current unreasonable treatment methods for titanium dioxide wastewater, resulting in low wastewater treatment efficiency, it is of great practical and economic significance to make reasonable and scientific improvements to wastewater treatment methods.

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