Method for converting titanium dioxide red gypsum into white gypsum and enriching titanium and iron

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly relates to a method for converting titanium dioxide red gypsum into white gypsum and enriching titanium and iron.The method comprises the following steps: preparing white gypsum, preparing the red gypsum, converting the red gypsum into acid white gypsum, and converting the acid white gypsum into the white gypsum; through control of a process and an end point of the reaction, the produced white gypsum can be directly used for a cement factory, and can be deeply processed into building material gypsum with higher added value; through dissolution of the red gypsum by a waste concentrated acid, the red gypsum is converted into the acid white gypsum, and a TiOSO4 and FeSO4 acidic solution with a high concentration is obtained, wherein the recovery utilization rate is 95% or more; and the acid white gypsum is diluted by using titanium dioxide wastewater, and after primary neutralization is performed, thewhite gypsum is obtained. The method provided by the invention has a simple technological process, a stable treatment effect, less equipment investment, no secondary pollution, low treatment costs, considerable economic benefits and broad market prospects.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a method for converting titanium white red gypsum into white gypsum and enriching titanium and iron. Background technique [0002] At present, most domestic titanium dioxide factories adopt the sulfuric acid method for production, and the main pollution factor of the titanium dioxide wastewater produced is H 2 SO 4 、TiOSO 4 , FeSO 4 . The wastewater treatment of most titanium dioxide factories is to prepare titanium gypsum and external drainage. Since the external drainage must meet the GB8978-1996 standard, it is necessary to treat FeSO 4 Pollution factor, only milk of lime can be used to reduce FeSO 4 Neutralization reaction produces Fe(OH) 2 and CaSO 4 2H 2 Mixed gypsum of O, due to Fe(OH) 2 Easily oxidized to red Fe(OH) in air 3 , so it is called red gypsum. Red gypsum not only moisture = 40-45% is too high, SO 3 = 27-29% is seriously low,...

AI Technical Summary

Problems solved by technology

The scheme adopts three-stage neutralization treatment, and the TiOSO that can be prepared 4 In acid solution, the F value is as high as 8-10, so the recovery rate of titanium is limited to 80%; the output of white gypsum and red gypsum, due to the existence of red gypsum, the white gypsum can only be mixed with red gypsum and dried , cannot be used for the development of other building materials

[0006] 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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