Device and process for treating silica-containing high-salt wastewater in silica acid precipitation process

Abstract

The invention provides a device and process for treating silica-containing high-salt wastewater in a silica acid precipitation process. The device comprises a pretreatment unit, a pre-concentration unit, a two-effect evaporation unit, an MVR evaporation crystallization unit and a drying unit, wherein the units are sequentially connected; the pretreatment unit comprises a sedimentation tank; the pre-concentration unit comprises evaporative cooling; the two-effect evaporation unit comprises a first-effect separator, a first-effect heater, a second-effect separator, a two-effect heater and a filter press; the MVR evaporation crystallization unit comprises an MVR heater, an MVR separator, an MVR compressor, an MVR thickener and an MVR centrifuge; and the drying unit comprises a dryer. Condensed water generated by the process is recycled as production water, a generated silica precipitate is sold as a hydrated silica product, generated anhydrous sodium sulfate can be sold as a chemical product, waste water, solid waste and the like in the process are avoided, zero emission of the wastewater is realized, and a traditional acid precipitation process is changed into a cleaning process.

Description

technical field [0001] The invention belongs to the field of sewage treatment, and in particular relates to a treatment device and process for high-salt wastewater containing silicon dioxide produced during the production process of hydrated silicon dioxide products such as white carbon black and silica gel by an acid precipitation method. Background technique [0002] Hydrated silica products such as white carbon black and silica gel are the general term for white powder X-ray amorphous silicic acid and silicate products, and the main component is silica. [0003] At present, the production methods of hydrated silica products such as white carbon black and silica gel at home and abroad are mainly gas phase method and precipitation method. The precipitation method mainly uses the sulfuric acid precipitation method in China. The existing domestic white carbon black equipment adopts the sodium silicate acidification method (also known as the precipitation method) to produce wh...

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Problems solved by technology

[0010] Based on the problems existing in the prior art, the object of the present invention is to provide a SiO 2 A treatment device for silicon dioxide-containing high-salt wastewater in the acid precipitation process; the purpose of the present invention is also to provide a SiO 2 The treatment process of silica-containing high-salt wastewater in the acid precipitation process; the use of this treatment device and its process can solve the traditional process of silica and silica gel and other hydrated silica products produced during the sulfuric acid precipitation process. In the process of salt wastewater treatment, the problem of large amount of solid waste, high operating cost, and bottleneck of equipment fouling can truly realize zero discharge of silica-containing high-salt wastewater, and transform the sulfuric acid precipitation process of hydrated silica into clean production craft

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