Device and process for preparing macromolecular aluminum salt coagulant by utilizing sludge of high-salinity wastewater zero discharge system

Abstract

The invention relates to a device and a process for preparing a high-molecular aluminum salt coagulant by using sludge of a high-salinity wastewater zero discharge system. Impurities in wastewater are removed in advance through optimal design of a process flow, and the content of Al2O3 in dechlorination precipitates is increased; and the dechlorination precipitate is used as a raw material to prepare a polymer aluminum salt coagulant such as PAC or polyaluminum sulfate (PAS), so that the problem of solid waste discharge is solved, and the running cost of a zero emission system is compensated at the same time. The indexes such as the mass fraction, the basicity and the heavy metal content of the prepared PAC or PAS aluminum oxide respectively meet the requirements of water treatment agent national standards of water treatment agent polyaluminum chloride (GB / T22627-2014) and water treatment agent polyaluminum sulfate (HG / T5006-2016), and the concept of solid waste recycling can be realized.

Description

technical field [0001] The invention belongs to the technical field of solid waste resource treatment, and relates to a device and a process for preparing a high-molecular aluminum salt coagulant from the sludge of a high-salt wastewater zero-discharge system. Background technique [0002] In recent years, high-salt wastewater has attracted much attention due to its large production volume, strong corrosiveness, and serious environmental pollution. As early as 2000, the European Union promulgated a social pact to prevent water bodies from being polluted by high-salt wastewater. In response to this problem, Beijing, Shanghai, Henan, Hebei, Guizhou, Sichuan and other provinces have successively promulgated local standards to limit the discharge concentration of wastewater salt. At present, with the improvement of discharge requirements for industrial production in my country, the chemical industry is in an important stage of transformation and upgrading. Coal chemical industr...

AI Technical Summary

Problems solved by technology

There are mainly two deficiencies in this preparation method. One is that there are too many types of raw materials for use, and the Al in bauxite 2 o 3 The mass fraction requirement is not less than 50%, and the mass fraction of CaO in high calcium stone is not less than 80%. The selection of raw materials is too harsh, and the production method is not universal; the second is that the production process is too complicated and needs to be pelletized and High-energy production steps such as rotary furnace calcination convert the aluminum source into calcium aluminate, which is easily reactive with acid, and the excessive amount of hydrochloric acid is not suitable for large-scale production of PAC

[0007] Therefore, in view of the outlet problem of a large amount of solid waste produced by the existing high-salt wastewater zero-discharge process, the present invention proposes a technical route for preparing high-molecular aluminum salt coagulant from the high-salt wastewater dechlorination precipitate. Compensate the operating cost of the zero-emission system while abolishing the outlet

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