Method and system for treating wastewater generated during production of high-purity ultrafine modified calcium carbonate

Abstract

The invention discloses a method for treating wastewater generation during the production of high-purity ultrafine modified calcium carbonate. The method comprises the following steps: performing adjustment, flocculating precipitation, hydrolytic acidification, bio-contact oxidation and bioprecipitation treatment on the to-be-treated wastewater, performing efficient filtration, ultrafiltration andreverse osmosis filtration sequentially to obtain freshwater reused in production, and performing multi-effect evaporation on the obtained strong brine to recover the salt. After the wastewater is treated by the treatment method, the water quality of the wastewater meets the high-standard requirement, the wastewater can be reused in production and waste of water resource is avoided; and pollutants are completely degraded and treated, no discharge is realized, environmental pollution is completely eliminated, the recovered salt can be industrially reused, and the production additional value isincreased. The treatment system provided by the invention is stable in operation, can treat the wastewater generated during the production of the high-purity ultrafine modified calcium carbonate completely and comprehensively, and has positive popularization significance and remarkable application value.

Description

technical field [0001] The invention relates to the technical field of calcium carbonate production wastewater treatment, in particular to a treatment method and a treatment system for high-purity ultrafine modified calcium carbonate production wastewater. Background technique [0002] In the production of calcium carbonate, the wastewater comes from domestic sewage, kiln gas washing wastewater and plate and frame filter press wastewater, and the production of kiln gas washing wastewater and plate and frame filter press wastewater is very large, and because the kiln gas washing wastewater is acidic, the plate and frame Press filtration wastewater is alkaline and contains a large amount of calcium and magnesium ions. Direct discharge not only pollutes the environment, but also causes serious waste of water resources. Therefore, it must be treated and reused. [0003] For the treatment of calcium carbonate production wastewater, the domestic sewage can be treated separately by...

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Problems solved by technology

[0002] In the production of calcium carbonate, the wastewater comes from domestic sewage, kiln gas washing wastewater and plate and frame filter press wastewater, and the production of kiln gas washing wastewater and plate and frame filter press wastewater is very large, and because the kiln gas washing wastewater is acidic, the plate and frame Filter press wastewater is alkaline and contains a large amount of calcium and magnesium ions. Direct discharge not only pollutes the environment, but also causes serious waste of water resources. Therefore, it must be treated and reused.

[0003] For the treatment of calcium carbonate production wastewater, the domestic sewage can be treated separately by the conventional domestic sewage treatment system; for the kiln gas washing wastewater and the plate and frame filter press wastewater, the kiln gas washing wastewater and the plate and frame filter press wastewater are usually mixed first, and then The treatment method of sedimentation in the sedimentation tank is to use the sediment as a building material, and the pH value of the supernatant is controlled at 6-8. Although it basically meets the pH value requirements in the discharge standard, due to the Oily substances and macromolecular organic substances cannot be removed, so that they cannot meet the requirements of wastewater discharge standards for other pollutants, and reuse production will also affect the production and quality of calcium carbonate due to oily substances and macromolecular organic substances. production hazard

[0004] The production of high-purity ultra-fine modified calcium carbonate, due to its special process and calcium carbonate properties, causes its production wastewater to contain about 0.16% of polyol organic matter, about 0.8% of sodium stearate, and And about 2% of calcium carbonate microcrystals and other pollutants, which is not conducive to the treatment and reuse of wastewater

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