Aluminum electrolysis flue gas wet desulphurization wastewater treatment system

Abstract

The invention discloses an aluminum electrolysis flue gas wet desulphurization wastewater treatment system. The system comprises a filtrate tank, a primary pre-sedimentation tank, a wastewater tank, aneutralization tank, a sedimentation tank, a flocculation tank, a clarification tank and an adjusting tank, and the system further comprises a primary pre-sedimentation sludge conveying pump, a clarified sludge conveying pump, a centrifugal dehydrator and an electric sludge bucket. The filtrate tank is communicated with a water outlet of a vacuum dehydrator and a top flow outlet of a thick-thin separation swirler through pipelines respectively, and the filtrate tank is connected with a spraying system of an absorption tower through a filtrate pump. The primary pre-sedimentation tank is communicated with the water outlet of the vacuum dehydrator through a pipeline. A water inlet of the primary pre-sedimentation sludge conveying pump is arranged at the bottom of the primary pre-sedimentation tank, and a water outlet of the primary pre-sedimentation sludge conveying pump is arranged in the filtrate tank. The system has the advantages that low-concentration slurry separated by the thick-thin separation swirler is subjected to desliming treatment and then returns to the absorption tower, so that the suspended matter content in gypsum slurry is reduced, the quality deterioration of gypsum absorbent slurry is prevented, and the desulfurization and defluorination efficiency of the absorption tower is ensured.

Description

Technical field: [0001] The invention relates to the fields of desulfurization and defluorination of flue gas from electrolytic aluminum, in particular to a waste water treatment system for wet desulfurization of flue gas from electrolytic aluminum electrolysis. Background technique: [0002] Due to the large amount of electrolytic aluminum flue gas, which contains low concentrations of dust, fluoride, SO 2 , CO and other pollutants, the cumulative effect of highly polluting fluorides that are not easy to degrade in the surrounding areas of electrolytic aluminum enterprises has a greater impact on the environment and biology. Limestone / gypsum wet desulfurization technology is currently the most mature and widely used technology in the world. The desulfurization process with the most achievements can also remove hydrogen fluoride and dust in flue gas while desulfurizing. It has high removal efficiency and removal agent utilization rate, wide adaptability to flue gas volume, ...

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Problems solved by technology

[0003] However, during use, the calcium salt slurry discharged from the absorption tower will return to the absorption tower through the low-concentration slurry separated by the thick-thin separation cyclone. There are too many suspended solids in it, which cannot be deslimed through the wastewater system, resulting in There are more and more suspended solids in the slurry, which affects the quality of the slurry and reduces the removal efficiency of the absorption tower

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