Integrated combination device for physicochemical treatment of black liquid

Abstract

The invention discloses a combination device for physicochemical treatment of black liquid. The combination device comprises chemical storage tanks, chemical feed tanks, an oxygenolysis bin, a coagulation polycondensation bin, a dehydration separator bin, a turning slag extractor bin and a clear water recycle bin all integrated. The oxygenolysis bin is connected with the coagulation polycondensation bin, a set of chemical storage tank and chemical feed tank are arranged at upper part, the oxygenolysis bin and coagulation polycondensation bin are be provided with a separating plates, with the lower parts being communicated, each bin is divided into two chambers, each chamber is provided with a set of stirring device, and the liquid is fed and discharged at the upper part. The coagulation polycondensation bin is connected with the dehydration separator bin, which is provided with a micro-filtering dehydrator at the upper part and with a water tank water pipe communicating with the clear water recycle bin at the lower part, the upper dehydrator communicates with the turning slag extractor bin, which is provided with a moving board for sludge discharge and connected with the clear water recycle bin, and a clear water bin is provided with a sloped tube sediment layer for sedimentation to obtain clear water and discharge into a water storage tank. The combination device adopts a black liquid lifting pump and chemical liquid, to rapidly decompose nano-lignin and perform polycondensation to obtain bulk-shaped solid substance with no viscosity, high dehydration speed and efficiency, chemical oxygen consumption removal up to 95% and chroma removal up to 98%. The combination device has reasonable design, high device integration level, small floor area, energy saving and environment friendliness, and can be matched with alkali recovery process to trap diluted black liquid for physicochemical treatment, and realize zero discharge of black liquid.

Description

technical field [0001] The invention relates to water treatment equipment, in particular to physical and chemical treatment equipment for papermaking black liquor, especially papermaking black liquor treatment equipment. Background technique [0002] For a long time, people have used a variety of processing technologies for papermaking black liquor, and have achieved huge environmental and social benefits. Existing physical and chemical black liquor treatment equipment usually uses black liquor to float the lignin sludge through oxidation reaction, and then discharges the sludge into the slag ditch with a mud scraper. The sludge produced by the existing equipment has a high moisture content, and The residual liquid after oxidation of the black liquor is acidic, and needs to be neutralized and decolorized again, resulting in high chemical consumption, poor effluent quality, and low operating efficiency. The traditional acid analysis lignin method is also difficult to dehydra...

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Problems solved by technology

[0003] At present, the most commonly used black liquor treatment method is: the "combustion method alkali recovery" process is the main method, which is also a trend formed under my country's macro-control policy for the paper industry. The "combustion method alkali recovery" process is especially suitable for The alkali recovery treatment of wood pulp and papermaking black liquor, and the alkali recovery treatment of wheat straw pulp papermaking black liquor, because of the high silicon content and high viscosity of wheat straw pulp black liquor, the extraction rate of high concentration black liquor is low, and the pulp The residual black liquor needs to be diluted and extracted by adding water. Therefore, a large amount of low-concentration dilute black liquor cannot be recovered by alkali and discharged into the middle water, which increases the difficulty and investment of middle water treatment.

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