Process for treating pulp black liquor by using viscose wastewater

Abstract

The invention belongs to the field of black liquor treatment processes in the pulp industry, and particularly relates to a process for treating pulp black liquor by using viscose wastewater. The process comprises the following steps: carrying out shoving on black liquor twice by a black liquor shoving machine to obtain dilute black liquor, then introducing the dilute black liquor into a first sedimentation tank, then sequentially introducing the dilute black liquor into a first regulating tank, a multi-bucket sedimentation tank, a second regulating tank, a second sedimentation tank, a third sedimentation tank and a reactor, and finally introducing the dilute black liquor into a sludge collecting tank after the dilute black liquor is settled in a final sedimentation tank. The viscose wastewater is added into the first adjusting tank, and the fiber wastewater is added into the second adjusting tank, so that the purpose of treating waste with waste is realized. Then a polyacrylamide solution is added into the final sedimentation tank, and the final sludge is pumped into a sludge collection tank through a pump under the flocculation action of the polyacrylamide solution. According to the process disclosed by the invention, the COD of the pulp black liquor can be reduced to the emission standard, and the generated precipitate can be incinerated through a boiler, so that the secondary pollution of the precipitate is eliminated.

Description

technical field [0001] The invention belongs to the field of black liquor treatment technology in the pulp industry, and in particular relates to a technology for treating pulp black liquor with viscose wastewater. Background technique [0002] In the production process of pulp, a large amount of black liquor is produced after the linters and lye are cooked. After being processed by the squeezer twice, the pulp is retained and sent to the washing tank. The first dilute black liquor needs to be poured in the white water tank and The circulation of the washing tank reaches more than 35000 COD, and the sodium carbonate content is more than 500g / L, which is difficult to deal with and restricts the development of the industry. The viscose industry also has problems in the treatment of acidic wastewater and alkaline wastewater. In the prior art, it is often necessary to add a large amount of reagents in the treatment process of black liquor, so that the treatment cost of black li...

AI Technical Summary

Problems solved by technology

In the prior art, in the treatment process of black liquor, it is often necessary to add a large amount of reagents, so that the treatment cost of black liquor is extremely high, and the treatment of waste water and fiber waste water in the viscose industry also requires a lot of cost, which is not conducive to Energy conservation and environmental protection, how to effectively solve the pollution problem and reduce the processing cost of enterprises has become a difficult problem at present.