Black liquor recovery agent for pulp making process

Abstract

The invention relates to a black liquor reuse agent used in the pulp manufacturing process, and belongs to the technical field of papermaking methods. The weight ratio of each component in this black liquor reuse agent is: sodium sulfite 28-32, sodium aluminate 8-12, sodium phosphate 8-12, aluminum sulfate 8-12, copper sulfate with a concentration of 95% 8-12, Ethylene glycol 8-12, each component is mixed evenly in proportion. The black liquor reuse agent used in the pulp manufacturing process proposed by the present invention makes all the black liquor reused, reduces the environmental pollution in the papermaking process, and has good social benefits; the black liquor in the cooking process can be reused. The black liquor does not need to add any additives, and its cost is low; the organic matter in the black liquor, such as caustic soda, soda sulfide, etc., can save the amount of alkali after repeated use of the black liquor, and save the alkali recovery process in the pulping process, reuse The black liquor replaces the clear water in the pulp cooking process, reducing production costs; the cellulose and hemicellulose in the black liquor can be recycled.

Description

technical field [0001] The invention relates to a black liquor reuse agent used in the pulp manufacturing process, and belongs to the technical field of papermaking methods. Background technique [0002] Papermaking industrial wastewater is a serious source of water pollution worldwide, and the pollution of papermaking industrial wastewater in my country is even more serious. Both the wastewater discharge per unit product and the pollutant content are much higher than those in industrialized countries. Moreover, the organic pollutants (in terms of COD) in the sewage discharged by my country's papermaking industry account for 42% of the total COD in the national industrial sewage, ranking first among all kinds of industrial sewage, and the sewage discharge accounts for 10% of the total industrial wastewater discharge in the country. 11%. [0003] The biggest source of pollution in paper mills comes from the black liquor in the cooking process, which has a strong diffusion abi...

AI Technical Summary

Problems solved by technology

Most of the black liquor is aerobic substances. If it is allowed to be discharged into the river, it will consume a large amount of dissolved oxygen in the water, causing serious pollution and directly endangering the living environment of human beings.

For this reason, the state closed tens of thousands of small and medium-sized paper mills, resulting in a large number of laid-off workers and no livelihood.

In order to maintain their survival, pulp and paper companies need to spend huge sums of money on alkali recovery of the main pollutant "black liquor" produced in the pulping process, but the cost is huge, which greatly increases the cost of paper

Generally, small and medium-sized enterprises are forced to stop production due to capital constraints, and large-scale enterprise alkali recovery systems also affect corporate profits due to large equipment investment and high operating costs.