Flotation process after bio-enzyme deinking

Abstract

The invention discloses a post-floatation process of deinking a bio-enzyme. The process comprises the following steps: repulping; flotation in the first section; dehydrating and washing; flotation in the second section; and washing. The process is characterized in that an environment-friendly floatation deinking assistant consisting of 45-55% of fatty acid methyl ester sulfonate, 35-45% of polyoxyethylene sorbitan fatty acid ester and 10-15% of propylene glycol is added in the step of flotation in the second section. Through the manner, the process disclosed by the invention has the advantages that the washing function in floatation to deink is improved while the bubbling amount of the flotation system and the effective discharge amount are ensured, so that a good deinking effect is realized and the production load is reduced. Meanwhile, more micro printing ink particles are removed in multiple disc concentration and sieving and purifhing stages to prevent the micro printing ink particles from agglomerating in a subsequent section step, so that the product quality is enhanced.

Description

technical field [0001] The invention relates to the technical field of papermaking, in particular to a flotation process after biological enzyme deinking. Background technique [0002] In the deinking process of waste paper recycling, biological enzymes are widely used and generally adopt the method of flotation for deinking. Biological enzymes and deinking aids are used together. Biological enzymes separate ink particles during the pulping process. Deinking aids are generally surfactant components. The amount of discharge, thus bringing out the ink particles. Most of the existing biological enzyme deinking processes use the method of directly adding deinking aids to the pulping section, but with the extension of the process, the deinking aids will be lost after flotation, purification, dehydration and other processes in the previous stage. Severe, resulting in a decrease in deinking efficiency in the latter stage of flotation. Existing bio-enzyme flotation deinking lines...

AI Technical Summary

Problems solved by technology

Most of the existing biological enzyme deinking processes use the method of directly adding deinking aids to the pulping section, but with the extension of the process, the deinking aids will be lost after flotation, purification, dehydration and other processes in the previous stage. Severe, resulting in lower flotation deinking efficiency

Existing bio-enzyme flotation deinking lines have two or three stages of flotation. Generally, a certain amount of deinking aid is added to the second or third stage of flotation to reduce the flotation, purification, and dehydration in the previous stage. The loss of deinking aids and the reduction of foaming discharge caused by other processes, but the existing process generally adds a large amount of non-degradable surfactant deinking aids in the post-flotation process

Since some large ink particles are screened or excluded in the previous stage of flotation, the smaller ink particles account for a large part in the post-flotation process, and it is difficult for these smaller ink particles to pass through the traditional method of adding a large amount of surfactants. Flotation of deinking aids is completely eliminated, and the entire system needs to be discharged through auxiliary processes such as concentration and washing to achieve the purpose of purification; moreover, a large number of non-degradable surfactant deinking aids will not only pollute the environment, but also cause Difficulty in defoaming, low liquid level in flotation device, decreased slurry passing rate, increased production load, which is not conducive to long-term and effective production

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