Improved P-RC APMP (preconditioning-refining chemical alkaline peroxide mechanical pulp) new flow path

Abstract

The invention provides an improved P-RC APMP (preconditioning-refining chemical alkaline peroxide mechanical pulp) pulping new flow path, which is characterized in that three or four in-series double helix press masters are added behind a conventional P-RC APMP flow path bleaching tower to extract a bleaching waste liquid, the gross extraction efficiency of the waste liquid is 80-95%, the improved P-RC APMP pulping new flow path is small in water consumption when the waste liquid is extracted, the extracted waste liquid is high in solid content, within the range of 4.0-8.0%, and the extracted waste liquid is processed by means of alkali recovery, so that the steam use level when the waste liquid is concentrated by means of alkali recovery can be reduced, the washing load of the pulp at a follow-up washing workshop section can be reduced, and the negative influence of anionic trash in the pulp to a wet part of a paper section paper machine can be further reduced simultaneously.

Description

1. Technical field: [0001] The invention relates to a new improved P-RC APMP pulping process. 2. Background technology: [0002] P-RC APMP is a classic pulping process in chemical mechanical pulp. The P-RC APMP pulping process is as follows: wood chips with a length of 15-20 mm, a thickness of 3-5 mm, and a width of less than 10 mm are washed with water to remove sediment; The screw dehydrator makes the dryness of the wood chips reach 30-40%; the wood chips are extruded into wood filaments by an extrusion tearing machine with a compression ratio of 1:4.0; the extruded wood chips are impregnated with chelating agent (DTPA), sulfuric acid Magnesium, sodium silicate, and alkaline hydrogen peroxide solution accounting for 20-40% of the total consumption, enter the reaction chamber for 30-60 minutes of reaction; after the reaction, the slurry is subjected to a high-concentration refining at a concentration of 35-40%; Then enter the high-concentration mixer and mix with alkaline ...

AI Technical Summary

Problems solved by technology

After the bleaching waste liquid produced in the reaction chamber after the first stage of immersion and the bleaching tower for the second immersion enters the 3-6% low-concentration submergence tank, the concentration is diluted, resulting in an overload of the washing load of the multi-disc pulp washer, which is harmful to the environment. The washing of the slurry is not thorough, and a large amount of anionic garbage remains in the slurry

And these negatively charged polygalacturonic acid, lignin macromolecules and dispersed colloidal particles of the extract will enter the papermaking system with the pulp, and can accumulate in the white water system of the paper machine, reducing the efficiency of retention and drainage aids. Increase the amount of anionic garbage collector in the wet end system, which will bring instability to the operation of the wet end

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