Method for improving hydrogen peroxide bleaching efficiency of paper pulp

A technology of hydrogen peroxide and pulp, applied in pulp bleaching, chemical/chemical mechanical pulp, etc., can solve the problems of low hydrogen peroxide bleaching efficiency, achieve the effect of improving bleaching effect, maintaining physical strength, and improving whiteness

Inactive Publication Date: 2012-02-29
MCC PAPER YINHE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The invention aims at the problem of low hydrogen peroxide bleaching efficiency of chemical mechanical pulp and waste paper deinked pulp, and provides a new method for improving hydrogen peroxide bleaching efficiency and pulp whiteness

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] The unbleached pulp of poplar PRC-APMP after the first stage of pulping, the brightness is 54% ISO, is put in a polyethylene plastic bag and placed in a water bath for hydrogen peroxide bleaching, and the bleaching chemicals added are as follows: urea 10kg / ton Pulp, DTPA 1.5kg / ton pulp, H 2 o 2 50kg / ton pulp, sodium hydroxide 25kg / ton pulp, sodium silicate 30kg / ton pulp, pulp concentration 30wt%, bleaching temperature 85°C, bleaching time 2.0h, pulp brightness after bleaching 82%ISO. When no urea is added in the bleaching process and other medicines are the same, the whiteness of the obtained bleached pulp is 80% ISO. The physical strength of the bleached pulp obtained after adding urea during bleaching was basically the same as that of the control pulp without adding urea.

Embodiment 2

[0017] Poplar CTMP unbleached pulp, whiteness 52% ISO, put in a polyethylene plastic bag and put it in a water bath for hydrogen peroxide bleaching, the bleaching chemicals added are as follows: urea 15kg / ton pulp, EDTA 5kg / ton pulp, H 2 o 2 40kg / ton of pulp, 20kg / ton of sodium hydroxide, 20kg / ton of sodium silicate, pulp concentration 25wt%, bleaching temperature 80°C, bleaching time 2.0h, bleached pulp brightness 79%ISO. When no urea is added in the bleaching process and other chemicals are the same, the whiteness of the obtained bleached pulp is 76.8% ISO. The physical strength of the bleached pulp obtained after adding urea during bleaching is basically the same as that of the control pulp without adding urea.

Embodiment 3

[0019]Pine CTMP unbleached pulp, whiteness 48% ISO, put in a polyethylene plastic bag and put it in a water bath for hydrogen peroxide bleaching, the bleaching chemicals added are as follows: urea 15kg / ton pulp, EDTA 5kg / ton pulp, H 2 o 2 50kg / ton pulp, sodium hydroxide 24kg / ton pulp, sodium silicate 18kg / ton pulp, pulp concentration 25wt%, bleaching temperature 75°C, bleaching time 2.0h, pulp brightness after bleaching 75% ISO. When no urea is added in the bleaching process and other medicines are the same, the whiteness of the obtained bleached pulp is 73% ISO. The physical strength of the bleached pulp obtained after adding urea during bleaching was basically the same as that of the control pulp without adding urea.

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Abstract

The invention discloses a method for improving hydrogen peroxide bleaching efficiency of paper pulp, and belongs to the technical field of pulp preparation and papermaking. According to the method, a urea active agent and a chelating agent are simultaneously added in the alkali hydrogen peroxide bleaching process of chemical mechanical pulp or waste paper ink removed pulp, the consumption of the urea is 2.0 to 20 kilograms per ton of pulp, the consumption of ethylene diamine tetraacetic acid (EDTA) or diethylenetriamine pentaacetic acid (DTPA) serving as the chelating agent is 1 to 10 kilograms per ton of pulp, and hydrogen peroxide, sodium hydroxide and sodium silicate are simultaneously added during bleaching. In the alkali hydrogen peroxide bleaching process of the paper pulp, the urea serving as the active agent is added at the same time of adding the chelating agent, so that the hydrogen peroxide bleaching efficiency can be improved. Compared with a method without adding the urea serving as the active agent during bleaching, the method has the advantages that: the whiteness of the bleached pulp is obviously improved after the urea is added during bleaching, and the physical strength of the bleached pulp is basically as same as that of the pulp when the urea is not added.

Description

technical field [0001] The invention relates to a pulp bleaching technology, in particular to a method for improving the hydrogen peroxide bleaching efficiency of chemical mechanical pulp and waste paper deinked pulp, and belongs to the technical field of pulp and papermaking. Background technique [0002] High-yield pulp such as chemical mechanical pulp is used more and more in paper production due to its high yield, low production cost, and high opacity, bulk, and stiffness. In addition, in order to save raw materials, waste paper deinking pulp is used more and more. At present, the bleaching process of high-yield pulp such as chemical mechanical pulp and deinked pulp mainly adopts hydrogen peroxide bleaching, and sodium hydroxide, sodium silicate, etc. should be added in the hydrogen peroxide bleaching process at the same time, so that the bleaching can be carried out under alkaline conditions. In the pulp hydrogen peroxide bleaching process, in order to achieve a higher...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21C9/16D21C9/10D21H11/02
Inventor 李宗全闫成珉曾金枝田中粟胡惠仁李翠张小丽耿金亮
Owner MCC PAPER YINHE
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