A kind of bleaching method of waste paper pulp

A technology for deinking pulp and pulp of waste paper, applied in pulp bleaching, adding inorganic compounds, secondary cellulose fibers, etc. Paper fiber loses papermaking ability and other problems, and achieves the effect of reducing consumption, reducing invalid decomposition and reducing production cost

Inactive Publication Date: 2015-10-28
SOUTH CHINA UNIV OF TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] After the raw plant fiber passes through the pulping and papermaking process, the quality decay phenomenon occurs, which is manifested in the decrease of fiber swelling performance, fiber strength and paper physical properties, and this decay gradually deteriorates in the subsequent fiber recycling process , and even make the waste paper fiber lose the ability to make paper

Method used

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  • A kind of bleaching method of waste paper pulp
  • A kind of bleaching method of waste paper pulp
  • A kind of bleaching method of waste paper pulp

Examples

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Embodiment 1

[0028] In this embodiment, after the waste newsprint (ONP) is deinked by alkali, the whiteness is 55.2%ISO, and the following steps are adopted to carry out the bleaching method:

[0029] (1) Add H to waste paper deinking pulp 2 SO 4 and NaHSO 3After acidifying pretreatment, directly add diethyltriaminepentaacetic acid (DTPA) without washing to carry out chelation pretreatment;

[0030] Adding H to the waste paper deinking pulp 2 SO 4 and NaHSO 3 Carry out acidification pretreatment, specifically:

[0031] Control slurry concentration is 5wt%, H 2 SO 4 The dosage is 1.5wt% of the dry pulp of waste paper deinking pulp, NaHSO 3 The dosage is 1%, the pretreatment temperature is 65°C, and the pretreatment time is 15min;

[0032] The chelation pretreatment is specifically:

[0033] The pulp concentration was controlled at 5wt%, the amount of diethyltriaminepentaacetic acid (DTPA) was 0.5wt% of the dry pulp of waste paper deinked pulp, the pretreatment temperature was 65°C...

Embodiment 2

[0043] In this embodiment, after the waste newsprint (ONP) is deinked by alkali, the whiteness is 55.2%ISO, and the following steps are adopted to carry out the bleaching method:

[0044] (1) Add H to waste paper deinking pulp 2 SO 4 and NaHSO 3 After acidifying pretreatment, directly add diethyltriaminepentaacetic acid (DTPA) without washing to carry out chelation pretreatment;

[0045] Adding H to the waste paper deinking pulp 2 SO 4 and NaHSO 3 Carry out acidification pretreatment, specifically:

[0046] Control slurry concentration is 8wt%, H 2 SO 4 The dosage is 2.0wt% of the dry pulp of waste paper deinking pulp, NaHSO 3 The dosage is 1.5%, the pretreatment temperature is 75°C, and the pretreatment time is 25min;

[0047] The chelation pretreatment is specifically:

[0048] The pulp concentration was controlled at 8wt%, the amount of diethyltriaminepentaacetic acid (DTPA) was 0.7wt% of the dry pulp of waste paper deinked pulp, the pretreatment temperature was 7...

Embodiment 3

[0058] In this embodiment, after the waste newsprint (ONP) is deinked by alkali, the whiteness is 55.2%ISO, and the following steps are adopted to carry out the bleaching method:

[0059] (1) Add H to waste paper deinking pulp 2 SO 4 and NaHSO 3 After acidifying pretreatment, directly add diethyltriaminepentaacetic acid (DTPA) without washing to carry out chelation pretreatment;

[0060] Adding H to the waste paper deinking pulp 2 SO 4 and NaHSO 3 Carry out acidification pretreatment, specifically:

[0061] Control slurry concentration is 5wt%, H 2 SO 4 The dosage is 2.0wt% of the dry pulp of waste paper deinking pulp, NaHSO 3 The dosage is 1%, the pretreatment temperature is 70°C, and the pretreatment time is 20min;

[0062] The chelation pretreatment is specifically:

[0063] The pulp concentration was controlled at 5wt%, the amount of diethyltriaminepentaacetic acid (DTPA) was 0.6wt% of the dry pulp of waste paper deinked pulp, the pretreatment temperature was 70°...

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Abstract

The invention discloses a method for bleaching waste paper pulp. The method comprises the following steps of: (1) adding H2SO4 and NaHSO3 in deinked waste paper pulp to implement acidification pretreatment; and without washing, directly adding diethyl pentetic acid (DTPA) to implement chelation pretreatment; (2) washing the deinked waste paper pulp treated in step (1) and implementing sodium borohydride pretreatment; and (3) washing the deinked waste paper pulp treated in step (2), adding an acid-base buffering agent, implementing hydrogen peroxide bleaching, and washing, thereby obtaining the bleached waste paper pulp. Under a short-process bleaching technology condition, the bleaching property of the paper pulp is improved, the strength property of the paper pulp is enhanced, the problem that the strength property of waste paper fibers degrades in the traditional bleaching process is solved, the reuse times of the waste paper fibers are increased, and the resource and environment problems hampering the improvement of Chinese paper manufacturing industry can be solved.

Description

technical field [0001] The invention relates to the technical field of pulping and papermaking technology, in particular to a method for bleaching waste paper pulp. Background technique [0002] With the need to protect forest resources and develop a low-carbon economy, the recycling of waste paper fibers has attracted the attention of countries all over the world. The rapid growth of waste paper utilization has become an important development trend of the world paper industry. Now the recovery rate of waste paper can be as high as 50%, among which the recovery rate of waste cardboard paper can reach more than 80%, and the recovery rate of waste newsprint can reach more than 70%. In the past 30 years, the consumption of waste paper in the world has increased sharply. About 30 million tons increased to 195 million tons in 2006, and the proportion of waste paper pulp in papermaking pulp in my country increased from 28.1% in 1990 to 68.2% in 2011. The recycling of waste paper ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D21C9/16D21H11/14D21H17/64
Inventor 万金泉孟庆林王艳马邕文黄明智陈杨梅
Owner SOUTH CHINA UNIV OF TECH
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