A kind of method of pulp metal ion removal and bleaching

A metal ion, pulp technology, applied in pulp bleaching, cellulose pulp post-processing, papermaking, etc., to achieve the effect of reducing Fe content, reducing long-term cumulative effect toxicity, and easy to obtain

Inactive Publication Date: 2011-12-07
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The metal ion removal process forms a new pollution-free bleaching process with peracetic acid and hydrogen peroxide, and no related technical reports have been seen so far

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] In pulp with a concentration of 5% by weight, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 The total dosage is 0.3%, the dosage of EDTA is 0.2%, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 The weight ratio of the amount used is 8:1. When pulp bleaching is performed to remove metal ions, the temperature of the treatment is controlled at 60° C. for 1.0 h. When the pulp is pretreated to remove metal ions, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 Mix for 0.5h, then add EDTA directly to continue the reaction until the specified time. Then carry out follow-up non-polluting bleaching treatment, in the peracetic acid bleaching section, the peracetic acid consumption is 1.5%, the DTPA consumption is 0.10%, the pulp concentration is 10% during processing, the temperature is 60 ° C, and the time is 1.5 hours; in the hydrogen peroxide bleaching section, hydrogen The amount of sodium oxide is 2.0%, the amount of sodium silicate is 1.5%, the amount of hydrogen peroxide is 1.0%, the amount of magne...

Embodiment 2

[0019] In pulp with a concentration of 5% by weight, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 The total dosage is 0.2%, the dosage of EDTA is 0.1%, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 The weight ratio of the amount used is 7:1. When pulp bleaching is performed to remove metal ions, the temperature of the treatment is controlled at 55°C and the time is 0.75h. When the pulp is pretreated to remove metal ions, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 Mix for 0.5h, then add EDTA directly to continue the reaction until the specified time. Then carry out follow-up pollution-free bleaching treatment, in the peracetic acid bleaching section, the peracetic acid consumption is 1.4%, the DTPA consumption is 0.10%, the pulp concentration is 10% during processing, the temperature is 55 ° C, and the time is 1.4 hours; in the hydrogen peroxide bleaching section, hydrogen The amount of sodium oxide is 1.8%, the amount of sodium silicate is 1.4%, the amount of hydrogen peroxide is 0.9%, the amou...

Embodiment 3

[0021] In pulp with a concentration of 5% by weight, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 The total dosage is 0.4%, the dosage of EDTA is 0.3%, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 The weight ratio of the amount used is 9:1. When pulp bleaching is performed to remove metal ions, the temperature of the treatment is controlled at 65° C. for 1.25 hours. When the pulp is pretreated to remove metal ions, Mg(CH 3 COO) 2 with Ca(CH 3 COO) 2 Mix for 0.5h, then add EDTA directly to continue the reaction until the specified time. Then carry out follow-up pollution-free bleaching treatment, in the peracetic acid bleaching section, the peracetic acid consumption is 1.6%, the DTPA consumption is 0.12%, the pulp concentration is 10% during processing, the temperature is 65 ° C, and the time is 1.6 hours; in the hydrogen peroxide bleaching section, hydrogen The consumption of sodium oxide is 2.2%, the consumption of sodium silicate is 1.6%, the consumption of hydrogen peroxide is 1.1%...

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PUM

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Abstract

A method for removing and bleaching pulp metal ions. The invention relates to a paper pulp metal ion removal process and its application in bleaching, belonging to the technical field of papermaking. The present invention mainly comprises the following steps: 1. paper pulp is carried out to remove metal ion pretreatment, promptly under the condition that Mg(CH3COO) 2, Ca(CH3COO) 2 and EDTA (disodium ethylenediaminetetraacetic acid) exist, oxygen desulfurization Bleaching pretreatment of salt pulp; ② Subsequent non-polluting bleaching, the pulp after the above-mentioned metal ion removal pretreatment is then subjected to a subsequent two-stage bleaching treatment consisting of a peracetic acid bleaching section and a hydrogen peroxide bleaching section. The invention is simple and easy to implement, and the effect is remarkable; the removal rate of metal ions is high, and the removal rate of Mn is 80.50%. Compared with conventional EDTA chelating treatment, the strength performance of pulp can be improved; Mg(CH3COO)2, Ca(CH3COO)2 can replace 60% of EDTA, and the cumulative effect toxicity of conventional chelating agents can be significantly reduced.

Description

technical field [0001] The invention relates to an oxygen-containing pulp bleaching process without pollution, in particular to a pulp metal ion removal process and its application in bleaching, and belongs to the technical field of papermaking. Background technique [0002] Due to the serious pollution of pulp chlorine bleaching and the high toxicity of wastewater, the pollution-free oxygen bleaching has been paid more and more attention and research. [0003] Hydrogen peroxide, peroxyacid, ozone, etc. are often used as bleaching agents in the oxygen bleaching process. When bleaching pulp with oxygen-containing bleaching agent, the metal ions in the pulp seriously affect the bleaching effect. Metal ions make the oxygen-containing bleaching agent decompose effectively, and the free radicals generated in it will have a negative impact on the quality of bleached pulp. Therefore, it is often necessary to use chelating agents such as EDTA and DTPA for chelating treatment before...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D21C9/00D21C9/16
Inventor 周学飞沈云霞卢秀娟
Owner KUNMING UNIV OF SCI & TECH
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