CN1940176A

CN1940176A - Two-sectional bleaching process of vegetable-fibre slurry

Info

Publication number: CN1940176A
Application number: CN 200610068657
Authority: CN
Inventors: 曹云峰; 李建华; 李忠正
Original assignee: HUATAI GROUP CO Ltd
Current assignee: HUATAI GROUP CO Ltd
Priority date: 2006-09-01
Filing date: 2006-09-01
Publication date: 2007-04-04

Abstract

This invention involves pulping and papermaking and textile industries in the field of pulp bleaching technology. The two main processes are as follows : DAF of the main process, chlorine dioxide to dry 0.1%-2% amount of pulp, -0.1 amount of hydrochloric acid and formaldehyde on dry 0.1%-2% amount of slurry, the slurry concentration 3%-15%; temperature of 10-90 degree C, 10-120 minutes of time, the pH of the main =1-6;P bleaching process, hydrogen peroxide to dry 0.5%-6% amount of pulp, dry sodium right amount of pulp 0.5%-5%. Sodium hydroxide to dry 0.5%-5% amount of slurry, the slurry concentration 5%-20%; temperature 10-120degreeC, Time 30-240 minutes. Effect of the invention: the invention than conventional CEH three of the bleached pulp brightness stability, high strength, bleach loss, and wastewater generated by COD, BOD and SS dropped more than 60%.

Description

Two-sectional bleaching process of vegetable-fibre slurry

Technical field: the present invention relates to the pulp bleaching technology in the industrial circles such as pulping and paper-making and weaving.

Prior art: China's association with pulp bleaching technical development is slow, especially the bleaching technology of straw pulp production is still using hypochlorite bleaching, most of H (hypochlorite) or HH (two sections of hypochlorites) driftage of adopting adopts CEH (chlorination-alkali extracting-hypochlorite) and CE individually _PH bleaching process and technology such as (chlorinations-hydrogen peroxide reinforced alkaline extracting-hypochlorite tri-stage bleaching), main hypochlorite and the elemental chlorine of adopting bleached, totally applied chlorine is up to 8-12%, the loss of not only bleaching slurry is big, brightness reversion is serious, intensity is low, and seriously polluted, bleaching effluent is not just handled and has been discharged.Now prove; contain a series of organochlorines that comprise bioxin in this type of bleaching effluent and all can cause huge harm human beings'health and environment; the chlorine bleach produced pollution is quite serious, far can not satisfy the requirement of environmental protection to organic chloride discharge capacity restriction in the bleaching effluent.And the bleaching process of international wood plant fibre slurry mainly adopts OC/DE0D, OC/DE ₀D ₁ED ₂Deng bleaching process and technology, these bleaching processes are long, and floor space is big, and investment is high.

Summary of the invention: the objective of the invention is to reduce floor space, save investment in order to shorten bleaching process; Reduce the loss of bleaching slurry, improve bleached stlck chest yield and intensity, alleviate the brightness reversion of slurry, especially reduce bleaching and pollute, and a kind of two-sectional bleaching process of vegetable-fibre slurry that proposes

The present invention adopts acid and aldehyde to activate chlorine dioxide-hydrogen peroxide post-bleach (D simultaneously to vegetable-fibre slurry _AFP) two sections bleaching processes and technology thereof, two sections main technique is as follows:

Chlorine dioxide activation: because in the ClO 2 bleaching system, chlorine dioxide, chlorite and chlorate exist simultaneously, although chlorite and chlorate have oxidation, but it does not have delignification and discoloration, cause the serious waste of chemicals, adopt acid and aldehyde to activate chlorate and chlorite simultaneously, make it in bleaching system, directly produce chlorine dioxide;

D _AFThe section main technique: chlorine dioxide is 0.1%-2% to the oven dry stock consumption, and the hydrochloric acid consumption is 0.1%-1%, and aldehyde is 0.1%-2% to the oven dry stock consumption, slurry concentration 3%-15% (mass percent); Temperature 10-90 ℃, time 10-120 minute, pH value=1-6;

P bleaching section main technique: hydrogen peroxide is 0.5%-6% to the oven dry stock consumption, and sodium metasilicate is 0.5%-5% to the oven dry stock consumption, and NaOH is 0.5%-5% to the oven dry stock consumption, slurry concentration 5%-20% (mass percent); Temperature 10-120 ℃, time 30-240 minute.

The invention effect: the present invention adopts D to vegetable-fibre slurry _FP (aldehyde activation chlorine dioxide-hydrogen peroxide bleaching) two sections bleaching processes and technologies thereof when unbleached vegetable-fibre slurry Kappa number is lower than 20, adopt D _FTwo sections bleaching technologies of P can be with the vegetable-fibre slurry bleaching to the whiteness more than 82% (ISO), realized the short-range order bleaching of element-free chlorine, more stable than the whiteness of conventional CEH tri-stage bleaching slurry, the intensity height, the bleaching loss is little, and wastewater generated by COD, BOD and SS descend more than 60%.With DQP, OC/DE ₀D, OC/DE ₀D ₁ED ₂Compare Deng bleaching process, flow process is simple, reduced investment, and operating cost is low.

Description of drawings: accompanying drawing is a process chart of the present invention

The specific embodiment:

Embodiment 1, D _AFSection main technique condition: chlorine dioxide is 0.5% to the oven dry stock consumption, and the hydrochloric acid consumption is 0.2%, and aldehyde is 0.2% to the oven dry stock consumption, slurry concentration 8% (mass percent); 20 ℃ of temperature, 50 minutes time, pH value=3.Adopt acid and aldehyde to activate chlorate and chlorite simultaneously in this process, make it in bleaching system, directly produce chlorine dioxide.P bleaching section main technique condition: hydrogen peroxide is 1.5% to the oven dry stock consumption, and sodium metasilicate is 1.5% to the oven dry stock consumption, and NaOH is 1.5% to the oven dry stock consumption, slurry concentration 10% (mass percent); 30 ℃ of temperature, 40 minutes time.

Embodiment 2, D _AFSection main technique condition: chlorine dioxide is 2% to the oven dry stock consumption, and the hydrochloric acid consumption is 0.9%, and aldehyde is 1.8% to the oven dry stock consumption, slurry concentration 15% (mass percent); 80 ℃ of temperature, 100 minutes time, pH value=5.Adopt acid and aldehyde to activate chlorate and chlorite simultaneously in this process, make it in bleaching system, directly produce chlorine dioxide.P bleaching section main technique condition: hydrogen peroxide is 5.5% to the oven dry stock consumption, and sodium metasilicate is 4.5% to the oven dry stock consumption, and NaOH is 4.5% to the oven dry stock consumption, slurry concentration 18% (mass percent); 100 ℃ of temperature, 140 minutes time.

Claims

1, a kind of two-sectional bleaching process of vegetable-fibre slurry is characterized in that acid and aldehyde activate chlorine dioxide (D simultaneously _AF) the segment process condition: chlorine dioxide is 0.1%-2% to the oven dry stock consumption, and the hydrochloric acid consumption is 0.1%-1%, and aldehyde is 0.1%-2% to the oven dry stock consumption, slurry concentration mass percent 3%-15%; Temperature 10-90 ℃, time 10-120 minute, pH value=1-6; Hydrogen peroxide post-bleach (P) segment process condition: to the oven dry stock consumption is 0.5%-6%, and sodium metasilicate is 0.5%-5% to the oven dry stock consumption, and NaOH is 0.5%-5% to the oven dry stock consumption, slurry concentration mass percent 5%-20%; Temperature 10-120 ℃, time 30-240 minute.