CN103726376A

CN103726376A - Intermittent low-temperature quick pulping process for broad-leaf wood

Info

Publication number: CN103726376A
Application number: CN201310743558.4A
Authority: CN
Inventors: 张军; 李清阳
Original assignee: MCC Meili Paper Industry Co Ltd
Current assignee: MCC Meili Paper Industry Co Ltd
Priority date: 2013-12-30
Filing date: 2013-12-30
Publication date: 2014-04-16

Abstract

The invention relates to an intermittent low-temperature quick pulping process for broad-leaf wood. The process comprises cooking and bleaching, wherein the cooking comprises the steps of adding the preset cooking liquid into a spiral pre-soaking device and sufficiently mixing with broad-leaf wood pieces, putting into a spherical boiler, and performing idling, heating, heat preservation and blowing before the next process. According to the process provided by the invention, by controlling the technical indexes such as cooking alkali dosage of 20%, vulcanization amount of 18%, penetrant dosage of 0.5%, cooling liquid ratio of 1:(2.5-2.8), cooling liquid temperature of 80-85 DEG C and cooking curve in which the idling lasts for 30 minutes before heating and the temperature is quickly increased until the pressure is 0.5MPa within 90 minutes and the heat preservation lasts for 60 minutes before blowing, the slurry uniformity and yield are obviously improved, the cooking quality is further improved, and the dosage of chemical materials and the energy consumption are remarkably reduced.

Description

Broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique

Technical field

The present invention relates to pulping technology for paper-making field, particularly relate to a kind of broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique.

Background technology

At present, the slurrying of domestic broad-leaved wood is mostly to adopt chemical wood pulp method tradition pulping process, and its technological parameter is as follows:

Relevant boiling and bleaching technology parameter are as follows:

Boiling hardness (permanganate number): 11-14K,

The residual alkali of boiling: 5-6g/L,

Boiling unscreened yield is 45-48%,

Bleaching chlorine consumption is 7.3%,

Bleached pulp whiteness is (blue light method) 73%.

There is following technological deficiency in above-mentioned technique: 1) pulping evenness is poor, and single ball yield is low.2) digestion time reaches 4.5 hours, and boiling efficiency is low.3) boiling vapour pressure is high, and boiling temperature is up to 170 degree, and the not only boiling steam consumption is high, and large to fibre damage.4) chemical industry consumption is high, and bleached pulp whiteness is low.5) it is rear nonflammable that its black liquor enters alkali recovery, and cost is higher.

Summary of the invention

The object of the invention is to overcome above-mentioned defect of the prior art, a kind of broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique is provided.

The technical scheme taked is for achieving the above object:

A kind of broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique, its technical process comprises boiling and bleaching, it is characterized in that: described boiling refers to the cooking liquor configuring is joined after fully mixing with broad-leaved wood chip in spiral Presoaker and packs rotary spherical digester into, through dry run, intensification, be incubated and spurt after enter lower road program;

Described boiling parameter is:

1) boiling alkali charge is 20%,

2) sulphidity consumption 18%,

3) bleeding agent consumption 0.5%,

4) cooking liquor is than 1:2.5-2.8,

5) cooking liquor temperature 80-85 ℃,

6) boiling curve: first dally after 30 minutes before heating up, can heat up, be warming up to rapidly 0.6MPa in 90 minutes, spurt after being then incubated 60 minutes.

Described bleaching adopts CEH tri-stage bleaching method.

Above-mentioned bleeding agent is the efficient digesting assistant of CL-3 type, it is the pulping and digesting special assistant of being produced by Baoji grand papermaking material of prosperity Co., Ltd, by anthraquinone, react and form with high molecular polymer and multi-functional anion active compound, base main feature is to improve thickness slurry interest rate, pulp brightness and fibre strength, improve the scourability of paper pulp, saves material, shorten digestion time, reduce production costs.

Broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique of the present invention has following technical advantage:

1) alkali charge is low, and liquor ratio is little.

2) pulping evenness obviously improves, and single ball yield obviously improves, and unscreened yield can reach 50-52%.

3) effectively digestion time is only 2.5 hours, than traditional cooking process, shortens 2.2 hours.

4) the high vapour pressure of boiling is only 0.6MPa, and boiling temperature is only 160 degree.

5) chemical industry consumption is low, and bleached pulp whiteness can reach more than 76%, and bleached pulp magma (bleached pulp is without making beating) weight in wet base can reach 2-2.5g.

In sum, broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique material digesting technoloy of the present invention, slurry evenness and pulping rate have clear improvement, and cooking quality is further enhanced, and chemical materials use amount and every energy consumption obviously decline simultaneously.The present invention can effectively be alleviated environmental protection pressure, alleviates alkali and reclaims load, and be easy to adjust and do not affect the stable of system, has certain promotional value.

Specific embodiments

Leaf wood is cut off, and the procedure for preparation of removal of impurities, dedusting is with in prior art.Then the cooking liquor configuring is joined after fully mixing with broad-leaved wood chip in spiral Presoaker and pack rotary spherical digester into, through dry run, intensification, be incubated and spurt after enter by single-screw press master extruding and extract black liquor, the slurry squeezing out is delivered to 2 vacuum pulp washing machines that extract workshop section and is carried out countercurrent washing and extract black liquor.Black liquor send between alkali recovery vehicle and processes.

In the present invention, digesting technoloy is as follows:

During cooking liquor configuration

1, according to using boiling alkali charge, liquor ratio, formulation cooking liquor concentration and volume.

2, determine after concentration and volume, use white liquid and the outsourcing caustic soda of alkali remanufacture to prepare by a certain percentage.

3, bleeding agent and cooking catalyst add according to consumption as requested.

4, cooking liquor temperature must be heated to 80-85 degree.

5, the cooking liquor configuring fills ball after adding spiral Presoaker and broad-leaved wood chip uniform stirring.

6, heat up after necessary idle running before, can heat up.According to heating-up time, vapour pressure, heat up rapidly.

7, utilize CEH tri-stage bleaching, its bleached pulp whiteness can reach more than 75%, and unscreened yield is 50-52%, and bleached pulp weight in wet base is that 2-2.5g(is without making beating).

Claims

1. a broad-leaved wood batch (-type) low temperature quickly preparing cement paste technique, its technical process comprises boiling and bleaching, it is characterized in that: described boiling refers to the cooking liquor configuring is joined after fully mixing with broad-leaved wood chip in spiral Presoaker and packs rotary spherical digester into, through dry run, intensification, be incubated and spurt after enter lower road program;