CN105200838A - Method of preparing bamboo willow bleaching pulp - Google Patents

Abstract

The invention discloses a method of preparing bamboo willow bleaching pulp. The method comprises the steps of cutting bamboo willow into segments, sending the segments into a digester, adding 2.5-3% potassium hydroxide and 0.2-0.3% anthraquinone, digesting the segments for 40-50 min at the temperature below 90-95 DEG C, sending digested materials into a double-screw pulp grinding machine, adding 2.2-2.5% PAM, 1-1.2% EDTA and 2.5-3% H2O2, controlling the outlet temperature at 100-105 DEG C, making the discharged materials react for 50-60 min, washing the materials, sending the materials into the double-screw pulp grinding machine again, adding 2.2-2.5% sodium tripolyphosphate, 1-1.2% magnesium sulfate and 5-5.5% H2O2, controlling the outlet temperature at 100-105 DEG C, making the discharged materials react for 50-60 min, washing the materials and obtaining the bamboo willow bleaching pulp. By the adoption of the method, the pulping yield is high, the BOD/COD ratio of sewage is high, and biodegradation is easy.

Description

A kind of method preparing bamboo willow bleached pulp

Technical field

The present invention relates to a kind of method preparing bamboo willow bleached pulp.

Background technology

Bamboo willow is new hybridization of willows kind, and because its fast grow is good, high dense planting, strong adaptability, material is excellent, so the whole nation has large area to introduce a fine variety from south to the north.The problem of outlet pendulum of bamboo willow, in face of grower, could not only be planted and could not form commodity from introducing a fine variety existing 8 years so far, along with the increase of cultivated area! And the integrated fiber cellulose content of bamboo willow is up to 89.8%, papermaking pulping ultrahigh in efficiency, and suffer from traditional pulping process investment too large, not that general enterprises can bear; And adopt the bad solution of existing pulping process water treatment.

Summary of the invention

The technical problem to be solved in the present invention overcomes existing defect, provides a kind of method preparing bamboo willow bleached pulp.

In order to solve the problems of the technologies described above, the invention provides following technical scheme:

Prepare a method for bamboo willow bleached pulp, comprise the steps:

(1) with peeler 2 to three years raw bamboo willows are cut grow into 40-50mm, material section that diameter is 3-4mm;

(2) section material is sent into boiling vessel, by section material OD wt. basis, add the potassium hydroxide of 2.5-3% and the anthraquinone of 0.2-0.3%, at temperature is 90-95 DEG C, boiling 45-50min;

(3) once bleach: double-screw pulp-milling sent into by the material that boiling obtains, and by material per ton, adds the H of the polyacrylamide of 2.2-2.5%, the EDTA and 2.5-3% of 1-1.2% ₂o ₂, double-screw pulp-milling outlet temperature controls at 100-105 DEG C, and reaction warehouse reaction 50-60min sent into by the slurry after mill, washing;

(4) secondary bleaching: step (3) is washed the slurry obtained and send into double-screw pulp-milling, by material per ton, add the Na of 2.2-2.5% ₅p ₃o ₁₀, 1-1.2% MgSO ₄with 5-5.5% H ₂o ₂, double-screw pulp-milling outlet temperature controls at 100-105 DEG C, and reaction warehouse reaction 50-60min sent into by the slurry after mill, and washing, namely obtains bamboo willow bleached pulp.

Further, during step (2) boiling, solid-liquid ratio is 1:4.5.

Compared with traditional pulping process, method tool of the present invention has the following advantages:

1, pulping yield is high, can reach 92-95%, and slurrying cost is low, and escapable cost about 1/3 compared by simultaneous interpretation controlling slurry.

2, raw material comprehensive utilization ratio is high, can get the raw materials ready by whole plant, does not strip off the skin, not except branch.

3, contain a large amount of nitrogen, phosphorus, potassium in paper mill sludge, be the excellent raw material of fertilizer after biological treatment.

4, the BOD/COD ratio of sewage is high, can reach about 0.5, and very easily biochemical, water treatment can adopt the way of biological treatment, for paper-making zero discharge specifies direction.

5, bleach without sulphur, not chloride element, environmentally safe, whiteness can reach 79-82.

Detailed description of the invention

Below the preferred embodiments of the present invention are described, should be appreciated that preferred embodiment described herein is only for instruction and explanation of the present invention, is not intended to limit the present invention.

embodiment 1

1, by 2 to three years raw whole plant bamboo willows (containing twig, bark), the material section of long 40-50mm, diameter 3-4mm is cut into peeler, for subsequent use after removing impurity and fines with drum sieve.

2, pretreatment: the material section cut delivers to even steam device with belt conveyor after metering, carry out continuously cooking, by over dry section material per ton in digestion process, add the potassium hydroxide of 1.5-2%, the ammonium sulfite of 1.2-1.5% and 1-1.5% sodium phosphate trimer, boiling solid-liquid ratio is 1:3.5, boiling temperature is 135-140 DEG C, and digestion time is 115-120min.

3, once bleach: the raw material after pretreatment is sent into double-screw pulp-milling, by material per ton, adds the H of the polyacrylamide (PAM) of 2.2-2.5%, the EDTA and 2.5-3% of 1-1.2% ₂o ₂, control double-screw pulp-milling outlet temperature at 100-105 DEG C, reaction warehouse sent into by fiberizer slurry out, reaction 50-60min, then carries out two sections of inverse formula washings;

4, secondary bleaching: sending once bleaching the slurry after washing into double-screw pulp-milling, by material per ton, adding the Na of 2.2-2.5% ₅p ₃o ₁₀, 1-1.2% MgSO ₄with 5-5.5% H ₂o ₂, double-screw pulp-milling outlet temperature controls at 100-105 DEG C, and reaction warehouse sent into by fiberizer slurry out, reaction 50-60min, and two sections of inverse formula washings, namely obtain bamboo willow bleached pulp.

Last it is noted that the foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, although with reference to previous embodiment to invention has been detailed description, for a person skilled in the art, it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein portion of techniques feature.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (2)

1. prepare a method for bamboo willow bleached pulp, comprise the steps:

(1) with peeler 2 to three years raw bamboo willows are cut grow into 40-50mm, material section that diameter is 3-4mm;

(2) section material is sent into boiling vessel, by section material OD wt. basis, add the potassium hydroxide of 2.5-3% and the anthraquinone of 0.2-0.3%, at temperature is 90-95 DEG C, boiling 45-50min;

(3) once bleach: double-screw pulp-milling sent into by the material that boiling obtains, and by material per ton, adds the H of the polyacrylamide of 2.2-2.5%, the EDTA and 2.5-3% of 1-1.2% ₂o ₂, double-screw pulp-milling outlet temperature controls at 100-105 DEG C, and reaction warehouse reaction 50-60min sent into by the slurry after mill, washing;

(4) secondary bleaching: step (3) is washed the slurry obtained and send into double-screw pulp-milling, by material per ton, add the Na of 2.2-2.5% ₅p ₃o ₁₀, 1-1.2% MgSO ₄with 5-5.5% H ₂o ₂, double-screw pulp-milling outlet temperature controls at 100-105 DEG C, and reaction warehouse reaction 50-60min sent into by the slurry after mill, and washing, namely obtains bamboo willow bleached pulp.

2. method according to claim 1, is characterized in that, during step (2) boiling, solid-liquid ratio is 1:4.5.