Paper pulp making method capable of reducing large amount of waste liquid and lowering consumption of materials

Abstract

The invention provides a paper pulp making method capable of reducing large amount of waste liquid and lowering consumption of materials. The method comprises the following steps of: before boiling pulp, cutting, crushing, rolling and screening rice straw, reed or wheat straw which serves as a raw material; removing impurities, such as silicide, micromolecular hemicellulose, starch, lignin, sand soil and the like from the mixture to reduce pollutants of black liquid to an amount which is only one-third of that generated by the conventional method; and adopting a kneading method pulp-boiling reaction to produce various kinds of high-quality paper pulp by using less chemical raw materials and at a lower temperature and under a lower pressure. By adopting the method, more than two-thirds of paper-making black liquid is reduced; For production of every 1 ton of paper pulp, by the method of the invention, more than 500 kilograms of standard coal are saved, more than 100 kilograms of sodiumhydroxide are less used, the production cost and the requirement on the strength of the equipment are lowered, useful resources, of which the weight is more than 30 percent of that of raw materials, are obtained, and more than half of the value of raw materials is recovered. The method has the advantages of energy conservation, emission reduction, synergy, safety, and recycling wastes; and after the method is popularized, huge social benefits, environmental protection benefits and economic benefits are created.

Description

technical field [0001] The present invention relates to an improvement of a method for producing pulp by chemical method using grass raw materials such as straw, wheat straw and reed, in particular to a pulp production method which can greatly reduce waste liquid and reduce raw material consumption. technical background [0002] China, India and other countries with less wood per capita mainly use grasses as raw materials to make pulp by chemical methods. Every ton of straw pulp paper needs to produce about 10 tons of pulp cooking black liquor, and the amount of black liquor in my country's straw pulp papermaking method will reach hundreds of millions of tons. The main components of this black liquor are silicide, small molecule hemicellulose, lignin, sand, etc., and also contain unconsumed sodium hydroxide, sodium sulfide, etc. The discharge of this kind of black liquor causes serious pollution to the environment, and the discharge is strictly prohibited in all countries. ...

AI Technical Summary

Problems solved by technology

Although these methods have relatively less pollution discharge and low energy consumption, they can only produce rough yellow paper and cannot meet people's higher requirements for paper.

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