Method for refining white clay calcium carbonate from green solution produced in alkali recovery from grass pulp

A technology of calcium carbonate and green liquor, applied in the field of papermaking industry, can solve problems such as secondary pollution, and achieve the effects of cost saving, uniform crystal form, and reduction of environmental pollution

Inactive Publication Date: 2012-01-04
SHAANXI UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Due to quality problems, the white mud calcium carbonate produced under this process cannot be used f...

Method used

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  • Method for refining white clay calcium carbonate from green solution produced in alkali recovery from grass pulp

Examples

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Effect test

Embodiment 1

[0010] Embodiment 1, quicklime is added in water and quicklime is digested and made mass concentration completely and is 10% lime solution; Add 0.02ml straw pulp green liquor by every gram of quicklime, straw pulp green liquor is added in lime solution and causticizing reaction occurs, reaction The temperature is 10°C, and the stirring speed is 5000rpm to make white mud calcium carbonate.

Embodiment 2

[0011] Embodiment 2, quicklime is added in water and quicklime is digested and made mass concentration completely and is 30% lime solution; Add the straw pulp green liquor of 0.08ml by every gram of quicklime, straw pulp green liquor is added in the lime solution and causticizing reaction occurs, reaction The temperature is 50°C, and the stirring speed is 100rpm to make white mud calcium carbonate.

Embodiment 3

[0012] Embodiment 3, quicklime is added in water and quicklime is digested and made mass concentration completely and is 20% lime solution; Add the straw pulp green liquor of 0.3ml by every gram of quicklime, straw pulp green liquor is added in the lime solution and causticizing reaction occurs, reaction The temperature is 80°C, and the stirring speed is 2000rpm to make white mud calcium carbonate.

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Abstract

The invention discloses a method for refining white clay calcium carbonate from green solution produced in alkali recovery from grass pulp, which comprises: adding quick lime into water to completely digest quick lime to obtain solution of lime; and adding grass pulp green solution into the solution of lime to carry out a causticizing reaction or adding the solution of lime into the grass pulp green solution to obtain white clay calcium carbonate. In the invention, based on study of mechanism of alkali recovery, the current alkali recovery process conditions are improved and a digestive reaction and the causticizing reaction are carried out separately under controlled reaction conditions; therefore, the form of white clay calcium carbonate produced by the causticizing reaction is needle-like, the white clay calcium carbonate byproduct of alkali recovery is high in whiteness and uniform in crystal form and can be used in paper filling with high quality in place or part or all commercial calcium carbonate, and the cost of pulp making enterprises and pollution to the environment are reduced.

Description

technical field [0001] The invention belongs to the field of papermaking industry, and in particular relates to a method for recovering green liquor from grass pulping soda and refining lime mud calcium carbonate. Background technique [0002] China lacks forest resources, and most pulp mills still use grass raw materials for pulping. In the pulping process, alkali recovery is an essential process, and the process of alkali recovery will produce a large amount of white mud calcium carbonate. The traditional alkali recovery process is to add quicklime directly to the grass pulp green liquor, that is, the digestion reaction and the causticization reaction are carried out simultaneously. The white mud calcium carbonate produced under this technological condition cannot be used for paper filling due to quality problems. Most enterprises can only choose to stack and landfill it, causing secondary pollution. Contents of the invention [0003] The purpose of the present inventio...

Claims

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Application Information

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IPC IPC(8): C01F11/18
Inventor 夏新兴刘峰吴盼李金宝李佩燚罗清殷学风王建
Owner SHAANXI UNIV OF SCI & TECH
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