Alkali recovery method for by-producing activated carbon and white carbon black by using paper making black liquid

Abstract

The invention relates to paper making industry clean production, in particular to an alkali recovery method based on paper making black liquid. The method comprises the following steps of: 1) adding carbon powder in paper making black liquid, introducing CO2 gas for carrying out primary hydrothermal carbonization, and carrying out filtering to obtain primary hydrothermal carbonization liquid and primary hydrothermal carbonization materials; 2) adding crude activated carbon into the primary hydrothermal carbonization liquid obtained in the first step, carrying out secondary hydrothermal carbonization under the CO2 gas introduction condition, carrying out filtering to obtain secondary hydrothermal carbonization liquid and secondary hydrothermal carbonization materials, evaporating the secondary hydrothermal carbonization liquid, regulating the pH (Potential Of Hydrogen), and carrying out causticization treatment to obtain alkali liquid. The method provided by the invention has the advantages that because the alkali recovery work procedure is a bottle neck of most alkali process pulp making paper making plants in prior art, after the efficiency of the process is improved, the pulp making capability of the paper making plants can be greatly improved, meanwhile, the by-production of high-added-value activated carbon and white carbon black can be realized, and further, the scale benefits of the paper making enterprises can be integrally improved.

Description

technical field [0001] The invention relates to clean production in the papermaking industry, in particular, the present invention relates to an alkali recovery method based on papermaking black liquor, a high temperature and medium pressure liquid phase acidification treatment of the papermaking black liquor, and by-producing high value-added activated carbon and silica products A new method for alkali recovery. Background technique [0002] The pollution of the paper industry to the environment, especially the water environment, has attracted worldwide attention. At present, the waste water pollution of the paper industry has been recognized as one of the "six major" public hazards in the world. At present, the environmental pollution of cooking black liquor in the alkaline pulping and papermaking industry is the most serious, accounting for about 90% of the pollution in the entire papermaking industry. About 1 / 3 of the polluting impurities contained in the black liquor ar...

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Problems solved by technology

[0004] To sum up, the traditional alkali recovery method has the problem of low alkali recovery rate and high energy consumption, and the acid analysis lignin method has the problem of secondary acid wastewater pollution, while the coagulation method only provides a simple idea of ​​pollution control. The chemical method is essentially only an improvement on the traditional alkali recovery method. As for the extraction of organic matter in black liquor to prepare building material bonding enhancers and sulfonated lignin, due to the large amount of black liquor, there is no wide use space, so the above methods are all Not to mention the full utilization of the components of papermaking black liquor

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