Method for pulping cotton linter

Abstract

The invention provides a method for pulping cotton linter, which can reduce COD (Chemical Oxygen Demand) in black liquor generated by stewing to be less than 8,000mg / L and simultaneously improve the reaction performance of cotton pulp. The method for pulping cotton linter comprises the stewing step, wherein the stewing step comprises the following concrete steps of: (1) mixing the cotton linter with sodium hydroxide solution and preserving the temperature at the stewing temperature; (2) releasing the steam; (3) adding hydrogen peroxide diluted solution when the gauge pressure is less than 0.05MPa, wherein the weight of H2O2 is 3-6 percent that of the cotton linter, and pouring materials treated at the temperature of 80-100DEG C. By using the invention, the stewing quality and bleaching of the stewing pulp can be ensured, and a large amount of organic matters in the black liquor can be oxygenolyzed and settled. Before washing materials, a sample is taken out from a washing pool and detected, wherein the fiber whiteness is more than 60 percent, the dust content is less than 0.9 percent, the iron content is less than 60ppm and the reaction performance is not more than 50s; meanwhile, the COD in the filtered black liquor is reduced to be less than 8,000mg / L from 100,000-160,000mg / L in the prior art.

Description

technical field [0001] The invention relates to a method for pulping cotton linters. Background technique [0002] In the field of chemical fiber and refined cotton production in China, cotton linter pulping includes the following steps: cooking, washing, beating, sand removal, bleaching, and pulping. The block diagram of the entire production process is as follows figure 1 shown. Among them, the cooking of cotton linters must go through ten procedures: feeding, first heating, first small steam release, second heating, second small steam release, third heating, heat preservation, large steam release, warming water, and feeding. Cooking achieves the purpose of heating up by introducing high-temperature water vapor into the steaming ball, and adopts the well-known small release of steam while heating up (see image 3 ) method to achieve the required temperature and gauge pressure during heat preservation. During cooking, cotton linters undergo saponification and emulsificat...

AI Technical Summary

Problems solved by technology

[0003] At present, the domestic counterparts and relevant scientific research institutes have successively studied the method of adding hydrogen peroxide for cooking and bleaching when the cotton linters are cooking and feeding, because the heating temperature in the later stage of cooking is reduced, and the cooking quality is affected.

Since hydrogen peroxide can only bleach the surface of the fiber and cannot penetrate into the interior, and hydrogen peroxide cannot remove the oil and wax of cotton linters, it cannot effectively improve the reactivity of cotton pulp and cannot be used to make chemical fiber cotton pulp

Images