Silicon decreasing method for non-lignine raw material soda pulping process black liquor

Abstract

The invention discloses a method for reducing silicon in black liquor from alkaline pulping with non-wood fiber raw material. In an alkaline pulping process, a reaction is carried out at a temperature of between 140 to 160 DEG C for 35 to 60 minutes according to the principles of a mass ratio of non-wood fiber to water of 1:3.5-5, a mass percentage of NaOH of 12 to 18 percent; a pressure of O2 of 8kg / cm; and a dosage of metal alkaline earth oxides of 5 to 40 kilograms per ton of absolutely dry non-wood fiber, wherein the grain diameter of the powder alkaline earth oxides is 100 to 200 meshes, and the powder alkaline earth oxides are CaO and MgO. In a pulp cooking process, a silicon-containing filling produced by adding the metal alkaline earth powder can improve the printing properties of paper products such as whiteness, opaqueness, smoothness and absorbency and improve the combustion performance of cigarette paper. The method is simple in operation and can be synchronously carried out with pulp cooking without high silicon removal efficiency and no addition of new devices. The method uses low-price and readily available metal alkaline earth powder and can ensure that the available metal alkaline earth powder is completely reacted with silicates in the whole the cooking process.

Description

technical field [0001] The invention belongs to the field of wastewater treatment, and in particular relates to a method for reducing the silicon content in pulping and papermaking black liquor. Background technique [0002] China's paper industry is developing rapidly, and the output and consumption of paper and cardboard ranks second in the world. Developed countries all use wood fiber to make paper, while non-wood fiber accounts for half of my country's papermaking raw materials. Pulp and paper black liquor used to be the most serious pollution produced by industrial production. With the development of papermaking science, wood pulp black liquor treatment technology is becoming more and more perfect. Wood pulp black liquor is concentrated, evaporated, burned and causticized. During the combustion process, the organic matter in the wood pulp black liquor is converted into carbon dioxide and water. In the causticizing process, the inorganic salts are converted into alkal...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the disadvantages of high investment, complicated operation, and inconspicuous silicon reduction effect in the prior art, the present invention provides a method for silicon reduction of non-wood fiber raw material alkaline pulping black liquor, which is simple to operate and carried out simultaneously with cooking , a new method for efficient silicon removal without adding new equipment

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