Self-coupling oxygen ion fast bleaching untwining pulping method

Abstract

The invention relates to a self-coupling oxygen ion fast bleaching untwining pulping method. The main technical characteristics includes: conveying plant fiber subjected to crushing, separating, screening and impurity removal into a fiber high efficiency untwining screening machine, then injecting hydrogen peroxide (4-6%, the ratio to an absolute dry raw material) and steam, making the temperature inside the machine reach 80-90DEG C, mixing the hydrogen peroxide and fiber evenly through rapid rotation of a stirrer in the machine, under ultraviolet excitation, making the hydrogen peroxide rapidly decompose into nucleophilic active oxygen ions (02-) to react with fiber lignin chromophoric groups, and changing chromophoric groups into colorless groups in 3-5min, making the fiber pulp whiteness become 75-85%ISO, further carrying out softening and untwining for 30min, and conducting screening to make the qualified pulp enter the next process.

Description

technical field [0001] The invention is a clean and environment-friendly pulping method for pulping and papermaking using plant fibers, and is a pioneering invention in the papermaking industry. Background technique [0002] Using rice straw, cotton stalks, mulberry twigs, and branches to make bleached pulp and paper, there are two key links: one is rapid bleaching; the other is efficient deflaking. In traditional pulping and bleaching, 300 kg of caustic soda is used for bleaching per ton of pulp, which is cooked at 180 degrees for 4 hours, washed again and again and then bleached with calcium hypochlorite. Therefore, 600 tons of clear water is required for each ton of bleached pulp, and the pulping black liquor The COD content in the water is 160000MG / L, which causes serious pollution to the ecological environment, especially the "dioxin" produced by chlorine bleaching, which is extremely harmful to the human body. During the whole pulping process, it is necessary to use a...

AI Technical Summary

Problems solved by technology

In traditional pulping and bleaching, 300 kg of caustic soda is used for bleaching per ton of pulp, which is cooked at 180 degrees for 4 hours, washed again and again and then bleached with calcium hypochlorite. Therefore, 600 tons of clear water is required for each ton of bleached pulp, and the pulping black liquor The COD content in the medium is 160000MG / L, causing serious pollution to the ecological environment, especially the "dioxin" produced by chlorine bleaching, which is extremely harmful to the human body

During the whole pulping process, it is necessary to use a disc refiner to refine the pulp again and again, which not only wastes manpower and electricity, but also damages the fiber and reduces the physical indicators of the fiber.

At present, there are two new technologies: one can reduce pollution, but the dosage is large, resulting in large fiber damage, high cost, and it is difficult to promote; The cost is also low, but the process flow is long, the equipment is complicated, and the power consumption is large. The present invention aims to overcome the above-mentioned defects, adopts a high-efficiency fiber bleaching and screening machine, uses ultraviolet light to excite hydrogen peroxide to generate nucleophilic active oxygen ions, and reacts with lignin The chain reaction of the chromophoric group of lignin breaks the chromogenic group of lignin, softens and decomposes the fiber raw material at the same time, and completes the fiber bleaching, softening, decomposing, screening, and pulping processes at one time, saving water, electricity, coal and cost.