METHOD FOR PRODUCTION OF FIBROUS SEMI-PRODUCT OF MISCANTHUS Russian patent published in 2020 - IPC D21C5/00 D21C3/02 D21H11/12 

FIELD: chemistry.

SUBSTANCE: method includes impregnating a miscanthus cutting in a solution containing an alkali metal hydroxide, a surfactant and a stabilizer at temperature not higher than 70 °C for 0.5–12 hours with subsequent separation of impregnating solution. After that thermo-chemical treatment of cutting in alkaline medium is carried out at temperature 80–120 °C for 20–60 minutes. Then, the cutting is condensed to concentration of 60–70 % with separation of the spent alkaline solution, diluted with water or solution of bleaching chemicals and milled to obtain a pulp. Mass is sorted, and screening wastes are milled together with a cutting after thickening. Alkali metal hydroxide used is sodium hydroxide or potassium hydroxide at concentration of 12–23 g/dm³ in amount of 2.0–4.0 % of the weight of absolutely dry material. Surfactant used is OP-7 or OP-10 - which is a product of treating a mixture of mono- and dialkylphenols with ethylene oxide, surfactants, in amount of 0.025–0.09 % of the weight of the absolutely dry material. Stabilizer used is trilon B - disodium salt of ethylenediaminetetraacetic acid (EDTA-Na₂), trilon C - diethylenetriamine pentaacetic acid (DTPA) in amount of 0.03–0.25 % of the weight of absolutely dry material. Bleaching chemicals used are sodium dithianite or an alkaline solution of hydrogen peroxide, with consumption of H₂O₂ equal to 2–4 %, NaOH equal to 0.8–1.2 % and Na₂S₂O₄ - 0.6–0.8 %.

EFFECT: invention relates to production of fibrous semi-products and can be used in pulp-and-paper industry in production of disposable tableware and in production of various types of cardboard.

5 cl, 1 tbl