Process of preparing chemical pulp with corn stalk peel

Abstract

The process of preparing chemical pulp with corn stalk peel includes the following steps: cutting dry corn stalk peel into 25-30 mm long material sections; and digesting the material sections in a digester with sulfite, alkali solution and enthraquinone at 120-180 deg.c for 0-85 min. The digestion liquid has total chemical amount of 7-20 % accounting in Na2O, sulfurous acid degree 0.2-1.0, enthraquinone amount 0.03-0.10 % and liquid ratio of 4-6. The produced AS-AQ and AS-AQ pulp have physical strength reaching relevant standard and quality higher than that of broad-leaved wood pulp. The present invention has short digestion period and high yield, and the effluent may be concentrated and further produced into adhesive, dispersant and cement water reducing agent.

Description

technical field [0001] The invention relates to the pulping technology in the field of papermaking, especially the pulping technology using corn stalks as raw materials. Background technique [0002] In the 1950s, my country used corn stalks for pulping, but the pulping methods at that time used corn stalks for pulping. Due to the large proportion of leaves and pith, the content of pulp-forming cells is high, and it is only suitable for the production of low-grade pulp. cardboard pulp. The Chinese patent (North Carolina State University, U.S.) of application number 00812212 still adopts full stalk pulping. There are two major disadvantages in this whole stalk pulping technology: one is the high consumption of chemicals, this is because only 35% of the stalk husks in the whole stalk of corn concentrate most of the fibers used in papermaking, and the remaining 40% are Leaves, leaf sheaths, and 15% culm pith are mainly composed of miscellaneous cells, but chemicals are also co...

AI Technical Summary

Problems solved by technology

There are two major disadvantages in this whole stalk pulping technology: one is the high consumption of chemicals, this is because only 35% of the stalk husks in the whole stalk of corn concentrate most of the fibers used in papermaking, and the remaining 40% are Leaves, leaf sheaths, and 15% of stalk pith are mainly composed of miscellaneous cells, but chemicals are also consumed during cooking, which greatly reduces the effective utilization rate of drugs (more than twice)

The second is that the pulp contains a large number of miscellaneous cells, which will seriously affect the quality of the pulp if it is not removed, and the production process will be complicated if it is removed, especially the discharge of substances will increase, and pollution control will be difficult

Application number is 200410050681 Chinese patent (Shenyang Natural Fiber Research Institute), its key technology is cooking with potassium base, in order to facilitate the cooking waste liquid for the production of potash fertilizer, solve the problem of waste liquid pollution; CN 99113340.4 (Yu Jingshu, Heilongjiang Province) and CN 00819684.2 (Korean CP&P Co., Ltd.) have improved the pulping technology, but its invention has great shortcomings, such as using "completely shaded corn stalks as raw materials", which brings difficulties to the acquisition and storage of corn stalks. Great difficulties, especially the unreasonable formulation of cooking agent for pulping, such as using only NaOH solution without additives in soda pulping, and not paying attention to sulfite in alkaline and neutral sulfite cooking liquor Therefore, the cooking time is long (1.5 to 4 hours) and the efficiency is low; the patent of Shenyang Shennong Green Waste Treatment Co., Ltd. (application number 200310124000.4) adopts caustic soda plus anthraquinone cooking, and oxygen-enhanced hydrogen peroxide bleaching to produce Bleached corn stalk pulp, but still cannot overcome the shortcoming of long cooking time. Under the condition of cooking temperature as high as 155℃, the cooking time still needs 1.5 to 3 hours

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