SU1172968A1 - Method of refining pulp - Google Patents

Abstract

A METHOD FOR LIVING PULP BY treating it with alkali in the presence of trisodium phosphate and an additive at a higher temperature, characterized in that polyacrylamide is used as an additive in order to increase the yield and quality of the cellulose. (L

Description

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Oi 00 is pulp from wood and other raw materials and can be used in the preparation of pulp for chemical processing. The purpose of the invention is to increase the yield and quality of pulp. The essence of the invention is that according to the method of cellulose refining, which involves processing it with alkali in the presence of trisodium phosphate and an additive at a higher temperature, polyacrylamide (PAA) is used as an additive. Polyacrylamide under alkaline treatment of cellulose at elevated temperatures prevents alkaline destruction of cellulose, resulting in a decrease in chemical loss of cellulose, thereby increasing the yield without decreasing the quality of cellulose (o-cellulose content, viscosity, degree of polymerization) polyacrylamide (on the basic substance) is 0.02-1.50% by weight of the initial absolutely dry cellulose taken for refining. The method is carried out as follows. Example 1. Experiments are carried out on sulphite pulp e for viscose after chlorination. Refining is carried out under the following conditions: refining temperature 100 ° C; refining time 120 min; NaOH consumption 10% by weight of the initial completely dry pulp taken for upgrading; consumption of trisodium phosphate, 0% by weight of the original absolutely dry cellulose, taken on a refining; module 1:10 ... Refining is carried out in autoclaves heated by a glycerin bath on a battery unit. The amount of cellulose loaded into an autoclave is 50 g of absolutely dry whole lulose. hot water (water temperature not less than 60 ° C) and injected into the autoclave before upgrading. Dp comparisons are carried out by refining cellulose in the presence of sodium borohydride (according to the prototype). The yield and quality of pulp after refining are given in table. 1. From the data table. As can be seen from Fig. 1, when enriched with polyacrylamide, the increase in yield is on average 2% compared to upgrading in the presence of borohydride while maintaining the quality indicators of pulp for chemical processing (o content (-cellulose and viscosity). The experiments were carried out on sulfite pulp for viscose after chlorination.When chlorination of cellulose, chlorine dioxide is added. Refining of strongly oxidized cellulose is carried out according to the following regime: the temperature of pulping is 115 ° C; 120 minutes; NaOH consumption by weight of the initial completely dry cellulose, taken at a refinement of 7%; consumption of trisodium phosphate 1%. Additions of polyacrylamide and sodium hydride are directly introduced into the autoclave before refining. Table 2. It can be seen from Table 2 that when refining highly oxidized cellulose in the presence of polyacrylamide, the yield increase is on average 4.3% compared with refining in the presence of sodium borohydride, while maintaining fir pulp quality obtained for chemical processing (content -tsellyu oses and viscosity).

Table 1

No additive

0.04% IAA proposed method

0.04% sodium borohydride prototype

0.05% PAA proposed method

0.05% sodium borohydride prototype

Oh, W% PAA-proposed method

0.10% sodium borohydride prototype

0.50% PAA proposed method

0.50% sodium borohydride prototype

1.00% PAA proposed method

1.00% sodium borohydride prototype

1.5% PAA-proposed method

1.5% sodium borohydride prototype

1.6% PAA proposed method

1.6% sodium borohydride prototype

Claims (1)

METHOD FOR TREATING CELLULOSE by treating it with alkali in the presence of trisodium phosphate and an additive. At elevated temperature, characterized in that, in order to increase the yield and quality of cellulose, polyacrylamide is used as an additive. SU „1172968 1 1172968