SU509679A1 - The method of bleaching pulp - Google Patents

Description

The invention of OTHCH HTCSI to the pulp and paper industry and casa-z-o from protein pulp. Known methods; bleaching and bleaching mass by treating it with bleaching agents with reagents, such as hypochlorite; chlorine pyuoxide or elemental chlorine in combination with P1b uaa (mi reagents followed by acidification with sulfuric acid solution to increase the growth of the bleaching process and increase the degree of whiteness; The cellulose pulping process takes place on the basis of electric discharges i appp cell 35 35 KB with a capacitor capacity of 0.110, 66 microfarads with a pulse frequency of 1 minute for a minute, and the consumption of sulfur dioxide for KiicrsOBKe, it is 2–4% of the weight of absolute dry fiber. Example -1. A dry sulphite cel lus ozu with a white sulphurite and a half a liter of Jl 8 (3.% O% white, selected on Kamsky Cellgltoz, but paper KotviOHuaTe after the first stage, bleaching with gioachlort, GALV-e) c) t with distilled water in the amount of 6.0 o of the total weight of water. The mixture is then held for 12 h and stirred in a disintegrator for 1 minute. After this, the remaining part of the water is applied to the remaining water and an aqueous solution of sulfuric a) hydride to obtain a suspension with a fraction of cellulose in the range of 1–2 ° C of the weight of the suspension and the amount of sericostam anhydrous equal to 2- 4% by weight abs.). And dry pulp. Then, svcneriGiiio is converted to an electrical treatment with a discharge voltage of 50 kV at GMKOCTJ 0.33 microfarads of co-frequencyrs with a frequency of Tiift 90 ipul CO / MPN for 5, O7; 5 MHi- ;. P1z processing; cellulose isogelite-otlpG.km .. stick them out to airborne condition and determine the whiteness according to GOST. The data are presented in tsblkie 1 P p M and e p 2, Nostsushno dry sulata cellulose with whitena equal to 75, 503% white, selected, and Syktyvkar pulp and bulk KOM6ifHaTe after the first stage of bleaching, used in the beginning of the first stage of bleaching, it used to melt out of the first half of the whitening process, it was out of the way, the first of the bleaching stage used chlorine dioxide, they used to melt out of the first half of the bleaching stage. in the amount of 7% of the total weight of the water. After the mixture is kept for 11 hours and stirred in a disintegrator for 1 min. Then the remaining portion of dispersed water and an aqueous solution of sulfuric anhydride are poured into the mixture to obtain a suspension with a cellulose concentration of 1–2% by weight of the suspension and an amount of sulfuric acid equal to 2 -4% by weight of absolutely dry pulp. After this, the suspension is subjected to treatment with electric discharges with a voltage of 50 kV | at a capacitance of 0.33 microfarads with a frequency of 90 pulses per minute for 5, ~ 7.5 minutes. Castings are made from the obtained cellulose suspension, dried to an air-dry state and the whiteness is determined according to GOST 769O-66. The data are presented in Table 2. ... PRI me R 3. Air-dried sulphate pulp with a whiteness equal to 87.66% white, selected at the Syktyvkar pulp and paper mill after the second bleaching stage with chlorine dioxide, is poured

Table 1 with distilled water in the amount of 7, About% of the total weight of water. The mixture is then incubated for 11 hours and stirred in a disintegrator for 1 minute, after which the remaining portion of distilled water and an aqueous solution of sulfurous anhydride are poured into the mixture to obtain a suspension with a cellulose concentration of 1% by weight of the suspension, and a consumption of sulfuric anhydride equal to 4 , 0% by weight of absolutely dry cellulose. The resulting suspension is subjected to electrical discharge treatment with a voltage of 50 kV at a capacitor capacitance of microfarads with a frequency of 90 pulses per minute for 7.5 minutes. I Castings are made from the treated pulp, dried to an air-dry state, and the whiteness is determined in the same way as in the above examples. Cellulose whiteness is 90, 11% white, whiteness increase is 2.45 abs. % white or 2.79 rel. % The proposed method allows reducing the time for finishing the pulp, reducing the consumption of bleaching agents and improving the working conditions.

1 1 1 1 2 2

four

2 4 4

four

5.0 5.0

7.5 7.5

7.5 5.0

Claims (1)

Invention Formula The method of pulping the pulp by the use of bleaching agents followed by a sour solution of sulfurous acid, characterized in that, in order to intensify the bleaching process and increase the efficiency of Table 6.42 6.48 6.21 6.51 cellulose lianes, in the process of kislovka, the cellulose mass is subjected to electrical discharges with a voltage of kV at a capacitor capacity of 0.11-0.66) with a frequency of 49-130 pulses per minute for 3-10 min, and the consumption of sulfur dioxide at kislovka it is 2-4% by weight of absolutely dry fiber.