Method for control of bleaching process for treatment of waste paper and bleaching device for realisation of this method

FIELD: textile fabrics, paper.

SUBSTANCE: invention is intended for application in pulp and paper industry. Method of bleaching process control for waste paper treatment is characterised by the following operations: preparation of fibrous suspension; measurement of fibrous suspension whiteness; mixing of fibrous suspension with bleaching substance; supply of mixed fibrous suspension to reservoir for bleaching; extraction of mixed fibrous suspension from reservoir for bleaching after certain time interval. Bleaching substance comprises mixture of separate substances, besides amount and/or composition of added bleaching substance is established depending on measured whiteness of fibrous suspension so that possible permanent specified whiteness of extracted fibrous suspension is achieved. Whiteness of extracted fibrous suspension is measured and compared in adaptation mode with specified whiteness, and depending on result of comparison compliance pattern is coordinated. Bleaching device contains reservoir for bleaching, supply pipeline with whiteness sensitive element, metering device, control device, discharge device.

EFFECT: prevention of large oscillations of fibrous suspension whiteness at the end of bleaching process, at that load of used bleaching substance is minimum.

7 cl, 2 dwg

 

The invention relates to a method of controlling the bleaching process for processing waste paper, as well as whitening device for implementing this method.

An important operation in the processing of paper recycled paper is bleaching. Due to the additive whitening remedies in the fibrous suspension change whiteness (for example, brightness) or, respectively, the coordinate of the color (e.g. red, green, blue). Bleaching agent usually contains bleaching chemicals like hydrogen peroxide, as well as activating and/or stabilizing chemicals like caustic soda and liquid glass.

Still the bleaching process is done with the help of supplements predetermined amount of the whitening means to achieve minimal bleaching steps, so that the white fibrous suspension after bleaching did not deviate below a certain criterion or, respectively, about lying within a certain range of values. Also part of the whitening means is set so that it always achieves a certain bleaching action. When changing the load paper due to the different qualities of the fiber may occur fluctuations in the white lead to the process of bleaching fibrous suspension. With the help of added in a Koli is este and part of the whitening means fibrous suspension thereby bleached too much or too little, so white fibrous suspension after the bleaching process is either too small or too large. If there is too much white it must again be lowered, for example, by using additive colors.

Since the time of passing the fibrous suspension at the beginning of the bleaching process to the availability of processed paper lasts a few hours, it is impossible to regulate the whitening process depending on the white paper at the end of the manufacturing process, because changes in the white fibrous suspension to be much faster at the beginning of the bleaching process.

The present invention is providing a method of implementation of the whitening process, which can help to prevent large fluctuations white fibrous suspension at the output of the whitening process and which load used bleaching agents is minimal.

This problem is solved by a method according to paragraph 1 of the claims, as well as whitening device according to the paragraph 7 of the claims.

Further preferred form of carrying out the invention are given in the dependent claims.

According to the first aspect of the present invention provides a method for control of the bleaching process for processing waste paper. In the prepared fiber is Uspenie measure the white and mixed fibrous suspension with a bleaching agent. Mixed fibrous suspension is served in the capacity of bleach to bleach it for a certain period of time. Mixed fibrous suspension after a certain period of time taken from the tank for bleaching. The quantity and/or composition added whitening set depending on the measured white fibrous suspension to achieve a possibly permanent set white selected fibrous suspension.

Corresponding to the invention a method for the control of the bleaching process involves thus, depending on the measured white fibrous suspension before bleaching process, to establish the quantity and/or composition of a bleaching agent that is added to the fibrous suspension. Thus, the bleaching process can be carried out for each share of the loaded fiber suspension with the same number and/or with added whitening means that the bleaching process is carried out with the corresponding part of the fibrous suspension so that at the end of the bleaching process reached a certain preset white.

According to a preferred form of execution of the bleaching agent may contain a mixture of substances from a variety of substances, and a bleaching agent contains the whitening chemical the Yu and/or chemikalie stabilizer.

Preferably the establishment number and/or bleaching composition tools are produced using schema matching to the white fibrous suspension. Schema matching can be performed, in particular, with the function, table, or graph matching.

You can provide adaptation mode in which the selected white fibrous suspension is compared with the preset white and depending on the result of the comparison will agree on a compliance scheme.

In particular, establishing the quantity and/or composition of the whitening means when the prescribed preset white produce such a way that the costs of preparing a bleaching funds are minimal. As a bleaching agent often consists of many different substances in various combinations to achieve comparable bleaching action is advisable to choose those combinations, that is, the number and/or part of the whitening means, so that the costs of these or, respectively, the costs of preparing a bleaching means are minimized.

According to further aspect of the present invention provide a device of bleaching for the implementation of the bleaching process for processing waste paper. The device contains whitening capacity for bleaching, in which otbelivanie suspension using a bleaching means. Using the feeder fiber suspension is introduced into the tank for bleaching. The sensor element of the measure white white fibrous suspension in the inlet line and through the metering device supply summed fibrous suspension bleaching agent. Provided by the control device, which is associated with a metering device to set depending on the measured white summed up the fibrous suspension quantity and/or composition of the bleaching means to achieve a possibly permanent set white selected fibrous suspension.

Corresponding to the invention the device whitening has the advantage that the bleaching process when setting the preset white obtained after the process of bleaching fibrous suspension and depending on the measured white summed up the fibrous suspension is affected due to the fact that the bleaching agent is added to the summed fibrous suspension in a suitable number and/or with a suitable composition.

According to the following form of execution of the invention the control device contains a drive to remember the schema matching in a function, table, or graph matching. Due to this, you can assign the measured whiteness in compliance with specific quantities and/or bleaching composition features what a bleaching agent is added to the summed fibrous suspension in a suitable manner.

According to the following form of the invention may provide for the discharge device so that after a certain period of time to output the fibrous suspension from the tank for bleaching, and the discharge device is associated with the following sensitive element white, to measure the whiteness of the allotted fibrous suspension. The control device is designed in such a way that adaptation to agree on a compliance scheme depending on white allotted fibrous suspension.

A preferred form of execution of the invention are explained in the following in more detail with reference to the attached drawings.

Figure 1 - schematic representation of part of a process for processing waste paper, which produce bleaching fibrous suspension.

Figure 2 - chart of conformity, which is a function to describe the quantity and/or composition to be adding a bleaching means.

Figure 1 presents part of the process for processing waste paper. Presents predilatation capacity 1, in which the display particles of printing ink formed from recycled paper fiber suspension. Cleansed so fibrous suspension cher the C supply line 2 serves to dispersing device 3. Dispersing device 3 are connected via the following supply line 5 with a capacity of bleaching means 4. In the following the supply line 5 is the Executive valve 6 to set the number of summed bleaching means.

In an alternative implementation can be provided by multiple containers for the whitening means 4, which are bleaching chemicals, chemicals-stabilizatory and the like, through which many of the following water-pipes 5 and corresponding Executive valves 6 are connected with dispersing device 3. Using the individual installation of the Executive valves 6 can be set as the summed number of substances, and the composition formed from these substances bleaching means. In addition, you can add a set amount of water to adjust the concentration of the added substances.

Dispersing device 3 serves to stir up substances with the fed through the supply line 2 of the fibrous suspension and submit to the vessel for whitening 7. Mixed with bleaching agent fibrous suspension is basically a lumpy or sticky so that it settles on already in the tank for bleaching 7 fibrous suspension, based in the nom without mixing with it.

Capacity for whitening 7 has at its lower end screw-mixer, which results in movement of the fibrous suspension in the discharge pipe 8 and brings it to posleprodazhnoy container 9. From posleprodazhnoy capacity 9 fibrous suspension gets to the next stages of the processing system of waste paper, end of which may be manufacturing processed paper.

Includes a control unit 11, which is connected with the sensor element white 12, which is located on the inlet line 2. The sensing element white 12 measures the brightness or the chromaticity coordinate just announced to the dispersing device of the fibrous suspension. The sensing element of whiteness can be performed, for example, in the form of an optical sensor, which measures the reflection of incident light from the fiber suspension and hence determines the whiteness or, respectively, the chromaticity coordinate of the fibrous suspension.

The control unit 11 is connected with an actuating valve 6 so that the actuating valve 6 may be adjusted by the control unit 11 according to the control action. If there are many Executive valves 6, they can be installed individually by the control unit 11 via the control actions. The control unit 11 includes a memory 14, to which the op saved the compliance scheme. Schema matching can be stored in a function, lookup table or chart compliance and ensures that depending on the measured sensor white 12 values of white summed up the fibrous suspension 2 to determine the control action for the Executive of the valve 6 or, respectively, the Executive valves 6.

Figure 2 shows a diagram of conformity, which presents the degree of bleaching (specified as ΔQ) depending on the concentration of NaOH as a chemical stabilizer and N2About2(hydrogen peroxide as the bleaching chemicals. Chart of conformity relates to a bleaching agent, which does not contain liquid glass. When setting the set value of the white allotted for fibrous suspensions depending on the values for white summed up the fibrous suspension can determine the degree necessary bleaching. It is applied on the z-axis of the chart of figure 2. If the desired degree of bleaching is defined, then, as a rule, there are many possible formulations of the whitening remedies from chemicals NaOH and H2About2because the same bleaching effect can be obtained by using many combinations of bleaching chemicals. Therefore, it is reasonable to choose the part of the whitening means is a, the expenditure on the preparation of which is possible for small and/or meets other requirements of the process. The number of possible compositions is obtained from the line-height to the height be installing the extent of bleaching in the chart matching.

The chart of conformity teach on the basis of process data in the form of models bleaching steps as a function of the concentration of chemicals, such as neural networks or Gaussian process. When given the white or, respectively, the chromaticity coordinate of the fibrous suspension in a discharge pipeline capacity for whitening and measured whiteness or, respectively, the measured chromaticity coordinate input capacity for whitening can thereby calculate the concentration of chemicals. Available degrees of freedom can be used to minimize consumption.

To perform the learning process on the outlet pipe 8 is following the sensing element white 13, which is connected to the control unit 11. In adaptation mode, you can now define the bleaching action added whitening remedies in the appropriate concentration, quantity and composition and to produce or, respectively, to align the compliance scheme to optimize the management of the bleaching process. In the adaptation of QCD is onania from the desired preset white and really reached the white on the outlet pipe 8 capacity for whitening 7 can be applied, for example, to determine the error.

1. The method of controlling the bleaching process for processing waste paper, with the following operations: preparation of the fibrous suspension; measurement of white fibrous suspension; mixing the fibrous suspension with a bleaching agent; applying the mixed fibrous suspension in the tank for bleaching (7); selection of mixed fibrous suspension from the tank for bleaching after a certain period of time, and a bleaching agent contains a mixture of many substances, and the quantity and/or composition added whitening tool set depending on the measured white fibrous suspension using schema matching to achieve a possibly permanent set white selected fibrous suspension, and the whiteness of selected fibrous suspensions measure and compare the adaptation mode with the specified white and depending on the result of the comparison will agree on a compliance scheme.

2. The method according to claim 1, wherein the bleaching agent comprises a mixture of many substances, and a bleaching agent contains a bleaching chemical and/or chemical stabilizer.

3. The method according to claim 1 or 2, characterized in that schema matching is performed by using the function, table, or graph matching.

4. The method according to claim 2,characterized in that that the installation number and/or composition at a given white carry out so that the expenditure on the preparation of bleaching agents is minimized.

5. The whitening device for the implementation of the bleaching process for handling paper capacity (7) for bleaching fibrous suspension using whitening tool; with a supply line (2) for feeding a fibrous suspension into the container (7) for bleaching; with the sensor element (12) white for measurement of white fibrous suspension in the inlet line (2); with a metering device (6)to provide summarized fibrous suspension bleaching agent; the device (11) control, which is connected with a metering device (6) for installation depending on the measured white summed up the fibrous suspension quantity and/or composition of the whitening means using schema matching to achieve as much as possible a constant preset white selected fibrous suspension; and a discharge device (8) for the discharge after a certain period of time the fibrous suspension from the tank for bleaching (7), and a discharge device connected with the next sensor element (13) white for measuring white allotted fibrous suspension, and a control device (11) is performed in which zmoznostjo matching schema matching in adaptation mode, depending on the white allotted fibrous suspension.

6. The device according to claim 5, characterized in that the control device (11) includes a memory (14)to remember as schema matching function, the table or chart matching.

7. The whitening device according to claim 5 or 6, characterized in that the control device (11) is arranged to set the number and/or composition at a given white so that the cost of preparing for whitening remedies are minimized.



 

Same patents:

FIELD: paper; chemistry.

SUBSTANCE: method of cellulose fiber modification is realised in the following manner. Suspension mass of cellulose fibers is prepared. In process of its bleaching cellulose derivative is added in at least one stage of acid bleaching. pH of suspension mass is in the interval from approximately 1 to approximately 4, and temperature - in interval from approximately 30 to approximately 95°C. As cellulose derivative carboxy-alkyl-cellulose is used, for instance, carboxy-methyl-cellulose. From this suspension of bleached fiber mass paper is produced by means of dehydration of this suspension on the mesh with formation of paper.

EFFECT: higher strength in wet condition and softness of paper.

42 cl, 2 dwg, 1 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: cellulose delignification process comprises alkali treatment, delignification with hydrogen peroxide with sodium hydroxide and sodium silicate additive, and acid treatment. Alkali treatment consumes 0.5% hydrogen peroxide and 2.0% sodium hydroxide based on the weight of absolutely dry cellulose and is conducted for 2.0-2.5 h at 60-90°C. Acid treatment of delignified product is accomplished with aqueous hydrochloric acid, which is consumed in amount 1.0% based on the weight of absolutely dry fibers, while treatment is conducted for 30-60 min at ambient temperature.

EFFECT: enhanced economical efficiency without loss cellulose characteristics.

2 tbl, 11 ex

FIELD: pulp-and-paper industry.

SUBSTANCE: unbleached sulfate cellulose obtained from hardwood is subjected oxygen-alkali delignification, after which treated with chlorine dioxide in presence of oxyethylidenediphosphonic acid and then consecutively hydrogen peroxide and chlorine dioxide solutions. Process may be used in production of bleached fibrous intermediates.

EFFECT: increased whiteness and strength characteristics of cellulose and improved environmental safety of bleaching process.

2 cl, 1 tbl

FIELD: pulp-and-paper industry, in particular method for pulp whitening.

SUBSTANCE: pulp mass with concentration of 5-10 % after oxygen-alkaline treatment in step I is treated with sulfuric acid in consumption of 5 % based on dry cellulose mass and pH 2.6-3.0. In step II peroxide treatment is carried out in alkali consumption of 1.0-1.3 % based on dry cellulose mass, and in step III pulp is treated with chlorine dioxide in consumption of 1.0-1.6 % based on dry cellulose mass at 70°C.

EFFECT: pulp with increased whiteness.

1 tbl, 17 ex

FIELD: pulp-and-paper industry, in particular method for PULP whitening.

SUBSTANCE: craft pulp mass with concentration of 2.5-5.0 % after oxygen-alkaline treatment is treated with potassium permanganate in consumption of 0.01-0.1 % based on dry cellulose at 40-80°C and pH 1.6-3.0 or with sulfuric acid solution in consumption of 1.0-1.5 % at 90°C for 30 min. In steps II and IV cellulose with concentration of 10 % is treated with hydrogen peroxide in consumption of 2 % based on mass of dry cellulose for 120 min at 80-90°C and pH 9.5-10.5 wherein consumption of sodium alkali and sodium silicate is 1.3 % and 2.5 %, respectively. In step III cellulose is treated with potassium permanganate in consumption of 0.01-0.4 % under step I conditions.

EFFECT: reduced consumption of whitening agents.

1 tbl, 9 ex

FIELD: cellulose production.

SUBSTANCE: invention relates to manufacture of cellulose from cotton lint after alkali pulping or from prehydrolyzed wood cellulose and can be utilized in paper-and-pulp industry or in manufacture of artificial fibers, films, and other cellulose materials. Pulped cotton lint or prehydrolyzed wood cellulose is bleached by sodium hypochlorite at modulus 1:20 to 1:30 and 20-30°C, washed, treated for 50-60 min with 1.0-1.5% sodium hydroxide solution at 80-90°C, and subjected to souring, after which desired product is recovered. More specifically, cotton lint after alkali pulping is bleached in two steps separated by washing. In the first step, bleaching is carried out for 0.5-2.0 h at active chlorine concentration 0.3-2.0 g/L and, in the seconds step, for 0.5-6.0 h with 1.0-6.0 g/L active chlorine concentration. Prehydrolyzed wood cellulose is leached in one step for 0.5-6.0 h with 0.3-6.0 g/L active chlorine concentration.

EFFECT: improved quality of product, reduced average degree of polymerization, and increased reactivity thereof.

2 tbl, 18 ex

The invention relates to the production of cellulose and can be used to produce bleached pulp without using chlorine-containing reagents

The invention relates to biotechnology; multicomponent system for mediated mediated enzymatic oxidation includes (a) an oxidation catalyst chosen from the group margantsovistyh oxidase, (b) an oxidizing agent chosen from the group comprising oxygen and oxygen-containing compounds, b) the mediator from the group of compounds containing Mn ions

The invention relates to a derived sulfinol acid of the formula I, in which M represents a hydrogen atom, ion, ammonium ion is monovalent metal or the equivalent of a divalent ion of a metal of groups Ia, IIa, IIB, IVa or Viiic of the Periodic table of elements; R1is a HE or NR4R5where R4, R5independently from each other, represent H or C1-C6-alkyl; R2represents H or alkyl group; R3represents the SOOMA, СООR4where M, R4are as defined above, or its salt

FIELD: cellulose production.

SUBSTANCE: invention relates to manufacture of cellulose from cotton lint after alkali pulping or from prehydrolyzed wood cellulose and can be utilized in paper-and-pulp industry or in manufacture of artificial fibers, films, and other cellulose materials. Pulped cotton lint or prehydrolyzed wood cellulose is bleached by sodium hypochlorite at modulus 1:20 to 1:30 and 20-30°C, washed, treated for 50-60 min with 1.0-1.5% sodium hydroxide solution at 80-90°C, and subjected to souring, after which desired product is recovered. More specifically, cotton lint after alkali pulping is bleached in two steps separated by washing. In the first step, bleaching is carried out for 0.5-2.0 h at active chlorine concentration 0.3-2.0 g/L and, in the seconds step, for 0.5-6.0 h with 1.0-6.0 g/L active chlorine concentration. Prehydrolyzed wood cellulose is leached in one step for 0.5-6.0 h with 0.3-6.0 g/L active chlorine concentration.

EFFECT: improved quality of product, reduced average degree of polymerization, and increased reactivity thereof.

2 tbl, 18 ex

FIELD: pulp-and-paper industry, in particular method for PULP whitening.

SUBSTANCE: craft pulp mass with concentration of 2.5-5.0 % after oxygen-alkaline treatment is treated with potassium permanganate in consumption of 0.01-0.1 % based on dry cellulose at 40-80°C and pH 1.6-3.0 or with sulfuric acid solution in consumption of 1.0-1.5 % at 90°C for 30 min. In steps II and IV cellulose with concentration of 10 % is treated with hydrogen peroxide in consumption of 2 % based on mass of dry cellulose for 120 min at 80-90°C and pH 9.5-10.5 wherein consumption of sodium alkali and sodium silicate is 1.3 % and 2.5 %, respectively. In step III cellulose is treated with potassium permanganate in consumption of 0.01-0.4 % under step I conditions.

EFFECT: reduced consumption of whitening agents.

1 tbl, 9 ex

FIELD: pulp-and-paper industry, in particular method for pulp whitening.

SUBSTANCE: pulp mass with concentration of 5-10 % after oxygen-alkaline treatment in step I is treated with sulfuric acid in consumption of 5 % based on dry cellulose mass and pH 2.6-3.0. In step II peroxide treatment is carried out in alkali consumption of 1.0-1.3 % based on dry cellulose mass, and in step III pulp is treated with chlorine dioxide in consumption of 1.0-1.6 % based on dry cellulose mass at 70°C.

EFFECT: pulp with increased whiteness.

1 tbl, 17 ex

FIELD: pulp-and-paper industry.

SUBSTANCE: unbleached sulfate cellulose obtained from hardwood is subjected oxygen-alkali delignification, after which treated with chlorine dioxide in presence of oxyethylidenediphosphonic acid and then consecutively hydrogen peroxide and chlorine dioxide solutions. Process may be used in production of bleached fibrous intermediates.

EFFECT: increased whiteness and strength characteristics of cellulose and improved environmental safety of bleaching process.

2 cl, 1 tbl

FIELD: paper-and-pulp industry.

SUBSTANCE: cellulose delignification process comprises alkali treatment, delignification with hydrogen peroxide with sodium hydroxide and sodium silicate additive, and acid treatment. Alkali treatment consumes 0.5% hydrogen peroxide and 2.0% sodium hydroxide based on the weight of absolutely dry cellulose and is conducted for 2.0-2.5 h at 60-90°C. Acid treatment of delignified product is accomplished with aqueous hydrochloric acid, which is consumed in amount 1.0% based on the weight of absolutely dry fibers, while treatment is conducted for 30-60 min at ambient temperature.

EFFECT: enhanced economical efficiency without loss cellulose characteristics.

2 tbl, 11 ex

FIELD: paper; chemistry.

SUBSTANCE: method of cellulose fiber modification is realised in the following manner. Suspension mass of cellulose fibers is prepared. In process of its bleaching cellulose derivative is added in at least one stage of acid bleaching. pH of suspension mass is in the interval from approximately 1 to approximately 4, and temperature - in interval from approximately 30 to approximately 95°C. As cellulose derivative carboxy-alkyl-cellulose is used, for instance, carboxy-methyl-cellulose. From this suspension of bleached fiber mass paper is produced by means of dehydration of this suspension on the mesh with formation of paper.

EFFECT: higher strength in wet condition and softness of paper.

42 cl, 2 dwg, 1 ex

FIELD: textile fabrics, paper.

SUBSTANCE: invention is intended for application in pulp and paper industry. Method of bleaching process control for waste paper treatment is characterised by the following operations: preparation of fibrous suspension; measurement of fibrous suspension whiteness; mixing of fibrous suspension with bleaching substance; supply of mixed fibrous suspension to reservoir for bleaching; extraction of mixed fibrous suspension from reservoir for bleaching after certain time interval. Bleaching substance comprises mixture of separate substances, besides amount and/or composition of added bleaching substance is established depending on measured whiteness of fibrous suspension so that possible permanent specified whiteness of extracted fibrous suspension is achieved. Whiteness of extracted fibrous suspension is measured and compared in adaptation mode with specified whiteness, and depending on result of comparison compliance pattern is coordinated. Bleaching device contains reservoir for bleaching, supply pipeline with whiteness sensitive element, metering device, control device, discharge device.

EFFECT: prevention of large oscillations of fibrous suspension whiteness at the end of bleaching process, at that load of used bleaching substance is minimum.

7 cl, 2 dwg

FIELD: textile fabrics, paper.

SUBSTANCE: method is related to bleaching of hardwood sulphate pulp and may be used in pulp and paper industry for production of fibrous semi-finished products for production of printing types of paper. Suggested method is realised in the following manner. Unbleached hardwood sulphate pulp is disintegrated in water, then squeezed, placed into bleaching bath and delignificated by sodium hypochlorite with its consumption of 3% (in units of active chlorine) from mass of absolutely dry fiber. Then cellulose mass is flushed by water. Then double-stage bleaching of cellulose is carried out by sodium chlorite in acid medium with intermediate alkaline extraction. At the first stage of bleaching sodium chlorite consumption makes 1.5-2.5% (in units of active chlorine), and at the second stage of bleaching it makes 0.4-0.5% (in units of active chlorine) from mass of absolutely dry cellulose. After the first stage of bleaching by sodium chlorite mass is flushed by water and exposed either to oxidising alkaline treatment in the presence of hydrogen peroxide at its expenditure of 0.5%, expenditure of sodium hydroxide of 2.0% from mass of absolutely dry fiber, or alkaline treatment with hydrogen peroxide at its expenditure of 1.0%, expenditure of sodium hydroxide of 0.5%, sodium silicate - 3.0% from mass of absolutely dry fiber. After alkaline extraction cellulose is flushed, and the second stage of bleaching by sodium chlorite is carried out. Afterwards mass is flushed with water, and its acid treatment is carried out with hydrochloric acid.

EFFECT: improved quality of bleached cellulose, enhanced efficiency of process and ecological safety.

1 tbl, 6 ex

FIELD: fabrics, paper.

SUBSTANCE: invention is related to pulp and paper industry. Waste paper recycling into finished paper mass is carried out in several stages of process. For extent of whiteness specified value is set for finished mass, besides extent of whiteness is measured between stages of process. Efficiency of process stage is identified with account of occurring expenses relative to increase of whiteness extent, and in system of process control dynamic tuning of separate process stages is performed with account of overall efficiency, in particular efficiency of overall expenses of process. Parametres of quality, such as extent of whiteness, are actually registered and assessed. Quality development and costs modeling is carried out in separate stages of process, and also dynamic continuous adjustment of data in separate stages of process.

EFFECT: improved efficiency of waste paper recycling and control of waste paper quality.

15 cl, 4 dwg

FIELD: textile, paper.

SUBSTANCE: procedure refers to production of wood pulp and can be implemented in pulp-and-paper industry. The procedure consists in whitening fibres of sulphate pulp with a whitening agent on base of chlorine and in washing whitened fibres of sulphate pulp. Upon washing fibres of sulphate pulp are subject to interaction with at least one optic whitener before mixing ponds. Interacting is carried out in solution at pH from 3.5 to 8.0 and temperature from 60 to 80°C during 0.5-6 hours. The invention also refers to wood pulp produced by the said procedure.

EFFECT: increased whiteness and optic brightness of paper at decreased utilisation of optic whitener.

22 cl, 11 dwg, 11 tbl, 7 ex

Up!