Matches 201 - 250 out of 389 < 1 2 3 4 5 6 7 8 >
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5100521 Process and an arrangement for preparing ozonic gases and solutions  
To produce an ozonic aqueous solution, optionally in addition to recovering a gas having an elevated ozone content, an aqueous solution is treated in an absorption vessel under pressure with an...
5091054 Process for bleaching and delignification of lignocellulosic  
Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid. The starting pH of the reaction with peroxomonosulfuric acid is...
5085734 Methods of high consistency oxygen delignification using a low consistency alkali pretreatment  
A method for the production of delignified wood pulp is provided which result in said pulp's having improved delignification ratios. In accordance with preferred embodiments, brownstocks are...
5074960 Lignin removal method using ozone and acetic acid  
Lignin contained in a cellulosic or lignocellulosic pulp product is removed by contacting the product with a gaseous medium containing ozone in the presence of a liquid agent which is a lower fatty...
5073301 Process for stabilization of the viscosity of wood pulps  
A process is described in which, by the addition of formamidinesulfinic acid in association with an ozone or ozone/oxygen treatment, the viscosity and strength of wood pulps are stabilized at the...
5043488 Process for preparing an explosive and the product therefrom  
A process for preparing an explosive comprising contacting a ketone with a compound capable of producing a product, or compound, containing nitro groups for a time sufficient to obtain a product...
5034095 Apparatus and process for the delignification of cellulose pulp  
A cellulose pulp slurry is delignified in an apparatus comprising a vertical cylindrical barrel chamber, a cone-shaped bottom chamber connected to the barrel chamber and having a circular inlet...
5034096 Process for bleaching and delignifying cellulose-containing products  
The present invention provides a process for bleaching and delignifying cellulose-containing products with peroxides and/or oxygen and/or ozone, wherein there is additionally used 0.01 to 2.5% by...
5030324 Sequential bleaching procedure using chlorine and chlorine dioxide in a first chlorination stage of a multistage bleaching process  
An improved process for bleaching cellulosic pulp in a first chlorination stage of a multi-stage bleaching process is provided, which involves an improved process for bleaching cellulosic pulp in a...
5011572 Two stage process for the oxygen delignification of lignocellulosic fibers with peroxide reinforcement in the first stage  
A process is provided for a two-stage oxygen delignification of chemical pulp in which 0.01% to 1% hydrogen peroxide is incorporated into the first and, optionally the second stage. The invention...
4978426 Production of high strength linerboard with oxygen and alkali  
Pulp of improved refinability for the production of high strength linerboard is obtained by digesting wood chips in alkaline cooking liquor, defibering, treating with oxygen and alkali in the...
4959124 Method of bleaching kraft pulp in a DZED sequence  
A method of enhancing the quality of a pulp which has been subjected to a chlorine-based bleaching agent, by subjecting the chlorinated pulp to ozonation prior to an extraction stage in the...
4946555 Apparatus and method for measuring vent gas flow rates and parameters in pulp and paper processing  
An inert gas such as helium is employed as a tracer gas in a pulp and paper mill to determine the utilization of oxygen by an aqueous cellulosic pulp particularly, as well as other parameters, in...
4946556 Method of oxygen delignifying wood pulp with between stage washing  
The viscosity of paper pulp is maximized, while chlorine bleaching is minimized or eliminated, by subjecting the pulp suspension to multiple consecutive oxygen bleaching stages, with a...
4908097 Modified cellulosic fibers  
Disclosed are modified cellulosic fibers comprising the reaction product of linear, water-wettable polysaccharides with N,N'-methylenebisacrylamide and methods of making same. The materials are...
4902381 Method of bleaching pulp with ozone-chlorine mixtures  
Ozone and chlorine are used to bleach cellulosic fibrous material pulp in the production of kraft pulp for paper and paper products, being applied together in a mixture. When the ozone and chlorine...
4897156 Process for activating cellulose pulp with NO and/or NO.sub.2 and oxygen in the presence of nitric acid and then delignifying bleaching the activated cellulose pulp  
A process is provided for activating cellulose pulp using NO and/or NO 2 plus oxygen gas in the presence of nitric acid, added in an amount within the range from about 0.1 to about 1.0 gmole per...
4895619 Method of delignification of cellulosic fiber material  
A method of delignification of cellulosic fiber material is described. The pulp containing said cellulosic fiber material is fed in a main line containing a main reactor in which the pulp is...
4886577 Method and apparatus for mixing oxygen gas with medium consistency pulp in a pump discharge  
Oxygen delignification of paper pulp (comminuted cellulosic material in a slurry) at medium consistency (i.e., about 6-18%) is practiced without the necessity of a separate mixer. The pulp is drawn...
4869783 High-yield chemical pulping  
A chemical pulping process is disclosed wherein wood chips are partially defiberized such that the fibers in the chips are substantially separated from one another but sufficient interfiber bonding...
4857145 Process for making a pulp from bamboo  
Bamboo can be formed into a suitable pulp if prior to digestion it undergoes a process of shredding, washing and wet depithing. The fibers are then chemically digested preferably by a process which...
4840703 Method for controlling an oxygen bleaching  
A method for controlling an oxygen-bleaching process of lignocellulosic pulp to a desired degree of delignification. The pulp is passed at a substantially constant temperature into a bleaching...
4834837 Method for delignification of cellulose with oxygen  
Method and apparatus for delignifying chemical pulp by means of oxygen, in which an aqueous slurry of chemical pulp is formed, then mixed with a caustic agent, followed by contact with a...
4806203 Method for alkaline delignification of lignocellulosic fibrous material at a consistency which is raised during reaction  
A process is disclosed for the pretreatment of lignocellulosic fibrous materials prior to delingification. The process in one of its embodiments is comprised of the following steps: 1....
4786365 Process of making cellulose pulp with a sulphite cooking liquor containing sulphide and a quinone or hydroquinone compound  
A process of manufacturing cellulose pulp from wood by digesting the wood with sulphite cooking liquor containing additions of sulphide and in the presence of a quinone or hydroquinone compound....
4764252 Process for pulping lignocellulosic material with a preoxidized alkaline sulfide pulping liquor containing a cyclic organic compound  
Lignocellulosic material is pulped by a process comprising the steps of: introducing a molecular oxygen-containing gas, such as air, into an alkaline sulfide solution containing NaOH, Na 2 S and...
4756798 Process for bleaching a mechanical pulp with hydrogen peroxide  
Mechanical pulp is bleached by a treatment with hydrogen peroxide wherein prior to or simultaneously with said treatment the mechanical pulp is subject to an oxygen pressure.
4756800 Method for producing salts of monoperoxysulfuric acid and simultaneously bleaching pulp  
A method of producing salts of monoperoxysulfuric acid comprising reacting together, in the presence of a catalyst consisting of cupric ions in a concentration of at least 0.01 part per milion, (a)...
4750973 Process for reducing carbohydrate losses in the sulfate pulping of wood by pretreating the wood with oxygen and nitrogen oxides  
A process is provided for reducing carbohydrate losses in the sulphate pulping of wood using sodium hydroxide and sodium sulfide, by pretreating the wood in the presence of water with oxygen gas...
4729817 Process for the oxidative delignification of demethylated chemical pulp  
The extent of delignification of chemical pulps by oxygen-containing chemicals, preferably hydrogen peroxide, is enhanced by demethylating the pulp prior to such oxidative delignification, to a...
4708829 Apparatus for the removal of impurities from fiber suspensions  
Apparatus for the mixing of gas bubbles into fiber suspensions in order to remove impurities from the fiber suspension by means of flotation is disclosed, including an inlet, an outlet including...
4689117 Thermomechanical digestion process for enhancing the brightness of cellulose pulp using bleachants  
The brightness of a thermomechanical pulp can be improved if a serial multiple blowdown technique is used and a bleachant is present at an effective concentration throughout the thermomechanical...
4684442 Oxygen reactor deaeration tank and system  
A small deaeration tank which may be either at atmospheric pressure on under low pressure or vacuum and a system of operating this tank which allows pulp which has been treated with oxygen to be...
4674888 Gaseous injector for mixing apparatus  
A gas injector element for use in a mixing apparatus having a plurality of mixing elements, where the injector element is airfoil-shaped and is installed adjacent to the first of the plurality of...
4657633 Delignification and bleaching of a cellulose pulp with an alkalioxygen-hypochlorite single stage sequential extraction  
An improved process for bleaching and delignifying cellulose pulp. The process comprises subjecting the pulp to a bleaching stage followed by washing, and thereafter extracting the bleached pulp as...
4626319 Process for the delignification and acid bleaching of cellulose with oxygen and hydrogen peroxide  
A process for the delignification and bleaching of cellulose with oxygen and hydrogen peroxide, in which in a given case the delignification is carried out with oxygen in the presence of MgO, and...
4622101 Method of oxygen bleaching with ferricyanide lignocellulosic material  
Delignifying bleaching of lignocellulosic materials, particularly wood pulps already partly delignified by conventional alkaline pulping processes by electrochemically generated ferricyanide in the...
4622100 Process for the delignification of lignocellulosic material with oxygen, ferricyanide, and a protector  
The use of primary and secondary amines and certain other compounds in ferricyanide assisted oxygen delignifying bleaching of lignocellulosic pulps permits more rapid removal of a desired amount of...
4619733 Pollution free pulping process using recycled wash effluent from multiple bleach stages to remove black liquor and recovering sodium hydroxide from the black liquor  
A pollution free pulping process wherein a lignocellulosic material is subjected to various pulping and bleaching steps without the use of sulphur and chlorine. The system is a closed one thus...
4612088 Reactor to perform chemical reactions with a disintegrating disc  
The present invention provides a reactor adapted to simultaneously accomplish chemical reactions and operations of size reduction of the solid materials in suspension and particularly for treatment...
4602982 Process for delignifying bleaching lignin-containing cellulose pulp by activating the pulp with NO.sub.2 and O.sub.2 gas in the presence of water, sodium nitrate and nitric acid  
A process is provided for delignifying bleaching lignin-containing cellulose pulp which comprises: (1) activating cellulose pulp by reacting the pulp at a pulp consistency within the range from...
4599138 Process for pretreating particulate lignocellulosic material to remove heavy metals  
A process is provided for pretreating particulate lignocellulosic material to remove heavy metals and resin without any delignification or defibration, which comprises washing particulate...
4595455 Method for controlling batch alkaline pulp digestion in combination with continuous alkaline oxygen delignification  
A method for batch pulp digestion with hydroxide-bearing cooking liquors in combination with continuous alkaline oxygen delignification is described. The brown stock washing plant and the connected...
4581104 Method of reducing the lignin in wood pulp with oxygen gas recirculation  
An exothermic reaction of a gas with a gas permeable material is performed in a retention vessel. Temperature control of the exothermic reaction is obtained by recirculating the gas from the top of...
4568420 Multi-stage bleaching process including an enhanced oxidative extraction stage  
A multi-stage process for the delignification and bleaching of lignocellulosic pulp is disclosed wherein the first alkaline extraction stage comprises extracting the pulp with caustic in the...
4560437 Process for delignification of chemical wood pulp using sodium sulphite or bisulphite prior to oxygen-alkali treatment  
In the delignification of chemical wood pulp with oxygen and alkali a larger reduction of the kappa number may be obtained without an increase in the charge of oxygen or alkali, provided the pulp...
4543155 Method for bleaching wood pulp including dissolving oxygen into the dilution water of an extraction stage  
Wood pulp is bleached in a process which includes passing pulp slurry from a chlorine tower through a washer to a downflow extraction tower which is open to the ambient atmosphere. Caustic and...
4534397 Method for producing chemimechanical high yield pulp using an oxygen alkali treatment followed by an oxygen mechanical defibration  
A method for producing pulp in high yield in order to achieve strength improvement and increased absorption of liquid in the end-product, the paper, whereby a lignocellulosic material is treated in...
4526651 Process for oxygen bleaching paper pulp using melamine as a viscosity stabilizer  
This invention is a process for maintaining pulp viscosity while enhancing brightness during the oxygen bleaching stage or stages of pulp preparation in the manufacture of paper comprising adding...
4468286 Method of gas treatment of fluffed pulp  
A method provides for the continuous treatment of a porous, fibrous material such as paper pulp, with a gas, such as ozone. The material is entrained with gas and passed in a first path. The...
Matches 201 - 250 out of 389 < 1 2 3 4 5 6 7 8 >