Abstract: A method in bleaching of pulp is described, in which the pulp is subjected to a peroxide bleaching step, whereupon the pulp is washed and the washing liquid from the washing is separated from the pulp in the form of a filtrate. The method is characterised in that the filtrate is treated with an aluminium compound, such as aluminium sulphate or polyaluminium sulphate, for precipitation of interfering substances, such as oxygen-demanding organic material and metals, that the precipitated material is removed from the filtrate, that the aluminium content of the filtrate after precipitation of interfering substances is adjusted to at most 20 ppm, and that the filtrate is then recirculated to the peroxide bleaching step. By the method, a reduced consumption of hydrogen peroxide in the peroxide bleaching step is achieved.
Abstract: Methods of sizing paper using a latex as a surface sizing agent are described, in which the latex is defined by acid number or particle size. Further described are methods of improving toner adhesion of papers that are surface sized with alkenylsuccinic anhydrides by employing latexes that have a glass transition temperature of from about 25 to about 65. Still further described are low shear methods of dispersing alkenylsuccinic anhydrides in sizing compositions using latexes as dispersing aids.
Type:
Application
Filed:
October 7, 2002
Publication date:
April 8, 2004
Applicant:
Kemira Chemicals, Inc.
Inventors:
Vaughn L. Irwin, Terrence Edward Cotter, Delos E. Boardman
Abstract: The invention relates to a method for the production of paper or board, wherein retention aids are added to the stream of stock. Improved retention and more effective dewatering are achieved by adding to the stream of stock a cationic polymer solution and a suspension-form microparticle mixture composed of a swellable clay of the smectite group and a colloidal synthetic metal silicate in which the prevalent cation is magnesium.
Abstract: The invention relates to a process for the preparation of compound fertilizer granules containing at least two of the plant nutrients nitrogen, phosphorus and potassium, said process including the steps of: providing a solid fee material including at least one solid fertilizer raw material and optionally recycle material, feeding the feed material or a part thereof into a melter for melting a desired portion thereof and keeping said portion in molten state, feeding the molten or partly molten material and optionally other desired solid raw materials to a granulator to obtain a granulated product, and cooling and optionally screening the granulated product to obtain dry compound fertilizer granules having a desired size distribution, provided that no water or aqueous liquid is introduced into the process.
Abstract: The invention relates to a solid antimicrobial product suitable for the preservation of an organic material and for combating of detrimental microorganisms, as well as for pH control. The product contains, absorbed into a support a concentrated formic acid partly neutralized with gaseous ammonia, the water content of the formic acid being below 2% by weight. In addition, the invention comprises a method for preparing the product.
Type:
Grant
Filed:
October 23, 2002
Date of Patent:
February 10, 2004
Assignee:
Kemira Chemicals Oy
Inventors:
Eero Aitta, Jouko Arvola, Pekka Johnson, Juha Kangastalo, Marjo Luoma, Ilkka Pollari
Abstract: The reaction medium and distillate of a conventional continuous peracetic acid process can be combined into a stable peracetic acid product if the acid catalyst present in the reaction medium is neutralized.
Type:
Grant
Filed:
April 3, 2002
Date of Patent:
January 13, 2004
Assignee:
Kemira Chemicals Oy
Inventors:
Seppo Pohjanvesi, Arto Pukkinen, Teemu Sodervall
Abstract: The conventional process for the production of a peracetic acid product, wherein hydrogen peroxide, acetic acid and water are fed into an aqueous reaction medium containing hydrogen peroxide, acetic acid, peracetic acid and an acid catalyst, wherein hydrogen peroxide and acetic acid react in the presence of the acid catalyst and form peracetic acid, and an aqueous peracetic acid concentrate is removed continuously from the reaction medium by distillation, has now been improved by feeding the acid catalyst continuously into the reaction medium and by withdrawing continuously a portion of the reaction medium as a bottom product. When the through flow of the reaction medium is thus increased, it is purified of impurities threatening the safety of the process. If the amount of acid catalyst in the reaction medium is further decreased, a product suitable, for example, for disinfection is obtained from the bottom product.
Type:
Grant
Filed:
April 3, 2002
Date of Patent:
January 13, 2004
Assignee:
Kemira Chemicals Oy
Inventors:
Seppo Pohjanvesi, Eva-Liisa Mustonen, Arto Pukkinen, Reino Lehtinen
Abstract: The process contemplates the use of a sizing dispersion that comprises an aqueous dispersion of rosin material, a synthetic sizing agent and a aluminum compound selected from the group formed by aluminum sulfate and aluminum polymers of formulas
[Al(OH)x(A)(3−x)]n (1)
or
[Al(OH)x(H3PO4)y(A)(3−x)]n (2)
where A=Cl−, NO3−, HCOO−, CH3COO−;
or
[Al(OH)x(H3PO4)y(SO4)(3−x/2)]n (3)
where “x” ranges from 0.03 to 2.7, and “y” ranges from 0.01 to 0.8 and n≧2;
and by mixtures thereof.
Abstract: Catalytic converter for treatment of exhaust gas from combustion engines, comprising a metal monolith (13) held together by interlocking ridges (15) between spirally wound layers without brazes or welds, with a mantle (14) held to the monolith by the same type of interlocking ridges (16), and where the mantle has an integral clamping flange (17) which is clamped between the exhaust manifold (12) and an exhaust port (11) of the engine block (10).
Abstract: A method of purifying sewage is described. The method relates to purifying sewage in sewage systems which comprise a toilet, by adding a precipitant for precipitation of phosphates and for binding organic substances. The method is characterized in that the precipitant is selected from the group consisting of iron salts and aluminum salts, such as sulphates, chlorides and nitrates and is adapted to be flushed with water in the toilet bowl when flushing. In the method, the sewage from the toilet is preferably conducted to a sludge separator through an outlet pipe which leads to the lower part of the sludge separator below its outlet.
Abstract: Methods for the preparation of an N-alkyl-N-bis-(2-( 1,2-dicarboxy-ethoxy)-ethyl)-amine derivative are described, products of the methods as well as uses of the products. The derivative is prepared by reacting an alkali or earth alkali metal salt of maleic acid with an N-substituted diethanolamine, the reaction taking place with the two ethanol groups of the diamine while the substituent group bound to the N atom remains unaffected, or alternatively by first reacting diethanolamine with an alkali or earth alkali metal salt of maleic acid to yield N-bis-(2-(1,2-dicarboxy-ethoxy)-ethyl)-amine, which is then reacted with a substitution reagent to obtain the final product. The derivative is useful as chelating agents, e.g., in the bleaching of chemical or mechanical pulp or in textile bleaches containing hydrogen peroxide or a peracid, or as a calcium binder in detergents and cleaning agents.
Type:
Grant
Filed:
September 8, 2000
Date of Patent:
July 8, 2003
Assignee:
Kemira Chemicals Oy
Inventors:
Reijo Aksela, Ilkka Renvall, Aarto Paren
Abstract: The present invention relates to a process for preparation of a granular composition, which comprises magnesium and phosphorus. In the process, magnesium oxide is granulated with addition of a granulating liquid, which contains phosphoric acid and water. According to the invention, the granulating liquid, besides phosphoric acid and water, also contains sulphuric acid.
Abstract: There is disclosed a frictionizing composition for imparting long-term anti-slip properties to the surface of a paper product comprising an aqueous sol of colloidal silica, glycerin, and at least one agent selected from the group consisting of N-methyl pyrrolidone, N,N-dimethyl acetoacetamide, urea, sorbitol, fructose and dextrose. The composition remains fluid, even after prolonged exposure to drying conditions, and thus is readily dispersible in water for easy cleanup of residue from apparatus and the work environment.
Abstract: A method for corrugating a metal foil (11), which together with a longitudinally flat foil (12) is intended to form a foil package pervious to liquid or gas, where the folds are made with a very small fold radius by rolling in at least two steps between rollers (42, 43) disposed in pairs, the fold radius (51) being large and the fold height (52) low in a first step, and after the final step, the fold radius (53) is less than 10%, preferably 2 to 5% of the fold distance (55), and the fold height (54) is greater than after the first step.
Abstract: A method for manufacturing alkali metal or alkaline-earth metal formate, starting from a formate anion comprises at least the following sequential steps: A) conversion of a solid anion exchanger to formate form by feeding into it a solution containing a formate anion, B) exchanging the formate anion in the anion exchanger for a replacing anion by feeding into it an alkali metal or alkaline-earth metal salt solution of this replacing anion, C) recovering the alkali metal or alkaline-earth metal formate solution eluted from the anion exchanger during the exchange of the formate anion. The anion exchanger is converted to formate form by feeding into it a sodium formate solution, a formic acid solution or a solution which contains both sodium formate and formic acid. The method can be used for production of potassium formate or calcium formate.
Type:
Grant
Filed:
April 16, 2001
Date of Patent:
December 10, 2002
Assignee:
Kemira Chemicals OY
Inventors:
Erkki Paatero, Marko Lahtinen, Kari Saari, Pekka Vapaaoksa
Abstract: A method for the preparation of sodium percarbonate granules having enhanced stability, comprising modifying the surface of the sodium percarbonate granules by a surface reaction between sodium percarbonate and carbon dioxide or bicarbonate species to form a dense solid film of essentially sodium bicarbonate on the surface of the sodium percarbonate granules, the method comprising the steps of:
Abstract: A sizing composition and a method of sizing a cellulosic fiber material are disclosed. The sizing composition comprises an aqueous dispersion of a rosin material and a polyaluminium compound, and is characterised in that the polyaluminium compound is a polyaluminium phosphate sulphate compound. The polyaluminium phosphate sulphate compound should comprise at least 5% by weight, calculated as aluminium on the amount of rosin material in the composition. It is preferred that the sizing composition also comprises a synthetic sizing agent in addition to the rosin material. The dispersion preferably also includes a dispersing agent and has a dry content of at least 1% by weight. The sizing composition is used for the sizing of cellulosic fibre materials, such as paper, board or paper board by adding 0.
Type:
Grant
Filed:
October 13, 2000
Date of Patent:
August 20, 2002
Assignee:
Kemira Kemi AB
Inventors:
Lars Ingemar Gillberg, Josep Lluis Bisbal Tudela
Abstract: The invention relates to a process for preparing a cationically modified (meth)acrylamide polymer by the Mannich reaction. There is prepared in advance a stable aldehyde-secondary amine adduct, which is obtained as a reaction product of an aqueous solution of the secondary amine and an aqueous solution of the aldehyde, and which, after the formation of the adduct, is stabilized to endure storage, by lowering the pH of the mixture of 7 or below and/or by adding methanol, and the adduct thus prepared is added to an aqueous solution of the (meth)acrylamide polymer and the pH is adjusted to an alkaline level, whereupon modification occurs. The invention also relates to the use of the modified (meth)acrylamide polymer as a flocculation, retention or dewatering agent.
Type:
Grant
Filed:
April 13, 2000
Date of Patent:
May 14, 2002
Assignee:
Kemira Chemicals Oy
Inventors:
Jonni Ahlgren, Lars Petander, Jussi Nikkarinen
Abstract: The invention relates to a hydrophobising system for paper or a similar fiber product, comprising
(1) a ketene dimer, and
(2) an alkenyl and/or alkyl succinic acid and/or a salt thereof.
The invention additionally relates to a method for hydrophobising paper or a similar fiber product comprising adding a hydrophobising system defined above to fibers.