Patents Assigned to Kemira
  • Patent number: 6331192
    Abstract: The invention relates to a process for the bleaching of chemical pulp, wherein the pulp is delignified and/or bleached with chlorine dioxide or with a combination of chlorine dioxide and a per-compound, and additionally the pulp is chelated in order to bind heavy metals, such as Fe, Mn and/or Cu, to a chelate complex. The chelate complex is selected from the group made up of N-bis-[(1,2-dicarboxylethoxy)-ethyl]-amine, N-bis[(1,2-dicarboxylethoxy)-ethyl]-aspartic acid and N-tris-[(1,2-dicarboxylethoxy)-ethyl]-amine, and the alkali metal and earth-alkali metal salts of these, and the chelating treatments are carried out simultaneously by combining the chelating chemical with the pulp in the same bleaching stage as chlorine dioxide.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: December 18, 2001
    Assignee: Kemira Chemicals Oy
    Inventors: Jukka Jäkärä, Reijo Aksela, Aarto Parén, Ilkka Renvall
  • Patent number: 6306256
    Abstract: A method and an agent for improving the retention when dewatering a cellulosic fiber suspension are disclosed In the method, there is added to the suspension a retention agent containing a phenol-formaldehyde resin and a polyethylene oxide, and the method is characterised in that a modified phenol-formaldehyde resin containing cationic groups is added to the suspension. The modified phenol-formaldehyde resin preferably has a cationicity of about 5-85% and the cationic groups preferably consist of amine groups. The polyethylene oxide in the retention agent preferably has a molecular weight of about 0.5-20×106. The modified phenol-formaldehyde resin and the polyethylene oxide are preferably added to the suspension in a weight ratio of modified phenol-formaldehyde resin:polyethylene oxide of from 1:5 to 50:1, and the amount of polyethylene oxide added preferably is about 10-1000 ppm, based on tie dry solids content of the suspension.
    Type: Grant
    Filed: January 4, 2000
    Date of Patent: October 23, 2001
    Assignee: Kemira Kemi AB
    Inventors: Bo Rosengren, Ulla Gytel
  • Patent number: 6290812
    Abstract: A method treats process water containing metal ions, in connection with bleaching of lignocellulosic pulp. The method is characterized by the steps of a) adjusting the Mg2+ content of the process water to form a flocculating base for metals and an organic substance; b) supplying a carbonate source to the process water to precipiate calcium as calcium carbonate; c) increasing the pH of the process water by adding white liquor to precipipate metals such as metal hydroxides; d) adding a flocculating agent to the process water; and e) separating the precipitated, flocculated metal compounds from the process water by flotation.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: September 18, 2001
    Assignee: Kemira Kemi AB
    Inventors: Christos Rampotas, Viveka Svensson, Jonny Hansson, Margareta Nilsson
  • Publication number: 20010021462
    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.
    Type: Application
    Filed: February 9, 2001
    Publication date: September 13, 2001
    Applicant: Kemira Metalkatoy
    Inventor: Sven Melker Nilsson
  • Patent number: 6284921
    Abstract: An oligomethylene urea product usable as a fertilizer can be more efficiently prepared in several steps by: a) introducing at least urea and an aqueous solution of formaldehyde in the overall molar ratio of urea to formaldehyde of the step 1:1-2:1 into a reactor with a retention time of at least 0.5 h, a temperature maintained in the range of 40 to 95° C. and a pH maintained in the range of 6.5 to 11, in order to produce a methylol urea composition, b) conducting the methylol urea composition to a second reactor with a temperature maintained in the range of 5 to 35° C. and a pH maintained in the range of 1.8 to 3.5, in order to produce a first oligomethylene urea slurry, and optionally, c) conducting the methylol urea composition or the first oligomethylene urea slurry to a third reactor with a temperature maintained in the range of 5 to 35° C. and a pH maintained in the range of 1.8 to 3.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: September 4, 2001
    Assignee: Kemira Agro Oy
    Inventor: Jarmo Luhtala
  • Patent number: 6274105
    Abstract: The present invention relates to a new selective process for producing high-purity potassium nitrate or potassium phosphate. The process uses a liquid agricultural or fermentation by-product, such as molasses, vinasse or potato thick juice as its potassium source and comprises the following unit operations: clarification, ion exchange, neutralization, concentration and crystallization. Importantly, the present invention also concerns a process for producing an ingredient for animal feed, said ingredient having a reduced potassium content.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: August 14, 2001
    Assignees: Avebe B.A., Kemira Agro Oy
    Inventors: Marcus Vorage, Per Eichner
  • Patent number: 6270564
    Abstract: The invention relates to a process for the bleaching of a mineral pigment or a synthetic pigment, in which process the pigment to be bleached is contacted with a solution which contains peracetic acid in order to obtain a pigment with a raised degree of brightness.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: August 7, 2001
    Assignee: Kemira Chemicals Oy
    Inventor: Pentti Hukkanen
  • Patent number: 6270738
    Abstract: The invention relates to a process for preparing a usable product, in particular a water treatment solution which contains ferric iron, from an impure ferric sulfate solution which contains as an impurity at least one other metal, the process comprising a first precipitation step in which a base is added to the said impure ferric sulfate solution in order to raise the pH to approx. 2-5, preferably approx. 3-4, whereupon ferric hydroxide precipitates; following the first precipitation step, a second precipitation step in which there are added to the solution an oxidant and a base to raise the pH to approx. 6-10, preferably approx. 8-9, whereupon the said impurity metal precipitates; and one or more separation steps to separate from the sulfate solution the solids precipitated in the first and the second precipitation steps; as well as possibly an additional step in which the said separated solids, or a portion thereof, are treated further in order to form a usable product.
    Type: Grant
    Filed: October 20, 1999
    Date of Patent: August 7, 2001
    Assignee: Kemira Chemicals OY
    Inventors: Simo Jokinen, Stefan Jäfverström, Timo Kenakkala
  • Patent number: 6267932
    Abstract: A catalytic converter reactor includes a substrate body and a very thin sheet metal mantle strip encircling the substrate body. The substrate body includes flat foil strips alternating with corrugated foil strips, the foil strips being wound-up to form axial flow through passages. The mantle strip has a thickness in the range of 0.1 to 0.8 mm, and is provided with radially inwardly projecting ridges received in radially outwardly open recesses of the substrate body, to axially lock the mantle strip to the substrate body.
    Type: Grant
    Filed: September 21, 1999
    Date of Patent: July 31, 2001
    Assignee: Kemira Metalkat Oy
    Inventor: Sven Nilsson
  • Patent number: 6264790
    Abstract: A process for the bleaching of chemical pulp, in which process the pulp is delignified with a peracid and additionally the pulp is chelated in order to bind heavy metals, such as Fe, Mn and/or Cu, into a chelate complex. According to the invention, the chelating is carried out using a chemical which has been selected from a group consisting of N-bis-((1,2-dicarboxy-ethoxy)-ethyl)-amine, N-bis-((1,2-dicarboxy-ethoxy)-ethyl)-aspartic acid and N-tris-((1,2-dicarboxy-ethoxy)-ethyl)-amine, as well as the alkali metal and earth-alkali metal salts thereof, and the peracid and chelating treatments are carried out simultaneously by combining the peracid and the said chelating chemical in the same solution phase. In the bleaching sequence the treatment according to the invention may follow, for example, an ozone delignification and precede an alkaline peroxide step, and in the latter case a magnesium compound, such as MgSO4, may be added to the pulp before the alkali step.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: July 24, 2001
    Assignee: Kemira Chemicals Oy
    Inventors: Jukka Jäkärä, Aarto Paren, Reijo Aksela, Ilkka Renvall
  • Patent number: 6262008
    Abstract: The invention relates to a stable sodium carbonate peroxyhydrate which is suited for use together with crystalline synthetic silicate-based detergents and is coated with an alkali metal sulfate and a copolymer or terpolymer of vinyl pyrrolidone.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: July 17, 2001
    Assignee: Kemira Chemicals Oy
    Inventors: Ilkka Renvall, Timo Korvela
  • Patent number: 6258328
    Abstract: The present invention relates to a catalyst comprising a honeycomb (1) and a surrounding jacket, the honeycomb comprising a structure formed of a stack of metal sheets, of which at least part are profiled, and the honeycomb structure including several through-flow channels for gas. The free ends of the said metal sheets are distributed over a part (S1) of the honeycomb periphery unsymmetrically to the center of the honeycomb so that part (F1) of the honeycomb's periphery is free from the free ends of the metal sheets. The said honeycomb is attached either directly or through an intermediate layer to the said jacket over an area (L1) comprising at least part of the said free ends.
    Type: Grant
    Filed: August 29, 1998
    Date of Patent: July 10, 2001
    Assignee: Kemira Metalkat Oy
    Inventors: Keijo Torkkell, Aimo Lehtimäki, Timo Avikainen
  • Patent number: 6217768
    Abstract: A method for treating sludge from wastewater purification is described. In the method, a sludge is treated, which contains phosphorus and at least one metal which originates from precipitation chemicals and which is selected among divalent iron and aluminum, the pH of the sludge being adjusted to below 4, preferably below 2, for dissolving the content of the phosphorus and said metal in the sludge; the remaining sludge is separated; the solution relieved of sludge and containing phosphorus and said metal is treated for precipitation of the phosphorus content of the solution as FePO4 at a pH of 2-3; and precipitated FePO4 is separated. The method is characterized in that the solution which remains after separation of FePO4 and which contains said metal from the precipitation chemicals, is recycled to the wastewater purification. The phosphorus content of the solution is precipitated as FePO4 by adding an at least equivalent amount of Fe3−.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: April 17, 2001
    Assignee: Kemira Kemi AB
    Inventors: Bengt Hansen, Simo Jokinen
  • Patent number: 6187143
    Abstract: The invention relates to a process for the manufacture of hydrophobic paper or board by using rosin sizing, an organic complexing agent being used together with the rosin size. The invention also relates to a sizing composition.
    Type: Grant
    Filed: August 27, 1999
    Date of Patent: February 13, 2001
    Assignee: Kemira Chemicals OY
    Inventors: Ari Juppo, Aarto Paren
  • Patent number: 6165318
    Abstract: A process for the delignification of a chemical pulp, such as a sulfate or sulfite pulp, in which process the pulp is treated with a peroxide and/or a peracid in the presence of an activating Ti-, V- or Cr-group transition metal, such as molybdenum, vanadium or tungsten. A compound containing at least one heteroatom, such as Si, P or B, which is capable of forming a heteropolyacid with the activating transition metal, is added to the pulp. The feeding of the activating transition metal and the heteroatom into the pulp may take place in one and the same alkaline solution, for example introduced into the solution or in the form of a compound of the silicomolybdenic acid type, formed in the solution. The peroxide and/or peracid treatment may constitute part of the bleaching sequence, which contains as potential other treatment steps, for example, a treatment with oxygen and a chelation for the removal of heavy metals such as iron, manganese and/or copper.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: December 26, 2000
    Assignee: Kemira Chemicals OY
    Inventors: Aarto Paren, Jukka Jakara, Juha Patola
  • Patent number: 6093849
    Abstract: The invention relates to N-bis- or N-tris-[(1,2-dicarboxy-ethoxy)-ethyl]-amine derivatives having the formula (I) ##STR1## and R.sub.2 is hydrogen, an alkali metal or an earth-alkali metal. The invention also relates to a method for preparing the same and their use as chelating agents.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: July 25, 2000
    Assignee: Kemira Chemicals Oy
    Inventors: Reijo Aksela, Ilkka Renvall, Arto Paren
  • Patent number: 6049002
    Abstract: The method for the preparation of aqueous solutions containing performic acid formed by reaction of formic acid and hydrogen peroxide n the presence of a catalyst, the catalyst being a compound containing at least one ester group and/or group (a) differing from a carboxylic acid group and an alcoholic group, preferably a carboxylic acid ester, and aqueous solutions containing performic acid, formic acid, hydrogen peroxide, and a compound containing at least one ester group and/or group (a) differing from a carboxylic acid group, and the use of such solutions.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: April 11, 2000
    Assignee: Kemira Chemicals B.V.
    Inventors: Tapio Mattila, deceased, Reijo Aksela
  • Patent number: 6010630
    Abstract: A method for recovering at least one metal from an acidified waste water sludge by liquid-liquid extraction by providing an acidified waste water sludge containing ions of at least one metal and organic material, treating the waste water with an oxidizer to convert the organic material into a form that does not have an unfavorable effect on a subsequent liquid-liquid extraction, and subjecting the treated, acidified waste water sludge to a liquid-liquid extraction thereby obtaining an organic phase loaded with ions of said at least one metal, and subsequently recovering ions of said at least one metal from said organic phase.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: January 4, 2000
    Assignee: Kemira Kemi AB
    Inventors: Pekka Oinas, Simo Jokinen
  • Patent number: 5997602
    Abstract: The invention relates to a stable, concentrated aqueous fertilizer suspension, which can be diluted with water to provide a working solution. The suspension contains 10 to 60% by weight of water and 40 to 90% by weight of a plant nutrient composition based on at least a calcium, and/or a magnesium and a phosphate ion, and the suspension comprises at least one plant nutrient containing water-insoluble solid particles with a particle size less than 50 .mu.m, the pH of the suspension being in the range of 0.5 to less than 2.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: December 7, 1999
    Assignee: Kemira Agro Oy
    Inventor: Hannu Aijala
  • Patent number: 5968504
    Abstract: The present invention relates to biological control of plant diseases and concerns new Gliocladium catenulatum fungi and their use for controlling fungal infections in plants. The invention concerns also compositions comprising new strains of Gliocladium catenulatum and their use to said purpose.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: October 19, 1999
    Assignee: Kemira Agro Oy
    Inventors: Risto Tapio Tahvonen, Milja Tuulikki Keskinen, Marja-Leena Lahdenpera, Pekka Tapani Seiskari, Esa Petri Teperi, Ulla Anita Tuominen, Hanna Helena Avikainen