Patents Assigned to Kemira
  • Patent number: 5968229
    Abstract: A process for the purification of solutions containing metals comprising neutralization of the solution, reduction of Fe(III) present, and elimination of ingoing dissolved zinc, whereby the ingoing solution containing metals is neutralized using magnetite and/or metallic iron, that the ingoing iron (III) is reduced to iron (II) by means of an addition of metallic iron, that ingoing heavy metals are precipitated by the addition of a precipitating amount of a sulphide, whereby the metal sulphides precipitated are recovered by means of filtration, that the solution is, optionally, subjected to an ion exchange operation to transfer ingoing zinc into non-complex bound form, whereupon zinc is recovered as zinc carbonate, that iron (II) in the remaining solution is oxidized to iron (III), whereupon the solution is used as such or is further treated for increasing the metal content for the purpose intended.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: October 19, 1999
    Assignee: Kemira Kemi AB
    Inventor: Stefan Jafverstrom
  • Patent number: 5942199
    Abstract: The invention relates to a method for the treatment of an impure aluminium oxide so that the organic impurities present therein it are converted into an insoluble and easily separable substance. According to the invention, aluminium oxide which contains organic matter as impurities is finely ground, the finely ground aluminium oxide is dissolved at an elevated temperature in sulphuric acid which has a concentration of at minimum 90% by weight, the amount of the sulphuric acid being at least stoichiometric in relation to the amount of aluminium oxide, the organic matter being carbonized into an insoluble and easily separable substance, and, if desired, the obtained mixture is treated further in order to form a solution-form or solid chemical which contains aluminium.
    Type: Grant
    Filed: April 9, 1997
    Date of Patent: August 24, 1999
    Assignee: Kemira Chemicals Oy
    Inventors: Simo Jokinen, Maire Iida Annikki Mattila, Anna-Mari Kristiina Stein, Sirpa-Liisa Katariina Mattila, Gerard Verkoijen
  • Patent number: 5904856
    Abstract: The present invention relates to a process for the preparation of solutions of aluminum salts, characterized in that an aluminate of an alkali metal and/or alkaline earth metal is dissolved in an acid solution to the formation of a solution which is used as such or is diluted to a suitable concentration.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: May 18, 1999
    Assignee: Kemira Kemi Aktiebolag
    Inventors: Magnus Kvant, Roger Barstrom
  • Patent number: 5888404
    Abstract: The invention relates to a method for treating waste water sludge comprising at least one metal originating from a waste water treatment coagulant, and phosphorus and heavy metals in order to recover said at least one metal and phosphorus and to discharge said heavy metals. In this method said waste water sludge is acidified to dissolve metals contained in the sludge thereby yielding an acidified sludge solution containing at least 1% by weight of at least one metal to be recovered. In a first precipitation stage the pH of said acidified sludge solution is raised to precipitate at least one metal to be recovered as a phosphate, and thereafter the phosphate precipitate is separated, thereby leaving a solution comprising heavy metals. In a second precipitation stage the pH of said solution comprising heavy metals is raised and, if necessary, an appropriate chemical is added to precipitate heavy metals, and thereafter the precipitate is discharged.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: March 30, 1999
    Assignee: Kemira Kemi Ab
    Inventor: Simo Jokinen
  • Patent number: 5851260
    Abstract: The invention relates to a stable aqueous fertilizer suspension suitable for drip irrigation, which suspension contains 5-55% by weight water and 45-95% by weight of one or several plant-nutrient containing substances, of which at least one contains water-insoluble solid particles, the particle size of the solid particles contained in the suspension being less than 50 .mu.m and the pH of the suspension being within the range 2-7. The invention also relates to a process for the preparation of this suspension.
    Type: Grant
    Filed: December 26, 1996
    Date of Patent: December 22, 1998
    Assignee: Kemira Agro Oy
    Inventors: Hannu Aijala, Thomas Ahlnas
  • Patent number: 5833892
    Abstract: In a method of producing TiO.sub.2 pigment particles a TiO.sub.a X.sub.b (OH).sub.c -based precursor is suspended in a liquid with or without fuel additives. The suspension is then sprayed to form droplets. The droplets are transported into a flow reactor with a carrier gas. The droplets are decomposed in the flow reactor at high temperatures to form TiO.sub.2 pigment particles which are collected downstream of the flow reactor. In a preferred embodiment, a colloidal suspension of an insoluble TiO(SO.sub.4).sub.b (OH).sub.c precipitate with suitable fuel additives was spray-calcined at 900.degree. to 1200.degree. C. to produce pigment-quality TiO.sub.2. The primary particle size of the TiO.sub.2 pigment particles is between 150-250 nm and the particles are minimally aggregated.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: November 10, 1998
    Assignee: Kemira Pigments, Inc.
    Inventors: Abhijit S. Gurav, Toivo T. Kodas, Bruce M. Anderson
  • Patent number: 5811082
    Abstract: A less dusty, more stable and more easily handlable protector against UV light than previously is obtained by supplying it in the form of solid particles having a mean diameter of at minimum 10 .mu.m and containing, dispersed in 90-20 parts by weight of wax, 10-80 parts by weight of a pigment which reduces the penetration UV light and is made up of metal oxide particles of a mean primary particle diameter smaller than 0.150 .mu.m.
    Type: Grant
    Filed: May 8, 1996
    Date of Patent: September 22, 1998
    Assignee: Kemira Pigments Oy
    Inventors: John Thomas Ahlnas, Timo Valdemar Lofgren
  • Patent number: 5811090
    Abstract: The present invention relates to biological control of plant diseases and concerns new microorganisms belonging to the genus Nectria, as well as their use for controlling fungal infections in plants. The invention also concerns compositions comprising new strains of the genus Nectria and their use for these purposes. The invention also provides a method of screening effective control organisms from microbial strains isolated from soil.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: September 22, 1998
    Assignee: Kemira Agro Oy
    Inventors: Risto Tapio Tahvonen, Milja Tuulikki Keskinen, Marja-Leena Lahdenpera, Pekka Tapani Seiskari, Esa Petri Teperi, Ulla Anita Tuominen
  • Patent number: 5766566
    Abstract: The invention relates to a process of preparing ferric sulfate by forming a slurry which contains ferrous sulfate and sulfuric acid, the slurry containing bivalent iron in both the solution phase and the solid phase, and by oxidizing this slurry to form a ferric sulfate slurry. When so desired, the obtained ferric sulfate slurry is solidified to form solid ferric sulfate. The obtained ferric sulfate may, as such or dissolved in water, be used for the treatment of waste waters or for preparing pure tap water.
    Type: Grant
    Filed: August 2, 1996
    Date of Patent: June 16, 1998
    Assignees: Kemira Pigments Oy, Kemira Chemicals Oy
    Inventors: Harri Mattila, Timo Kenakkala, Olli Konstari
  • Patent number: 5764203
    Abstract: The invention relates to a breathing mask (1) having a display unit (5) comprising a display screen, the function of the unit being to display measurement data in the visual field of the mask wearer, the display screen being implemented by using a mechanical and/or electronic light modulator, the scales, symbols or other signs produced in the light modulator transmitting the measurement data to the wearer.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: June 9, 1998
    Assignee: Kemira Oy
    Inventors: Timo Erkki Holmlund, Raimo Antero Kujanpaa, Rauno Aulis Ollila
  • Patent number: 5741954
    Abstract: This invention relates to a process for the preparation of m-alkylphenols, particularly of 3-ethylphenol, from the mixture of alkylbenzenesulfonic acid isomers by selective desulfonation, removal of formed alkylbenzene and caustic fusion. In the present invention the inventive desulfonation is accomplished by addition of steam to the mixture of sulfonic acid in an excess in relation to the amount of evaporable water, simultaneously maintaining the temperature of the mixture above 160.degree. C. until the desired purity of isomers is obtained, and until the content of the sulfuric acid in the mixture is decreased below 40%.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: April 21, 1998
    Assignee: Kemira Agro Oy
    Inventors: Elias Suokas, Markku Niemi, Pekka Somersalo, Jouko Kujala
  • Patent number: 5731437
    Abstract: The invention relates to a process for the preparation of melamine from urea by feeding molten urea and hot ammonia gas into a reactor having a pressure within the range 50-150 bar and a temperature within the range 360.degree.-430.degree. C., whereby a reaction product is obtained which contains a liquid melamine melt and a gas mixture. This gas mixture is separated from the liquid melamine melt, and the liquid melamine melt thus obtained is directed to a vaporizer and is vaporized therein, and the melamine-containing gas obtained from the vaporizer is cooled in a quencher, in which case the melamine crystallizes in a very pure state, the purity being typically at minimum 99.9%.
    Type: Grant
    Filed: June 13, 1996
    Date of Patent: March 24, 1998
    Assignee: Kemira Agro Oy
    Inventors: Ilkka Turunen, Pekka Oinas
  • Patent number: 5725837
    Abstract: The invention relates to a process for the preparation of hydrogen peroxide by the anthraquinone process, comprising the oxidation of a hydrogenated organic working solution for the formation of hydrogen peroxide and the extraction of the hydrogen peroxide into an aqueous phase, the oxidation and the extraction being carried out in the same space by directing into one and the same reactor (1) a hydrogenated organic working solution, an oxygen-containing gas and an aqueous extraction solvent in order to form a mixture of three phases, i.e., an organic phase, a gas phase and an aqueous phase, whereby the dissolving of the oxygen in the working solution and the oxidation reaction in the working solution, as well as the transfer of the hydrogen peroxide to the aqueous phase are achieved, whereafter the product leaving the reactor is subjected to phase separation (2) for the recovery of an aqueous solution of hydrogen peroxide.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: March 10, 1998
    Assignee: Kemira Chemicals Oy
    Inventor: Ilkka Turunen
  • Patent number: 5720882
    Abstract: Waste water sludge which contains phosphorous, heavy metals and at least one metal originating from a waste water treatment coagulant, is treated in order to recover the phosphorous and the at least one metal, and to discharge the heavy metals. The at least one metal includes iron.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: February 24, 1998
    Assignee: Kemira Kemi AB
    Inventors: Kjell Stendahl, Simo Jokinen
  • Patent number: 5695609
    Abstract: The invention relates to a process for the production of paper by adding to an aqueous fiber suspension, which possibly contains a filler, auxiliary agents for improving retention and/or dewatering, the auxiliary agents being a cationic long-chain polyacrylamide and an aluminum salt, and by dewatering the obtained fiber suspension during the sheet-forming stage. According to the invention, the said aqueous fiber suspension, possibly containing a filler, to which the cationic long-chain polyacrylamide has first been added, is subjected to shearing forces, whereafter there is added to it, directly before sheet forming, a polymeric aluminum salt or an aluminum salt, in which case a base or an acid is added, when necessary, to the said fiber suspension so that the pH be within the range 7-9 before the sheet forming, in which case aluminum hydroxy particles having anionic surface charges will be formed in situ.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: December 9, 1997
    Assignee: Kemira Oy
    Inventors: Lars Harald Petander, Tore Anders Duvnas
  • Patent number: 5674402
    Abstract: A method for the treatment of sludge obtained from such a water treatment process wherein an aluminium or iron chemical is used as a coagulant, so as to reduce the amount of sludge, which method comprises the steps of:a) treating the water treatment sludge with an inorganic acid to produce an acidic sludge comprising dissolved aluminium or iron,b) optionally separating insoluble material from the acidic sludge to produce an acidic solution comprising dissolved aluminium or iron,c) treating said acidic sludge or said acidic solution with a +1-cation compound in the presence of sulphate ions in such conditions that the pH of the sludge or solution remains at a level where aluminium precipitates as an alunite compound or iron precipitates as a jarosite compound, andd) separating the precipitated alunite or jarosite compound from the remaining sludge.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: October 7, 1997
    Assignee: Kemira Kemi Ab
    Inventors: Rolf Nilsson, Simo Jokinen
  • Patent number: 5671730
    Abstract: The invention relates to a method for regulating the rate of air fed into a gas mask, as well as to a gas mask. The power of the gas mask blower is regulated on the basis of the current and rotation speed of the blower. The invention can be applied in any facial parts of breathing masks.
    Type: Grant
    Filed: February 24, 1995
    Date of Patent: September 30, 1997
    Assignee: Kemira Safety Oy
    Inventor: Rauno Ollila
  • Patent number: 5670021
    Abstract: A process for the production of paper by forming and dewatering a suspension of cellulose containing fibers and optional fillers and cationic starch on a wire or fabric, characterized in that the forming and dewatering takes place in the presence of an alkali metal silicate and a phenolic resin added at the same point into the suspension, and polyethylene oxide added at a subsequent point into the suspension. The amount of alkali metal silicate is 0.1 kg per ton to 50 kg/ton based on silica content per ton of dry fibers. The amount of phenolic resin is 0.01 kg/ton to 5 kg/ton based on weight of resin in the as-supplied material per ton of dry fibers. The amount of polyethylene oxide is 0.01 to 2.0 kg/ton based on weight of polyethylene oxide per ton of dry fibers.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: September 23, 1997
    Assignee: Kemira Kemi Aktiebolag
    Inventor: Michael Owens
  • Patent number: 5662826
    Abstract: The present invention relates to a process for the preparation of a coagulant for water purification, in particular purification of sewage water, for pulp and paper manufacture, for dewatering organic matter, for concentrating minerals, and containing a metal salt and silicate, whereby a solid zeolite is dissolved in a solution of trivalent metal salt in a molar ratio Me.sup.3+ :Si of >2:1, preferably 2-500:1, as well as a coagulant.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: September 2, 1997
    Assignee: Kemira Kemi Aktiebolag
    Inventors: Rolf Olof Nilsson, Kjell-Erik Stendahl
  • Patent number: 5637286
    Abstract: The invention relates to a method for producing hydrogen peroxide by the anthraquinone process, by feeding into the top part of a fixed bed reactor (4) hydrogen (3) and a working solution (1), i.e. an anthraquinone derivative in an organic solvent, and by making these infed substances flow downwardly in the reactor, in order to catalytically hydrogenate the anthraquinone derivative owing to the influence of the catalyst bed (6) and by removing the hydrogenated working solution (9) from the reactor. According to the invention, there is used a fixed bed reactor provided with a stationary catalyst bed that has an open structure.
    Type: Grant
    Filed: March 14, 1995
    Date of Patent: June 10, 1997
    Assignee: Kemira Chemical OY
    Inventor: Ilkka Turunen