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.

Abstract: The present invention relates to a process for treating more or less concentrated aqueous effluents, such as processing waters, industrial or urban waste waters, and sludges, in particular sludges derived from these waste waters. The said process comprises at least one step of physical separation of a liquid phase and of a solid phase dispersed in the said liquid phase and at least one addition of chemical conditioning reagents and optionally of antifoaming agents. The process also comprises the injection of carbon dioxide (CO2) into the said aqueous effluents, in an amount which is sufficient to give them a pH of less than 7.8.

Abstract: Apparatus for removing fine impurities from a fibrous suspension comprises a dissolution device, a pre-purification device, a wet straining device, and at least one flotation device. The wet straining device comprises at least two sorting devices present in sequence, each sorting device having a wire for separating the fibrous suspension into an “accepts” portion and a “rejects” portion. The flotation device is adapted to purify the “accepts” portion of at least one sorting device, and further separates the fibrous suspension into an “accepts” portion and a “rejects” portion. The process for removing fine impurities from a fibrous suspension comprises the steps of subjecting the fibrous suspension to a dissolution process, subjecting the fibrous suspension to a pre-purification process, purifying the fibrous suspension in a wet straining process, and purifying “accepts” portions from the wet straining process by a flotation process.

Abstract: This invention is directed to a method of removing color bodies from paper mill waste water comprising adding to the water an effective color-removing amount of a hydrophilic cationic dispersion polymer prepared by polymerizing i. a cationic diallyl-N,N-disubstituted ammonium monomer of formula (H2C═CHCH2)2N+R1R2X−  wherein R1 and R2 are independently C1-C20 alkyl, aryl, alkylaryl or arylalkyl and X is an anionic counterion and ii. an acrylamide monomer of formula  wherein R3 and R4 are independently hydrogen, C1-C10 alkyl, aryl or arylalkyl; R5 is hydrogen or methyl and R6 and R7 are independently hydrogen or C1-C10 alkyl, in an aqueous solution of a polyvalent anionic salt wherein the polymerization is carried out in the presence of a dispersant.

Abstract: Cellulosic fines and cellulosic fibers are separated from a suspension containing the fines, the fibers and hydrophobic materials by screening the suspension to remove the fibers, and then subjecting the resultant filtrate to dispersed air flotation in the presence of calcium and generally a separation aid to form an upper Reject fraction in which the hydrophobic material is concentrated and a lower Accept fraction in which the cellulosic fines are concentrated.

Abstract: An aqueous slurry containing dissolved solids and a high concentration of suspended solids is positioned as a mat between a pair of porous endless belts to provide a composite structure. The composite structure is moved through a treating zone and subjected to alternate stages of compression and relaxation. In a preferred mode, the compression and relaxation are achieved by passing the composite structure over a series of spaced rolls in a manner such that a first belt of the pair is in direct contact with one of the rolls and a second belt of the pair is in contact with the next adjacent roll. A liquid stream containing a high concentration of dissolved solids is cascaded over the mat in a countercurrent fashion, with the result that dissolved solids of the liquid stream are dissolved in the aqueous phase of the mat when the mat is subject to relaxation. The mat containing the increased concentration of dissolved solids and suspended solids can then be compacted and the solid residue can be landfilled.

Abstract: This invention is directed to a method of clarifying and dewatering industrial waste water using anionic and nonionic dispersion polymers.

Abstract: The present invention relates to a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, and to the use of a thus obtained pigment slurry for the preparation of a coating compound for the paper industry or in the paper stock for papermaking. An essential element of the invention is a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, characterized in that the residual water sludges containing the fillers and coating pigments are subjected to mixing and then milling together with fresh pigments or fresh fillers in the form of powders, fresh-pigment containing slurries and/or fresh-filler containing slurries to yield a pigment slurry.

Abstract: Wastewaters and circulation waters in papermaking, in deinking and in pulp bleaching are treated by adsorption of water-soluble anionic compounds and compounds dispersed in water from the wastewaters and circulation waters over finely divided adsorbents which consist of insoluble, only slightly swellable polymers which contain polymerized vinylamine units, and these polymers are used as adsorbents for treating water circulations in papermaking and for treating paper machine wastewaters and wastewaters from the deinking process and from pulp bleaching.

Abstract: A method in a paper machine for arrangement of water circulation therefor and arrangement of a water circulation system in a paper machine. In view of full or partial closing of the water circulations in a paper machine, the wash water flows from the fabrics and from other devices in the paper machine as well as the water drained from the paper web to be produced are recovered selectively based on the place of origin thereof in the paper machine. At least a part of the recovered different water flows are cleaned, and the cleaned water flows are recirculated to applications of reuse suitable in view of their washing potential in the papermaking process.

Abstract: A composition comprising the product precipitated in the admixing of a soluble metal salt and one or more compounds having a component selected from silicates, phosphates and borates; and a method for controlling drainage and/or retention in the formation of a paper matrix or for treating water comprising the use of such product.

Abstract: In wet oxidizing process of an aqueous alkali waste which contains absorbed hydrogen sulfide and carbon dioxide, a convenient method for improving the safety in oxidizing operation and the efficiency in oxidation reaction.

Abstract: This invention relates to a process for recovering raw materials from a stream of residual or collected material (R) which comprises a plurality of different materials and which arises during the manufacture of paper (P) in a paper mill (1) and/or in a material processing installation (2) and/or in a paper machine (3) and which is discharged therefrom, wherein the stream of residual or collected material (R) is fed to an installation (4) for separating at least one fiber fraction contained in the stream of residual or collected material (R) via a screening operation and for separating an ash fraction (A) comprising black particles.

Abstract: Polynucleate metal hydroxide anionic compounds and method for their production. The compounds have the formula: MaNb(OH)cXdYeZf.(H2O)g wherein M is a tri- or more valent metal ion; N is a divalent metal ion that forms a soluble salt with anions X, Y or Z; OH represents the level of basicity; X is a monovalent anion; Y is a divalent anion; Z is a trivalent anion; a is 1; b is from 0.15 to 2.0; c is from 0.3 to 5; d is from 0 to 3; e is from 0.1 to 2.25; f is from 0 to 1; and g is greater than 4 where the compound is in the form of an aqueous solution, or from 0 to 20 where the compound is not in the form of an aqueous solution. The compounds are useful for water treatment for removal of suspended solids and for various applications in the paper industry.

Abstract: The invention is a method for clarifying, dewatering or improving retention and drainage of industrial waste water or paper furnish with an effective amount of at least one dispersion of a water soluble cationic polymer flocculant wherein the improvement comprises the addition of said polymer which has a concentration of at least twenty five percent to said waste water or paper furnish. The industrial waste is preferably food processing waste water, oily waste water, paper mill waste water and inorganic contaminated waste water. The paper furnish may be an aqueous cellulosic suspension.

Abstract: According to the present invention there is provided a method of treating reject from a plant for de-inking waste paper which reject comprises in an aqueous medium a mixture of suspended solids comprising at least ink particles, inorganic particles and fibers, which method includes the steps of (i) chemically treating an aqueous suspension comprising said reject by adding to the aqueous suspension a source of alkaline earth metal ions and a source of carbonate ions to react with the alkaline earth metal ions to form therein a composite particulate material comprising a substantially white insoluble alkaline earth metal carbonate compound precipitated by the said reaction which compound bonds to and entrains material comprising ink particles, inorganic particles and fibers contained in said reject, whereby the darkness of the reject is reduced by formation of the precipitate of the carbonate compound; and (ii) recovering the composite particulate material and delivering the composite particulate material for r

Abstract: Methods for removing suspended particles from a solution are disclosed. These methods generally comprise adding to the solution to be treated an effective amount of a composition comprising a Mannich derivatized polyether. The polyether is generally described as the condensation polymer of Mannich derivatized bisphenol and a difunctional monomer. The methods have broad application in a wide variety of industries and are effective in removal of all types of suspended particles even when numerous types of particles are contained within the same solution.

Abstract: A sludge, preferably derived at least in part from a paper mill, pulp mill or deinking plant, and which contains at least secondary sludge or primary sludge comprising deinking waste, recycled paper waste or mechanical pulping waste, is flocculated by being mixed with a phenolic material and a polyalkylene oxide and is then subjected to dewatering.

Abstract: A composition for treating nutrient deficient wastewater from a paper-making process, which eliminates the use of conventional treatments and efficiently provides essential nutrients for biologically degrading organic pollutants, comprising urea and phosphoric acid. A method for treating nitrogen and phosphorus deficient wastewater with a treatment composition of urea and phosphoric acid in varying concentrations depending on the nitrogen and phosphorus content of the wastewater.

Abstract: A method of treating solid-containing material contained in or produced from an effluent or waste from a process for the treating of waste paper. The solid-containing material includes constituents of the waste paper and organic material including cellulose fibers and inorganic particulate material including calcium carbonate and other inorganic particulate material included in the waste paper. The solid-containing material is subjected to a heat treatment that incinerates the organic material present and forms from the inorganic particulate material present a calcined product including calcium oxide from thermal decomposition of calcium carbonate. The calcined product is formed into an aqueous suspension wherein calcium oxide is converted to calcium hydroxide.

Abstract: The inventors have discovered a new method of treating paper machine white water aqueous systems and surfaces in the paper machine white water aqueous systems that prevents or inhibits the adhesion of bacterial cells to the surfaces and thereby controls the biological fouling of the surfaces. The process comprises adding to the aqueous system an adhesion-inhibiting amount of vinyl cationic polymer. This method effectively inhibits the adhesion of the bacterial cells to exposed surfaces without killing the fouling organisms and also without harming non-target organisms. In addition, the method of the present invention advantageously does not cause the formation of harmful substances in the effluent from the systems treated.

Abstract: Processes for spray drying water-soluble and water-swellable vinyl-addition polymer-containing dispersions, emulsions and microemulsions to obtain substantially dry water-soluble or water-swellable polymer particles, compositions of substantially dry water-soluble or water-swellable polymer particles, methods of agglomerating spray-dried polymer particles, and methods of using spray-dried polymer particles and agglomerates in water-treating, mining, paper, food processing, soil conditioning, solution thickening, biotechnological, and oil recovery applications are disclosed.

Abstract: Provided is a process for removing metals from a bleaching plant spent liquor and recovering a chelating agent which includes the steps of: heating a spent liquor containing a chelate comprising metals bound in a chelating agent to a temperature of at least about 140.degree. C.

Abstract: The invention comprises a method for clarifying ink-laden water obtained from the recycling of paper stocks by treating said water with a hydrophilic dispersion polymer. The hydrophilic dispersion polymer of the invention is a copolymer of a diallyl N,N-disubstituted ammonium halide cationic monomer and (meth)acrylamide (AcAm). Following dosing with the polymer, a floc is formed. The floc contains ink and impurities which are removed from the water process stream by means of solid liquid separation; the solid liquid separation comprising a dissolved air flotation method. A preferred copolymer is formed from DADMAC and AcAm.

Abstract: There is disclosed a process for improving one or more properties of kaolin comprising:(a) providing an aqueous suspension of particulate kaolin clay;(b) introducing into the aqueous suspension a first reagent comprising a source of alkaline earth metal ions and a second reagent comprising a source of carbonate ions to precipitate an alkaline earth metal carbonate in the said aqueous suspension of the said particulate kaolin clay whereby the said particulate kaolin clay present at the start of the process becomes entrained by and bonded to the alkaline earth metal carbonate to form a composite particulate product which may be used in paper making or paper coating or as a filler or extender in compositions for other applications. The alkaline earth metal ions may be calcium ions provided by calcium hydroxide obtained by slaking lime either in the aqueous suspension or separately. The carbonate ions may be provided by carbon dioxide.

Abstract: The present invention provides a composition and method of administering same for inhibiting the growth of microorganisms. The composition of the present invention includes sufficient amounts of peracetic and a non-oxidizing biocide. The method of the present invention includes the step of adding sufficient amounts of peracetic acid and the non-oxidizing biocide to industrial process waters.

Abstract: A process for reducing the production of biomass during activated sludge treatment of pulp and paper mill effluents, involving a conditioning of the recycled activated sludge (RAS) prior to its return into the aeration tank is described. The conditioning is typically performed within the sludge return line and involves RAS exposure to a waste acidic effluent originating from bleach plants of kraft, sulphite mills or other mill sources.

Abstract: A method for burning secondary sludge in a recovery boiler, in which method secondary sludge is mixed with black liquor. According to the method, an alkali is added to the secondary sludge so as to obtain a mixture having a pH of over 7, whereafter the mixture of alkali and secondary sludge is heated to a temperature of over 80.degree. C. and kept at this temperature for over 30 minutes. Thereafter the heat treated mixture of alkali and secondary sludge is supplied to the thick end of a black liquor evaporation plant.

Abstract: A method for arranging water circulation in a paper mill including a pulp manufacturing plant provided with a water circulation system, such as a TMP plant, and a paper machine provided with a water circulation system. In order to reduce the amount of fresh water supplied to the paper mill, a part of the amount of fresh water supplied to the paper mill is substituted for by water or waters cleaned locally from waters contaminated at the paper mill. The concentrate or concentrates obtained from the stages of water cleaning is/are utilized where applicable by arranging the concentrate(s) to flow upstream in relation to the raw-material flow for reuse at the paper mill. By means of these operations, the amount of contaminants circulating in the paper mill is controlled.

Abstract: Processes for removing color from a paper mill waste effluent and for removing color from a textile plant waste effluent utilizing an amphoteric copolymer/polyamine combination are described. A preferred amphoteric copolymer is poly(dimethylaminoethylacrylate methyl chloride quaternary salt/acrylic acid) and a preferred polyamine is a polymeric reaction product of epichlorohydrin and dimethylamine.

Abstract: A process using an amphoteric ion-exchange resin, also known as a "snake-cage polyelectrolyte" resin separates kraft white liquor into sulphide-rich and caustic-rich components. The sulphide-rich component can be used in the initial stage of pulping, pretreatment of wood chips prior to pulping, or it can be used to make polysulphide-rich liquor. The caustic-rich component can be used in the final delignification phase, in place of sodium hydroxide or white liquor in oxygen delignification, pH adjustment and flue gas scrubbing. The same system can be used to separate green and polysulphide liquors into sulphide-rich and sulphide-poor components, and to remove sulphide from other mill caustic streams contaminated with sulphide.

Abstract: Hydrophilic cationic copolymers of acrylamide are prepared as dispersions in a salt media. These polymers have high molecular weights and are readily soluble by diluting in water. These polymers are useful flocculants for such applications as sludge dewatering, raw water clarification aids, emulsion breakers and waste water clarification aids.

Abstract: Extraction of minerals from papermaking sludge or sludge-derived ash is accomplished by mixing with a solution of an inorganic or organic acid--generally 0.1% to 35% by weight, preferably 2% to 20%, and most preferably 3% to 8% by weight. In preferred embodiments, the material is carried as an aqueous solution and combined with 2% to 20%, and most preferably 3% to 6%, HCl; 2% to 25%, and most preferably 8%, HNO.sub.3 ; 2% to 30%, and most preferably 8%, acetic acid. Generally, the amount of acid added into the reaction mixture preferably is 0.8 to 2.0 times the stoichiometric calcium carbonate content in the mixture, more preferably 0.8 to 1.2 times the stoichiometric content, and most preferably matched to the stoichiometric content of calcium carbonate in the mixture. The acid-containing mixture is incubated (with agitation, if desired, to shorten the reaction time) to solubilize the desired minerals, following which the liquid phase is isolated, and mineral salts recovered therefrom.

Abstract: Paper mill sludge is reclaimed and useful products produced therefrom. A predetermined amount of paper mill sludge is continuously discharged from a storage reservoir onto a mixer/conveyor to create a first reactant stream. A predetermined amount of calcium oxide is input into the first reactant stream from a calcium oxide reservoir. The calcium oxide and paper mill sludge are mixed as they travel along the mixer/conveyor to form a first intermediate mixture. After a time period sufficient to allow for the reaction of the calcium oxide and paper mill sludge, a predetermined amount of diatomite is added to the reactant stream from a diatomite storage reservoir. The first reactant stream, now comprising the first intermediate mixture of paper mill sludge and calcium oxide combined with diatomite, forms a useful, environmentally safe product.

Abstract: A paper mill and method of producing paper from waste paper in which no liquid effluent is produced, and wherein the spent treatment liquors are subjected to an oxidative treatment, microfiltration, and reverse osmosis.

Abstract: A method is described for the treatment of a solid containing material obtained from effluent from an industrial plant or process, eg. a plant for the de-inking of waste paper. Such effluent comprises an aqueous suspension of solids comprising organic material and inorganic particulate material. The inorganic particulate material contains a substantial amount of calcium carbonate and is likely also to contain kaolin or metakaolin. The solids may also contain carbon particles. The method includes subjecting the solid containing material to a heat treatment process such that the temperature is controlled to be maintained in the range 600.degree. C. to 800.degree. C. preferably 600.degree. C. to 750.degree. C., to cause burning of the organic material without decomposition of more than about 50% by weight, preferably not more than about 10% by weight, of the calcium carbonate present to produce a particulate calcium carbonate-containing inorganic material substantially free of organic material.

Abstract: A suspension is dosed with a coagulant and then with a flocculant and is dewatered to form a thickened sludge or cake and separated liquor, and control of the dewatering performance is improved by adding the flocculant at a predetermined dosage, monitoring the charge in the separated liquor (or monitoring other dewatering parameter of the separated liquor or suspension) and adding coagulant at a dosage selected in response to the monitored charge or other parameter value in order to maintain the value substantially at a preselected optimum value.

Abstract: A method for recovery and use of a particulate waste material, i.e. inorganic and/or organic solid fines, present in an aqueous suspension, comprising the steps of:a) treating the aqueous suspension so as to precipitate, in the presence of the solid fines, crystals of an alkaline earth metal carbonate whereby the solid fines become entrained by and bonded to the crystals, thereby forming in the aqueous suspension a mixed aggregated particulate solid comprising the crystals and the fines; andb) recovering the mixed aggregated particulate solid and supplying such solid for use as a filler or pigment in a filler- or pigment-containing composition.

Abstract: The present invention provides a method for removing secondary fiber contaminants from paper mill process waters comprising adding a polyvinyl chloride, a cationic polymeric coagulant and a polymeric flocculant to paper mill process waters containing secondary fiber contaminants in an amount sufficient to agglomerate the secondary fiber contaminants to larger particles sizes, and removing the secondary fiber contaminants from the process water by a dissolved air flotation clarification technique. The addition of particulate polyvinyl chloride in combination with a polymeric coagulant and flocculant prior to the DAF clarification process causes the contaminants to become preferentially coated with the polyvinyl chloride particles. This coating is what causes the subsequent removal of the secondary fiber contaminants in the DAF clarification process to be more effective.

Abstract: A wet oxidizing process for waste soda to attain stable cooling and complete gas-liquid separation of waste soda which is discharged from a wet oxidation reactor for alkali waste liquid, and which process comprises the steps of (1) and (2) and optionally any one of steps (3) to (5), wherein (1) a wet oxidation step in which the alkali waste liquid is brought into contact with excess molecular oxygen, said alkali waste liquid being obtained by bringing an aqueous alkali into contact with a hydrocarbon fluid containing acidic substances of hydrogen sulfide and carbon dioxide, (2) a reducing step to reduce the pressure of a mixture of the oxidized alkali waste liquid from said wet oxidation step and a surplus gas, (3) a separation step to separate said mixture into a gas phase and a liquid phase in a gas-liquid separation tank, (4) a cooling step to cool the separated liquid phase and (5) another cooling step to cool the separated gas phase.

Abstract: A method for processing recycling mill sludge into pulp, and cellulosic products made from such pulp, is described. The method for forming cellulosic pulp comprises first forming an aqueous composition in a pulper comprising recycling mill sludge, caustic agent, bleaching agent and a chelating agent. The aqueous composition also preferably includes a deinking agent and sodium silicate. The composition is then processed in the pulper for a period of time sufficient to form pulp from recycling mill sludge. The disclosure also describes a method for forming cellulosic products. The method comprises forming a cellulosic pulp from recycling mill sludge, and thereafter forming cellulosic products from the pulp. The method for forming cellulosic products may further comprise forming a pulp mixture comprising from about 1 to about 40 percent pulp from recycled materials and recycling mill sludge, and from about 99 to about 60 percent virgin pulp.

Abstract: Alum process residues (APR) are used to remove colored contaminants from waste waters. In addition, in accordance with the invention, up to 0.1% by weight of alum and up to 5 ppm of a polyelectrolyte polymer is added to improve color removal, turbidity removal and the settling rate. The resultant APR-alum-polymer mixture together with contaminants in the waste water settles rapidly, reducing the costs of the color removal process.

Abstract: In a method of recovering fibers from white water using a filter including a vat and a rotating filter surface (such as a disc filter), auxiliary pulp is supplied to the area of the vat where the cleaned and rotating filter surface meets the pulp surface in the vat. The consistency difference in the filter vat is adjusted by controlling the auxiliary pulp flow, or by adding cloudy filtrate to the auxiliary pulp prior to the filter vat. The auxiliary pulp is preferably supplied to the filter by using directing nozzles or other supply structures, and essentially evenly over the entire radial width of the filter surface.

Abstract: The invention comprises a method for clarifying ink-laden water obtained from the recycling of paper stocks by treating said water with a conventional coagulant followed by treatment with a hydrophilic dispersion polymer. The hydrophilic dispersion flocculant of the invention is a copolymer of dimethylaminoethyl (meth)acrylate methyl chloride quat (DMAEA.multidot.MCQ) cationic monomer and (meth)acrylamide (AcAm). Following dosing with the flocculant, a floc is formed. The floc contains ink and impurities which are removed from the water process stream by means of solid liquid separation; the solid liquid separation comprising a dissolved air flotation method.

Abstract: Stickies derived from pulping or deinking of cellulosic material are controlled by adding to the cellulosic liquor containing the stickies an emulsion in water of cross-linked, insoluble, ionisable and swellable polymer particles.

Abstract: Compositions of precipitated cationic polymers containing mixtures of certain salts as well as processes for making and using the same are disclosed.

Abstract: A method for inhibiting the microbial adhesion on surfaces in contact with an aqueous system is disclosed, which comprises adding to the system a treatment comprising an alkylsulfosuccinate surfactant.

Abstract: There is disclosed a process for separating fine solids from water in the used water recovery system of a sheet forming mill, wherein the used water recovery system includes at least one stage in which an alkaline earth metal carbonate is precipitated in the aqueous suspension constituting the used water whereby the particulate material present in the used water becomes entrained in the alkaline earth metal carbonate precipitate. By the invention it is possible to recover the water and the fine solid materials which pass through the wire mesh belt of a paper or board forming machine, and optionally recycle those recovered materials.

Abstract: Compositions of precipitated anionic polymers containing mixtures of certain salts as well as processes for making and using the same are disclosed.

Abstract: Mannich (alk)acrylamide microparticles are produced at high solids contents without a significant increase in bulk viscosity by inverse microemulsion polymerization and provide superior dewatering characteristics.