Abstract: In an iron ore pelletization process in which particulate ore is mixed with particulate polymeric binder in the presence of moisture and the mixture is pelletised, the particulate binder is a blend of ionic synthetic water soluble polymer, such as a copolymer of acrylamide and sodium acrylate having intrinsic viscosity 2 to 16 dl/g, with a larger amount of a guar gum.

Abstract: Particulate superabsorbent polymeric material which is a partially neutralised polymer of an ethylenically unsaturated carboxylic monomer cross linked by a triethylenic or higher ethylenic cross linking agent, preferably tetra allyl ammonium chloride, absorbs above 15 grams, and often above 18 grams, aqueous saline per gram polymeric material in 60 minutes under a load of 63,000 dynes per square centimeter. The polymer preferably has surface cross linking caused by contacting the polymer particles with inorganic and/or covalent cross linking agent for the polymer.

Abstract: A mill waste or deinking waste or other suspension containing cellulosic material and hydrophobic material is flocculated by a cationic polymeric flocculant and the flocculated material, is then aggregated by a swelling clay or other anionic colloidal material, optionally further cationic flocculant is added, and the aggregated material is then separated by belt pressing or other pressure filtration as a cake.

Abstract: Vinyl ester of an alcohol (such as benzoin) is made by reaction of the alcohol with a 3-haloalkyl acid halide (such as 3-chloropropional chloride or bromide) in an anhydrous liquid reaction medium comprising an aprotic solvent (such as toluene) and a hydrogen halide acceptor (such as a tertiary amine) at a temperature of at least 20.degree. C.

Abstract: Paper is made by forming a thick stock cellulosic suspension, flocculating the thick stock by adding a relatively high molecular weight and relatively low cationic charge density polymer, diluting the flocculated thick stock to form a thin stock and then draining the thin stock to form a sheet. Usually coagulant is added to the thin stock before drainage and best results are achieved by adding coagulant followed by anionic colloidal material such as bentonite. The process can be operated to give good retention and good formation and, if the thick stock is dirty, to minimise pitch problems.

Abstract: Apparatus for wetting particulate material comprises a duct 1 that is open at its base 2 and that is provided at its top 3 with a duct inlet 4 defined by inlet walls 5 down which water flows continuously from a weir 6 around the top of the walls. Sprays 19 at or just beneath the duct inlet 4 direct water downwardly so as to wet the particulate material. Preferably the apparatus is used for wetting friable particulate material, in which case the sprays direct water across the path of the downflowing particulate material so as to disintegrate it into individual particles and to wet these. Downflow of air is minimized by providing a cowl 9 over the top of the duct and by feeding the particulate material, generally by a screw feed 13, into a passage that leads from an inlet 15 that is exposed to the atmosphere to an outlet that discharges direct into the duct inlet 4.

Abstract: A process of de-inking waste paper can be operated under conditions using a simple combination of chemicals to result in a waste liquor that is substantially environmentally friendly. The process comprises forming a pulp from the waste paper in a aqueous medium that has a pH of between 6 and 9 and that is substantially free of dissolved phosphate and that includes an ink-dispersing amount of polycarboxylic acid dispersing agent, and separating the ink from the pulp. The use of a cationic surfactant for promoting flotation is particularly desirable.

Abstract: A sedimentation or other dewatering process conducted on a suspension is controlled by filling a body (1) that is open at its top end (2) with the suspension, establishing quiescent conditions and allowing the suspension to settle to form a supernatant layer at the top end (2), generating light from an assembly (14) and measuring the amount of scattered light (19) from the supernatant layer by a collector (21) and utilizing the measured amount of scattered light to control the dewatering.

Abstract: A pet litter composition comprises a particulate substrate having bonded onto its surfaces a fine particulate superabsorbent polymeric material and a particulate soluble polymer to promote clumping. When wetted with urine, the exposed superabsorbent and soluble polymer localise the urine and result in the rapid formation of a strong agglomerate that can easily be removed from the pet litter composition and that disintegrates when added to water.

Abstract: Leather is rendered flexible and water repellent by treatment with a low molecular weight, generally monomeric, amphoteric surfactant having at least one surfactant hydrophobe, at least two cationic groups and at least two anionic groups which are carboxylic groups.

Abstract: Addition polymers suitable for imparting stain resistance to nylon carpets and other polyamide products are formed of styrene or other ethylenically unsaturated monomer containing cyclic hydrocarbon groups, sodium vinyl sulphonate or other ethylenically unsaturated strong acid monomer, and ethylenically unsaturated weak acid monomer that is preferably acrylic acid. The proportions of the monomer are, respectively, 7 to 50%, 1 to 20% and 40 to 90% by weight.

Abstract: Bauxite that is to be used in the Bayer process for the recovery of alumina is washed with aqueous wash liquor having a caustic content of at least 50 g/l and which comprises aqueous caustic from the alumina recovery circuit of the Bayer process and, after removing organic material from the wash liquor, the wash liquor is included in the digestion stage, the separation stage or the alumina recovery circuit of the Bayer process.

Abstract: According to the invention, a process of making paper comprises forming a cellulosic suspension, adding retention aid to the suspension, draining the suspension through a screen to form a sheet, and drying the sheet and in this process we add to the suspension a retention system comprising polyethylene oxide and a greater amount (dry weight) of a phenolsulphone-formaldehyde resin (PSR resin) consisting essentially of recurring units of the formula--CH.sub.2 --X--wherein (a) 10 to 100% of the groups X are di(hydroxyphenyl) sulphone groups, (b) 0 to 90% of the groups X are selected from hydroxy phenyl sulphonic acid groups (i.e., groups which contain at least one hydroxy-substituted phenyl ring and at least one sulphonic group) and naphthalene sulphonic acid groups and (c) 0 to 10% of the groups X are other aromatic groups.

Abstract: A copolymer for use in rendering leather water repellant is formed from ethylenically unsaturated monomer and ethylenically unsaturated monofunctional monomer, wherein the monomers include mono- or di- fatty alkyl ester of dicarboxylic acid and a free carboxylic acid monomer and provide a carboxylic acid equivalent weight of 100 to 1000 and at least 20% by weight of fatty alkyl groups.

Abstract: The systemic activity of systemic active ingredients in sprayed foliar systemic compositions is improved by incorporating water soluble polyacrylamide in the sprayed composition. The polyacrylamide can have a molecular weight sufficiently low that its presence does not substantially affect the spray pattern of the composition, and the polyacrylamide can have low solution viscosity such that a convenient concentrate can comprise an aqueous solution of the active ingredient and the polymer. Alternatively, the polymer can be supplied as a powder or as a reverse phase emulsion or dispersion. The sprayable composition is preferably formulated such that the spray droplets have a small particle size.

Abstract: The systemic activity of systemic active ingredients in sprayed foliar systemic compositions is improved by incorporating water soluble polymer. The polymer can have a molecular weight sufficiently low that its presence does not substantially affect the spray pattern of the composition and such that the polymer can initially be supplied as an aqueous solution having 1 to 25% concentration. When the active ingredient is water soluble, for instance glyphosate or chlormequat, a concentrate can comprise an aqueous solution of the active ingredient and the polymer.

Abstract: Water soluble polymer flocculants are formed from monomers derived from ethylenically unsaturated dibasic carboxylic acids of formula (I) where R.sup.1 =H and R.sup.2 =COOH or R.sup.1 =COOH and R.sup.2 =H. Flocculants are provided for use in Bayer process liquors which are copolymers of acids of formula (I) with ethylenically unsaturated copolymerisable monomer and which have molecular weight above 300,000. Preferably the polymer is a terpolymer of dibasic acid, monobasic and polymerisable termonomer. A particularly preferred flocculant is formed from at least 10 mol % maleic acid with acrylic acid and acrylamide as comonomers and is used preferably for flocculation of red mud in the primary settler and/or the various red mud washing stages.

Abstract: Paper is made by adding nonionic or anionic polymeric retention aid to a suspension that contains a high electrolyte content, shearing the flocculated suspension, aggregating the sheared suspension by adding anionic particulate material (especially bentonite), and draining the suspension.

Abstract: Filled paper is made by providing an aqueous feed suspension containing filler and cellulosic fibre, coagulating the fibre and filler in the suspension by adding cationic coagulating agent, making an aqueous thinstock suspension by diluting a thickstock consisting of or formed from the coagulated feed suspension, adding anionic particulate material to the thinstock or to the thickstock from which the thinstock is formed, subsequently adding polymeric retention aid to the thinstock and draining the thinstock for form a sheet and drying the sheet.

Abstract: This invention relates to the encapsulation of active ingredient within polymeric material so as to protect the active ingredient from the ambient environment, for instance atmospheric moisture when the product is exposed to the air, or the liquid phase of a liquid detergent when the product is incorporated in such a detergent. A dispersion in oil of an aqueous solution of a matrix polymeric material containing enzyme or other active ingredient is subjected to distillation to provide a substantially anhydrous dispersion in oil of particles of matrix polymer containing active ingredient, and during or after the distillation the polymer solution is converted into a solid polymer. In the invention, we use a matrix polymer that is so hydrophobic that it partitions preferentially into the oil rather than into the aqueous solution of encapsulating polymer.