Abstract: Fine particles are dewatered in an energy efficient process in which a non-polar liquid or a mixture of different hydrophobic liquids are used to displace the water from the particle surface. Thermodynamically, this process is spontaneous. The only energy required for this process is to recover the hydrophobic liquid(s) for recycling purposes. The hydrophobic liquids are recovered in gaseous form either by lowering the pressure or by heating, and converted back to liquid form for re-use. The most economical reagents that can be used for this purpose include propane, butane, pentane, and ethane. Carbon dioxide may also be used for the dewatering process described in the present invention. The process of dewatering by displacement is capable of achieving the same or better level of moisture reduction as thermal drying but at substantially lower energy costs.

Abstract: Described is a process for separating a mixture of finely divided minerals into constituents thereof. In particular, the invention relates to a procedure for effecting such separation by a novel selective flocculation technique wherein a dispersed aqueous pulp containing the mixture of minerals is preconditioned for selective flocculation with an anionic polymer by addition of both a fatty acid such as oleic acid and source of polyvalent cation such as calcium chloride. The fatty acid and cation of the salt selectively coat the component of the mixture that is subsequently flocculated with the anionic polymer. A polyacrylate salt dispersant is preferably used in the process. The invention is especially adapted to the separation of colored titaniferous impurities from kaolin clay in which case both a white purified kaolin product and a strongly flocculated dun-colored titania/kaolin mixture are recovered and then dispersed producing a material useful as a paper coating pigment.

Abstract: A low brightness pigment and method is provided from a heretofore rejected waste kaolin stream. Kaolin processing rejects are high in iron-stained TiO.sub.2. After separating the stained TiO.sub.2 from the high brightness kaolin and concentrating the resulting fraction, the material can be processed to produce a low brightness pigment suitable of many applications where lower brightness is desirable, such as coating paper board without mottling.

Abstract: Finely divided solids suspensions can be dewatered by adding to the solids suspension a mixed hydroxy ether of the formula ##STR1## wherein R.sup.1 is a linear hydroxy alkyl group containing from 2 to 16 carbon atoms with the hydroxyl group on the carbon atom adjacent to the carbon atom with the ether linkage and R.sup.2 is a linear alkyl group with 1 to 15 carbon atoms with the proviso that the sum of the total carbon atoms in R.sup.1 and R.sup.2 is 5 to 17, R.sup.3 is a linear or branched alkyl group with 1 to 12 carbon atoms and n is a number of from 1 to 20. The mixed hydroxy ethers are readily biodegradable, generate very little foam and have a low solidification point.

Abstract: Disclosed is a process for treatment of bulk materials which are loaded with impurities and pollutants. Preferably the process treats bulk material from the category of clay-bonded used foundry sand. Depending on the provenance of the sand, composition of the sand, and the type of binders employed, this sand is subjected to a regeneration process including dry mechanical pretreatment and wet attrition treatment to produce regenerated sand and fine grain-containing waste water. The fine grain-containing waste water is subjected to a multiple-stage waste water treatment based on agglomeration processes after adjustment of the pH level of the waste water.

Abstract: This invention relates to a process for separating a mixture of finely divided minerals into constituents thereof. In particular, the invention relates to a procedure for effecting such separation by a novel selective flocculation technique wherein a dispersed aqueous pulp containing the mixture of minerals is preconditioned for selective flocculation with an anionic polymer by addition of both a fatty acid such as oleic acid and source of polyvalent cation such as calcium chloride. The fatty acid and cation of the salt selectively coat the component of the mixture that is subsequently flocculated with the anionic polymer. A polyacrylate salt dispersant is preferably used in the process. The invention is especially adapted to the separation of colored titaniferous impurities from kaolin clay.

Abstract: A method is disclosed for separating a substance from a liquid medium. The method comprises combining the liquid medium containing the substance with magnetic particles under conditions for non-specific chemical binding of the magnetic particles. Thereafter, the medium is subjected to a magnetic field gradient to separate the particles from the medium. The preferred non-specific binding is achieved as the result of charge interactions between the particles usually by means of a polyionic reagent. The method of the invention has particular application to the separation of cells and microorganisms from aqueous suspensions and also to the determination of an analyte in a sample suspected of containing the analyte. The analyte is a member of a specific binding pair (sbp). The sample is combined in an assay medium with magnetic particles and a sbp member complementary to the analyte.

Abstract: The invention provides an improved method for dewatering coal tailing aqueous slurries in a twin belt press process. The method including the step of adding to the slurry a high molecular weight anionic flocculant followed by a coagulant containing vinylamine. The flocculated coal is then mechanically dewatered using a twin belt press.

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: A chemically assisted process for dewatering mining waste solids on mechanical separation devices with at least one flocculant and at least one coagulant. It comprises using as the coagulant a diallyldimethyl ammonium chloride copolymer which contains from 3-25 mole % of acrylamide and which has been cross linked with from 0.01 to 0.5 mole % of triallyl amine.

Abstract: A composition comprising a blend of an inverse emulsion of a hydroxamated polymer and a second inverse emulsion of a second polymer selected from the group consisting of alkali metal (meth)acrylate homopolymers, ammonium (meth)acrylate homopolymers, and copolymers of the (meth)acrylates with (alk)acrylamides, wherein the molar ratio of hydroxamated polymer to said second polymer in the emulsion is within the range of about 99:1 to 15:85 when the second polymer is an alkali metal (meth)acrylate homopolymer or copolymer and is within the range of about 99:1 to 58:42 when said second polymer is an ammonium (meth)acrylate homopolymer or copolymer. Processes for removing suspended solids from Bayer alumina process streams using these compositions are also provided.

Abstract: Soil including sand and clays contaminated with elemental mercury are decontaminated by forming slurries with anhydrous liquid ammonia. An ammoniacal liquid, such as anhydrous liquid ammonia facilitates decontamination by breaking up soil into fine slurries for releasing droplets of mercury metal. The high density of the mercury metal permits precipitation with larger soil particles and for recovery from soil particulates. Contaminated soils having mixed wastes comprising metallic mercury with organic compounds like PCBs are decontaminated first by slurring with anhydrous liquid ammonia to release droplets of mercury for coalescing and recovery. Solvated electrons are formed in the slurry in-situ by treating the slurry with an alkali metal or alkaline earth metal to reduce or degrade toxic organic compounds to more environmentally benign substances.

Abstract: A method and composition for controlling deposition of scale and the like in waters having a high calcium ion content is disclosed. The composition comprises a combination of an alkylidene diphosphonic acid and a water soluble polymeric material.

Abstract: Alginic acid is used in combination with high molecular weight synthetic water soluble polymers to flocculate red mud from Bayer process liquors. Superior clarity of supernatant liquor is achieved using the process of the invention.

Abstract: Fine coals are dewatered in an energy efficient process in which a non-polar liquid or a mixture of different hydrophobic liquids are used to displace the water from the coal surface. This process works with higher rank coals that are naturally hydrophobic so that the coal surface from which the water is displaced has a stronger affinity for the hydrophobic liquid than the water. Thermodynamically, this process is spontaneous and, hence, requires no energy. The only energy required for this process is to recover the spent hydrophobic liquid(s) for recycling purposes. The hydrophobic liquids are recovered in gaseous form either by lowering the pressure or by heating, and coverted back to liquid form for re-use. The most economical reagents that can be used for this purpose include propane, butane, pentane, and ethane. Carbon dioxide can also be used for the dewatering process described in the present invention.

Abstract: The use of a dewatering aid comprising a sulfosuccinate and an oil in the filtration of alumina trihydrate is disclosed.

Abstract: A method of dewatering mineral-containing sludge by adding to the sludge (a) an aqueous solution or emulsion of acrylamide polymer flocculating agent and (b) a microfiber additive. By using this method, such mineral-containing sludges can be quickly dewatered into a cake having 25-35% solids which can then be further processed to a 60% solids-containing material. The method is particularly suitable for use in methods for treating, recovering, rehabilitating and recycling residue of mining operations. The method also enhances the filtration characteristics of certain mineral residues. With modification, the method is also suitable for dewatering organic sludges. Kaolin clay and red mud from the Bayer process are disclosed among the mineral-containing sludges which may be dewatered in accordance with the process of the invention.

Abstract: The invention provides a method for dewatering coal tailing aqueous slurries. The method including the step of adding to the slurry a flocculant composition including a vinylamine polymer including from about 1 to about 100 mole percent vinylamine and from about 1 to about 99 mole percent of at least one monomer selected from the group consisting of vinylformamide, vinyl acetate, vinyl pyrrolidinone, vinyl alcohol and the esters, amides and salts of acrylic acid and methacrylic acid.

Abstract: A microbial process for removing heavy metals such as bismuth, cadmium, lead, thorium, uranium and other transuranics from soils and sediments, utilizing indigenous, or isolates of indigenous, microorganisms and reducing agents, such as cysteine or sodium thioglycollate, or complexing agents such as the amino acid glycine, to effect the mobilization or release of the metals from the soil particles.

Abstract: Compounds and methods are disclosed for reversibly aggregating particles suspended in a liquid medium. The method comprises combining the liquid medium containing the particles with a polyionic polymer capable of aggregating the particles under conditions suitable for such aggregation. Thereafter, the particles are contacted with a chemical reagent capable of cleaving the polyionic polymer under conditions sufficient to reverse the aggregation. Optionally, magnetic particles are added to the liquid medium in the present method under conditions for non-specific binding and the medium including the aggregates is subjected to a magnetic field gradient to separate the aggregates from the medium. The compounds of the present invention are polyions. The aggregation of the particles is reversible upon contact with chemical agents which cleave at least some of the bonds within the polyionic polymer.

Abstract: A low brightness pigment and method is provided from a heretofore rejected waste kaolin stream. Kaolin processing rejects are high in iron-stained TiO.sub.2. After separating the stained TiO.sub.2 from the high brightness kaolin and concentrating the resulting fraction, the material can be processed to produce a low brightness pigment suitable of many applications where lower brightness is desirable, such as coating paper board without mottling.

Abstract: Addition of alkyl and/or alkenyl polyalkylene glycol ethers as filtration aids in the filtration and/or dehydration of mineral or coal suspensions reduces the dehydration time, and filter cakes with a low residual moisture content are obtained.

Abstract: Compounds and methods are disclosed for reversibly aggregating particles suspended in a liquid medium. The method comprises combining the liquid medium containing the particles with a polyionic polymer capable of aggregating the particles under conditions suitable for such aggregation. Thereafter, the particles are contacted with a chemical reagent capable of cleaving the polyionic polymer under conditions sufficient to reverse the aggregation. Optionally, magnetic particles are added to the liquid medium in the present method under conditions for non-specific binding and the medium including the aggregates is subjected to a magnetic field gradient to separate the aggregates from the medium. The compounds of the present invention are polyions. The aggregation of the particles is reversible upon contact with chemical agents which cleave at least some of the bonds within the polyionic polymer.

Abstract: The present invention provides a process for recovering alkali carbonates such as alkali sesquicarbonates from slurries of minerals such as Trona which contain those carbonates as well as clays and shales. The invention further provides a method for recovering alkaline earth carbonates from caustic slurries of those carbonates, as well as to clarifying the supernatant liquids which result from recovery of the alkaline earth carbonates.

Abstract: Separation of impurities from kaolin clay is accomplished by conditioning a dispersed aqueous pulp of the clay with an anionic flotation collector, followed by centrifugation or the like to cause the impurities to settle from a dispersed pulp of the clay without an intermediate froth flotation step or a flotation waste froth is centrifuged or hydrocloned to recover valuable kaolin contained in the froth.

Abstract: A water treatment method and device can perform a regeneration treatment of the muddy water once used in a water excavation work to decrease its specific gravity for reuse in the water excavation work, and a dehydration treatment of various waste waters such as muddy water from the water excavation work and industrial waste water for final disposal.

Abstract: Separation of impurities from kaolin clay is accomplished by conditioning a dispersed aqueous pulp of the clay with an anionic flotation collector, followed by centrifugation or hydrocloning to cause the impurities to settle from a dispersed pulp of the clay without an intermediate froth flotation step or a flotation waste froth is centrifuged or hydrocloned to recover valuable kaolin contained in the froth.

Abstract: The described invention relates to the processing of iron ore, particularly taconite ore. In particular, the invention relates to the separation of the iron containing component from the silicious and other gangue components such as phosphorus compounds in low grade iron ore. Typically, the separation is accomplished by a flotation process to remove the gangue to recover the iron component.

Abstract: Additive composition for use in separating particles of a desired material from particles of an undesired material in a froth flotation process using a frother. The composition includes an alkylated polymer of vinylpyrrolidone and a liquid carrier comprising the frother.

Abstract: 3-acrylamido-3-methylbutanoic acid copolymers of acrylamide or acrylic acid are selective flocculant for coal present in coal refuse slurries.

Abstract: This invention relates to a process for obtaining dry sodium aluminum hydride from a slurry containing the production products from a sodium aluminum hydride plant.

Abstract: An improved process for the mechanical separation of complex, intergrown ores containing mineral of at least one of lead or zinc comprises a differential flotation process followed by an agglomeration process. The improved separation process is useful for bulk separation of mixed, intergrown minerals or for separation of one mineral from another, e.g., separation of lead-containing mineral from zinc-containing mineral.

Abstract: A method of dewatering mineral-containing phosphatic clay sludge comprising adding to the sludge (a) an aqueous solution or emulsion of acrylamide polymer flocculating agent and (b) a microfiber additive. By using this method, such mineral-containing sludges can be quickly dewatered into a cake comprising 25-35% solids which can then be further processed to a 60% solids-containing material. The method is particularly suitable for use in methods for treating, recovering, rehabilitating and recycling residue of mining operations. With modification, the method is also suitable for dewatering organic sludges.

Abstract: Hydrophobic contaminants are removed from a particulate matter by contacting the particulate matter with a solid organic phase. The hydrophobic contaminants have greater affinity for the solid organic phase than for the particulate matter and repartition to the solid organic phase. The solid organic phase is then separated from the particulate matter. A typical embodiment utilizes polystyrene particles to remove polychlorinated biphenyls from soil.

Abstract: A method and apparatus for dewatering an aqueous coal slurry includes imparting high shear forces to the aqueous coal slurry in the presence of a peptizing agent to render coal particles hydrophobic by stripping clay from the coal particles and peptizing the clay in the aqueous medium of the slurry. The slurry is separating to recover coal particles and the aqueous medium is draining medium from the hydrophobic surface of the coal particles.

Abstract: Deinking of printed paper is accomplished by repulping printed wastepaper in an aqueous medium containing a deinking chemical. The presence of the deinking chemical causes initial agglomeration of ink particles to produce an ink pulp medium. Agglomerated ink particles are removed from the ink pulp medium by size and density separation procedures to separate coarse ink and produce a fine ink particle stream. The fine ink particle stream is recirculated to cause additional agglomeration of ink particles. The reagglomerated ink particles are removed from the fine ink particle stream by size and density separation procedures to produce a substantially ink free pulp medium. The invention provides agglomeration processes with high ink removal from printed paper.

Abstract: Particles of a desired mineral are separated from an aqueous slurry containing the desired particles and particles of an undesired mineral by adding a collector, a frother and an alkylated polymer of vinylpyrrolidone, and then floating off the desired particles in a froth flotation cell.

Abstract: The use of mixed hydroxyethers of the general formula IR.sup.1 O--(CH.sub.2 CH.sub.2 O).sub.x --CH.sub.2 --CH(OH)R.sup.2 (I)in whichR.sup.1 denotes an alkyl group having 1 to 10 carbon atomsR.sup.2 denotes an alkyl group having 8 to 20 carbon atoms and x denotes a number in the range from 1 to 20 as auxiliaries for the dehydration of water-containing finely divided solids, gives solids having a low water content without foaming in the water separated therefrom.

Abstract: A process for inducing flocculation involving the mixing of an aqueous solution of a chitosan salt with a material to be flocculated (e.g., oil, algae, or the like) and then adding a halogenating agent (e.g., sodium hypochlorite) thus forming a N-halochitosan.

Abstract: An aqueous suspension of coagulatable material is coagulated by adding polymeric coagulant to the suspension and then separating the resultant coagulated material from the liquor. The coagulatable material may be present in the aqueous suspension as a suspension of suspended solids or as colloidally dispersed solids. The suspension may be coal tailings or other aqueous (generally mineral) suspension. The polymeric material must be a low molecular weight, highly ionic, polymeric material. It is added to the aqueous suspension while in the form of polymeric particles having a size mainly above 30 .mu.m and that will dissolve into the suspension and coagulate the coagulatable material. A counterionic, high molecular weight, flocculant is generally added subsequently in order to flocculate the coagulated material.

Abstract: Large and medium-sized particles of sand which is contained in building rubble are separated from a mixture of rubble and water prior to introduction of water, contaminants and small particles of sand into a separator with internal laminations to segregate the small particles of sand. The thus obtained residue containing contaminants and water is flocculated and is thereupon treated in one or more settling units or flotation units to segregate the contaminants which are skimmed off the surface of the body of liquid in the unit and/or removed by a feed screw in the bottom zone of the unit. The thus purified water is reused, and the segregated solid contaminants are dehydrated, if necessary, to be disposed of at special dumping facilities. Separation of small particles of sand increases the percentage of reusable rubble and reduces the percentage of material which must be delivered to special dumping facilities.

Abstract: A process of selectively agglomerating coal in an aqueous environment while leaving the mineral matter dispersed has been developed. This process is autogenous for hydrophobic particles in that neither an agglomerating agent nor an electrolytic coagulant is needed. It is based on the finding that hydrophobic particles are pushed against each other by the surrounding water structure. This process, which is referred to as selective hydrophobic coagulation, is driven by the so-called hydrophobic interaction energy, which is not included in the classical DLVO theory describing the stability of lyophobic suspensions. The relatively small coagula formed by the selective hydrophobic coagulation process can be readily separated from the dispersed mineral matter by several different techniques such as screening, elutriation, sedimentation and froth flotation.

Abstract: The invention is directed to a method for reducing the viscosity and increasing the brightness of a kaolin clay by removal of mineral slimes having a particle size of less than about 0.2 micron. The process includes reflocculating an aqueous clay slurry by the addition of an overdose of dispersing agent. The reflocculated slurry is aged and dewatered by fractionation.

Abstract: A method for producing a low abrasion calcined kaolin pigment which comprises forming an aqueous pulp of crude kaolin dispersing the pulp by adding thereto sufficient water-soluble organic cationic dispersant to impart a positive zeta potential to said particles and, preferably, an acidic pH to said pulp, removing coarse particles from said dispersed pulp and fractionating the dispersed pulp to separate a fine particle size fraction of mineral particles from coarser particles. The fine particle size fraction is dried, pulverized, calcined and repulverized.

Abstract: A process for improving a solid/liquid separation of tails from acidulated or non-acidulated liquors obtained by leaching phosphate ores or waste comprising: adding a mixture of dissolved polymers of hydroxyalkyl cellulose and polyoxyethylene into an aqueous slurry of leached phosphate wastes to obtain flocks of phosphatic clay wastes; allowing said flocks to settle into an agglomerated mass; decanting luqiid from insoluble residues to obtain tails having a solid content from about 55 to 70%.

Abstract: A method and composition for dewatering coal and mineral slurries by centrifugation or filtration wherein a dewatering aid in combination with a clay dispersant is added to the slurry prior to centrifugation. The dewatering aid is preferably an alkylphenolethoxylate surfactant and the clay dispersant is preferably sodium hexametaphosphate. The combination aids in dewatering and also reduces the ash content of coal treated with the combination.

Abstract: A method of preventing and inhibiting scale on solid surfaces in contact with mineral processing waters which comprises treating such waters with a scale preventing or inhibiting amount of a composition comprising:______________________________________ Ingredients % By Weight ______________________________________ A. Polyacrylic acid 25-65 B. An acrylic acid lower alkyl acrylate ester 25-65 copolymer which contains from 1-6 carbon atoms in the alkyl group C. An acrylamide terpolymer which contains 0-30 from 1-80 mole % of acrylic acid and from 1-50 mole % of an alkyl sulfonate substituted acrylamide wherein the alkyl group contains from 1-6 carbon atoms ______________________________________with polymers A, B, and C having a molecular weight range between 1,000 to 50,000.

Abstract: A process for removing finer than uniform size particles from a powder in a container including the steps of suspending the finer particles in a liquid rinse containing a charged compound such as a quanternary ammonium compound to reduce the static attraction of the finer particles from being bound to larger particles allowing the large particles to settle and decanting the suspensed finer particles in the liquid.

Abstract: Disclosed is a graded metal powder for metallic pigment, comprising a metal powder wherein the metal powder has a mean particle size of from about 2.5 to about 15.0 .mu.m, the content of particles having a particle size of not greater than 1 .mu.m is not larger than about 0.5% by volume, and the metal powder has a particle size distribution such that not smaller than 97% by volume of the particles of the metal powder fall within the range between half the mean particle size of the metal powder and double the mean particle size of the metal powder. Also is disclosed a process for producing a graded metal powder by classifying metal particles dispersed in a mineral oil containing a nonionic-anionic surfactant.

Abstract: Certain dithiocarbamates are used as reverse demulsifiers, corrosion and scale inhibitors, flocculants, biocides, flotation aids, water clarifiers, interface control agents and antifoaming agents.