Abstract: A process for defluorinating a solution of a sulphate of Zn, Ni, Cd, Mn and/or Mg, in which Al.sup.3+ and PO.sub.4.sup.3- ions are added to the solution, then the solution is neutralized up to a pH higher than 4 and lower than that one that causes a substantial precipitation of Zn, Ni, Cd, Mn and/or Mg, thereby producing a fluorinated precipitate, and the precipitate is separated from the solution.

Abstract: An oil-containing slurry waste containing a soap component in the oil component thereof is foamed by stirring so that the oil component adheres to the froth produced by the foaming and rises to the surface of the slurry waste by virtue of buoyancy. Consequently, the oil component in the slurry waste is separated from the slurry waste in a highly concentrated form as entrained by the froth. The oil thus separated is suitable for reuse. The slurry waste having a low oil content can be easily treated for disposal.

Abstract: The invention relates to a process, which is characterized by mixing sewage sludge with comminuted, dried autumn foliage or the solvent extraction residue thereof. It also relates to the use of the deformable and optionally dried material obtained as a fuel briquette, and the use of the ash obtained after burning the fuel briquette as a fertilizer component.

Abstract: The invention relates to the chemical removal of phosphorus compounds from waste water, this waste water being treated with one or more metal compounds, without any problems presenting themselves as regards the separation of the metal phosphate compounds. To achieve this, the waste water is treated with the metal compound in a fluidized bed of metal phosphate particles.The invention also relates to a process for the purification of waste water in which the effluent from a biological purification is subjected to the above-mentioned method for the removal of phosphorus.

Abstract: A continuous process of removing silica from spent pulping liquors (black liquors) which have been obtained by the alkaline digestion of annual plants. The spent liquor is preconcentrated and contacted with a CO.sub.2 -containing gas. The CO.sub.2 -containing gas is supplied at a rate of 30 to 40 m.sup.3 s.t.p. per m.sup.3 of spent liquor. The precipitated silica is removed from the treated liquor. The silica-containing precipitate which has been separated is diluted and washed with water and causticized by an addition of lime or milk of lime. Solid and liquid phases are separated from each other and the resulting residue is combusted.

Abstract: A method for dewatering clay slimes comprised of treating the slimes with a fly ash coated with a silane coupling reagent to which is bonded a polyacrylamide flocculant.

Abstract: A method for continuously demulsifying a viscous, stable water-in-oil emulsion, which emulsion comprises from 50 to 80% water as the dispersed phase, comprises passing the emulsion and a chemical demulsifier through a mixing device having at least one flow restriction and recycling part of the mixture leaving the mixing device back to the device at or upstream of the restriction.

Abstract: Salt caverns or cavities are used only for intermediate storage and not for permanent storage of liquid pumpable wastes, to avoid above ground installations for such operations as phase separation, neutralization and sedimentation. The caverns may be used in combination or in series.

Abstract: A method for separating carbon and iron bearing particles from zinc and lead bearing particles contained in an aqueous slurry of blast furnace dust and the recovery and reuse of the carbon and iron bearing particles as charge material in a blast furnace is described.An aqueous slurry of blast furnace flue dust is collected in a thickener. The thickened aqueous slurry is strained to remove large foreign matter and make a size separation at about 4 mm. The plus 4 mm particles are generally wasted. The aqueous slurry containing the minus 4 mm particles is fed into at least one hydrocyclone where a size separation is made at between about 3 and 5 microns. A substantial portion of the carbon and iron bearing particles report to the hydrocyclone underflow and a substantial portion of the zinc and lead bearing particles report to the hydrocyclone overflow. The carbon and iron bearing particles are passed to a preparation plant to be prepared for reuse in the blast furnace.

Abstract: Spilled liquid hydrocarbon products ranging from crude oil to refined fractions and discrete compounds are converted from a liquid to a gel or to a semi-solid or solid state by contacting a liquid petroleum product with a slurry of cryogenically comminuted polymer particles in a liquified refrigerant gas. The technique is particularly appropriate for control of oil spills in a water environment wherein the oil is either floating on or dispersed in water. Contact of the polymer particles with liquid hydrocarbons results in virtually instantaneous solvation of the polymer in the hydrocarbon to produce a cohesive gel or a semi-solid to solid material at a polymer concentration ranging generally from about 0.2% to 1% for gel formation and from about 1% to 30% for formation of a semi-solid to solid material based on hydrocarbon weight.

Abstract: Carbonates and bicarbonates are removed from the sludge of tar sands tailings ponds whereby solids settle from the sludge more rapidly than in the presence of the carbonates and/or bicarbonates. Hydrolyzed starch is used as a flocculant in the process and alcohol may also be used to assist in the settling and/or to improve the characteristics of the settled sludge for subsequent dewatering.

Abstract: Process for the irreversible treatment of toxic waste by means of a silicate, in the presence of water, in such a way as to form a solid aggregate includes treatment of the silicate in an acid medium, for the purpose of obtaining silicic acid of low molecular weight; mixing the silicic acid with the waste to be treated, in the presence of water and controlling the pH between 0 and 4 in a sufficiently acid medium to cause the waste to undergo at least partial solution; precipitation of a gel of high molecular weight from the resultant aqueous mixture; addition thereto of a mixture which reacts with the gel of high molecular weight to form a silicate, possibly in the presence of a cementation agent, in such a way as to produce a sludge, and the hardening of the sludge into a solid aggregate which can not be changed physically so as to release again the harmful or toxic waste into the environment.

Abstract: A pumpable water-purifying dispersion containing iron(II)sulphate, the iron(II)sulphate being dispersed in an aqueous phase with a dispersing agent containing an alkaline earth metal and a basic anion. The best dispersion properties are obtained when the dispersing agent is calcium carbonate or calcium hydroxide, whereby the resultant composition having a content of up to about 70% solid iron(II) sulphate, calculated as heptahydrate on the total weight of the composition, can be obtained and handled without difficulty. The aqueous phase can, to advantage, comprise metal ions active in water-purification, such as Fe.sup.2+, Fe.sup.3+ and Al.sup.3+.The invention also provides a method for producing the composition.

Abstract: Fine-crystalline silicates are separated by filtration from an aqueous mother liquor which contains at least 30% v of a water-miscible alcohol, ketone, sulphoxide or cyclic ether which, per molecule, contain at most five carbon atoms with a boiling point below 85.degree. C.

Abstract: A process for obtaining calcium fluoride from the pond water of phosphoric acid plants and recycling the high phosphate defluorinated water to the pond is disclosed. Sufficient calcium carbonate is added to a solution having a pH of about 0.8, containing about 1% fluoride, 1% phosphate and less than 0.4% sulfate, to raise the pH thereof to 2-3, whereby calcium fluoride is precipitated as a major component, calcium phosphates and calcium sulfates are precipitated as minor components. The calcium fluoride precipitate obtained is washed with raw pond water to reduce the phosphate content and with ammonium carbonate solution to reduce the sulfate content. In this manner an industrially useful fluorspar is obtained. The low fluoride supernatant liquid is then mixed with sufficient raw pond water to bring the pH into the range 1.5-2.0 and the resulting suspension is then held in a lagoon for 5-21 days to permit separation of silica.

Abstract: An apparatus and a process are provided which are particularly suited for treatment of sludge eminating from a metal finishing solution regeneration process, especially aluminum finishing solution. The sludge is washed on a horizontal belt vacuum filter from which a majority of the washing fluid is returned to the regeneration process. A portion of the washing water is wasted. After washing, the sludge is reslurried. Thereafter, the reslurried sludge is pumped to a reaction vessel in the presence of carbon dioxide under pressure. Sufficient carbon dioxide is provided to react with excess lime in the sludge to produce calcium carbonate and a substantially neutral pH. The sludge after carbonation is dewatered in a rotary drum vacuum filter and thereafter is suitable for placement in a landfill.

Abstract: An installation for spreading clayey mud on ground which is free from water and which is prepared to receive the mud by laying a filtering bottom above the level of ground water, said installation comprising a decanting tank in which a mixture of mud and flocculating agent settles, a mud extraction pump for extracting said settled mixture of mud and flocculating agent from the decanting tank and pushing it into a pipe to convey said mixture up to at least one high mud pouring point located above said prepared ground, said installation further comprising means for adding more flocculating agent to said mixture in the vicinity of said mud pouring point.

Abstract: Process for removal of water from a mixture of water and certain solid residues of carbonaceous material, such as a coal char-water slurry, which comprises mixing the slurry with an acid, preferably hydrochloric acid, a surfactant, preferably water-immiscible such as lecithin, and an organic compound such as a liquid hydrocarbon, e.g. mineral spirits, causing the char to agglomerate, and thereby facilitating separation of the char from the mixture, as by screening, and filtering or centrifuging.

Abstract: A process for producing leach-resistant consolidate from the slack sludge precipitated from the flocculating of dilute aqueous latex paint waste is shown. It comprises: rapidly heating said slack sludge with agitation to a temperature which at least approaches the boiling point of the water present in said sludge; settling the resulting heated mixture into a consolidate fraction and a serum fraction; and separating said fractions. Such consolidate can be used for landfill, structural units, or dispersed as a component of a paint.

Abstract: A method for treating a water containing waste such as industrial sludges and animal excrements. The method comprises a first step of mixing the waste with an alkaline earth metal oxide such as calcium oxide to obtain a preliminarily dried mixture and a second step of further drying and granulation of the mixture. Fuel consumption is saved by utilization of the exothermic reaction of an alkaline earth metal oxide with water contained in the waste. The waste may be converted by the method to usable products such as fertilizers, cement materials or cement additives.

Abstract: Aqueous slurries of fine coal are dewatered by a process which comprises mixing an organopolysiloxane with the slurry, separating the slurry to recover the fine coal and further drying the fine coal, if desired. The use of water-soluble organopolysiloxanes or water-emulsifiable organopolysiloxanes provides improved separating and/or improved drying of fine coal in the dewatering process that is disclosed.

Abstract: Aqueous slurries of fine coal are dewatered by a process which comprises mixing a mixture of a water-soluble organopolysiloxane and a water-emulsifiable organopolysiloxane with the slurry, separating the slurry to recover the fine coal and further drying the fine coal, if desired. The use of a mixture of a water-soluble organopolysiloxane and a water-emulsifiable organopolysiloxane unexpectedly provides improved separating and/or improved drying of fine coal compared to a dewatering process that uses only one of the organopolysiloxanes.

Abstract: There is disclosed a method for the preparation of an animal feed supplement from fish cannery waste process water in which the water is maintained under aerobic conditions and is processed through a flotation cell to separate the oils and proteins contained in the water as a concentrated sludge. The sludge is dewatered, blended with a bulk, solid carrier preserved against oxidative spoilage of the lipids with an effective anti-oxidant, and dried in vacuum under low temperature conditions to obtain an animal feed supplement in dry particulate form. The processing of the waste water is done under aerobic conditions to promote the growth of yeast and non-toxic, aerobic, bacterial improve color and odor and texture, and enhance the feed value of the sludge recovered from the processing.

Abstract: The method of treating an activated sludge to facilitate dewatering thereof comprising the steps of acidifying the sludge to a pH below about 2.2, heating the acidified sludge to a temperature of from about 150.degree. to 210.degree. F. and maintaining the sludge at said temperature for a period of time sufficient to obtain a settling rate of solids in the first three minutes of at least two-sixteenths inch per minute.

Abstract: A method and apparatus for treating a water containing waste such as industrial sludges and animal excrements. The method comprises a first step of mixing the waste with an alkaline earth metal oxide such as calcium oxide to obtain a preliminarily dried mixture and a second step of further drying and granulation of the mixture. The apparatus comprises a reactor for a mixture of the waste and an alkaline earth metal oxide, a drying kiln equipped with a stirrer means, a furnace surrounding the drying kiln and an exhaust collector means adapted to collect an exhaust gas from the reactor and drying kiln and transfer it to the furnace. Fuel consumption is saved by utilization of the exothermic reaction of an alkaline earth metal oxide with water contained in the waste. The waste may be converted by the method to usable products such as fertilizers, cement materials or cement additives.