Abstract: Process for softening hard water by precipitation of calcium carbonate. The hard water is rendered alkaline, e.g. by the addition of sodium hydroxide, and is then contacted with a large excess of calcium carbonate crystals whose size does not exceed 100 microns, whereby precipitation occurs within a short contact time of the order of 2-60 seconds. Upon separation of soft water from calcium carbonate the bulk of the latter is recirculated and excessive amounts are removed.

Abstract: There is disclosed a pulsating sludge bed clarifier especially for the treatment of low turbidity waters, which uses incline plates in the sludge bed and some recirculated sludge. The clarification is greatly enhanced by recirculating a relatively small part of the sludge concentrate to a reactor chamber used for the premixing of water to be treated and the coagulant. The small amount of recirculated sludge cuts down significantly on the polymer flocculant, which is the most expensive chemical in the process that is required to be used, and can also serve to improve the adsorption of colors and similar materials, increase the density of the sludge blanket, and improve the rate of throughput of the system.

Abstract: New systems for the purification of liquids containing suspended solids and/or dissolved solid materials basically include a conical flocculator unit and a conjoined conical clarifier unit. The flocculator has a cylindrical lower portion, frustum middle portion and large diameter cylindrical top portion while the clarifier is essentially a large diameter cylindrical top portion over a lower frustum portion. Water or other liquid to be purified enters the flocculator lower portion via opposed, unequally sized nozzles to assume a helical flow upward past a series of deflector plates positioned at the top of the lower flocculator portion while a sludge blanket forms therein. A double flume plus slot arrangement located at the junction of the flocculator with the clarifier separates solids from liquid as fluid flow from the flocculator passes into the clarifier where it is subjected to further separation of sludge from clarified liquid with part of the sludge being recycled to the flocculator.

Abstract: A two-stage process for treating acidic gypsum pond water for reuse or for discharge is disclosed. The first stage blends raw acidic pond water with recycled lime-treated slurry from the second stage of the process. The resulting elevation in pH causes CaF.sub.2 and SiO.sub.2 to precipitate and the precipitated material is discarded onto the gypsum storage area. The supernatant water can be used in the wet grinding mill and/or further treated in a second stage with lime to produce treated water which meets government environment standards for discharge. The slurry of calcium phosphate formed in the second (liming) stage is recycled to the first stage.

Abstract: An improved process for removal of soluble contaminants from wastewater is disclosed which provides significantly enhanced contaminant removal and overall process efficiencies. The improved contaminant removal process is especially suitable for treatment of industrial effluents having high levels of dissolved cyanide and arsenic contaminants. Wastewater undergoes multiple stage sludge treatment, wherein sludge is mixed with wastewater sequentially in a plurality of discrete reaction stages for relatively short retention times. Reaction conditions which promote chemical and/or physical reaction of soluble contaminants with sludge are maintained, and liquid/solids separation is effected after each sludge treatment stage. Oxidizing agent is preferably mixed with the wastewater prior to multiple stage sludge treatment to change the oxidation state of inorganic contaminants and remove cyanide contaminants from solution.

Abstract: A method is provided for removing a solid phase from a liquid substance, which is kept in a continuous turbulent flow. The method is characterized by adding simultaneously at consecutive places in the flow direction of the liquid substance, cement, iron (III)-chloride-sulfate and an anion polyelectrolyte. Cement is added at a first place, iron (III)-chloride-sulfate at a second place and anion polyelectrolyte at a third place.

Abstract: An improved process for removing dissolved metals from waste water using a recycle high density sludge is described. Specifically, the process comprises the steps of: (1) treating waste water containing dissolved metals with a recycle stream containing alkaline surface active recycle particles to precipitate the dissolved metals on the surface of the recycle particles; (2) treating a portion of the treated waste water containing metal precipitate solids with an alkaline reagent to form alkaline surface active recycle particles; (3) recycling the alkaline treated stream containing the alkaline surface active particles; and (4) separating the portion of the stream from step (1) not treated with alkaline reagent into a water component which is free of dissolved metals and solids and a sludge component which contains solids.

Abstract: The invention provides a chemical process for the treatment of water containing dissolved calcium and sulphate ions, so as to produce a purified product water having a reduced sulphate ion concentration. Barium sulphide is added to the water to cause precipitation of barium sulphate from the water. The water from which the barium sulphate has been precipitated is then treated with carbon dioxide to form hydrogen sulphide in the water, and the hydrogen sulphide is stripped from the water.

Abstract: The sewage treatment process combines physico-chemical clarification using fine material or clay particles with anaerobic digestion of a concentrated sewage. The particles are preferably magnetite. The sewage (10) is mixed with magnetite (12) having a hydroxylated surface layer in tanks (14, 16, 18, 20) in which acid, inorganic flocculant and polyelectrolyte may be added if necessary. The organic material in the sewage is adsorbed on the particles during the mixing contact and a clarified liquid effluent (28) is separated from the loaded particles in a clarifier (22). The organic material may be separated from the particles before or after treatment in an anaerobic digestion assembly (36). The particles are preferably cleansed and regenerated in a two stage countercurrent flow washing system (38, 40, 58, 60, 62) into which a dilute solution of caustic soda or lime (32) is introduced.

Abstract: The invention involves a process for the flocculation of matter suspended in water. According to the invention, the water is passed through a granular medium in a fluidized bed, without prior saturation of the granular medium in a fixed bed, and flocculated aggregates are collected downstream and subjected to settling or some other liquid/solid separation procedure, in order to obtain an effluent which is partially freed of its pollution.

Abstract: Hydroxylammonium salts are eliminated from wastewaters containing such salts by a process which comprises treating a wastewater containing such salts with not less than 0.5 mole of manganese (IV) oxides per mole of hydroxylamine in the form of hydroxylammonium salts at a pH of from 1 to 4 and at from 10.degree. to 100.degree. C.

Abstract: A process is disclosed for reducing the level of sulfides in aqueous solutiuons which comprises contacting a sulfide-containing solution having a pH value in the range from about 8.5 to 12 with oxygen in the presence of a flocculent manganese-containing catalyst having been prepared by aerating an aqueous solution of a divalent manganese salt, said salt solution having a pH value in the range from about 8.5 to about 12.

Abstract: A process for purifying an aqueous, hydrogen sulfide-scrubbing solution which contains a water-soluble transition metal component, such as a vanadium component or an iron component, in addition to at least one water-soluble organic compound, such as an aromatic sulfonate or an alkanolamine, in which the scrubbing solution is mixed with particles of a spent solid catalyst containing molybdenum and aluminum and a basic aqueous solution, preferably a solution comprising sodium aluminate, to form a slurry which is subsequently contacted with an oxygen-containing gas under conditions such that the molybdenum in the catalyst is solubilized. Thereafter, molybdenum is precipitated from the solution along with the water-soluble transition metal component and a wastewater substantially free of the transition metal component and the organic compound originally present in the scrubbing solution is recovered.

Abstract: A method is provided herein for the treatment of sewage or other impure water. The method includes adding, to the sewage or other impure water in a mixing zone, all three individually but no more than two premixed together of the following: (a) an inorganic coagulant, (b) an anionic polymer, and (c) a cationic polymer, with intimate mixing of the added chemicals with the sewage or other impure water, with the proviso that (d) the inorganic coagulant, either alone or with the anionic polymer or the cationic polymer, cannot be added last; and (e) the anionic polymer and the cationic polymer cannot be intimately mixed and added together. This provides chemically-treated effluent having large, compact, firmly bonded, substantially-shear resistant and rapidly-separatable flocs therein. The flocs are separated from the liquid in a separating zone. Finally treated effluent effluent is removed from the separating zone.

Abstract: A method for removing suspended impurities and colored substances from water which is hard and/or has a pH in excess of 5 which comprises contacting the water at its natural pH with a coagulant/adsorbent which comprises a finely divided particulate mineral material, the individual particles of which have a thin hydroxylated surface layer having a positive zeta potential at the adsorption pH, and separating the thus treated water from the coagulant/adsorbent.

Abstract: A process and apparatus is provided for reducing the concentration of fine, residual solids still remaining suspended in clarified geothermal brine overflow from a primary brine clarification stage in which hot, flashed, silica-rich geothermal brine, containing suspended siliceous material, is gravity separated, comprises flowing the brine overflow from the primary clarification stage into a closed secondary clarifier vessel having an internal reaction well. Capacity of the secondary clarifier vessel provides a brine residence time in the vessel of between about 45 and about 150 minutes, the brine residence time in the reaction well being between about 10 and about 20 minutes. Brine in the vessel is blanketed with steam flashed from the brine to exclude air from the vessel. In the reaction well, the brine is contacted with a flocculating agent, such as a cationic, anionic, or non-ionic polyacrylamide having a molecular weight of at least about 1 million, in an amount of between about 0.

Abstract: An apparatus and method of electro-dewatering sewage sludge and other high water sludges. The sludge is passed through a conveyor means that is electrically charged. The anode has metal bristles or wires that protrude into the sludge mass. Water that migrates to the cathode is removed by conventional means. The dried sludge, which is attached to the bristles, is removed by vacuum means. About 30 percent of the sludge mass can be dewatered per pass.

Abstract: A method of removing macromolecular organic dissolved and colloidal compounds from the effluents of a paper and cellulose mill by using waste sludge containing fibers and chemicals. The sludge is acidified to a pH of approx. 2 by a mineral acid prior to adding into the effluent. Organic material is precipitated with fibers in a sedimentation vessel at a pH of 4.5-6.

Abstract: A method of removing lignin from bleach plant effluents by using cellulose fibres. The method comprises an acidous phase during which sludge containing cellulose fibres is added to the acidous effluent, and an alkaline phase during which alkaline waste water is added to the effluent-sludge solution. A portion of the produced fraction containing fibres is recirculated to the acidous phase for reuse of the fibres.

Abstract: A process for separating ash particles from an aqueous slurry containing a mixture of regenerated adsorbent (e.g., carbon) and ash particles includes the steps of settling the slurry to produce a solid phase including the mixture of adsorbent and ash particles and a supernatant or a clarified aqueous phase. After separation of the aqueous phase, a slurry of the solid phase is diluted with water and a dispersing agent for promoting suspension of the ash particles and an anionic polymer for promoting settling of the adsorbent particles are added. The thus-treated, dilute slurry is settled to produce an aqueous phase containing primarily suspended ash particles and a solid phase including carbon particles. After separation, the solid phase can be returned to a wastewater treatment system.

Abstract: A process for treating hot, pressurized geothermal brine in a liquid-vapor phase separator comprises contacting the brine in the separator with between about 0.2 and about 1.5 parts per million of a defoaming agent so as to substantially reduce the amount of foaming in the separator caused, in part, by steam bubbling through the brine. The preferred defoaming agents are polyglycols having molecular weights between about 1000 and about 2500, those agents having molecular weights below about 1000 being too volatile and those above about 2500 being too difficult to solubilize in the brine.

Abstract: A process is provided for simultaneously clarifying brine in a geothermal facility and producing silica seed material for use within the facility. A clarifier having an agglomeration zone therein is utilized and unclarified geothermal brine comprising silica solids is introduced into the agglomeration zone and thereafter circulated and mixed with the brine being clarified within the agglomeration zone to cause agglomeration of the particles therein. A circulation rate is maintained within the agglomeration zone to enable agglomerated solids therein to settle toward a lower portion of the agglomeration zone to form a sludge blanket, consisting essentially of silica and compounds of naturally occurring elements in the unclarified brine, while enabling clarified brine, having less solids than the unclarified brine, to pass out of the agglomeration zone for collection thereof.

Abstract: Regenerated adsorbent particles, such as activated carbon, are recovered from a wet oxidation-regenerated mixed liquor sludge from a wastewater treatment system by diluting and settling a blowdown slurry from the wet oxidation reactor to obtain a first aqueous phase containing primarily regenerated adsorbent particles and fine ash particles and a first solids phase containing primarily grit particles. The first aqueous phase is combined with a portion of the regenerated adsorbent particle slurry withdrawn from the upper portion of the wet oxidation reactor and, after treatment with a dispersing agent and then an anionic flocculating agent, the resulting mixture is settled to obtain a second aqueous phase containing primarily fine ash particles and a second solids phase containing primarily regenerated adsorbent particles.

Abstract: The invention involves a process for the flocculation of matter suspended in water.According to the invention, the water is passed through a granular medium in a fluidized bed, without prior saturation of the granular medium in a fixed bed, and flocculated aggregates are collected downstream and subjected to settling or some other liquid/solid separation procedure, in order to obtain an effluent which is partially freed of its pollution.

Abstract: An improved process for the preparation of TiCl.sub.4 comprising(a) chlorinating a raw material containing titanium and vanadium impurities to produce a crude TiCl.sub.4 reaction product,(b) separating the crude reaction product into solid by-products and TiCl.sub.4 -containing liquid,(c) reacting the TiCl.sub.4 -containing liquid with a reducing agent whereby vanadium impurities are converted into solid compounds, and(d) separating TiCl.sub.4 from the solid vanadium compounds, is improved by adding solid products of the vanadium reduction reactions to the crude TiCl.sub.4 reaction product prior to the separating step (b).

Abstract: A process for reducing the concentration of fine, residual solids still remaining suspended in clarified geothermal brine overflow from a primary brine clarification stage in which hot, flashed, silica-rich geothermal brine, containing suspended silicious material, is gravity separated, comprises flowing the brine overflow from the primary clarification stage into a closed secondary clarifier vessel having an internal reaction well. Capacity of the secondary clarifier vessel provides a brine residence time in the vessel of between about 45 and about 150 minutes, the brine residence time in the reaction well being between about 10 and about 20 minutes. Brine in the vessel is blanketed with steam flashed from the brine to exclude air from the vessel. In the reaction well, the brine is contacted with a flocculating agent, preferably a cationic polyacrylamide having a molecular weight of at least about 1 million, in an amount of between about 0.25 and about 2 parts per million.

Abstract: A novel sewage purification method is provided herein. The method includes adding particular amounts of at least alum, a cationic polyelectrolyte and an anionic surface active compound to the sewage or other impure water in any order, then turbulently mixing the added chemicals within the sewage or other impure water, then allowing particulate matter to settle as sludge, and finally drawing off pure water. Preferably, part of the sludge is recycled to the sewage or other impure water to be treated.

Abstract: A method is provided for treating contaminated wastewater of pH ranging from about 1.5 to 3 containing phosphate ions and fluoride ions. The method comprises treating the said wastewater with an amount of alkaline agent selected from the group consisting of limestone (CaCO.sub.3) and lime [CaO or Ca(OH).sub.2 ] sufficient to raise and maintain the pH at a level of about 3.5 to 6.5 following uniform mixing thereof in a first stage precipitation step to effect substantial precipitation of the contaminants. The treated wastewater is passed to a first stage settler to effect solid/liquid separation and provide a sludge of the precipitated contaminants which is removed and separated to provide an effluent substantially impoverished in the aforementioned contaminants, following which the contaminant-impoverished effluent is treated in a second stage precipitation step with lime in an amount sufficient to raise and maintain the pH of the effluent at a level of at least about 10.

Abstract: In the process for the purification of water by flocculation, a porous granular material is used as a decantation accelerator and is preferably constituted by pyroclasts which can act as a substrate for a bacterial growth which achieves biological purification together with the chemico-physical purification of the flocculation.

Abstract: A method for softening a fluid containing hardness constituents, comprising the steps of: (a) mixing the fluid with sufficient amounts of a softening agent, and previously precipitated hardness constituents in a reactor to establish a softening reaction in the reactor for precipitating a substantial portion of the hardness constituents contained in the fluid; (b) removing a portion of the fluid and precipitated hardness constituents from the reactor as a slurry and filtering the slurry through a cross-flow microfiltration module containing at least one elongated filtration tube, whereby substantially all of the precipitated hardness constituents are removed from the portion of the fluid exiting from the module as filtrate; and (c) returning at least a portion of the filtered out precipitated hardness constiuents exiting from the module to the reactor as the previously precipitated hardness constituents.

Abstract: A method and apparatus for treating a liquid in a hot process softener. An eductor tube positioned within a reaction chamber causes liquid from a mixing and recirculation zone to enter the lower end thereof and be continuously recirculated therethrough. Chemicals and recirculated sludge are directed into the eductor tube and are intimately mixed with the liquid therein before exiting therefrom to mix with raw liquid being sprayed into the mixing and recirculation zone.

Abstract: A method is provided for the treatment of wastewater of pH ranging from about 1.5 to 3 containing at least about 100 ppm phosphorus as phosphate ions, at least about 50 ppm fluorine as fluoride ions and ammonia in excess of about 15 ppm NH.sub.3 (N)--T, the method comprising removing the phosphate and fluoride ions from the wastewater in a two-stage precipitation step; the first stage precipitation being conducted at a pH ranging from about 3.5 to 6.5 using an alkaline material selected from the group consisting of limestone (CaCO.sub.3) and lime [CaO or Ca(OH).sub.2 ] sufficient to form a precipitate which is removed to provide a filtrate of the wastewater which is treated in a second stage precipitation at a pH of at least about 10.5 using lime as the alkaline material sufficient to form a precipitate which is removed to provide substantially a clear effluent containing ammonia.

Abstract: A method of removing complexed zinc-cyanide from wastewater involving a multiple stage process including, in a first step, control of ferrous ions to a critical minimum concentration of 250 to 400 ppm, together with pH control in the first and also a second step, together with recycling of a portion of sludge precipitated in the process. Improved sludge stability is achieved by aeration to oxidize precipitated ferrous hydroxide to ferric hydroxide, immediately before settling the sludge in a thickener.

Abstract: An organic solution (2) of a water-immiscible chloride of an organic cation is mixed with a basic reagent and with water (3) in a reaction chamber (1), the mixture (6) which has reacted is transferred into a phase separation chamber (5) where the organic solution of the base (8) and an aqueous phase (7) containing a solid residue are separated and at least a part of a sludge (9) formed between the organic solution and the aqueous phase which have separated is recycled into the reaction chamber (1).

Abstract: A method and apparatus for treating sludges that have resulted from chemical treatment of sulfuric acid wastes with lime are shown. The sludges are subjected to fluidization, dilution, and acidification to solubilize solids, clarification to concentrate solids for reacidification and produce a supernatant for carbon adsorption to remove organics and color, with regeneration of spent carbon including incineration of solids, and finally incineration of the spent carbon and all other remaining unsolubilized solids.

Abstract: The invention relates to a method for purifying aqueous solutions containing at least one impurity element from the group consisting of arsenic, phosphorus, mercury and other heavy metals and solid matter by precipitation in at least two stages with the aid of precipitation reagents possessing ions capable of forming not-readily dissolved hydroxide precipitate. In accordance with the invention the main part of the precipitation reagent is introduced to the stage or stages following the first stage. The impurity element-containing precipitate formed in the aqueous solution subsequent to adding the reagent is separated therefrom substantially completely, and is returned so as to be present in the first precipitation stage, while that part of the solution which has been freed from precipitate in a later stage is withdrawn from the system. Substantially all the impurity element amount present in the ingoing aqueous solution are separated therefrom in the form of a sludge prior to the second precipitation stage.

Abstract: Effluents from cyanidation operations are treated by contacting the effluent with powdered sulphur and iron to reduce the base metal content and cyanide ion content of the effluents.

Abstract: A method and system for dewatering coal fines from the centrate of a pipeline slurry centrifuge, to recover the coal and purify the water, includes blending the centrate from the centrifuge with slurry from the pipeline in the proportion of about 4:1. The blend is chemically conditioned agglomerating polymer, and then dewatered on a belt press. The cake from the belt press is dry enough to burn in the boiler, and the filtrate is clarified in a gravity clarifier. The clarifier effluent is clean enough for plant purposes or to return to the environment, and the clarifier underflow is returned to the blend for dewatering in the belt press. In a second embodiment, the blend is dewatered directly in a disphragm filter press without chemical conditioning, and the filtrate is clean enough to use directly without clarifying.

Abstract: A method of removing complexed zinc-cyanide from wastewater involving a multiple stage process including, in a first step, control of ferrous ions to a critical minimum concentration of 250 to 400 ppm, together with pH control in the first and also a second step, together with recycling of a portion of sludge precipitated in the process.

Abstract: The cyanide content of waste waters containing the same is removed by treatment with sulfur dioxide or an alkali or alkaline earth metal sulfite or bisulfite in the presence of excess oxygen and a metal catalyst which is perferably copper.

Abstract: A method of treating chemical process water which contains dissolved solids, usually of a biodegradable organic nature. According to the invention, the dissolved organic solids, which are objectionable because they cause process equipment corrosion, undesirable product and process odors and pollution, are treated with ultraviolet light. The light treatment causes dissolved materials of relatively simple chemical structure to react and create more complex, less soluble materials which can easily be removed from the system as they become less soluble. The method is applicable to papermaking and numerous other industrial processes using large quantities of process water.

Abstract: A method of purifying uraniferous aqueous solutions containing impurities, particularly at least one of the elements zirconium and/or hafnium, and also containing at least one of the anions SO.sub.4.sup.=, NO.sub.3.sup.-, Cl.sup.- or F.sup.- acting as complexing agents for the uranium and impurities, by precipitation of said impurities by means of an alkaline agent, characterized in that the following stages are carried out for the purpose of selectively and quantitatively separating the impurities from the uranium:(a) said uraniferous solution is brought to a temperature of at least 40.degree. C.,(b) the content of complexing agent is adjusted to bring the molar ratio: [complexing agent]/[soluble U+Zr and/or Hf] to at least 3,(c) the pH of said solution is adjusted between 2.2 and 4.3 by introducing an alkaline agent.

Abstract: A process for treatment of an acidic solution containing ferric iron and at least one non-ferrous metal, prior to removal of ferric iron therefrom, is characterized by adding a specified amount of at least one neutralizing agent, and separating off from the solution any residue or undissolved neutralizing agent remaining after neutralization, thereby producing a solution possessing an acid consuming capacity termed "negative acidity", and still containing substantially all the dissolved ferric iron in solution, and from which ferric iron can subsequently be removed with the generation of less acid compared to that generated from solutions partially neutralized according to the prior art.

Abstract: To reduce the amount of high quality energy utilized in removing water from a dilute ethanol solution, a two-stage process is used. The first stage removes eighty-five percent of the water using a low temperature apparatus and process and the remainder of the energy is removed by any of the other conventional processes. In the first stage, anhydrous sodium sulfate is dissolved in a dilute aqueous solution of 10 weight percent alcohol at approximately thirty degrees centrigrade. The solution is cooled to approximately twenty degrees centrigrade, at which temperature decahydrate crystals of sodium sulfate precipitate from the solution are removed. The solution is increased to a value in excess of 45% of alcohol which requires removal of approximately 82 percent of the water in the form of crystals. The crystals are dried to the anhydrous state at substantially room temperature and reused.

Abstract: Use of ferri-magnetic reactive iron oxide particles to react hydrogen sulfide in water, hydrocarbon liquids or drilling mud affords quick, effective scavenging of these liquids without accumulation of particulate matter and without wasting the reactive particles. The reaction product is environmentally safe, so that it may be disposed of on a simple waste heap.A quantity of the magnetic iron oxide particles, principally a synthetic porous Fe.sub.3 O.sub.4, is suspended in the liquid. The quantity added is in excess of that required for the reaction with the hydrogen sulfide in order to speed the reaction time and provide a large margin of safety. In use, the reactive iron oxide particles contact and react the hydrogen sulfide, forming a non-magnetic particulate product of reaction. Thus, if used to scavenge a drilling mud, this contact and reaction occurs as the mud, bearing the drill cuttings, rises through the drilling formation.

Abstract: An industrial wastewater treatment method is described whereby heavy metals dissolved in the wastewater are precipitated as a slurry which, when allowed to settle, will form a sludge containing at least 10 weight percent solids. In the method, an aqueous suspension or solution of a neutralizing agent is introduced into a first reactor. A suspension containing particles of carrier agent is also introduced into the first reactor. A portion, if not all, of the neutralizing agent is adsorbed on the surface of the particles of the carrier, which are maintained in suspension in the first reactor. The carrier, with its adsorbed neutralizing agent, is passed to a second reactor and simultaneously the contaminated industrial wastewater is added to the second reactor. The pH of the wastewater is adjusted to a range between 8.4 and 10.6 by the neutralizing agent. Within such pH range, a substantial portion, if not all, of the heavy metals are precipitated in the form of a slurry.

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: A process for dewatering petroleum-containing sludges by a two-stage method using finely divided additives and organic flocculants, wherein(a) finely divided additives, such as ash, coal, sand or mixtures of these, in a free-flowing form or as an aqueous suspension, are homogeneously dispersed in the petroleum-containing sludge, in an amount such that the total solids content of the resulting mixture is from 10 to 30% by weight, especially from 12 to 20% by weight,(b) this sludge mixture is treated with an aqueous solution of an organic flocculant, preferably of anionic nature,(c) the greater part of the sludge water is removed by gravity filtration,(d) the pre-dewatered sludge mixture is treated with an aqueous solution of aluminum salts or trivalent iron salts and(e) this mixture is substantially dewatered by pressure filtration, in the course of which the greater part of the petroleum present is also removed.

Abstract: Inorganic salts are removed from an unpotable water stream, which contains suspended living microorganisms and their debris products, particularly seawater or agricultural field drainage water. Chemicals such as caustic soda and/or chlorine, and derivatives therefrom, sterilize the water and remove from it certain dissolved and suspended constituents. From the sterilized water is separated a more concentrated stream of waste brine containing debris and other suspended materials, and most of the dissolved sodium chloride. From the remaining portion of the water is separated a more concentrated stream of sodium chloride, which is electrolized to provide a source of caustic soda, chlorine, and derivatives therefrom; the less concentrated portion is recovered as a source of potable water.