Abstract: A process of treating industrial waste water contaminated with environmentally unacceptable amounts of sulfuric acid and heavy metals such as lead, copper or zinc is disclosed which permits lowering of the concentration of the contaminants to a level permitting discharge to the sewer. Waste water resulting from floor wash and spray washing of lead acid batteries prior to shipment from the manufacturing facility contains sufficient sulfuric acid to cause the pH to normally be at a level of about 2 along with heavy metal contaminants present in concentrations which require treatment for removal before the discharge water will meet EPA standards. The water to be treated is directed to a first reaction and settling vessel where calcium carbonate is added along with an oxidation medium such as air which also functions to stir the stored waste water.

Abstract: Zinc is extracted from an aqueous zinc containing brine (3) by contacting the brine with an organic reagent (5) consisting essentially of an extracting agent comprising a quaternary amine salt, a phase modifier, and an organic diluent so as to form a zinc amine complex (7) whereby a substantial portion of the zinc ions in the brine is transferred to the organic phase. The quaternary amine salt is a methyl triakyl ammonium chloride herein the alkyl groups contain from 8 to 10 carbon atoms. The zinc amine complex (7) is then contacted with an aqueous strippant (11) comprising a solution of sodium sulfate in water so as to form a sulfated quaternary amine salt whereby a substantial portion of zinc in the zinc amine complex is stripped therefrom and transferred to the aqueous phase as an aqueous zinc chloride solution (13) from which zinc may be recovered by electrowinning or chemical precipitation.

Abstract: The present invention relates to a process for purifying flue gases developed during the combustion of waste materials and containing solids of various compositions as well as pollutant gases and heavy metals in gaseous form, wherein the primarily solid components are removed from the flue gas in a separating system and are collected as flue ashes and wherein the flue gas is washed for the purpose of binding the pollutant gases of the residual solids components, particularly in the slag.It is the object of the present invention to provide a process wherein, during flue gas purification, the gaseous heavy metal contaminants as well as the heavy metal contaminants which are present in the flue ash and in the slag in soluble form, can be removed from the flue gas purification process in the most compact form, with simultaneously achieving good, or even improved, initial purification of HCl, SO.sub.2. NO.sub.x. All other residues should be returnable for further use.

Abstract: A hydrometallurgical process is provided for separating heavy metal nuisance elements such as As, Sb, Bi, Sn and Pb from precious metals and/or selenium. The process can be used as a step in an overall hydrometallurgical process for treating refinery residues such as anode slimes for the separation and recovery of valuable metal values.

Abstract: A method for removing heavy metals from wastewater streams removes such heavy metal by treating heavy metal-containing wastewater with a water soluble tri-thio carbonate, particularly an alkali metal tri-thio carbonate, such as sodium tri-thio carbonate (Na.sub.2 CS.sub.3) to precipitate heavy metals therefrom.

Abstract: The effluent of a process for making a preform from which an optical fiber is drawn is directed into a scrubber (40) of a loop (20) where it is treated with an aqueous solution to provide a solvent mixture which comprises particulates and a solvent solution including germanium. Subsequently, the solvent mixture is moved into a first filter system (55) which provides a filtrate free of particulates above a first size that is returned to the scrubber for reuse and a residue. Then the residue from the first filter system is moved into a second filter system (80) which provides a filtrate free of particulates larger than a second size that is smaller than the first size and a residue. The filtrate from the second filter system also is returned to the scrubber for reuse while the residue from the second filter system is recirculated therethrough.

Abstract: A method of substantially removing a trace metallic contaminant from a liquid containing the same comprises,adding an oxidizing agent to a liquid containing a trace amount of a metallic contaminant of a concentration of up to about 10.sup.-1 ppm, the oxidizing agent being one which oxidizes the contaminant to form an oxidized product which is insoluble in the liquid and precipitates therefrom, and the conditions of the addition being selected to ensure that the precipitation of the oxidized product is homogeneous, andseparating the homogeneously precipitated product from the liquid.

Abstract: There is disclosed a novel method of recovering valuable metals from an industrial by-product containing copper and arsenic and at least one metal selected from among lead, zinc, iron, silver and cadmium, said method comprising leaching the by-product with sulfuric acid in an SO.sub.2 gas atmosphere at a temperature of 70.degree. C. or higher in the presence of a solid sulfide to thereby precipitate copper selectively as copper sulfide while dissolving other metal or metals in the leach solution and then separating the copper containing precipitate from the leach solution, said leach solution containing substantially no copper.

Abstract: The invention relates to a process for removing nickel from lead chloride dissolved into chloride brine to obtain lead chloride solution wherein the nickel concentration is under 50 mg/liter. The present invention comprises the following steps:(a) adjusting the content of an element selected from the group of arsenic and antimony to a value of at least 1/5 of the concentration in nickel expressed in grams per liter;(b) contacting the solution from (a) with lead powder thus precipitating nickel and the said element selected from the group of arsenic and antimony.

Abstract: A process for separately recovering zinc and lead values from zinc and lead containing sulphidic ore which also contains iron comprises subjecting ground ore to a first flotation step to float an initial lead concentrate containing zinc and produce zinc and iron containing tailings. The zinc and iron containing tailings are subjected to a second flotation step to float an initial zinc concentrate containing iron and also produce tailings. The initial zinc concentrate is subjected to a third flotation step to float a further zinc concentrate containing iron and also produce zinc and iron containing tailings. The zinc and iron containing tailings from the third flotation step and at least a lead and zinc containing portion of the initial lead concentrate are leached in a first leach step under oxidizing conditions at a temperature in the range of from about 130.degree. to about 170.degree. C.

Abstract: A process for separating lead includes the steps of dissolving a water insoluble lead salt in an acetate solution and precipitating the lead by treating the acetate solution with a sulfite so as to form an insoluble lead sulfite. The acetate is recovered by concentrating the solution and precipitating the acetate therefrom, drying the acetate crystals and dissolving them in methanol. The methanol is then evaporated leaving purified acetate crystals. The process is shown as part of a precious metal recovery system in the treatment of tankhouse slime.

Abstract: A process for purifying an acid aqueous solution containing heavy metals by adding sulfide ions to said acid aqueous solution at a first pH lower than 3.4, precipitating a first heavy metal, adding sulfide ions again to said first precipitate containing acid aqueous solution, after adjusting to a pH of higher than 4, to precipitate a second heavy metal, and then removing the resultant first and second precipitates from the acid aqueous solution.

Abstract: Anhydrous zinc chloride is produced from an aqueous feed solution containing zinc chloride from an aqueous feed solution containing zinc chloride. The zinc chloride is extracted onto an organic extractant known to the art such as tributyl phosphate, primary, secondary or tertiary amines, and quaternary amine salts. The loaded extractant is then stripped with aqueous stripping solution containing ammonium chloride and ammonium hydroxide. The zinc ammine chloride formed in this aqueous stripping solution is separated from the stripping solution and can then be heated to form anhydrous zinc chloride and ammonia. This anhydrous zinc chloride is suitable as a feed material to a fused salt electrolysis process for the production of zinc.

Abstract: A process for the separation of heavy metal components, especially of compounds of cadmium, mercury and lead, from crude phosphoric acid obtained according to the Odda process, which comprises adjusting this crude phosphoric acid with ammonia to a pH of from 0.5 to 1.5, contacting it subsequently with a diorganyl-dithiophosphorus compound and an adsorbent, and then separating the acid from the absorbent containing the heavy metal impurities.

Abstract: In the method the ground scraps are screened to separate the pole active material, i.e. Pb and PbO.sub.2, as fines. This active material is then reacted in the presence of a strong alkaline solution to yield a minium precipitate.Minium may be subsequently treated with an appropriate acid, such as fluoboric acid, freed of antimony by precipitating the latter with metal lead, and then subjected to electrolysis to recover lead.

Abstract: A process for separating inorganic substances involving their abstraction from a mixture with near-supercritical inorganic fluids. One or more inorganic substances are abstracted and then separatively recovered by retrograde condensations. The process particularly is applicable with mixtures obtained from the chlorination of metalliferous ores and may be conjoined to many ancillary metal abstraction processes such as volatilizations, distillations or electrolyses.

Abstract: A process for recovering zinc from zinc containing sulphidic material which also contains iron together with lead and/or silver includes leaching the material under oxidizing conditions at a temperature in the range of from about 130.degree. to about 170.degree. C. in aqueous sulphuric acid solution with a stoichiometric excess of sulphuric acid relative to the zinc content of the material of from about 40 to about 100% to produce an undissolved residue containing a major proportion of lead and/or silver and a leach solution containing a major proportion of the zinc and iron. The residue is separated from the leach solution and treated to recover lead and/or silver values. The leach solution is treated to recover zinc by feeding the solution to another process in which zinc-containing material is treated to recover zinc and which includes an iron-precipitation step.

Abstract: The present invention relates to a process for removing heavy metals, particularly cadmium, from differing qualities of wet-process phosphoric acids. The invention is based on the concept of removing the heavy metals in sulfide form.

Abstract: The invention relates to a process for the removal of heavy metal ions, particularly chromium, lead and/or zinc ions, from aqueous liquids by precipitation wherein the aqueous liquid containing the heavy metal ions and an aqueous liquid containing a base which precipitates the heavy metal ions in the form of their hydroxide or basic salt are added simultaneously to an amount of water at a pH between 5 and 10 and a temperature between 60.degree. and 100.degree. C. and the pH and the temperature are maintained in the specified ranges during the precipitation.

Abstract: A process is provided for the preparation of high purity basic lead carbonate and high purity normal lead carbonate by a double precipitation reaction employing a single lead acetate feed solution. The process is particularly applicable to processes for producing lead monoxide from solid lead sulfate-bearing materials such as battery mud.

Abstract: Disclosed is a process for the preparation of lead compounds which comprises reacting lead monoxide according to the wet method with an inorganic acid or organic acid in the presence of hydroxylamine under such conditions that the initial pH value of the reaction system is not higher than 7.Lead monoxide according to the wet method has an excellent reactivity with an inorganic acid or organic acid, but it contains higher oxides such as lead dioxide and minium, which cause coloration in lead compound products. According to this process, this undesirable coloration can effectively prevented.

Abstract: A method of recovering metallic tellurium from a residue dust containing a major amount of lead oxide, a minor amount of tellurium oxide, and a minor amount of iron oxide which comprises the steps of introducing the residue into a leach tank containing water, sulphuric acid and ferric sulphate, the sulphuric acid being present in the leach tank in an amount equal to about 5% to 10% by weight in excess of that stoichiometrically required to react with the lead and tellurium, the ferric sulphate being added as an oxidizing agent, reacting the residue with the sulphuric acid and ferric sulphate to produce lead sulphate and a tellurium solution, removing the lead sulphate and tellurium solution from the leach tank and separating the lead sulphate from the tellurium solution, adding the separated tellurium solution to a tumbler containing particles of metallic iron, agitating the tumbler so that the tellurium solution reacts with the iron to produce ferrous sulphate and metallic tellurium, withdrawing the mixture

Abstract: A cobaltic oxide hydrate is mixed with spent sulfate electrolyte and the slurry is sparged with air to liberate any entrained chloride ions as gaseous chlorine. Thereafter a reducing agent is used to enable dissolution of the cobalt and obtaining of a chloride-free solution from which, after purification, cobalt can be electrowon.

Abstract: In connection with the recycling of lead-acid batteries, lead-acid battery mud containing lead sulfate is desulfated by adding to the battery mud, which is maintained at a temperature less than 140.degree. F., an aqueous solution containing an ammonium reagent such as ammonium carbonate or ammonium bicarbonate. The ammonium reagent reacts with the lead sulfate to form an aqueous solution of ammonium sulfate and a lead carbonate precipitate. The aqueous solution of ammonium sulfate is then separated from the battery mud containing the lead carbonate precipitate.

Abstract: An efficient and inexpensive method for producing lead monoxide from lead sulfate bearing materials such as recycled battery mud is provided comprising:(a) reacting said material with an ammonium carbonate solution to convert lead sulfate to lead carbonate;(b) decomposing the lead carbonate to form impure lead monoxide;(c) reacting the impure lead monoxide with acetic acid to form a lead acetate solution;(d) contacting the lead acetate solution with carbon dioxide to produce insoluble lead carbonate; and(e) decomposing the lead carbonate to form lead monoxide.

Abstract: In connection with the recycling of lead-acid batteries, battery muds are desulfated by adding an aqueous solution of a treating agent comprising soluble alkali metal salts or alkali metal hydroxides to crushed battery components. The treating agent reacts with sulfuric acid and lead sulfate to form an aqueous solution of alkali metal sulfates and precipitated lead compounds. Following separation of the reacted battery mud and other crushed battery components, separation of the soluble alkali metal sulfates and solids such as PbO, PbO.sub.2, and precipitated lead compounds is effected.

Abstract: A process of regenerating and recovering lead from lead sulphate-containing wastes which comprises(i) contacting the lead battery scrap with an aqueous solution of ammonium carbonate to form lead carbonate and ammonium sulphate,(ii) subjecting the solid phase containing the lead carbonate obtained by solid-liquid separation of the reaction product so formed to roast-reduction at a temperature ranging from about 350.degree. C. to about 700.degree. C. in the presence of a carbon material reducing agent to generate and recover the lead,(iii) double decomposing the liquid phase containing the ammonium sulphate obtained by said solid-liquid separation by the addition of calcium hydroxide in an amount such that the molar ratio of the calcium hydroxide added, expressed as Ca(OH).sub.2 /(NH.sub.4).sub.2 SO.sub.4, is about 1.05 to about 1.

Abstract: An efficient and inexpensive method for producing lead monoxide from impure lead sulfate bearing materials such as recycled battery mud is provided comprising:(a) reacting said material with an ammonium carbonate solution to convert lead sulfate to lead carbonate;(b) decomposing the lead carbonate to produce impure lead monoxide;(c) reacting said impure lead monoxide with an acidic ammonium acetate solution to form a lead acetate solution;(d) reacting ammonium hydroxide with the lead acetate solution to form lead hydroxide; and(e) dehydrating the lead hydroxide to produce lead monoxide.

Abstract: Silver-precipitating nuclei are prepared by partially oxidizing a stannous salt reducing agent and then reducing a noble metal salt or complex with said reducing agent.

Abstract: Aqueous lead solutions obtained by hot chloride leaching of residues containing lead and silver ore are subjected to selective precipitation of the silver as silver sulphide, with e.g. hydrogen sulphide. The silver can then be recovered in a known manner. Lead can be precipitated from the remaining solution as a basic salt also in a known manner. If the initial residue contains copper, it is also precipitated as sulphide. The copper sulphide can be separated from the precipitate by selectively dissolving the copper with sulphuric acid under an elevated oxygen pressure. Elemental sulphur is formed and the silver sulphide can be separated from the elemental sulphur in a known manner.

Abstract: A hydrometallurgical process for recycling the paste and electrolyte of junk lead-acid batteries begins by separating the paste and electrolyte from the junk batteries. The paste and electrolyte are then reacted to increase the lead sulfate content of the paste and reduce the acid content of the electrolyte. Excess liquid is then removed from the mixture of paste and electrolyte, after which the paste is mixed with an aqueous ammoniacal ammonium sulfate solution to dissolve a substantial portion of the lead sulfate from the paste. The remaining solid materials are then separated from the resulting pregnant lead solution, after which lead carbonate is precipitated from the pregnant lead solution by the addition of ammonium carbonate, ammonium bicarbonate or carbon dioxide.

Abstract: 1. The process of photosensitizing lead sulfide comprising adding a persulfate solution to intermixed solutions of thiourea, lead acetate and sodium hydroxide whereby activated lead sulfide is precipitated therefrom.

Abstract: The invention provides a process for recovering germanium as germanium oxide from a germaniferous metallic zinc which involves distilling the germaniferous metallic zinc under non-oxidizing conditions, recovering the distillation residue which contains the germanium, leaching the recovered distillation residue with chlorine water to convert the germanium into germanium tetrachloride, hydrolyzing the germanium tetrachloride into germanium oxide, and recovering the germanium oxide. Optionally, the germanium oxide may be reduced to metallic germanium, if desired.

Abstract: Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating, urea reacts with water from the solution leaving a molten urea solution containing the metal values. The molten urea solution is heated to above about 180.degree. C. whereupon metal values precipitate homogeneously as a powder. The powder is reduced to metal or calcined to form oxide particles. One or more metal oxides in a mixture can be selectively reduced to produce metal particles or a mixture of metal and metal oxide particles.

Abstract: Aqueous process streams or waste waters destined for merging with public waters sometimes contain deleterious amounts of heavy metals, e.g., lead (Pb) compounds. The heavy metal compounds may be substantially removed or reduced to harmless levels by treating the acidic aqueous streams with chromate or dichromate ions, then heating the solution to oxidize organics and/or heavy metal-organics, then raising the pH to an alkaline pH to precipitate the heavy metal chromate, and separating the heavy metal chromate from the aqueous stream.

Abstract: A process is disclosed for the production of lead carbonate by treatment of fluorine-containing mud produced in the polishing of lead glass with etching acid comprising:A. separating said mud from the etching acid;B. reacting the same with an aqueous alkali carbonate solution and filtering the solution;C. dissolving the residue in nitric acid and precipitating the fluorides in the form of alkali hexafluorosilicates by the addition of alkali ions at a pH of the solution under 4 and filtering out the precipitate; andD. adjusting the pH of the resulting solution to above 6.5 by the addition of alkali carbonate to the solution to precipitate basic lead carbonate.

Abstract: There is disclosed a process for separating iron, zinc and lead from flue dust and/or flue sludge, wherein the three following reaction stages are performed in the aqueous phase:A. Oxidation of the iron and filtration of the resulting first turbid liquid;B. Suspension and acidification of a first filtration residue and subsequent filtration of the resulting second turbid liquid, whereby a second filtration residue containing mainly iron sludge is obtained;C. Neutralization of the filtrate and subsequent filtration of the resulting third turbid liquid, whereby a third filtration residue containing the precipated heavy metals is obtained.

Abstract: A process for the extraction and recovery of hydrated stannic oxide and alkali metal ferrocyanide from the sludge formed in a halogen tin electrodeposition bath is described. The process comprises dissolving the ferrocyanide compounds and the tetravalent tin compounds present in the sludge in an alkaline medium, removing any insoluble materials, precipitating hydrated stannic oxide from the solution by neutralization of the solution, and separating the hydrated stannic oxide from the solution which then contains ferrocyanide ion together with acid and base counterions.

Abstract: A hydrometallurgical process for separating iron and nickel contained in iron and nickel-bearing sulphide materials, comprising selective leaching of iron with respect to nickel with hydrochloric or other mineral acid to provide a leach solution and leached solids. The nickel contained in the leach solution is separated from the dissolved iron as nickel sulphide by precipitation with hydrogen sulphide in the presence of an iron-bearing substance in which the iron is present in a form selected from the group comprising oxides, hydroxides and combinations thereof.

Abstract: A pollution-free process for the recovery of high purity zinc from zinc containing material including sulfide ores which provides for maximum conservation and re-use of reagents, the process consisting of chlorinating the materials either with ferric chloride or chlorine gas followed by selective removal of metals other than zinc by standard procedures, such as, lead chloride crystallization, cementation, etc. to produce a solution containing essentially only zinc chloride and ferrous chloride. To enhance the purity of the zinc end product zinc chloride is separated from the ferrous chloride solution with a zinc selective extraction agent from which the zinc chloride is stripped with sodium chloride solution in a sodium chloride stripping circuit followed by precipitation of zinc as the carbonate.

Abstract: An improved process for preparing highly concentrated salt solutions of metals of high purity from waste metal sludges at superior dissolution rates is achieved by preparing, concentrating and washing the sludge containing insoluble metal hydroxide under specific conditions to safeguard against the solids being exposed to air or dried out. The wet sludge is then dissolved in a dilute acid. The resultant solution can be used directly e.g. as make up in many electrolytic metal finishing processes to compensate for drag out losses occurred, or as the primary metal source in electrolytic processes employing insoluble anodes. Other specific uses for the process include the preparation of aluminum sulfate coagulants.