Abstract: A method for recycling lead from spent lead-acid battery paste, relating to the technical field of hydrometallurgy. In the method, firstly a reducing agent, and a lead paste are added into a zinc chloride solution for leaching in a stirring mill to cause lead in the lead paste to enter the solution, a lead cementation is performed by using zinc in the leached solution, after the lead cementation, the electrolytic zinc is produced by controlling an electrodeposition on the zinc chloride solution for a short time, the reducing agent is zinc, lead or hydrogen peroxide, a part of the electrolytic zinc is returned as the reducing agent for leaching, the step of returning the electrolytic zinc as the reducing agent can be omitted when the lead or the hydrogen peroxide is used as the reducing agent.

Abstract: The present invention relates to methods for recovering precious metals including silver and gold, rare metals including indium and gallium, base metals including copper, lead and zinc or a combination of precious, rare and base metals from complex oxide ores, sulfide ores or oxide and sulphide ores using an acid chloride oxidizing leach.

Abstract: The invention relates to a process for preparing electrically conductive pigments based on F−- and/or PO43−-doped tin mixed oxides applied as an electrically conductive layer to a substrate, in which, first of all, SnO2-coated substrates are prepared by precipitation and subsequent calcining and then, in further process steps, this SnO2 layer is converted into a tin mixed oxide layer doped with F− and/or PO43−. The invention further relates to electrically conductive pigments prepared by the process of the invention, to the use of these pigments for pigmenting lacquers, printing inks, plastics systems or coatings, and to lacquers, printing inks, plastics systems or coatings pigmented with an electrically conductive pigment prepared by the process of the invention.

Abstract: The present invention relates to a process for treating fly ash/APC residues chlorides, sulphates, earth alkali metals selected from the group consisting of calcium, potassium, and sodium, and heavy metals selected from the group consisting of lead, which residues are obtained from air pollution control processes that utilize dry/semi-dry line injection, such that said residues may be disposed of as non-hazardous materials. The process comprises the sequential steps of: (a) washing and agitating the fly ash/APC residue (20) with water (50) to form a residue slurry containing solubilized lead salts and calcium chloride; (b) filtering (42) the residue slurry to remove a filtrate (46) having a pH of higher than about 11.8 and containing the solubilized lead salts and calcium chloride; and (c) recovering a first calcium enriched filter cake (44).

Abstract: The present invention is concerned with a process for extracting and recovering lead or lead derivatives in high purity from various materials containing lead sulphate, and particularly copper smelter flue dusts. The present process also allows the substantially complete recovery or recycling of precious metals otherwise lost in flue dusts wastes.

Abstract: In a process for the treatment of electric arc furnace (EAF) dust, the dust is first subjected to atmospheric leaching with a ferric chloride solution and thereafter subjected to treatment in an autoclave at an elevated temperature and pressure for conversion of low temperature stable goethite (FeO.OH) to a filterable crystalline hematite (Fe.sub.2 O.sub.3) in an acidic chloride solution. Zinc is recovered from the solution by solvent extraction using a solvating extractant followed by stripping and zinc recovery by electrolysis of zinc chloride solution. Lead is separated from the solution by cooling to precipitate lead chloride.

Abstract: The thallium content of lead bullion is decreased in that iron chloride is stirred into the lead bullion so as to form a salt slag which contains thallium.

Abstract: Transparent conductive coatings excellent in transparency are provided on substrates such as glass, plastics, etc. by the use of conductive coating materials obtained by maintaining aqueous solutions of hydrolyzable tin containing or indium containing compounds at pH of 8-12, and gradually hydrolyzing said compounds in the solutions to form sols containing colloidal particles, followed by drying and calcining.

Abstract: An emulsion-forming composition for forming an emulsion for use in a process for selectively recovering germanium or arsenic from an aqueous solution thereof by liquid membrane technology is disclosed, said composition consisting essentially of: a solvent mixture consisting essentially of specified amounts of a hydrocarbon which is a predominantly straight-chain saturated C.sub.16 -C.sub.20 hydrocarbon or kerosine, a mononuclear aromatic hydrocarbon (pref. xylene), and a halogenated C.sub.1 -C.sub.5 hydrocarbon (pref. CCl.sub.4); and more than 0.1% by weight of an oil-soluble polyisobutylene-succinic anhydride/polyamine condensation product.

Abstract: A method for removing and recovering toxic heavy metal contaminants from an iron-bearing sludge is provided. The method comprises one or more cycles of a two step, controlled chloride leach comprising a first non-acidic chloride leaching solution and a second acidic chloride leaching solution, wherein said toxic heavy metals are separated from said sludge and said iron-bearing sludge is a substantially non-hazardous material.

Abstract: A redox battery electrolyte is prepared from a chromium and/or iron base raw material containing nickel as impurities by dissolving the raw material in a hydrochloric acid-containing aqueous liquid to form a solution containing chromium ions and/or iron ions and nickel ions, the resulting solution being subjected to a cathodic reduction in the presence of lead ions until the electric potential thereof becomes lower than -0.6 V vs. saturated calomel electrode, thereby to remove the nickel ions therefrom.

Abstract: This is a method for the complete leaching of the valuable metals in a metal sulphide material which contains copper, zinc, lead, silver and iron by the use of a solution which essentially contains cupric chloride/sulphates. After the valuable metals have been recovered, the solution is regenerated whereby ferrous chloride and cuprous chloride/sulphate is oxidized to a ferric hydroxide solid and a cupric chloride solution respectively. The regenerated solution is split into two part-solutions and returned to the process.One part-solution goes to a metathesis stage where the fresh metal sulphide material is added in large excess with respect to the part-solutions's content of copper. The result is that only the valuable metals like zinc, lead and silver are leached while copper and iron remain in the residue.The other part-solution goes to a leach stage where the residue from the metathesis stage is added.

Abstract: A process is provided for hydrometallurgical processing of steel plant dusts containing cadmium, lead, zinc, and iron values, along with impurities such as chloride and fluoride salts of sodium, potassium, magnesium, etc. The first step in the process involves leaching the dust in a mixed sulfate-chloride medium that dissolves most of the zinc and cadmium. Any iron and aluminum dissolved in this step is precipitated by oxidation and neutralization. Zinc is recovered from the resulting solution by solvent extraction which provides a raffinate which is recycled to the leaching step with a bleed stream also provided for recovery of cadmium and removal of other impurities from the circuit. The lead sulfate residue from the leaching step is leached with caustic soda, and zinc dust is used to cement the lead out from the caustic solution, which then joins the main solution for zinc recovery.

Abstract: A process is provided for recovering zinc from zinc residues containing iron, and lead. The residue is leached with hydrochloric acid to provide a pregnant liquor containing zinc, iron, and lead. The iron is selectively removed from the pregnant liquor and the zinc extracted from the liquor by an organic solvent extraction system. The zinc is subsequently stripped from the organic solvent using water or hydrochloric acid to provide a zinc chloride solution which is then fed to an electrowinning cell for the production of marketable electrolytic zinc.

Abstract: The invention is concerned with a method for the selective dissolution of lead in relation to zinc that is present as a sulphurized compound.The method comprises treating said compound to lixiviation with a solution containing ferrous chloride, while bubbling a gas that contains oxygen through the lixiviating solution.

Abstract: A process for selectively leaching lead and silver chlorides from a sulfide ore residue in a rapid time which comprises brine leaching the residue under pressure at a temperature above the normal boiling point of the solution, preferably above 100.degree. C.Modifications are leaching at the agglomeration temperature of sulfur when present in the residue to agglomerate the sulfur for ease of recovery, and flashing from leach temperature to ambient as a lead chloride crystallization recovery step to produce a large crop of lead chloride crystals per pass.

Abstract: In a process for producing aromatic aldehydes by reacting chlorinated methylbenzenes with nitric acid, the improvement wherein a lead compound is added to the residue left after separation and recovery of the resulting aromatic aldehydes from the reaction mixture thereby to remove a chlorine ion present in the residue as a precipitate of lead chloride, and the residue left after removal of the lead chloride is recycled to the reaction of the chlorinated methylbenzenes with nitric acid.

Abstract: Residues containing lead as lead sulphate and silver in the form of native silver or silver chloride, sulfide or sulphate, as well as silver complexes with other metals, and resulting from the roasting and leaching of sulfide concentrates containing lead, zinc, copper, and silver are treated to produce a high grade lead and silver product containing lead predominantly as calcium plumbate in a process wherein the residue is leached with brine, the resultant leach solution treated with lime to precipitate lead as oxychlorides, and the resultant lime-oxychloride precipitate is calcined to produce a mixture of calcium orthoplumbate and lead oxide. Residual chloride can be washed easily from this product which may then be treated in a lead blast furnace to recover lead and associated silver in their elemental state.

Abstract: A hydrometallurgical process is used to recover lead from a lead-bearing ore concentrate. The lead-bearing ore concentrate is leached with a solution of cupric chloride in order to precipitate lead as lead chloride, produce elemental sulfur and substantially leave the balance of the ore concentrate sulfides in unreacted form. The residue of the cupric chloride leach is leached with a brine solution in order to solubilize the lead chloride to the exclusion of the balance of the residue. Thereafter, the lead chloride is crystallized from the brine solution. Elemental lead may be obtained by the reduction of the lead chloride crystals.The present process avoids air pollution problems inherent to smelting processes, allows for a high recovery of lead of 97% or greater and allows for the direct production of a high purity lead.

Abstract: Tin is recovered from a molten tin-bearing silicate slag by stirring the molten slag in the presence of calcium chloride and a carbonaceous material. The tin in the slag is rapidly converted to a volatile tin chloride compound, which is removed and contacted with a hot calcium chloride solution trickling over a bed of limestone rock to precipitate tin oxide, which is separated from the calcium chloride solution, which may be reused.

Abstract: Lead sources, and particularly lead sulfide concentrates, are halogenated utilizing a halogen gas in a dry atmosphere at a relatively low temperature to selectively halogenate the lead. The process is improved by effecting the halogenation in a fluidized state in a fluidized bed reactor, the fluidized state of the lead sulfide being accomplished by introducing a mixture of halogen gas and an oxygen-containing gas at a rate sufficient to maintain the lead sulfide in the desired fluidized state. Thereafter, metallic lead may be obtained by leaching the halogenated mixture with brine, filtering to separate elemental sulfur and residue from soluble lead halide. The soluble lead halide is then crystallized and the desired metallic lead is obtained by fused salt electrolysis.

Abstract: A process for the recovery of lead from battery scraps by mixing the lead raps at elevated temperature with an aqueous solution of an alkali metal chloride and hydrochloric acid in order to dissolve, in the form of lead chloride, the lead compounds present in the lead scraps, separating an aqueous solution of this lead chloride from insoluble hard lead, which is recovered, crystallizing lead chloride from the cooling aqueous solution, which is separated from the lead chloride crystals, and finally subjecting the obtained lead chloride to electrolysis for the recovery of metallic lead.

Abstract: Copper, iron, and lead impurities are removed from molybdenum flotation concentrates by mixing the feed concentrates with a nonvolatile chloride salt, heating the mixture to a temperature of from about 200.degree. to 350.degree. C for a time sufficient to activate the lead impurities in the concentrates so that they can be leached therefrom during the subsequent leach step, and leaching copper, iron, and lead impurities from the heat-treated concentrates with a mildly oxidizing leach solution containing chloride ions and having a pH of no more than 4. Preferably, the mixing of the chloride salt and the feed concentrates is achieved by thoroughly mixing an aqueous solution of the salt with the feed concentrates.

Abstract: A process for the treatment of complex lead sulfide-containing concentrates additionally containing at least one metal of the group consisting of iron, copper, zinc, silver, arsenic, antimony, bismuth and gold which comprises the steps of selectively leaching a concentrate with iron-containing lixiviant for converting lead sulfide in said concentrate to lead chloride and forming a leach residue and a leach solution, subjecting said lead chloride in the leach residue to a two-stage, countercurrent, hot brine leach to dissolve the lead chloride in a brine-leach solution, subjecting the brine leach solution to crystallization by evaporative cooling for the separate recovery of crystallized lead chloride, residual brine and crystallization condensate, and returning said residual brine to said brine leach, subjecting crystallized lead chloride in admixture with sodium chloride to electrolysis in a fused bath for production of lead and evolution of chlorine, absorbing chlorine in a first portion of said leach solut

Abstract: A process for the re-utilization of the sulphate residues from the electrolytic treatment of zinc.The residues are digested hot with concentrated HCl in the presence of CaCl.sub.2. PbCl.sub.2 crystallizes on cooling. FeCl.sub.3 is extracted with TBP circulating in the direction of a series of columns and FeCl.sub.3 is extracted in a first column, washed in a second column and re-extracted a third column. The solution which issues is treated with NH.sub.3, resulting in precipitation of the majority of the hydroxides of the metals contained therein, which are subsequently separated, while Ag, Zn and Cu are complexed. Ag is precipitated with (NH.sub.4).sub.2 S.NH.sub.3 is recovered by means of lime. CaCl.sub.2 is re-cycled to the start of the process and Cu and Zn are leached together with the mineral.Application of the process to the recovery of the metals contained in the residues from the digestion of blends.

Abstract: Bismuth is recovered as elemental bismuth or as a Pb-Bi alloy from an air-pervious residue cake of de-bismuthizing dross of concentrated alkaline bismuthide content, by heating the cake in air to the ignition temperature of the cake to ignite the cake, and burning autogenously in a flameless or substantially flameless combustion the thus-ignited cake to oxidize the alkali and a portion of the lead to the exclusion of the bismuth. A powder-like residue, formed by the burning, comprises bismuth, lead, lead oxide and alkali oxide. The lead oxide and alkali oxide of the residue are then selectively dissolved in an oxide-dissolving flux, e.g. molten lead chloride, and the flux containing the lead oxide and alkali oxide is skimmed from the resulting lead bismuthide alloy. The lead of the alloy can, if desired, be separated to recover elemental bismuth, for example, by reacting the Pb-Bi alloy in molten droplet or molten particulate form with Cl.sub.2 to form PbCl.sub.

Abstract: An improvement in conventional processes for recovering metal values from sulfide ores containing lead, zinc and silver sulfides in which process the metal sulfides are converted to chlorides by chlorination followed by solubilization of the chlorides with a sodium chloride leach and subsequent recovery of the metals from their chlorides in accordance with a conventional flow sheet including crystallization, cementation, precipitation, fused salt electrolysis, etc., with chlorine being recovered for reuse by electrolysis of the sodium chloride leach solution substantially depleted of lead, silver and zinc, the improvement being a pollution-free process which comprises:1. recycling the sodium chloride solution depleted of a major percentage of lead and silver to the sodium chloride or brine leaching step; and2.

Abstract: Complex sulfide ores or concentrates are decomposed by treatment with a combination of chlorine and oxygen, the amount of chlorine being limited to that necessary to convert sulfides of the desired metals, such as zinc, lead, copper, cadmium, silver, nickel and cobalt to chlorides.