Abstract: A hydrometallurgical process for the treatment of polymetallic ores and sulphide concentrates of copper and zinc, and by-products of lead and zinc from smelting plants, treated independently and/or as mixtures thereof, which contain relevant amounts of lead, copper, zinc, iron, gold and silver, such as the matte-speiss mixture of lead foundries, and copper cements from the purification processes of electrolytic zinc plants. The process allows the recovery of metallic copper, zinc, copper as copper and zinc basic salts, which may be hydroxides, carbonates, hidroxysulphates or mixtures thereof; the production of stable arsenic residues; and the effective and efficient recovery of Pb, Au and Ag as a concentrate of lead sulphide and/or lead, Au, and Ag sulphate.

Abstract: Disclosed is a method for recycling lead from waste glass containing lead, which comprises the following steps: mechanical crushing waste glass containing lead, ball milling and screening to obtain glass powder containing lead; alkaline roasting the glass powder containing lead to obtain a roasted material; mixing polycarboxylic acid complexant and nitric acid to produce leaching agent, and then placing the roasted material into the leaching agent to obtain leachate; regulating pH value of the leachate to solidify metal ion to obtain precipitate, separating and removing impurities, rinsing and drying to obtain chemical product containing lead. The method avoids environment pollution caused by waste glass containing lead.

Abstract: Disclosed is a method for recycling lead from waste glass containing lead, which comprises the following steps: mechanical crushing waste glass containing lead, ball milling and screening to obtain glass powder containing lead; alkaline roasting the glass powder containing lead to obtain a roasted material; mixing polycarboxylic acid complexant and nitric acid to produce leaching agent, and then placing the roasted material into the leaching agent to obtain leachate; regulating pH value of the leachate to solidify metal ion to obtain precipitate, separating and removing impurities, rinsing and drying to obtain chemical product containing lead. The method avoids environment pollution caused by waste glass containing lead.

Abstract: Wet process of low environmental impact recovers the lead content of an electrode slime and/or of lead minerals in the valuable form of high purity-lead carbonates that are convertible to highly pure lead oxide by heat treatment in oven at relatively low temperature, perfectly suited for making active electrode pastes of new batteries or other uses.

Abstract: Disclosed is a process for removing metals from waste, particularly electronic waste (or “e-waste”). The process generally includes the steps of dissolving at least some of the metals from the waste with nitric acid reagent and then causing at least some of the metals to precipitate as metal oxides and/or metal nitrates. NOx gases produced as by-product by the nitric acid dissolution of metallic components in the electronic waste are reused, in particular for generating permanganate when one of the metallic components comprises manganese.

Abstract: An outstandingly low environmental impact wet process recovers the lead content of an electrode slime and/or of lead minerals in the valuable form of high purity lead oxide or compound convertible to highly pure lead oxide by heat treatment in oven at relatively low temperature, perfectly suited for making active electrode pastes of new batteries or other uses.

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: A method of removing mercury from a mercury-containing flue gas, especially flue gas from a refuse incinerator, is provided. The mercury-containing flue gas may also contain dust, further heavy metals, and further gaseous noxious gas components. The mercury, using an alkali sulfide solution, especially sodium sulfide solution, and in particular sodium tetrasulfide solution, is converted to mercury sulfide and the mercury sulfide is precipitated out via a dust separator. The alkali sulfide solution is introduced into the flue gas accompanied by the simultaneous addition of heat.

Abstract: Lead oxide is used for neutralizing the sulfuric acid wastewater received from washing charged (formed) electrodes during lead battery production. The neutralization product, including lead sulfate and excess lead oxide, is returned directly to production of the active mass paste. The mother liquor, after a possible use as cleaning water, is subjected to another neutralization with lead oxide, separate from the wastewater received from the electrode washing procedure in view of its possible content of impurities. The resulting lead sulfate is sent to a metal-processing facility for recycling. The neutral mother liquor, after the removal of lead residues by conventional precipitation methods and filtration, is discharged as treated water.

Abstract: A process is disclosed for recovering zinc, lead, copper and precious metals from zinc plant residue, said process comprising leaching the residue with return zinc spent electrolyte, neutralizing residual acid and reducing ferric iron in the solution by addition of zinc sulphide concentrate in the presence of a limited quantity of oxygen, flotation of the resulting slurry to separate unreacted zinc sulphide, treatment of flotation tailings with sulphur dioxide and elemental sulphur to further leach iron, zinc and impurity elements and precipitate copper, flotation of the resulting slurry to separate a copper sulphide concentrate, thickening, filtering and washing of the flotation tailings followed by addition of lime and sodium sulphide to activate lead sulphate and flotation of a lead concentrate from the residue.

Abstract: A method for site remediation for mitigating contamination from metals or metal compounds, particularly resulting from the situation of mine tailing waste on or near water sources, including the reprocessing and redeposit of separated sands and slimes in-site in a manner to encourage rather than inhibit leaching of residuals by chelating agents or biological agents with recovery of leachate and removal of metals or metal compounds.

Abstract: The invention relates to a process for the recovery of metal values contained in a ferric gangue.The process comprises the following stages:(a) dissolution of the metal values from the ferric gangue with sulphuric acid;(b) recovery of the metal value or values by a method which is known per se,(c) evaporation of the acid ferric solution resulting from stage (b) so as to increase the acidity to a value of between about 50 and 100%,(d) crystallization from this solution, at a temperature of between -10 and 50.degree. C., of a hydrated iron sulphate of formula Fe.sub.2 (SO.sub.4).sub.3.9H.sub.2 O.Application to the recovery of strategic metals.

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: A process for recovering in pure metal form substantially all lead from battery sludge is disclosed. The battery sludge is desulfurized, leached with acid, and separated by filtration. Lead is recovered from the filtrate by electrowinning. The residue from the leaching and filtration is treated with concentrated sulfuric acid to cause the simultaneous occurring of the following reactions:C.sub.n (H.sub.2 O).sub.m +H.sub.2 SO.sub.4 .fwdarw.nC+H.sub.2 SO.sub.4 .multidot.mH.sub.2 O (1)C+2PbO.sub.2 +2H.sub.2 SO.sub.4 .fwdarw.2PbSO.sub.4 +CO.sub.2 +2H.sub.2 O (2)up to the quantitative reduction of substantially all of the lead dioxide PbO.sub.2 and elimination of substantially all the organic substances C.sub.n (H.sub.2 O).sub.m contained in the insoluble residue. Lead sulfate from the above reaction is recycled to the desulfurization step.

Abstract: A highly concentrated silver salt suspension and tin salt suspension from which a silver and tin oxide powder can be made under utilization of the reaction spray method is made by adding in small steps a tin II salt solution into a small volume of concentrated nitric acid while maintaining a temperature below 40 degrees C. to obtain an injection suspension of a tin II salt solution, the injection suspension is then mixed with about a three fold quantity (volume) of concentrated 65% nitric acid, the latter mixture is then added in small steps to a watery citrate solution and combined with tin granules until all tin granules are dissolved and changed into a tin IV oxide hydrate suspension; the completed tin IV oxide hydrate suspension as per the preceding step is mixed with a watery silver nitrate solution.

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 hydrometallurgical process is provided to electrogalvanize steel, utilizing primary and secondary zinc sources. The process consists of leaching the feed in a mildly acidic solution. The zinc is selectively recovered from the leach liquor in a solvent extraction system and thereafter stripped from the solvent using a stronger acidic solution to provide a strip solution which is fed to an electrogalvanizing bath for electrogalvanizing steel products, e.g., sheet steel, using insoluble anodes. Acidic solutions and organic solvent are recycled in the process.

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 method of concentrating silver from anode slime which comprises reacting an intermediate product obtained by treatment of the slime, the intermediate product containing lead in sulfate form and silver in chloride form, with an aqueous solution of an alkali hydroxide or carbonate. The obtained reaction product is then subjected to solid-liquid separation, and the resulting residue is reacted with a nitric acid solution so that the lead therein may be separated into a filtrate, while the silver will remain in the residue.

Abstract: The impure jarosite residue of an electrolytic zinc process is leached in a sulfuric-acid-bearing solution in order to produce a leach residue which contains lead, silver and gold and a ferrisulfate-bearing solution and to separate them from each other, whereafter the leach residue is sulfidized and froth-flotated in order to recover a combined concentrate which contains lead, silver and gold, and the ferrisulfate-bearing solution is fed to a ferritic treatment stage, in which ferrisulfate and ferrites react in the presence of ions of alkali and ammonium at 80.degree.-105.degree. C. and form pure jarosite and zinc sulfate.

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 process for treating sulfide ores to reduce the sulfur content or recover the metal content therefrom comprises the use of enzymatic action to solubilize the sulfur and metal content.A nutrient, such as a saccharide, is used along with yeast spores which feed on the sugar and produce enzymes which act on sulfur in the sulfide ore to cause the sulfur to go into solution and to dissolve those metals which are soluble in strongly acidic solution. Sulfuric acid can be formed from the sulfide ores or from free sulfur by reaction with water, with evolution of hydrogen sulfide gas. Oxidation of at least a portion of the hydrogen sulfide can be achieved to regenerate sulfuric acid.

Abstract: A multi-step process for recovering metal values from lead smelter matte. The matte is mixed with sulfuric acid and manganese oxide and leaching is effected at atmospheric pressure to form an aqueous solution including dissolved metal sulfates and a residue containing sulfur and lead sulfate. The sulfur is removable by conventional means and the lead sulfate may be returned to the smelter. The pH of the aqueous sulfate solution is adjusted to 3.5 to 4.5 to precipitate ferric iron and arsenic and pH is readjusted to about 3.0 to redissolve coprecipitated copper. After separation from the precipitate, the aqueous solution is mixed with a sulfiding agent, such as sodium sulfide at a pH of not more than 3 to selectively precipitate copper sulfide. After separating the copper sulfide, the aqueous solution is mixed with further sulfiding agent at a pH of 3 to 4.5 to form a cobalt-nickel sulfide precipitate in which the weight ratio of copper-nickel to sulfur is 1.8.

Abstract: This invention relates to a process for hydrometallurgical treatment of concentrates of sulphides of copper, nickel, cobalt, lead and iron and copper-containing mattes. A first embodiment of the process includes subjecting a finely ground slurry of a sulphide concentrate to an oxidation leach at elevated temperature and pressure in the presence of an oxygen-bearing gas to preferentially leach cobalt and nickel and to convert galena to lead sulphate. The reaction mixture is heated to a further elevated temperature, in the absence of oxygen, to convert a portion of chalcopyrite to insoluble simple copper sulphides and ferrous sulphate solution and to decompose complex insoluble ferric compounds. The resulting mixture is subjected to differential flotation whereby a lead concentrate and a copper concentrate are obtained.

Abstract: A process for the treatment of lead sulphide with an aqueous solution of sulphur dioxide at a temperature of at least 20.degree. C and in the absence of oxygen is disclosed. In a preferred embodiment the lead sulphate and/or lead sulphite so formed is heated with lead sulphide at a temperature of 700.degree. to 1200.degree. C in the absence of oxygen. Metallic lead is obtained. In the preferred embodiment the lead sulphide may contain zinc sulphide whereby both metallic lead and metallic zinc may be obtained.

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.

Abstract: A hydrometallurgical process for treating iron containing metal sulfides for rendering iron and non-ferrous metal values active and amenable for selective extraction and separate recovery. Sulfur values can be controllably produced as elemental sulfur or as sulfuric acid to supply acid requirements of the process, while substantially obviating the discharge of sulfur-containing gases to the atmosphere. Ores and concentrates of the sulfides are thermally activated by sequentially heating and reducing said sulfides in a countercurrent flow of heating and reducing gases respectively in a reactor whereby the reaction products of the reducing gas and sulfides, together with liberated labile sulfur, are controllably combusted with oxygen to satisfy heat requirements of the thermal activation process and to convert sulfur values to SO.sub.2 gas. The activated sulfides are subjected to an acid leach in aqueous sulfuric acid for production of ferrous sulfate and evolution of H.sub.

Abstract: Lead is recovered from lead sulfide concentrates or mixed lead-zinc concentrates containing iron sulfide by forming a slurry of such concentrates in an aqueous medium containing ammonium sulfate and free ammonia, and introducing such slurry into a closed reaction vessel at a pressure not exceeding 30 psig. Oxygen also is introduced into such vessel to establish therein a partial oxygen pressure of at least a few psi, while vigorously agitating the slurry. The lead sulfide content of the concentrates thereby is converted to the form of substantially water-insoluble oxidic lead compounds, while any zinc sulfide present is dissolved. The slurry then is withdrawn from the reaction vessel and the insoluble residue is separated from the aqueous solution. The latter is treated for recovery of its zinc and ammonia content, and the residue is subjected to a froth flotation operation to form a concentrate containing substantially all the iron sulfide and a tailing containing the oxidic lead compounds.