Abstract: A process for recovering a metal chloride or mixed metal chloride from a solid waste material comprising recoverable metal containing constituents produced by lead, copper or zinc smelting and refining processes, said process comprising the steps of: (i) heating the solid waste material; (ii) treating the heated material of step (i) with a gaseous chloride to form a gaseous metal chloride containing product; and (iii) treating the gaseous metal chloride containing product of step (ii) to recover the metal chloride or mixed metal chloride. The metal chloride may be further treated to extract the metal itself.

Abstract: A method of removing lead sulfide contained in refined molybdenite powder concentrates (major component; MoS2) is provided. More specifically, in order to solve the problems associated with a leaching method using a leaching agent that is employed for conventional hydrometallurgical process, oxygen-free inert gas is circulated in a furnace for pyrometallurgical treatment to evaporate lead sulfide at high temperature, followed by condensing process to recover lead sulfide at low temperature. The method is characterized in that, it can reduce environmental contamination and can easily recover sulfides of valuable metals such as lead, indium, zinc and the like.

Abstract: A method of removing lead sulfide contained in refined molybdenite powder concentrates (major component; MoS2) is provided. More specifically, in order to solve the problems associated with a leaching method using a leaching agent that is employed for conventional hydrometallurgical process, oxygen-free inert gas is circulated in a furnace for pyrometallurgical treatment to evaporate lead sulfide at high temperature, followed by condensing process to recover lead sulfide at low temperature. The method is characterized in that, it can reduce environmental contamination and can easily recover sulfides of valuable metals such as lead, indium, zinc and the like.

Abstract: A method for extracting metals from metal-containing materials, especially waste, by pyrohydrolysis. The metal-containing materials which contain at least one or more of the metals from the group consisting of Zn, Cd, Pb, Hg, Cu, Sn (as Sn(0) and Sn(II)), As, Sb, Au, Ag and Bi, are made to react at 700-1100.degree. C., advantageously 800-900.degree. C., with a gas composition which at least comprises 25-45% by volume of water vapor, 0-12% by volume of carbon dioxide, 2-20% by volume of hydrogen chloride, 0-15% by volume of carbon monoxide, the remainder being nitrogen and possibly oxygen. The metals from the above-mentioned group are extracted in the form of volatile metal chlorides.

Abstract: An improved method for the recovery of metal and/or chemical values from an industrial waste stream containing zinc, cadmium, lead and/or iron compounds by heating the waste stream in a reducing atmosphere, treating the resultant fumes in an ammonium chloride solution, separating any undissolved components from the solution, adjusting the pH of the solution, if necessary, to less than about 6.3, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, adjusting the pH of the solution to about 6.5 to about 7.0, and further treating the zinc compounds and the undissolved components, as necessary, resulting in the zinc products and the optional iron-carbon feedstock.

Abstract: A process for the removal of volatilizable inorganic contaminants from solid waste is provided. The process comprises the steps of: (a) providing solid waste containing volatilizable inorganic contaminants; (b) heating the waste to a temperature sufficiently high for the volatilization of the inorganic contaminants and sufficiently low so as to prevent slag formation of the solid waste, thereby producing a contaminant-rich vapor phase and a contaminant-poor solid phase; and (c) separating the solid phase and the vapor phase.

Abstract: Residual metallurgical materials which contain zinc and lead are reprocessed by a thermal treatment in a circulating fluidized bed. The required heat is generated in that solid carbon is combusted in the fluidized bed reactor of the circulating fluidized bed. A solid carbon content of 5 to 30% is maintained in the lower part of the fluidized bed. Oxygen-containing gases are supplied to the upper part of the fluidized bed reactor, and CO.sub.2 is formed only in such an amount that zinc metal will not be reoxidized. Substantially all solids are removed from the discharged suspension in a recycle cyclone and are recycled. The gas is cooled to a temperature at which zinc metal is oxidized to ZnO. The dustlike compounds of zinc and lead are separated from the gas.

Abstract: A process and apparatus for the separation of vaporous heavy metal compounds from a carrier gas wherein the heavy metal compounds are cooled and desublimed. An apparatus for carrying out this process has a melting furnace with a discharge opening for a gas/ vapor mixture, which leads to a cooling device.Vaporous heavy metal compounds can be separated from a carrier gas on a large industrial scale. In addition, the apparatus for carrying out this process is easy to operate. The gas/vapor mixture is turbulently mixed immediately after the discharge from the furnace in a mixing section with cold air and is thus cooled. During this cooling, the vaporous heavy metal compounds desublime and are filtered as particles in a filter.

Abstract: A zinc- and lead-containing residue from a metallurgical plant is reprocessed by a thermal treatment in a circulating fluidized bed system. A major part of the heat demand is satisfied by a combustion of solid carbonaceous material in the fluidized bed reactor of the circulating fluidized bed system. A reducing fluidizing gas, which is virtually free of free oxygen, is fed to the lower part of the fluidized bed reactor. A solid carbon content of from 5 to 30% is adjusted in the fluidized bed in the lower portion of the fluidized bed reactor, which is supplied in its upper portion with oxygen-containing gases and in which CO.sub.2 is formed only at such a rate that zinc metal is not reoxidized. Substantially all solids are removed in a recycling cyclone from the suspension discharged from the reactor and the removed solids are recycled. The gas is cooled to a temperature at which zinc metal is oxidized to ZnO. The dust-like zinc compounds and lead compounds are removed from the gas.

Abstract: This invention relates to the metallurgy of iron and particularly to the separation and recovery of metals from electric arc furnace (EAF) dusts. While the invention discloses a process for the separation and recovery applicable to zinc, lead, cadmium and antimony contained in such EAF dusts, the invention is particularly applicable to the separation and recovery of zinc. This invention describes a method for reducing the zinc contained in an EAF dust, volatilizing the metallic zinc so produced from the mass of the dust, and reoxidizing the metallic zinc to zinc oxide along with the simultaneous regeneration of hydrogen which can be recycled to treat additional EAF dust.

Abstract: A method of producing a .beta.-sialon fine powder which comprises using a silane compound represented by the general formula of SiH.sub.x Cl.sub.4-x (0.ltoreq.x.ltoreq.4) as a Si source, aluminum chloride as an Al source and an ether represented by the general formula of ROR' (R,R'=C.sub.y H.sub.2y+1, 1.ltoreq.y.ltoreq.5) as an oxygen source respectively, dissolving them in an organic solvent capable of dissolving them to obtain a solution, introducing ammonia gas into the solution to produce a precipitates, and burning the precipitates in a nonoxidative atmosphere. In the .beta.-sialon fine powder obtained by the method of the invention, respective elements of Si, Al, O and N are uniformly distributed in a chemical viewpoint. A high density high strength sintered body can be produced even at a relatively low temperature by using the .beta.-sialon fine powder.

Abstract: A process for treating electric furnace dust comprising mixing electric furnace dust and a reducing agent with a material for reducing the slag melting point, preheating the mixture, adding the preheated mixture to molten slag which is being subjected to bubbling using oxygen-containing gas, heating the whole mixture, collecting volatilized material, and cooling the remainder.

Abstract: Metallic constituents, especially heavy metal constituents are removed from dust electrostatically separated from a gas mixture consisting substantially of carbon monoxide and phosphorus in vapor form obtained during the electrothermal production of yellow phosphorus. To this end, the dust is initially calcined with continuous agitation under oxidizing conditions at temperatures of 300.degree. to 800.degree. C.; next, the resulting calcined matter is mixed with carbon and the mixture is treated at temperatures of 950.degree. to 1200.degree. C. under reducing conditions with volatilization of the metallic constituents; and the volatized metallic constituents are ultimately condensed and separated.

Abstract: Ultra-fine spherical particles of a metal oxide having an average particle diameter of 40 nm or smaller can be prepared by a method in which a vaporizable metal compound is vaporized and decomposed under heating to give ultra-fine particles of a metal oxide followed by immediate cooling down to a temperature at which coalescence of the fine particles are prevented from coalescence. The fine particles have characteristics such as an excellent power of ultraviolet scattering.

Abstract: Zinc and other metals are recovered form strongly bound zinc ferrite compounds in furnace dust. To the dust is added 1 weight percent of free zinc oxide unless already present. The dust is treated for 1 hour at 750C with a 20:1 air:chlorine mixture whereby the zinc, lead and cadmium are removed from the dust as volatilised chloride.

Abstract: According to the instant invention fine and very fine granular zinc- and lead-containing oxidic byproducts are mixed with thermally inert additives and are hot briquetted with caking coal as a binder at a temperature of 490.degree..+-.40.degree. C. using sufficient carbon to reduce all of the metallic components in the byproducts. Then this mixture is briquetted and heated to more than 700.degree. C. and is maintained at this high temperature for a predetermined time to reduce, that is deoxidize, most of the oxidic components of the briquets, especially zinc, lead, and iron oxides. When the byproducts are not dry, which is standard with a wet scrubbing system for cleaning stack gases, the resultant slurry must be dried before it can be treated according to this invention. The carbon according to the invention is added as fine-granular caking coal in portions of at least 20% by weight. Preferably the portion is between 25% and 35% and up to 40%.

Abstract: Hazardous waste containing inorganic compounds which contain heavy metals or particular hazardous anionic groups or which are hazardous halides or non-metal oxides or sulfides is contacted with molten aluminum to provide reduction to lower less hazardous oxidation state.

Abstract: Lead constituents may be removed from a dross to produce a copper matte low in lead assay by melting the dross at temperature in excess of 900.degree. C., allowing the molten dross to separate into a lead bullion layer and a matte layer, removing the lead bullion layer from the matte layer, then heating the matte layer to a temperature in excess of 1000.degree. C., and removing the lead sulphide therefrom as a fume.

Abstract: A process for selective vaporization of oxides from recovered waste dust collected from a bag house. Pellets are formed from the waste dust and dried to permit charging in an oxidizing chamber wherein an oxidizing atmospheric is maintained. The chamber is heated to a temperature sufficient to vaporize lead oxide and, if present, also oxides of cadmium, potassium and sodium. The vapors are cooled and separated from furnace gas. The residual oxidized mass is cooled after removal from the oxidizing chamber and fed into a reduction chamber wherein a reducing atmosphere is maintained. The reduction chamber is heated to a temperature of between 1800 and 2000 degrees Fahrenheit to reduce zinc oxide and form zinc vapors which are cooled and separated from furnace gas. Lead oxide particles recovered from the oxidizing process are reduced to lead.

Abstract: A method for separating non-ferrous metals from an iron-containing waste material which includes providing separate contiguous layers of the waste material and a sintering mixture containing a finely divided carbonaceous fuel, passing hot combustion supporting gases, first through the layer of sintering mixture and then through the layer of waste material in a sintering zone under conditions sufficient to sinter the iron containing constituents, and volatilizing off the non-ferrous metals to produce a charge suitable for feeding to a blast furnace.

Abstract: In a method for recovering zinc and lead from a dust containing ferric oxide, zinc oxide and lead oxide discharged from a metal refining metallurgical furnace, the dust is charged into the entry of a rotary kiln together with a granular carbonaceous reducing agent. The atmosphere of the interior of the kiln comprises a reducing atmosphere zone accounting for a major portion of the interior including the entry section of the kiln and an oxidizing atmosphere zone accounting for a minor portion of the interior including at least a part of the exit section of the kiln. The temperature of the interior of the kiln is increased by the combustion of a fuel from at least one burner installed at the exit section of the kiln directed toward the interior of the kiln. The dust is reduced in the reducing atmosphere zone to vaporized zinc and lead, and also to reduce the ferric oxide into ferrous oxide.

Abstract: The invention comprises a process for the manufacture of metal chlorides by the double-decomposition reaction between a metal chlorinating agent and a metal oxide having greater affinity for chlorine than does the oxide of the metal chloride, and in the presence of small amounts of boron chloride or functionally equivalent boron compounds that increase the rate and degree of completion of the reaction.A major application of this invention is for the making by the chlorination of clay of aluminum chloride and alumina intermediates for the manufacture of aluminum metal.SiCl.sub.4 is formed in the carbo-chlorination of clay or other aluminous-siliceous ores. The SiCl.sub.4 by this invention is catalyzed with BCl.sub.3 and reacted with calcined clay to produce AlCl.sub.3 and SiO.sub.2. The practical use of SiCl.sub.4 to make AlCl.sub.3 thus eliminates the previous costly burden of waste SiCl.sub.4 production.

Abstract: A process for thermally treating fine-grained solids with high-oxygen gases at temperatures at which the solids can form molten and gaseous reaction products comprises carrying out the thermal treatment at least in part in a cyclone chamber. The solids, high-oxygen gases and, if desired, an energy carrier (usually a carbon-containing solid, liquid or gas) are mixed to form a suspension at a temperature below the reaction temperature. The suspension is fed to a vertical combustion path (tube) and reacts therein to form another suspension of primarily molten particles which is admitted to the cyclone chamber. Reactants are added to the gas phase within a core-flow region of the cyclone chamber and/or immediately after the discharge of gas therefrom to a cooling chamber.

Abstract: A process for substantially reducing the presence of impurities from a sulfur-containing feed material such as dust and hydrometallurgical wastes that result from smelting and refining operations. Pelletized feed materials are heated to 800.degree. to 1150.degree. C and reacted with a gas stream containing chlorine and oxygen. In the presence of sulfur dioxide formed in situ and due to the presence of residual sulfur, the order of volatilization of the elements contained in the feed material is changed from that known for conventional chloridization processes to a more advantageous order. The elements Cd, Bi, Re, Pb, Mo, Sn, Sb, Zn, and As are volatilized and thereby separated from the solid feed material which is consequently enriched in Cu, Ag, Co, Fe, Ni, Au, and precious metals. The feed material is subsequently refined conventionally.

Abstract: This invention relates to refining platinum group metal concentrates and the separation therefrom of silver and of the majority of base metals with which they naturally occur. In more detail the process comprises the steps of:(a) contacting a solid particulate mixture of base, silver and precious metal components, any of which components may be in metallic or chemically combined form, with a halogen-containing gas at a temperature which is sufficiently high for the base metal and silver components to form their halides and for the said halides substantially to volatilize from the said solid mixture, and(b) removing the said volatilized halides from the solid precious metal-containing component which remains.

Abstract: This invention relates to refining platinum group metal concentrates and the separation therefrom of silver and of the majority of base metals which are present with them. In more detail, the process comprises reacting together gaseous hydrogen and chlorine so as to produce a flame and passing into the reaction zone of the said flame the said mineral concentrate in finely divided particulate form.The specification also describes an apparatus for carrying out the above process comprising a tubular burner having a hydrogen-chlorine flame discharging into an inner heat resistant tube and means for maintaining the inner tube at an elevated temperature up to at least 2500.degree. C.

Abstract: A process for the treatment of a concentrate of by-metals comprises heating he concentrate at between 1100.degree. C and 1500.degree. C, preferably at about 1300.degree. C, in a gaseous stream which comprises oxygen. The heating step is effected for a period of time sufficient to ensure quantitative removal of one or more of lead, arsenic, silver, bismuth and/or tellurium and the oxidation of ruthenium, rhodium and iridium to their oxides.