A pyro-metallurgical process for producing at least one non-ferrous metal or a compound thereof, wherein said metal is selected from the group consisting of arsenic (As), antimony (Sb), lead (Pb), cadmium (Cd), mercury (Hg), silver (Ag), tin (Sn), nickel (Ni), and zinc (Zn), and wherein at least one raw material is fed into a rotary kiln, wherein said at least one raw material comprises at least said metal, and wherein said raw material is heated to produce a volatized material, in which the non-ferrous metal or compound thereof is produced from the volatized material, in which process a magnesium-based additive, is additionally fed in the rotary kiln in an amount of between 0.5 wt. % and 9.5 wt. % relative to the total weight of said raw materials, which magnesium-based additive is heated together with said raw material to produce at least the volatized material and a solid product, thereby counteracting ring formation in the rotary kiln.

Disclosed herein is a method for reducing a metal oxide in a metal containing precursor. The method comprises providing a reaction mixture comprising the metal oxide containing precursorand an aluminium reductant; heating the reaction mixture in the presence of solid or gaseous aluminium chloride to temperature at which reactionsthatresultin the metal oxide being reduced are initiated; controlling reaction conditions whereby the reaction mixture is prevented from reaching a temperature at which thermal runaway can occur; and isolating reaction products that include reduced metal oxide.

Disclosed herein is a method for reducing a metal oxide in a metal containing precursor. The method comprises providing a reaction mixture comprising the metal oxide containing precursorand an aluminium reductant; heating the reaction mixture in the presence of solid or gaseous aluminium chloride to temperature at which reactionsthatresultin the metal oxide being reduced are initiated; controlling reaction conditions whereby the reaction mixture is prevented from reaching a temperature at which thermal runaway can occur; and isolating reaction products that include reduced metal oxide.

A method of recovering lead, antimony tin from lead acid batteries, lead bearing scrap and other lead bearing materials which includes smelting lead bearing materials in a reverb furnace to recover metallic lead; leaching the resultant slag produced in the reverb furnace with ammonium chloride (NH.sub.4Cl) to produce a slurry; precipitating antimony from the slurry with ferric chloride (FeCl.sub.3); performing a solid-liquid separation of the slag away from the resulting pregnant leach solution; precipitating lead carbonate (PbCO.sub.3) from the pregnant leach solution with carbon dioxide (CO.sub.2); recovering the precipitated lead carbonate (PbCO.sub.3) through solid-liquid separation; and processing the precipitated lead carbonate (PbCO.sub.3) in a reverb furnace to recover metallic lead.

A method of recovering lead, antimony tin from lead acid batteries, lead bearing scrap and other lead bearing materials which includes smelting lead bearing materials in a reverb furnace to recover metallic lead; leaching the resultant slag produced in the reverb furnace with ammonium chloride (NH.sub.4Cl) to produce a slurry; precipitating antimony from the slurry with ferric chloride (FeCl.sub.3); performing a solid-liquid separation of the slag away from the resulting pregnant leach solution; precipitating lead carbonate (PbCO.sub.3) from the pregnant leach solution with carbon dioxide (CO.sub.2); recovering the precipitated lead carbonate (PbCO.sub.3) through solid-liquid separation; and processing the precipitated lead carbonate (PbCO.sub.3) in a reverb furnace to recover metallic lead.

A stabilization process for an arsenic solution comprising thiosulfates, the process comprising: acidifying the arsenic solution to decompose the thiosulfates, to yield an acidified solution; oxidizing the acidified solution to oxidize residual As.sup.3+ to As.sup.5+ and reduced sulfur species to sulfates, to yield a slurry comprising elemental sulfur; separating elemental sulfur from the slurry to yield a liquid; oxidizing the liquid to oxidize residual reduced sulfur species, to yield an oxidized solution; and forming a stable arsenic compound from the oxidized solution.

A stabilization process for an arsenic solution comprising thiosulfates, the process comprising: acidifying the arsenic solution to decompose the thiosulfates, to yield an acidified solution; oxidizing the acidified solution to oxidize residual As.sup.3+ to As.sup.5+ and reduced sulfur species to sulfates, to yield a slurry comprising elemental sulfur; separating elemental sulfur from the slurry to yield a liquid; oxidizing the liquid to oxidize residual reduced sulfur species, to yield an oxidized solution; and forming a stable arsenic compound from the oxidized solution.

A method for supercritical fluid extraction of metal from a source, the method comprising: providing a reactor chamber; providing a source comprising a target metal; optionally, providing a chelating agent; providing a solvent; adding the source comprising the target metal, the chelating agent and the solvent into the reactor chamber; adjusting the temperature and pressure in the reactor chamber so that the solvent is heated and compressed above its critical temperature and pressure; optionally, providing mechanical agitation to the reactor chamber; recovering a chelate comprising the target metal.

A method for supercritical fluid extraction of metal from a source, the method comprising: providing a reactor chamber; providing a source comprising a target metal; optionally, providing a chelating agent; providing a solvent; adding the source comprising the target metal, the chelating agent and the solvent into the reactor chamber; adjusting the temperature and pressure in the reactor chamber so that the solvent is heated and compressed above its critical temperature and pressure; optionally, providing mechanical agitation to the reactor chamber; recovering a chelate comprising the target metal.

A method for production of potassium antimony tartrate by utilizing one or more residues bearing antimony includes the step of leaching of the one or more residues bearing antimony for a first pre-determined time interval in each of one or more jacketed reactors. In addition, the method includes filtering obtained slurry from a leached solution of the one or more residues products bearing antimony to obtain an aqueous solution and a solid residue. The method also includes crystallizing the obtained aqueous solution to form one or more crystals of the potassium antimony tartrate in a jacketed crystallizer. The antimony contained in the one or more residues is in an oxidic form and the oxidic form of the antimony is more than 20%. The solid residue is a leached cake.