Abstract: An apparatus for recovering solder from solder coated scrap pieces includes a first centrifuge comprising a centrifuge receptacle having perforation holes, rotatably mounted about a first centrifuge axis for containing and rotating a quantity of solder coated scrap pieces. A solder collection container can surround the centrifuge receptacle. A heater can surround the solder collection container for heating the solder coated scrap pieces and melting the solder thereon. A drive system can be configured for rotating the centrifuge receptacle while the first centrifuge axis is in about a horizontal position at a low speed that tumbles the scrap pieces along a longitudinal length of the centrifuge receptacle, and later rotating the centrifuge receptacle at a high speed for centrifugally extracting molten solder from the centrifuge receptacle, radially outwardly through the perforation holes into the solder collection container.

Abstract: Methods of treating of stannous oxide particles having at least a partial surface crust of stannic oxide by contacting the particles with a reducing agent for a period of time sufficient to produce stannous oxide are provided. The stannous oxide particles produced are readily soluble in organic sulfonic acids.

Abstract: Disclosed herein are processes for oxidising Sn2+ dissolved in an aqueous solution to stannic compounds using NO2 and optionally O2 as oxidants, wherein the aqueous solution is kept at a pH in the range of 0 to 7, wherein a salt Sn2+(Xn?)2/n and the oxidants are used according to the reaction scheme a Sn2+(Xn?)2/n +b O2+c NO2??stannic compounds in which scheme a, b and c are mole numbers; with the proviso that when b is essentially zero, then the aqueous solution is essentially free of Cl?, HSO4? and SO42?.

Abstract: Methods of treating of stannous oxide particles having at least a partial surface crust of stannic oxide by contacting the particles with a reducing agent for a period of time sufficient to produce stannous oxide are provided. The stannous oxide particles produced are readily soluble in organic sulfonic acids.

Abstract: A mineral processing facility is provided that includes a cogen plant to provide electrical energy and waste heat to the facility and an electrochemical acid generation plant to generate, from a salt, a mineral acid for use in recovering valuable metals.

Abstract: The invention relates to a method, composition and apparatus for stabilizing mercury and other heavy metals present in a particulate material such that the metals will not leach from the particulate material. The method generally involves the application of a metal reagent, a sulfur-containing compound, and the addition of oxygen to the particulate material, either through agitation, sparging or the addition of an oxygen-containing compound.

Abstract: In a process for separating tin as well as, if required, copper from scrap melts, in particular, tinplate melts or metallic melts as formed in the working up of waste or metal-oxide-containing combustion residues, the carbon content of the melt is adjusted to 3 to 4.2% by weight and hot wind, oxygen or air enriched with oxygen is locally blown on partial regions of the surface of the melt bath, whereby SnO is discharged, via the gaseous phase, from the redox-gradient-exhibiting zone formed between the carbon-rich bath and the iron oxides produced by top-blowing.

Abstract: A process for removing tin from seasoned photographic color developers containing tin as stannous or stannate complex ions, comprising the steps of:(a) collecting seasoned photographic color developer containing tin;(b) treating the collected developer with a resin having a chelating group selected from the group consisting of diphosphonic acid, amidoxime and thiol, thereby removing tin from the composition.

Abstract: A process is described for recovering tin from oxide or oxide/sulphide low-grade starting materials and concentrates containing little or relatively low concentrations of tin, in which such low-grade starting materials are mixed with KOH and decomposed at high temperatures. The decomposed substance is then leached with water, and metallic tin is separated out electrolytically in one or more stages from the lye. The electrolyte with reduced tin content is concentrated by evaporation, impurities being removed, and dehydrated. The potassium hydroxide solution recovered is re-used for decomposition.

Abstract: A process is disclosed for treating tin scraps such as tin cans and home scrap, to reduce the tin content of the scrap to a sufficient level to permit the scrap to be reprocessed in an electric furnace. In the process, the scrap metal is first shredded, or chopped, to a managable size which is then utilized as a charge to a kiln. The kiln is maintained as an oxidizing atmosphere. The beginning feed end temperature is not less than 2000 degrees F. The temperature is reduced to not less than about 1650 degrees F. to convert a part of the iron-tin alloy into its epsilon phase. The kiln temperature is then further reduced to not less than 1400 degrees F. to further convert a part of the iron-tin alloy to form the zeta phase. The epsilon and zeta phases additionally produce an oxide laden dust that is then removed. As the charge moves through the kiln, the temperature is further reduced to not less than 900 degrees F. to form the eta phase of the iron-tin alloy and additionally a metallic scale formation.

Abstract: A method of detoxifying organotin-containing paint residues that are sandblasted from the bottom of a ship's hull comprising cleaving the tincarbon bond by application of an oxidizing agent, preferably nitric acid.

Abstract: Scrap tin plate is detinned in a continuous process by conveying it through a detinning bath containing concentrations of sodium hydroxide and of sodium nitrate or sodium nitrite which are substantially higher than standard practice. The solution is heated to a temperature higher than is used in standard practice. With this relatively high concentration and temperature the tin reacts with the sodium salts in the solution to form sodium stannate, which precipitates out of the solution and is continuously separated therefrom in a centrifuge or filter press. The detinned scrap is rinsed with water as it emerges from the detinning bath and the used rinse water drains into the detinning bath to serve as a makeup liquid.

Abstract: Copper is processed via solutions of copper salts, both cupric and cuprous, in acidified aqueous solutions containing organic nitriles. Methods of producting solutions of cuprous salts include reduction of cupric salts and oxidation of copper and copper sulphides. Solutions of cuprous salts are thermally or electrochemically disproportionated to produce copper and solutions of cupric salts.

Abstract: Methods of reducing aqueous solutions of cupric sulfate to cuprous solutions by using organic nitrile compositions are disclosed. The particular nitrile used is acetonitrile and the reductant is sulphur dioxide. The method has application commercially to leaching ores containing oxidised copper to obtain cuprous ion solutions. Such solutions can be treated by electrochemical or thermal disproportionation methods to obtain very pure copper.

Abstract: Method of preparing cuprous sulfate and bisulfate solutions from materials containing copper and impurities by a leaching process are disclosed. The leaching composition contains sulfuric acid, cupric ions, water and an organic nitrile. The leaching composition may be used with copper sulfide ores in particulate form. The cuprous solutions resulting from the leaching can be treated by disproportionation methods to recover pure copper.