Abstract: There is provided a process for converting a silver-mercapto-s-triazine precipitate to a solid containing silver and a solution containing mercapto-s-triazine by contacting the silver-mercapto-s-triazine precipitate with one or more reducing agents. In preferred embodiments, at least one of the reducing agents has a redox potential more negative than about -0.9 V vs. Normal Hydrogen Electrode, NHE.

Abstract: The known method comprises the following steps. (1) the de-copperized anode slime is chlorination-leached with HCl and H.sub.2 O.sub.2. (2) Na.sub.2 CO.sub.3 is added to the chlorination-leach residue of (1). (3) NH.sub.3 is added to the residue of (2). (4) Distillation of NH.sub.3 to remove NH.sub.3 contained in the ammonia leach solution of (3). (5) Distillation residue is washed with water to yield refined AgCl. (6) Conversion of AgCl to Ag.sub.2 O. (7) Reduction of Ag.sub.2 O to Ag. In order to enhance the purity of the reduced silver, the present invention provides the following improvements (a) to (d). (a) Dechlorination (2) with the use of Na.sub.2 CO.sub.3 is carried out at ambient temperature. (b) After dechlorination, the residue is washed with hot water. (c) Sulfuric acid is added instead of carrying out distillation (4). (d) Prior to conversion (6), the chlorination is again carried out.

Abstract: A method of recovering fine lead-containing particles (battery paste) from expended lead-acid batteries in a form which can be used as battery paste in the manufacturing of new batteries without smelting is disclosed. A method of heating lead carbonate particles to about 315.degree. C. to convert them to lead monoxide particles for use in battery manufacturing is also disclosed.

Abstract: Improvement on the recovery of palladium from aqueous acidic solutions employing ketoximes, including novel ether oximes and palladium complexes, comprising contacting the aqueous acidic solution containing the palladium with an organic solvent containing the oxime to form two immiscible phases, separating the organic and aqueous acidic phases and stripping the palladium values from the organic phase using an aqueous ammonia solution. The organic phase may contain phase transfer agents and modifiers.

Abstract: A method for recovering precious metals from carbonaceous ore comprising leaching the ore with a lixiviant solution and then preg-robbingly concentrating the precious metal-lixiviant complexes in solution on to the native carbonaceous component of the ore for subsequent recovery. The preg-robbing capacity of the native carbonaceous component of the ore can be augmented by adding recycled carbonaceous matter or finely ground carbon to the ore-lixiviant mixture. Furthermore, after the carbonaceous component of the ore is separated from the gangue, the gangue material can be treated in a hot CIL process to further increase the recovery of the precious metal.

Abstract: A process for recovering nickel that is in soluble form and in relatively low concentrations, typically up to 2% by weight in a liquor, comprises: (a) precipitating nickel from solution (preferably as a hydroxide or sulphide); (b) adding an inert particulate carrier and a flocculent to the liquor to form flocs comprising nickel precipitate, inert particulate carrier, and flocculent; (c) separating the flocs from the liquor (preferably by gravitational settling or magnetic separation); and (d) separating the nickel precipitate from the flocs (preferably by agitating the flocs). The nickel precipitate and flocs are preferably then passed through a filter to remove the nickel as filter cake. The inert carrier is preferably sand, alumina, magnetite, hematite, ilmenite or calcite. The flocculent is preferably a cationic, non-ionic or anionic flocculent.

Abstract: A method for recovering precious metals from carbonaceous ore comprising leaching the ore with a lixiviant solution and then preg-robbingly concentrating the precious metal-lixiviant complexes in solution on to the native carbonaceous component of the ore for subsequent recovery. The preg-robbing capacity of the native carbonaceous component of the ore can be augmented by adding recycled carbonaceous matter or finely ground carbon to the ore-lixiviant mixture. Furthermore, after the carbonaceous component of the ore is separated from the gangue, the gangue material can be treated in a hot CIL process to further increase the recovery of the precious metal.

Abstract: A process for recovering precious or base metals from particulate refractory sulfide materials comprises: a) contacting the sulfide material with an aqueous solution containing a thermotolerant bacteria culture capable of promoting oxidation of the sulfide material at a temperature in the range from 25.degree. to 55.degree. C., b) separating the oxidized residue from the aqueous liquid, and, c) treating the oxidized residue and/or the aqueous liquid to recover metal. In this context, a thermotolerant bacterium is one which has an optimum growth temperature of 40.degree. to 45.degree. C., and an operating temperature of 25.degree. to 55.degree. C.

Abstract: A method in which a contaminated aqueous solution produced as a result of a hydrometallurgical extraction operation is passed through a filtering bed comprising a plurality of elements, optionally of differing sizes and shapes, formed from materials including plastics and their derivatives, polypropylene, polyester, nylon, teflon, etc., so as to remove organic phase residues, solids, and other contaminants therefrom. The method is complemented by a back wash stage using air and water to dislodge the contaminants from the bed to permit subsequent collection and/or treatment of these materials. The method exhibits technical and economic advantages that are very significant in comparison to traditional methods.

Abstract: Materials and methods for the enhancement of the biooxidative acid leaching of heavy metals from sulfide ore are disclosed and claimed. The enhancement of bioleach solutions with a nutrient supplement selective for a particular sulfide oxidizing strain of bacteria significantly increases copper solubilization of chalcopyrite ore. Likewise, copper solubilization is enhanced by enriching bioleach solutions with a non-selective growth mediums.

Abstract: A method for recovering precious metals from carbonaceous ore comprising leaching the ore with a lixiviant solution and then preg-robbingly concentrating the precious metal-lixiviant complexes in solution on to the native carbonaceous component of the ore for subsequent recovery. The preg-robbing capacity of the native carbonaceous component of the ore can be augmented by adding recycled carbonaceous matter or finely ground carbon to the ore-lixiviant mixture. Furthermore, after the carbonaceous component of the ore is separated from the gangue, the gangue material can be treated in a hot CIL process to further increase the recovery of the precious metal.

Abstract: A method of degassing and decarburizing molten stainless steel in a vacuum, which molten steel is produced in a steel making furnace. Molten steel is foamed in a vacuum tank. Before foaming the [N] (%) in the molten steel is increased. The foam is produced by denitrification of the steel during vacuum degassing. Oxidizing gas is blown through a top-blow lance onto the surface of the steel in a vacuum tank, causing the reaction C+1/2O.sub.2 .fwdarw.CO to decarbonize the steel. Temperature decrease of the molten steel is resisted by combustion of CO produced by the reaction of C+1/2O.sub.2 .fwdarw.CO.

Abstract: A process for removing metals from a waste including uranium and a second metal comprising dissolving the uranium and the second metal in a first aqueous solution, removing the dissolved uranium from the first aqueous solution by redissolving in an organic solvent, stripping the uranium from the organic solvent by redissolving in a second aqueous solution, precipitating the uranium from the second aqueous solution, and removing the second metal from the first aqueous solution.

Abstract: A method for recovering precious metals from carbonaceous ore comprising leaching the ore with a lixiviant solution and then preg-robbingly concentrating the precious metal-lixiviant complexes in solution on to the native carbonaceous component of the ore for subsequent recovery. The preg-robbing capacity of the native carbonaceous component of the ore can be augmented by adding recycled carbonaceous matter or finely ground carbon to the ore-lixiviant mixture.

Abstract: The invention is a process for removing a chromium containing coating from an aluminum article. The chromium containing coating is removed from the aluminum article by contacting the aluminum article having the chromium containing coating with an alkaline treating bath to form an ultrasonically removable chromium containing coating and treating the aluminum article with the ultrasonically removable coating with ultrasonic vibrations to remove the chromium containing coating.

Abstract: A metal element adsorbent in the form of a hydrogel prepared by treating a condensed tannin with a base, in the presence or absence of an aldehyde so as to avoid precipitation of cross-linked tannin and produce a hydrogel. The inventive adsorbent exhibits high adsorption properties for metal elements and a low flow resistivity when used in a packed column. Methods for use of the inventive adsorbent are disclosed.

Abstract: Geothermal brine and other platinum-containing solutions are passed through a carbon-containing zone to recover platinum from the aqueous medium.

Abstract: A composition of bibenzimidazoles of the Formula (I): ##STR1## wherein X & Y which may be the same or different and, taken together, contain a total of from 12 to 52 saturated carbon atoms, are (a) each selected from --R, --COR, --CH.sub.2 COOR, --CH(COOR).sub.2 and --COOR; or (b) together form a group selected from ##STR2## wherein R is an optionally substituted hydrocarbyl group,A & B taken together with the two carbon atoms to which they are linked form an optionally substituted benzene ring; andC & D taken together with the two carbon atoms to which they are linked form an optionally substituted benzene ring;characterised in that at least 50% by weight of the bibenzimidazoles in the composition are of Formula (II) ##STR3## wherein X and Y are as hereinbefore defined;T, U, V & W which may be the same or different, are H, R.sup.1 or OR.sup.1 provided at least one of T, U, V & W is R.sup.1 or OR.sup.1 ;and R.sup.1 is C.sub.

Abstract: A process for de-oiling mill sludge employs the steps of admixing mill sludge with water and surface active agent to form a mill sludge slurry which is subjected to high shear agitation to form an oily water emulsion. Then at least 40 weight percent of the solids present in the mill sludge treated is separated from the oily water emulsion.

Abstract: Hydrophilic hydrogels capable of a high degree of water imbibition are contacted with aqueous feedstocks containing metal and metal anion values to collect the water and dissolved or suspended values or materials. The term metals includes the free base and precious metals, alloys, salts (including their solvated and complex precious metal ions) and compounds, including base metal anions, and mixtures of the above which are soluble or insoluble in water. The feeds can be ores, industrial or other wastes. After contact, the hydrated hydrogel can be partially dehydrated and separated from the aqueous feedstock. The material values can be recovered by using a strong oxidant to destroy the hydrogel. The aqueous feedstock can be recycled or further purified.

Abstract: A process for de-oiling mill scale which comprises(a) collecting mill scale and analyzing for oil content; and then(b) slurrying the portion of mill scale containing more than 0.5 weight percent oil in water to achieve an aqueous mill scale slurry having at least 25 weight percent solids content; and then(c) high shear agitating the aqueous mill scale slurry to form a reduced oil mill scale suspension in an oily water emulsion; and then(d) phase separating the reduced oil mill scale from the oily water emulsion forming a reduced oil mill scale and an oily water emulsion; and then(e) fresh water rinsing the reduced oil mill scale to form an oil-free mill scale and a waste wash water; and then(f) recycling the waste wash water to form at least a portion of the aqueous mill scale slurry of step b; and then(g) repeating steps (a) through (f) until the oil-free mill scale contains less than 0.

Abstract: A method of treating a gold-bearing ore to render the gold component of the ore more amenable to standard cyanidation treatment in a reduced amount of time is disclosed. An aqueous slurry of the gold-bearing ore is introduced into at least one vessel. An oxidizing agent, such as chlorine gas, an alkali metal hypochlorite and an alkaline earth metal hypochlorite, is rapidly introduced into the vessel so that it intimately contacts the aqueous slurry. While the oxidizing agent is being introduced into the vessel, the slurry is agitated with agitating means including a plurality of impeller blades that provide high shear agitation and a large interfacial surface area between the oxidizing agent and the liquid phase of the slurry to enhance the mass transfer of the oxidizing agent so that it becomes substantially completely adsorbed by the aqueous slurry in about 5 to about 15 minutes.

Abstract: Nickel and cobalt are reversibly extracted from nickel and cobalt bearing aqueous solutions using solvent extraction techniques by contacting the aqueous solution with a hydrocarbon solvent containing a N-alkylalkanohydroxamic acid having at least about 8 carbon atoms.

Abstract: Methods are disclosed for recovering one or more of the metals of tungsten and molybdenum from metal-cellulose material. One method involves digesting the material in a mineral acid selected from the group consisting of hydrochloric acid having a concentration of at least about 4 normal, and sulfuric acid having a concentration of at least about 9 normal at a temperature of at least about 50.degree. C. for a sufficient time to form a digestion solid containing the major portion of the tungsten and a digestion solution containing a portion of any molybdenum which is present in the material, and separating the solid from the solution. Another method involves having as the starting material a metal-cellulose material comprising one or more of the metals of tungsten and molybdenum and elements selected from the group consisting of arsenic, phosphorus, silicon, and combinations thereof.