Abstract: A process for recovery of zinc values contained in thermally activated iron containing copper and zinc sulfides in which said activated sulfides have been subjected to an acid leach in aqueous sulfuric acid to produce a solution of ferrous sulfate and a solids residue containing copper and zinc values. The solids residue containing copper and zinc values is reacted with an acidic copper sulfate solution to precipitate copper values as a simple copper sulfide with concurrent dissolution of iron and zinc values to form a solution of ferrous sulfate containing said dissolved zinc values and said solution of ferrous sulfate is separated from the simple copper sulfides and reacted with H.sub.2 S for precipitation of zinc values therefrom as zinc sulfide. Any nickel and cobalt values present in said activated sulfides is dissolved in said solution of ferrous sulfate and reacted with the H.sub.2 S at elevated temperature for selective precipitaton.

Abstract: Substantially pure copper is produced from impure cupriferous materials by leaching the cupriferous material with an ammonium sulfate-containing ammoniacal solution in the presence of oxygen, followed by separating the copper-containing aqueous liquor from the insoluble leach residue and contacting the thus separated leach liquor with an organic extractant of the metal ion exchange type to extract the copper from the leach liquor. The organic phase comprising the copper-bearing organic extractant is separated from the aqueous phase comprising the leach liquor of reduced copper content, and the resulting copper-bearing organic extractant is contacted with an aqueous solution of sulfuric acid to strip the copper from the copper-bearing extractant.

Abstract: An improvement in the process of producing substantially oxide free copper from copper salts by reacting an acidic aqueous solution which contains the copper salts with a reducing gas at elevated temperature and pressure to precipitate metallic copper. The improvement for producing copper in free-flowing powder form comprises providing in the aqueous solution a finite amount of an addition agent selected from the group consisting of polymeric polyamine compounds having amino groups linked by alkyl groups having 2 to 4 carbon atoms.

Abstract: Direct pressure leaching of zinc and iron containing mineral sulphides in dilute H.sub.2 SO.sub.4 is carried out in a two-stage countercurrent process in which finely divided sulphides are leached in a first leaching stage with solution from the second leaching stage to produce a first stage leach solution containing a high zinc concentration and low iron and H.sub.2 SO.sub.4 concentrations. The first stage solution, after suitable purification treatment, may be treated for zinc recovery by conventional electrowinning. The residue from the first stage leach is pressure leached with return electrolyte from the electrowinning operation with the leach end solution being passed to the first stage leach as already stated. The acid and sulphides concentrations in each of the first and second leaching stage is controlled such that (1) sufficient acid and sulphides enter the leaching circuit to ensure that the final leach solution exiting from the first leaching stage will contain sufficient dissolved zinc, e.g.

Abstract: A process is described for recovering metals which are present in aqueous solution as complex metal ammine ions having an ammonia co-ordination of at least two. According to the process, the complex metal ammine bearing solution is contacted with a cationic ion exchange resin in the ammonium form to effect loading of the complex metal ammine ions from the solution onto the resin. The loaded resin is then stripped by contacting it with a controlled volume of aqueous ammonium salt stripping solution having an ammonium ion concentration of at least two molar. The free ammonia and ammonium salt concentrations in the stripping solution are controlled such that the controlled volume of stripping solution is effective to substantially completely strip the free ammonia and metal values from the resin.

Abstract: A process is described for producing cobalt powder having a particle size of about 2 microns or smaller. The process involves two basic operations: Firstly, finely divided cobaltous carbonate is prepared by precipitation from a cobaltous ammine-ammonium sulphate solution by reacting the solution with carbon dioxide. Secondly, the cobalt carbonate precipitate is separated from the solution and is dry-reduced with hydrogen under controlled conditions of time and temperature to produce finely divided elemental cobalt powder. Cobalt powders produced in accordance with the invention are particularly suitable for manufacture of sintered carbide products as well as for use in magnetic products such as magnetic inks and tapes.

Abstract: The process involves subjecting finely divided particles of copper-bearing mineral sulphide ores or concentrates to a first stage leach in which the particles are leached in an aqueous ammoniacal ammonium carbonate solution in the presence of free oxygen to provide a first stage leach slurry which contains dissolved copper values. Residue is separated from the first stage leach slurry and is subjected to attrition in order to rub off an outer layer therefrom and expose surfaces of the residue beneath the layer. The resulting residue is passed to a second stage leach which is carried out in the same way as the first leach. Solution is removed from the second leach stage and is recycled to the first leach stage. The first stage leach solution is further treated for recovery of copper and ammonium sulphate.

Abstract: A cobalt powder product is described which is composed of cobalt particles about 0.8 microns or smaller in size and have refractory oxide particles fixed on the surfaces thereof. The powder is particularly suitable for manufacture of sintered carbide products as well as for use in magnetic products such as magnetic inks and tapes.

Abstract: According to the process described, non-ferrous metal values, particularly nickel, copper and/or cobalt, are extracted from metallurgical intermediates, such as matte and speiss, by reacting the material under oxidizing conditions at a pH of about 4.5 to 6.5 with an ammonia free aqueous solution containing ammonium sulphate, sodium sulphate and/or nickel sulphate. The reaction-products of this operation are then mixed with sulphuric acid under ambient conditions to decrease the pH to about 3-4.5 and to dissolve the non-ferrous metals in the solution which is then separated from the undissolved residue. The process is particularly useful in treating intermediates containing precious metals in that the precious metals are substantially completely recovered in concentrated form in the undissolved residue.

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: A two-component blank suitable for minting into a coin is described. The blank consists of a low-carbon steel core completely encased in nickel. The blank has magnetic properties sufficiently similar to a solid nickel coin of the same size that the minted blank is accepted by magnetic property testing coin discriminating devices which accept pure nickel coins.

Abstract: A method is disclosed for leaching finely divided lead sulphide bearing material to convert contained lead values to soluble lead acetate with concurrent conversion of sulphur values associated with the lead sulphide to an elemental state. The method involves forming a slurry consisting of the material dispersed in an aqueous medium containing free acetate ions and having a pH below 5.1. The slurry is reacted at a temperature of 60.degree. to 120.degree.C. with a free oxygen-bearing gas under a partial pressure of oxygen of 20 to 60 p.s.i. in order to convert lead sulphide to soluble lead acetate with concurrent production of insoluble elemental sulphur.