Abstract: A process for obtaining pure aluminum oxide (Al.sub.2 O.sub.3) from siliceous aluminum ore is disclosed. The aluminum ore is digested in a hydrochloric acid solution to obtain aluminum chloride, the aluminum chloride is crystallized as the hexahydrate, the aluminum chloride hexahydrate is purified and, subsequently, decomposed to give pure aluminum oxide and secondary products. The mother liquor of the crystallization step and the secondary products of the decomposition step are recycled.

Abstract: A process for the treatment of raw materials which contain arsenic and metal to produce a metal-free arsenic product and an arsenic-free metal sulfate is disclosed, in which the raw material is leached by using an aqueous solution of sulfuric acid and then the metals are crystallized as sulfates from the separated aqueous solution, which is separated from the metal sulfate crystals. The leach is performed at elevated temperature under oxidizing conditions, in order to bring the arsenic to a 5-valent form, the metal sulfates are crystallized out from the selectively separated, arsenate-bearing aqueous solution by cooling, and arsenic is removed from at least part of this aqueous solution before the aqueous solution is returned to the leach.

Abstract: Clusters or galaxies of noble metal silver-precipitating nuclei for use in silver diffusion transfer processes are formed by reducing a noble metal salt or complex to form a colloid of noble metal nuclei and inducing instability to said colloid, whereby said galaxies are formed.

Abstract: Silver-precipitating nuclei are prepared by partially oxidizing a stannous salt reducing agent and then reducing a noble metal salt or complex with said reducing agent.

Abstract: A process for precipitating iron as a jarosite from a sulphate solution containing ferric iron, free acid and valuable non-ferrous metals, characterized by cooling the solution; partially neutralizing the free acidity, and then clarifying the solution; heating the clarified solution to a temperature not exceeding the boiling point at atmospheric pressure, in the presence of at least one ion selected from the group consisting of sodium, potassium and ammonium ions, and in the presence of recycled jarosite, and without the addition of any further neutralizing agent, so that substantially all of the ferric iron is precipitated as a jarosite; and separating precipitated jarosite from the solution; thereby producing a jarosite contaminated with only minor amounts of non-ferrous metals, and a solution which may be further processed by established procedures for the recovery of dissolved valuable non-ferrous metals therefrom. The invention also contemplates a dilution step, and recycle of jarosite.

Abstract: H.sub.2 S and CO.sub.2 from a waste gas are absorbed in an ammoniacal or alkali metal hydroxide solution. The resultant sodium, potassium or ammonium sulfide solution is reacted with pulverized copper oxide and the resultant copper sulfide precipitate is separated and the resultant solution of increased sodium hydroxide, potassium hydroxide or ammonia content is recycled as absorbent for hydrogen sulfide and CO.sub.2. The copper sulfide is roasted to form recyclable copper oxide and product sulfur dioxide.

Abstract: A process for treating very dilute solutions containing ecologically noxious heavy metal ions, in which the solutions are made acceptable for return to the environment, and the typically valuable heavy metal present in the solution is recovered at an economic profit. The dilute solution is flowed through an ion exchange resin, as a cross-linked polystyrene having quaternary ammonium functional groups which hold the heavy metal ions, allowing an ecologically benign effluent to return to the environment or the water to be re-used in industrial processing. Typically, an alkali metal halide is subsequently placed in contact with the resin to recover the heavy metal ion for subsequent reduction to a solid.

Abstract: An electrosensitive recording sheet consists of an electroconductive material of cuprous iodide, an electrosensitive color forming material, a binder and a support. A color forms in the recording sheet in response to an electric signal when an electric current flows therein. The cuprous iodide is whitened by adding an alkaline substance thereto, so as to only slightly increase the resistance of the cuprous iodide and to increase the contrast of recorded mark and the ordinary appearance of the recording sheet.

Abstract: A process for separating and recovering metal values and salts from brine, such as brine produced from a subterranean geothermal reservoir, in which the brine is pressurized to above the bubble point pressure and thereafter a precipitating agent, such as a soluble sulfide, is added to the brine to form insoluble metal sulfide precipitates. The precipitates are separated from the brine while maintaining the brine at a pressure above the bubble point pressure, and the hot brine is subsequently utilized to derive energy therefrom. The brine effluent after such energy derivation and the precipitate are optionally processed to primarily recover saleable salts and metal values, respectively.

Abstract: Aqueous lead solutions obtained by hot chloride leaching of residues containing lead and silver ore are subjected to selective precipitation of the silver as silver sulphide, with e.g. hydrogen sulphide. The silver can then be recovered in a known manner. Lead can be precipitated from the remaining solution as a basic salt also in a known manner. If the initial residue contains copper, it is also precipitated as sulphide. The copper sulphide can be separated from the precipitate by selectively dissolving the copper with sulphuric acid under an elevated oxygen pressure. Elemental sulphur is formed and the silver sulphide can be separated from the elemental sulphur in a known manner.

Abstract: A process for recovering silver present in cuprous chloride solutions as a soluble silver chloride which comprises saturating the cuprous chloride solution with sodium chloride, subjecting the saturated solution to evaporation to co-crystallize the sodium chloride and silver chloride, separating the solid chlorides from the liquid, recovering silver from the sodium chloride-silver chloride crystals and reclaiming the sodium chloride, adding water to the liquid and cooling it to crystallize cuprous chloride. The procedure is adaptable to processes for recovering copper from its ores in which copper is reduced to cuprous chloride in a leach slurry followed by cooling the leach slurry to crystallize out the cuprous chloride from which copper is recovered by conventional techniques.

Abstract: A process for the selective extraction of copper chlorides from aqueous solutions by forming a solid addition compound of cuprous chloride with an unsaturated aliphatic hydrocarbon having from 2 to 6 carbon atoms, separating and decomposing the addition compound and recovering solid cuprous chloride. The process can also be used for the separation of copper chlorides from silver-chloride. The process may be applied to the recovery of copper from hydrometallurgical process solutions.

Abstract: A hydrometallurgical process for the separate recovery of non-ferrous, ferrous, and precious metal values and sulfur from metal sulfide ore concentrates by leaching of metal sulfides with a lixiviant containing ferric chloride, cupric chloride and chlorine, precipitating cuprous chloride from the leach solution with butadiene, separating and decomposing the formed addition compound to recover the cuprous chloride, oxidizing and hydrolyzing the cuprous chloride to precipitate cupric oxychloride, converting the cupric oxychloride to cupric oxide, and reducing the cupric oxide with hydrogen for the recovery of copper. The leach residue is treated for the recovery of elemental sulfur and gold. Brine solution resulting from the conversion of cupric oxychloride to cupric oxide is electrolyzed for the production of sodium hydroxide for the cupric oxychloride conversion, hydrogen for the cupric oxide reduction and chlorine, which is partly used in the recovery of gold and partly recycled to the concentrate leach.

Abstract: Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating, urea reacts with water from the solution leaving a molten urea solution containing the metal values. The molten urea solution is heated to above about 180.degree. C. whereupon metal values precipitate homogeneously as a powder. The powder is reduced to metal or calcined to form oxide particles. One or more metal oxides in a mixture can be selectively reduced to produce metal particles or a mixture of metal and metal oxide particles.

Abstract: Copper is recovered from solutions containing cupric ammoniacal complexes by reducing copper in the complexes to the cuprous state and thereafter precipitating the copper as cuprous acetylide by passing acetylene through the solution. After the cuprous acetylide is separated from the solution and washed thoroughly, it is reacted with acetonitrile and an acid to form acetylene and a cuprous-acetonitrile complex: Cu(CH.sub.3 CN).sub.2.sup.+. The solution containing this complex is then flash distilled to remove the acetonitrile and to disproportionate unstable cuprous ions into copper metal and cupric ions. Following the disproportionation, the components are separated and copper metal is collected. SUBACKGROUND OF THE INVENTIONThis invention relates to the recovery of copper from ammoniacal solution which may also contain nickel, cobalt, and other ions. In practicing the invention, very pure copper metal is obtained without the need to employ ion exchangers, acid stripping, electrowinning, or electrorefining.

Abstract: Copper values are recovered from an acidic solution of solubilized cupric ions by the reduction of cupric copper to cuprous copper with hydrogen gas in the presence of a solid hydrogenation catalyst and in the presence of a cuprous ion stabilizing ligand. Catalyst poisoning by precipitation of copper metal on the surface of the catalyst during the reduction is avoided by controlling the ratio of Cu.sup.+/ligand/Cu.sup.+.sup.+ and by terminating the hydrogenation before copper metal precipitates on the catalyst. The solution containing the cuprous ions is separated from the solid catalyst and the cuprous ions are then disproportionated to produce copper metal and cupric ions.The removal of the last amounts of cupric ions from solutions, after several stages of reduction and disproportionation is achieved by allowing the cupric ions to precipitate on the catalyst as copper metal.

Abstract: Process for control of SO.sub.x emissions from copper smelter operations involving pyrometallurgical reduction of copper ores to elemental copper in which the gases from reverberatory furnaces, roasters, and/or converters are scrubbed with a sodium alkali sorbent to produce sodium sulfate and sulfite wastes. The cleaned flue gases are exhausted to the atmosphere. The waste sodium sulfate/sulfite material is then reacted with excess acid from the smelter acid plant and ferrous ion-rich barren solution from the associated cement copper operations to produce co-precipitated double salts of sodium ferric hydroxy-disulfates and/or sulfites (SFH), having low water solubility and being suitable for landfill type disposal without posing serious water pollution problems. This disposes of the sodium sulfite/sulfate waste materials from the air pollution control process and also strips the barren solution of iron prior to its recycle to heap or dump leaching operations.

Abstract: Aqueous solutions and suspensions of solid particles, even those containing less than one percent of organic materials, may be combusted with air, oxygen, or their mixtures in a process which provides for preheating in countercurrent batches of the raw original liquid by either open (direct contact) or closed (heat transfer surface) condensation of steam generated by multiple flash evaporations which cool earlier batches of hot liquid after the wet combustion. Excess heat may often be withdrawn from the process for power generation or other use as high pressure steam, with or without combustion gases and other non-condensibles. No pumps are necessary, liquid batches are pressurized by steam generated in the flash evaporations for which only one pressure vessel is required instead of the many in the continuous processes.

Abstract: A process is disclosed for separating cuprous chloride from a solution comprising cuprous chloride and one or more of a number of metal impurities, the process comprising crystallizing the cuprous chloride from the solution in the presence of copper as cupric chloride in a concentration of at least about 20 grams per liter.

Abstract: Silver-II-oxide for use in galvanic elements is produced by adding an oxidant to a metallic silver powder suspension in an alkaline solution.An exceptionally stable material results.

Abstract: A method is provided for removing silver from aqueous systems contaminated therewith with 2-mercaptopyridine-1-oxide and for recovering the 2-mercaptopyridine-1-oxide.

Abstract: Silver is recovered from photographic waste liquids containing emulsified silver, silver compounds, and gelatin by reacting therewith a proteolytic enzyme while the reactants are maintained in an alkaline condition. Then the reactants are acidified to a pH of 4.2 or less by introducing an acid such as HCl or H.sub.2 SO.sub.4. Precipitation of gelatin-bound silver and silver compounds occurs upon acidification, and the precipitate is allowed to settle out in a settling tank. Supernatant liquid is removed from the top, neutralized and sent to sewer. Settled sludge is removed from the bottom and silver recovered, as by incineration. The operation can be conducted either batch-wise or continuously.

Abstract: Sulfur monochloride is reacted with an ore containing iron, sulfur and a metal which forms a water soluble ammine complex or an ammonium-containing double salt, to yield metal chlorides and sulfur. The metal sought is solubilized with an aqueous solution containing ammonium ions to produce an aqueous solution of metal ammine complex or double salt and thereby separate such complex or salt from the iron and sulfur. The solution containing the sought metal values can then be subjected to electrowinning to recover the metal, or the metal can be precipitated as the metal oxide by the addition of sodium hydroxide. Sulfur and chlorine are recovered during the process and used to regenerate sulfur monochloride.

Abstract: A process for purifying aqueous solutions, of metal ions precipitating as arsenides, antimonides, tellurides, selenides, and tin and mercury alloys, wherein arsenic, antimony, tellurium, selenium, tin, mercury and/or compounds of the same are added to the aqueous solution as auxiliary agents, whereafter the impurities are cemented under reducing conditions by means of the auxiliary agent, and the cementation is catalyzed by means of the formed cementate by contacting the aqueous solution with the cementate, the quantity of which is substantially greater than that primarily cemented from the aqueous solution.

Abstract: A process is disclosed for separating cuprous chloride from a solution comprising cuprous chloride and at least one metal chloride compatible with the solubility of cuprous chloride, the process comprising crystallizing the cuprous chloride from the solution in the presence of cupric chloride in an amount such that the cupric chloride to compatible metal chloride mole ratio is at least about 0.1.

Abstract: Uranium values are obtained from phosphate rock by acidifying phosphate rock containing uranium values and at least one other heavy metal with a mineral acid so as to obtain a crude acid, solvent extracting the crude acid with an organic solvent so as to separate a raffinate from a relatively pure, wet process phosphoric acid and treating said raffinate with a base so as to raise the pH to 1-2 whereby uranium hydroxide or phosphate and other heavy metal hydroxides or phosphates are coprecipitated. The uranium content of the coprecipitate after drying is at least as high as 0.3% which is comparable to that of uranium ores of the highest quality.

Abstract: The disclosure relates to a method for reclaiming silver from photographic substrates and particularly a method wherein silver halide coated substrates, such as plastic film, is subjected to a bleach solution for removing the silver bearing emulsion from the substrates the emulsion it is then placed in a settling tank and subjected to the use of sodium hydroxide and a flocculating agent, such that the sodium hydroxide acts to precipitate the silver, while the flocculating agent tends to flocculate it. Then removing the silver sludge from the lower strata of the settling tank and placing it in canvas bags to allow liquids to drain from the sludge while the flocculating agent retains the sludge in the bags. The sludge then dries to a substantially mud like consistency and then the silver sludge, of mud like consistency, is placed in an oven and heated, until the moisture thereof is released, and thereby rendering the mud like sludge dry and in a substantially hard cake like form.