Abstract: A process for the extraction of bitumen from bitumen froth generated from tar sands is disclosed. In this process, bitumen froth is extracted from tar sands using a water process without requiring the use of caustic soda. The froth is treated in a counter-current decantation circuit with a paraffinic solvent to remove precipitated asphaltenes, water, and solids from the bitumen froth. A dilute bitumen product is produced having final water and solids contents of about 0.01 to about 1% by weight. This renders the dilute bitumen product amenable to direct hydrocracking. The process provides an alternative route to the conventional process of utilizing centrifuges to separate bitumen from precipitated asphaltenes, water, and solids and thus avoids the high capital and operating costs associated with the conventional bitumen froth treatment by centrifugation. The invention utilizes bitumen froth produced from a water process in which the use of caustic soda is not required.

Abstract: A bioleaching method is provided for recovering nickel from an ore selected from the group consisting nickel-containing lateritic ores and nickel-containing sulfidic ores or concentrates thereof. Where the ore selected is a nickel-containing lateritic ore, at least one micro-organism selective to the leaching of the lateritic ore is provided as an aqueous solution thereof maintained at a pH ranging from about 1 to 3 including a nutrient for the micro-organism. The ore may be in the form of a heap, or a charge in a vat, or as a slurry. Where the ore selected is a nickel-containing sulfidic ore or concentrate thereof, at least one micro-organism comprising a biooxidizing bacterium selective to the leaching of sulfidic ore is added as an aqueous solution to the sulfidic ore or concentrate maintained at a pH of about 1 to 3, including a nutrient for the bacterium.

Abstract: A method is provided for recovering nickel from high magnesium-containing lateritic ores which also contain iron. The ores which are referred to as saprolitic ores are subjected to leaching with a mineral acid from the group consisting of HCl, H.sub.2 SO.sub.4 and HNO.sub.3, HCl being preferred.Following leaching with HCl, for example, the pregnant solution obtained is separated from undissolved solids and the nickel preferably recovered by contacting the solution with a resin selective to nickel absorption. The raffinate remaining which contains iron and magnesium chlorides may be subjected to pyro-hydrolysis to produce their respective oxides and free HCl for recycle into the leaching system. The nickel is extracted from the resin using a stripping solution of said acid, and the nickel thereafter extracted from the nickel-loaded stripping solution.

Abstract: A hydrometallurgical process for producing zinc oxide from an aqueous solution containing zinc ions is provided. The process comprises the steps of contacting a zinc solution with an insoluble organic solvent selective to the extraction of zinc and thereby produce a zinc-loaded organic solvent. The zinc is then stripped from the zinc-loaded organic solvent with a solution of nitric acid to form a solution of zinc nitrate. The zinc nitrate solution is subjected to thermal hydrolysis at an elevated temperature in the presence of pressurized water vapor, the temperature being at least sufficient to decompose the zinc nitrate to zinc oxide which is thereafter recovered.

Abstract: A process is provided for separating minerals from a mixture of minerals having different densities. The minerals are provided in the comminuted state to liberate the minerals one from the other, following which the minerals are slurried in an aqueous solution of lithium metatungstate selected to provide a density between the densities of the minerals to be separated, whereby the minerals having a density greater than that of the solution will sink and the minerals having a density less than that of the solution will float.

Abstract: A method is provided for recovering at least one platinum group metal from an ore containing the same. The method comprises reducing the particle size of the ore to provide the platinum group metal in a leachable condition following which the ore is subjected to leaching with a sulfuric acid solution maintained at a pH of less than 1 during leaching. The solution contains an amount of a soluble bromide compound at least sufficient to complex the platinum group metal while maintaining an amount of an oxidizing agent dissolved in the solutions at least sufficient to maintain the platinum group metal in an ionic form conducive to forming a soluble bromide complex, thereby dissolving substantial amounts of the platinum group metal.

Abstract: Geothermal brines are passed through a bed of an anionic resin selective to the removal of boron while maintaining a pH value between about 4 to 5.5 to load the boron on the resin from which the boron is thereafter recovered. If the brine contains large quantities of constituents have Lewis acidities greater than boric acid, these constituents are preferably removed before the boron is recovered. The invention is particularly applicable to geothermal brines of temperature above ambient, e.g., 90.degree. C. and above, such as 95.degree. C. and above.

Abstract: A process is provided for the recovery of substantially pure zinc from geothermal brine also containing recoverable amounts of lead and silver. The process comprises selectively extracting lead and silver from the brine and then contacting the brine impoverished in lead and silver with a substantially insoluble organic extractant (e.g., an ion exchange resin [IX] or an organic solvent [SX]) selective to the extraction of zinc to produce a spent brine, and a zinc-loaded organic extractant. The zinc-loaded organic extractant is separated from the spent brine and the zinc-loaded extractant is contacted with an aqueous solution to remove the zinc as an aqueous zinc chloride solution. The pH of the zinc solution is adjusted, if necessary, to a level to condition the solution to promote the extraction thereof by a cationic organic solvent.

Abstract: Lithium metatungstate as a new composition of matter and the production thereof are disclosed. A solution of lithium monotungstate is treated with an extractant to remove sufficient lithium ions to produce a dilute solution of lithium metatungstate and the dilute solution is then concentrated. Lithium metatungstate solutions are more dense than other alkali metal metatungstates and have lower viscosities which properties make the solutions highly useful for heavy media separations.

Abstract: A hydrometallurgical method is provided for recovering copper from particulate copper sulfide flotation concentrate containing at least about 20% copper by weight as cuprous and cupric sulfide, a significant portion of the copper in the copper sulfide concentrate being in the cuprous state. The flotation concentrate in the finely divided state is subjected to leaching with an alkaline solution of ammonia plus ammonium sulfate at a temperature ranging from about 10.degree. C. to 95.degree. C., preferably about 20.degree. C. to 40.degree. C. the amount of concentrate being proportioned at least stoichiometrically to the ammonia concentration of the leaching solution.

Abstract: A process is disclosed for the hydrometallurgical treatment of finely divided iron-containing steel plant dusts containing zinc, lead and such other metal values as calcium, manganese, silicon, magnesium, aluminum, cadmium, copper, and the like. The process is carried out by forming an aqueous slurry of the flue dust with a mixed lixiviant comprising HCl and H.sub.2 SO.sub.4, the amount of sulfate ion concentration being in excess of the chloride ion concentration and in stoichiometric excess of that required to sulfate substantially all of the lead and calcium present. The amount of chloride ion present as HCl should be sufficient to maintain the pH at about 1 to 4. The leaching is conducted at a temperature ranging from ambient to below the boiling point for a time at least sufficient to effect dissolution of at least zinc and other metal values and form a residue containing iron oxide, calcium sulfate and lead sulfate.

Abstract: A process is provided for hydrometallurgical processing of steel plant dusts containing cadmium, lead, zinc, and iron values, along with impurities such as chloride and fluoride salts of sodium, potassium, magnesium, etc. The first step in the process involves leaching the dust in a mixed sulfate-chloride medium that dissolves most of the zinc and cadmium. Any iron and aluminum dissolved in this step is precipitated by oxidation and neutralization. Zinc is recovered from the resulting solution by solvent extraction which provides a raffinate which is recycled to the leaching step with a bleed stream also provided for recovery of cadmium and removal of other impurities from the circuit. The lead sulfate residue from the leaching step is leached with caustic soda, and zinc dust is used to cement the lead out from the caustic solution, which then joins the main solution for zinc recovery.

Abstract: A process is provided for selectively recovering zinc from steel plant dust containing substantial amounts of iron. The process comprises atmospherically leaching the steel plant dust in a first stage wherein an amount of steel plant dust is mixed with an amount of acidic zinc sulfate solution to leach zinc therefrom, the leaching of the dust being such that the solution is controlled to a terminal pH ranging from about 2 to 3.5 and preferably from about 2.5 to 3.5, thereby limiting iron dissolution. The mixture is then subjected to a crude liquid/solid separation step whereby a thickened pulp is produced containing zinc and iron values and a separated liquid containing low iron and substantial amounts of zinc, the solution being sent to zinc recovery.

Abstract: A method is provided for converting iron-containing steel plant dust to recyclable agglomerates. The method comprises mixing the dust with sufficient water and about 1 percent by weight Portland cement to permit pelletization. The pellets are dried at temperatures under 100.degree. C. to result in strong easy-to-handle agglomerates. In a preferred embodiment of the process, the dust is treated by hydrometallurgical processes to recover cadmium, lead, and zinc prior to agglomeration. The resulting pellets can then be recycled to the steel furnace or stored as a nontoxic waste.

Abstract: A process is provided for recovering zinc from zinc residues containing iron, and lead. The residue is leached with hydrochloric acid to provide a pregnant liquor containing zinc, iron, and lead. The iron is selectively removed from the pregnant liquor and the zinc extracted from the liquor by an organic solvent extraction system. The zinc is subsequently stripped from the organic solvent using water or hydrochloric acid to provide a zinc chloride solution which is then fed to an electrowinning cell for the production of marketable electrolytic zinc.

Abstract: A hydrometallurgical process is provided to electrogalvanize steel, utilizing primary and secondary zinc sources. The process consists of leaching the feed in a mildly acidic solution. The zinc is selectively recovered from the leach liquor in a solvent extraction system and thereafter stripped from the solvent using a stronger acidic solution to provide a strip solution which is fed to an electrogalvanizing bath for electrogalvanizing steel products, e.g., sheet steel, using insoluble anodes. Acidic solutions and organic solvent are recycled in the process.

Abstract: In leaching a slurry of nickeliferous oxide ore containing less than about 35% iron with sulfuric acid under superatmospheric pressures at temperatures between about 230.degree. C. and about 300.degree. C. a water-soluble alkali metal or ammonium compound is added to the slurry after leaching is more than about 50% complete whereby the settling characteristics of the leached slurry during solids-liquids separation are improved.

Abstract: Nickel values contained in oxidic ores are recovered by leaching with sulfuric acid. The ore is slurried with water, preheated to a leaching temperature between about 230.degree. C and about 300.degree. C and the preheated slurry is fed to one or more vigorously agitated autoclaves, operating continuously in series. Sulfuric acid is added incrementally to the preheated slurry to minimize the amount of iron and aluminum in solution until between about 0.15 part and about 0.8 part of acid per part of dry ore is added to the slurry, thereby minimizing the deposition of scale in the autoclaves.