Abstract: A method for producing finely divided stable cupric hydroxide comprising contacting solutions of an alkali metal carbonate or bicarbonate and a copper salt, precipitating a copper carbonate, contacting the precipitate with an alkali metal hydroxide and converting the copper carbonate to cupric hydroxide and re-forming alkali metal carbonate and repeating the sequence of additions of copper salt and alkali hydroxide for up to 20 cycles without addition of any additional alkali metal carbonate or bicarbonate.

Abstract: A process for recovering copper and copper oxide for spent ammoniacal etchant, electroless and copper persulfate bath fluids used in the manufacture of copper printed wiring boards such that the treated baths contain no ammonia. The spent solutions are placed in a cooking vessel having its inner surface made of titanium and the formaldehyde is added. The ingredients are then stirred while air is bubbled through the ingredients until thoroughly mixed after which the pH of the mixture is adjusted to between 12.0 and 14.0. The adjusted mixture is now heated to a temperature within the range of 200.degree.-210.degree. F. and air is bubbled through the heated mixture until copper and copper oxide precipitates form in the mixture. After the precipitates form the mixture is allowed to cool to permit the precipitates to settle to the bottom of the vessel and the mixture is decanted from the vessel. The copper and copper oxide precipitates are washed and then collected.

Abstract: Heavy metal ions bonded to complexing agent can be precipitated from waste streams with a combination of a magnesium ion, calcium hydroxide and peroxygen compound.

Abstract: A process for selectively removing ions of copper and/or cadmium from a sulphate solution containing nickel and/or cobalt values. The solution is treated at a temperature in the range of from about 85.degree. to about 95.degree. C. and at a pH in the range of from about 4.5 to about 5.5 with hydrogen sulphide to precipitate copper and/or cadmium ions as copper and/or cadmium sulphide, and the precipitated copper and/or cadmium sulphide is separated from the solution.

Abstract: Process for the recuperation of an insoluble salt of a metal from the rinsing solution of an electrodeposition of the metal.

Abstract: Dissolved selenium values are removed from an acidic aqueous copper sulphate solution by treating the solution at a temperature of at least about 140.degree. C. with a stoichiometric excess relative to the dissolved selenium of sulphur dioxide or a sulphite solution to produce a selenium-containing precipitate and dissolved cuprous copper. The temperature of the treated solution is maintained at at least about 140.degree. C. and an oxygen containing gas is passed into the treated solution under a pressure of at least about 350 kPa to oxidize dissolved cuprous copper to dissolved cupric copper.

Abstract: Selenium (IV) and selenium (VI) are removed from acidic copper-nickel sulphate solutions in a two-stage process by adjusting and maintaining the sulphuric acid content of the solution in a range of 10 to 50 g/L and, in a first stage, contacting the solution with sulphur dioxide or a sulphite-containing solution at an elevated temperature in the range of about 140.degree. to 175.degree. C. and, in a second stage, maintaining the said solution at an elevated temperature in the range of about 140.degree. to 200.degree. C. and pressure within the range of about 400 to 1750 kPa in an essentially oxygen-free atmosphere for a sufficient retention time to reduce and precipitate selenium (VI) as cuprous selenide.

Abstract: Disclosed is a process for separating gold from acidic solutions having a pH below about 3 which comprises the steps of:(a) adding a sufficient amount of the sodium salt of 2-mercaptopyridine-N-oxide to cause at least a portion of the gold in the aqueous acidic solution precipitate from the solution; and(b) separating the precipitated gold from the acidic solution.Also disclosed is that gold is selectively precipitated from acidic solutions containing other metals [e.g., Fe, Cu, Zn, Sn] when the molar ratio of added sodium 2-mercaptopyridine-N-oxide to gold in the acidic solution is less than about 1.5:1.

Abstract: A process is provided by which dissolved metals may be recovered from aqueous waste solutions and converted to a particulate material, which may in turn be used as a filler for products such as asphalt. The process involves effecting reaction in the solution to produce a sludge comprised of metal hydroxides and sulfides, and admixing lime with a concentrate thereof to ultimately produce the filler.

Abstract: A tire curing press has a loader assembly comprising a bead grip for engaging and lifting the axial interior of the upper bead of a green tire and a tread positioning ring movable axially to an adjusted position to engage the tire tread shoulder and to force a predetermined distance between the upper bead and tread to identify precisely the transaxial middle or crown plane of the tread. The loader includes means to swing the bead grip and tread register from a tire pick-up position to a load position centered in the press and to position the lower bead of the green tire on or close to a movable toe ring, and then to lower the bead grip, tread register and toe ring uniformly with the green tire held open and firmly therebetween to match the transaxial middle plane of the tread to that of a bladder mounted in a center mechanism in the press by independently movable top and bottom bladder bead clamps.

Abstract: A process for removing dissolved selenium IV values from an acidic aqueous copper sulphate solution includes passing the solution through a tubular member in a plug flow manner and injecting sulphur dioxide or a sulphite solution into the solution as it enters the tubular member. When the sulphate solution also contains dissolved selenium (VI) values, the ratio of dissolved selenium (IV) values to dissolved selenium (VI) values is preferably at least 3 to 1.

Abstract: A method for the separation of bismuth from a complex chloride solution obtained by leaching with chloride reagents ores containing bismuth and high concentrations of other metals comprising adding to said complex chloride solution at least a stoichiometric amount of a precipitating agent selected from the group consisting of hexamminecobalt (III) salts and hexamminechromium (III) salts soluble in said solution to precipitate said bismuth as a hexamminecobalt (III) bismuth salt or a hexamminechromium (III) bismuth salt and separating said precipitate from said solution.

Abstract: A rapid, energy efficient, low cost, nonhazardous method for the selective removal of mercury from mercury-containing metal cyanide solutions, particularly the cyanide solutions resulting from the cyanidation of gold ore and the like, wherein a reactive sulfide is admixed with the solution for a time sufficient to form an insoluble mercuric sulfide precipitate. The mercuric sulfide precipitate is then separated from the metal cyanide solution by filtration or other conventional means.

Abstract: The invention relates to a method of controlling acid soluble iron while obtaining solutions of copper (I) salts in water containing an organo nitrile (selected from the group consisting of acetonitrile, 2-hydroxycyanoethane, acrylonitrile and propionitrile) from materials containing copper and iron compounds, said solutions having a low iron content, which method comprises leaching the material with a solution of copper (II) salt in water containing the selected organo nitrile, the amount of nitrile present being sufficient to stabilize the resulting copper (I) solution and the pH of the mixed solution being controlled in relation to the relative concentrations of the copper (II) salt, copper (I) salt and nitrile to ensure that the iron compounds are not significantly soluble therein, and then separating the copper (I) solution from the insoluble materials.

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: Copper (Cu.sup.++)-ions are separated from an effluent containing complexing agents which are ethylenediamine tetraacetic acid and/or diethylenetriamine pentaacetic acid or their anionic salts, by using an HS-containing triazine compound and Fe.sup.+++ -ions in a quantity at least equal to the amount of complexing agent.

Abstract: A process for recovering gold from a gold bearing liquor arising from a cyanidation process including the steps of treating the liquor with ozonized air or ozonized oxygen, adsorbing the gold values from the treated liquor on activated carbon, and recovering the gold values from the loaded activated carbon.

Abstract: Metals are removed from waste materials that contain an organic component and a bimetallic salt complex component that comprises complexes having the formula M.sub.I M.sub.II X.sub.n .multidot.Aromatic and/or the formula M.sub.I M.sub.II X.sub.n .multidot.M.sub.II OX.multidot.Aromatic, wherein M.sub.I is a Group I-B metal, M.sub.II is a Group III-A metal, X is halogen, n is the sum of the valences of M.sub.I and M.sub.II, and Aromatic is a monocyclic aromatic hydrocarbon or halogenated aromatic hydrocarbon having 6 to 12 carbon atoms by contacting the waste material with water and sufficient alkali metal hydroxide to form a hydrolysis mixture which has a pH above 5 and which separates into an upper organic phase and a lower aqueous phase. After separation of the phases, there is obtained a slurry of M.sub.I oxide, M.sub.I hydroxide, and/or M.sub.II hydroxide from which the metals can be recovered or which can be discarded in ways that are not damaging to the environment.

Abstract: This invention provides a method and apparatus for treating photographic film to recover silver and the plastic base layer for re-use. A wash tank containing warm water at about neutral pH contains at least one enzyme from the following group: protease, amylase, lipase. The water in the wash tank is agitated and the enzymes attack the adhesive and organic layers on the plastic base, in order to loosen and remove these materials. The film is then placed in a rinse tank containing either a weak aqueous glycol solution or a weak caustic solution which is agitated. Finally the film is removed from the rinse tank and dried. Liquid is removed from the wash tank and treated to remove silver therefrom.

Abstract: A method of preparing silver nitrate of an improved purity comprising adding about 50 to about 1000 ppm of Al.sup.3+ ion to a crude silver nitrate solution resulting from dissolving metallic silver in nitric acid, adjusting the pH of the silver nitrate solution to about 5.5 to about 6.5 by adding silver oxide thereto, and then separating the precipitate formed.

Abstract: A process and a product formed thereby for the recovery of chromium values from aqueous solutions (e.g., waste liquors) comprises contacting an acidic solution containing sulfate ion and trivalent chromium ion with at least about 4 molar equivalents of MgO or Mg(OH).sub.2 per 3 molar equivalents of trivalent chromium in addition to the amount required to neutralize the free acid to a pH of about 4 to form an amorphous, dense solid, grainy, easily settleable, trivalent chromium-containing precipitate in an alkaline solution according to the equation: 3Cr.sub.2 (SO.sub.4) + 8 MgO .fwdarw.Cr.sub.2 (OH).sub.4 SO.sub.4 .multidot. 4Cr(OH).sub.3 .multidot. 4H.sub.2 O + 8 MgSO.sub.4. The trivalent chromium-containing product can be readily separated from the water and is a useful source of chromium for subsequent processing. The water remaining after separation of the precipitate contains less than 0.5 mg/l chromium.

Abstract: Hydrometallurgical process for the recovery of copper arsenate from zinc plant cement copper residues and the use thereof in the purification of zinc electrolyte, with the attendant upgrading of the copper value in the treated cement copper residues.

Abstract: The ore is subjected to nitric acid leaching and the leach solution is heated to a temperature at which one of the additional sulfur and iron values is selectively insolubilized with respect to the solution, while the other is maintained in solution for subsequent separation from the liquor after the insolubles have been removed and the liquor has been neutralized. In addition, in one embodiment of the invention the heating and acid neutralization steps are controlled within certain prescribed limits to make it possible to remove the metals from the liquor by solvent extraction without the problem of lasting precipitates forming in the liquor and fouling the extraction process. Where there is a sizable amount of dissolved iron in the liquor, the liquor may be subjected to autoclaving at a temperature above about 149.degree. C (300.degree. F) to precipitate the iron as the oxide thereof. This effect is possible even where the liquor is high in sulfate concentration.

Abstract: A process for separating and recovering nickel and cobalt is provided wherein a sulfide material containing cobalt and nickel is first oxidation-roasted to remove volatiles and to convert the metallic values into their oxides. These oxides are then dissolved in an aqueous solution of HCl. The solution of chloride salts thus produced is contacted with an extraction solvent comprising an admixture of trinormaloctylamine and xylene whereby the bulk of the cobalt along with the iron, copper and zinc impurities and a portion of the manganese impurities present in the original material are stripped by the extraction solvent while the bulk of the nickel and the remainder of the manganese impurities remain in the aqueous phase. The aqueous phase containing the nickel and manganese impurities is treated with chlorine gas and nickelous carbonate whereby the manganese is precipitated as manganese dioxide. The nickelous chloride solution is then subjected to electrolysis to produce metallic nickel.

Abstract: A process for removing chlorine from a solution of zinc sulfate, in which the pH of the solution is reduced to below 2.6 with sulfuric acid. Cupric ions are established in the solution in an amount such that after removal of the chlorine by precipitation as cuprous chloride, there remains an excess of cupric copper in the solution which is greater than 0.5 g/l. The cupric ions can be added by adding cupric sulphate and zinc powder, or cupric salt and metallic copper, or cupric copper followed by cuprous oxide. The cuprous chloride precipitate is collected and washed and treated with sodium hydroxide in an amount to raise the pH to more than 7, thereby to precipitate cuprous oxide which is separated by filtration.

Abstract: A method is provided for extracting silver from a silver sulfate-bearing substance, such as oxide materials, metal or metal sulfate mixtures containing silver sulfate which comprises subjecting said substance to aqueous leaching to remove soluble salts therefrom and leave a residue, taking the residue containing silver sulfate and other insoluble materials, such as insoluble salts, and forming a slurry with an aqueous solution of a metal sulfate, such as calcium nitrate, the amount of calcium nitrate being at least sufficient to effect metathetical exchange with the silver sulfate and form a silver nitrate solution containing substantially the silver originally present in the silver-sulfate bearing substance, and separating the silver nitrate solution from the residue remaining, and then purifying said solution, the silver being thereafter recovered from the silver nitrate solution by hydrolytic precipitation, electrowinning or other suitable means.

Abstract: The present invention relates to an improved process for removing iron ions from an aqueous acid solution with a minimum removal of copper ions contained therein comprising the steps of combining an organic quaternary salt with the aqueous acid solution in an amount of at least about 0.01% by weight of said solution, adjusting the pH of the solution to a value in the range of from about 2.0 to about 2.5 so that iron ions contained in the solution are hydrolyzed and precipitated and then separating the precipitate from the solution.

Abstract: The ore is subjected to nitric acid leaching and the leach solution is heated to a temperature at which one of the additional sulfur and iron values is selectively insolubilized with respect to the solution, while the other is maintained in solution for subsequent separation from the liquor after the insolubles have been removed and the liquor has been neutralized. In addition, in one embodiment of the invention the heating and acid neutralization steps are controlled within certain prescribed limits to make it possible to remove the metals from the liquor by solvent extraction without the problem of lasting precipitates forming in the liquor and fouling the extraction process. Where there is a sizable amount of dissolved iron in the liquor, the liquor may be subjected to autoclaving at a temperature above about 149.degree.C (300.degree.F) to precipitate the iron as the oxide thereof. This effect is possible even where the liquor is high in sulfate concentration.