Abstract: Refractory carbonaceous sulfide ores are treated in a manner so as to improve gold recovery by a treatment in specific combination of steps whereby the ore is treated with chlorine after pretreatment and before cyanidation; the particular steps in the treatment of the ore have been found to be necessary as the conventional pretreatment will not improve the yields on any economic basis.

Abstract: Compositions comprising carbon-based supports and containing heteropolycyclic compounds such as bipyridyl, phenanthroline or derivatives thereof are used in separation of dissolved late transition metals such as Fe, Co, Ni and Cu from solutions, in particular when such solutions contain high concentrations of other dissolved metals such as Zr, Hf, La, Al and Ba. Such compositions are also used to separate late transition metals such as Pt group metals from each other.

Abstract: A method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z .multidot.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion, and w, x, y, z and n satisfy the following: 0.ltoreq.z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.3/2x; a calcined product of said compound and mixtures thereof; and (b) separating the substance from the solution. A method for removing substantially all metal-cyanide, -thiocyanate, -thiosulfate, -citrate and/or -EDTA complex from a solution containing one or more of said complexes is also disclosed. The latter method comprises contacting the solution with a sufficient amount of substance consisting essentially of a compound selected from: hydrotalcite, calcined hydrotalcite and mixtures thereof.

Abstract: Methods of and apparatus for recovering silver and other metals from solutions containing compounds of those metals. The solution being treated is pumped upwardly under pressure and at a constant rate through a reaction mass or medium to promote ion exchange reactions between the metal of interest in the solution and the material making up the reaction mass and thereby precipitate the metal of interest from the solution being treated.

Abstract: A process for extracting metals from aqueous solutions containing such metals comprising contacting such an aqueous solution with an asphaltene to extract at least one metal from the aqueous solution to the asphaltene, and recovering the thus extracted at least one metal from the asphaltene. Also disclosed is a process for sulfonating a petroleum fraction containing asphaltenes, the thus sulfonated asphaltenes being advantageously employable in the process for extracting at least one metal from an aqueous solution containing such metal.

Abstract: A technique for producing baked products, such as bread with very high protein levels, up to about 45% on a dry basis (18 to 25% on a wet basis), by incorporating in the unrisen dough the desired high protein levels, large amounts of ascorbic acid, e.g. 450 to 850 PPM and small amounts of potassium bromate; and steam treating the full fat wheat germ and soy flakes to remove sulfhydril as measured by the absence of glutathione; and then rising and baking to produce a product of good taste, shelf life and density comparable to what would have been produced in the absence of the high protein levels.

Abstract: A process for concentrating gold and/or uranium minerals by rendering the nonmagnetic minerals magnetic or weakly magnetic by causing a coating to form on the surfaces of the minerals. The gold and/or uranium are concentrated by use of a gravity-magnetic separator or a suitable high intensity magnetic separator.

Abstract: A material is, herein disclosed for collecting radionuclides and heavy metals that comprises an acrylic fiber element having MnO.sub.2 and/or ferrocyanide compound of the formula K.sub.2 M.sup.II [Fe(CN).sub.6 ] (wherein M.sup.II is a divalent metal such as cobalt, zirconium, zinc or nickel) supported thereon. The material of the present invention is used in collecting and concentrating radionuclides present in liquid radioactive wastes discharged from nuclear power plants and other facilities using radioisotopes such as hospitals and non-destructive testing laboratories. The material is also used in collecting and concentrating radionuclides and heavy metals present in the seawater, rivers and industrial waste-water.

Abstract: Noble metals are recovered from their cyanide complexes in aqueous solution by reaction with red phosphorus. To this end, red phosphorus is used in quantities of 1 to 5 weight %, based on the aqueous solution of the noble metal cyanide complex, in combination with an additional strong oxidizing agent.

Abstract: A method of beneficiation of complex sulfide ores comprises crushing and grinding complex sulfide ore containing sulfides of copper, zinc, iron and other minerals, subjecting the ground ores to differential flotation to obtain a bulk copper-zinc concentrate which is separate from pyrite and gangue, and passing the bulk copper-zinc concentrate through a high-gradient magnetic separator having an open-bore magnetic field filled with a matrix element, so as to recover separately a magnetic copper concentrate and a non-magnetic zinc concentrate. By combining the differential flotation with high-gradient magnetic separation, the present invention enables individual separation of copper and zinc concentrates without using many reagents in high volumes and by a simple process control.

Abstract: A method for preparing a .sup.195m Au-containing liquid is provided. In the method, .sup.195m Hg is adsorbed on an adsorption agent and then the daughter radioisotope .sup.195m Au is eluted from the adsorption agent with an eluant containing a gold-complexing agent. The adsorption agent comprises a mercury ion-binding material having a substantially stronger adsorption affinity for mercury ions than for gold ions.Also disclosed are a radioisotope generator capable of producing a .sup.195m Au-containing liquid and a process for conducting a radiodiagnostic examination on a warm-blooded animal using a .sup.195m Au-containing liquid.

Abstract: Metal is removed from particlized metal bearing refractory ores in an efficient manner utilizing pressure metallurgy with heat recovery. The particlized ore is mixed with a heated liquid, and preferably a flocculant and fibers, to form a slurry. The ore in the slurry is oxidized at superatmospheric pressure, and elevated temperatures (e.g. around 300.degree. F.). The oxidized ore is washed to remove acids, and like products of oxidation, and the washed ore is subsequently subjected to conventional leaching processes to effect an actual metal recovery. Heat recovery is practiced by utilizing spent wash water as part of the slurrying liquid, and using two or more liquid-interconnected vessels in effecting the oxidization.

Abstract: A method of recovering gold and silver efficiently and almost completely from an aqueous solution containing cyanic compounds of gold and silver and which comprises adjusting the pH of the aqueous solution containing cyanic compounds of gold and silver to 6.0 or less, preferably to pH 3.0-5.0, by adding mineral acid, such as sulfuric acid or hydrochloric acid, preferably together with a small amount of active carbon, and subsequently passing the aqueous solution through an active carbon bed, preferably pretreated with mineral acid.

Abstract: The extent of recovery of precious metals, preferably gold and silver, from precious metal ores, concentrates, tailings and wastes which are also sulphide- and arsenic- and/or antimony-bearing, is enhanced by treatment with Caro's acid (H.sub.2 SO.sub.5).

Abstract: The present invention provides in one aspect a process in which a particulate material containing water and having adsorbed thereon a solubilized gold compound is located in packed form in a fractionating column, a liquid containing a major proportion of water miscible organic liquid is boiled in an evaporator such that it enters the packed fractionating column as a vapor, said water miscible organic liquid being more volatile than water and being preferentially retained in the column.The present invention provides in another aspect a method of recovering gold from an aqueous solution, which comprises placing the gold containing aqueous solution in a cell comprising a gold, silver, aluminium or copper cathode and an inert electrode, subjecting the solution to electrolysis in the cell so as to deposit a gold foil on the cathode.

Abstract: A method for preparing a .sup.195m Au-containing liquid is provided. In the method, .sup.195m Hg is adsorbed on an adsorption agent and then the daughter radioisotope .sup.195m Au is eluted from the adsorption agent with an eluant containing a gold-complexing agent. The adsorption agent comprises a mercury ion-binding material having a substantially stronger adsorption affinity for mercury ions than for gold ions.Also disclosed are a radioisotope generator capable of producing a .sup.195m Au-containing liquid and a process for conducting a radiodiagnostic examination on a warm-blooded animal using a .sup.195m Au-containing liquid.

Abstract: A modified liquid-liquid extraction system is disclosed in which a particulate solid and a liquid, both insoluble in a second liquid, are mixed to form agglomerate particles which efficiently extract metal ions from dilute solutions. The extraction is rapid and requires a much lower volume of extracting phase for good contacting than conventional liquid-liquid extraction. Mixing energy is low, clean-up of effluent water is easily accomplished and metal values are readily stripped from the agglomerates by well-known techniques, such as treatment by aqueous acid solution.

Abstract: The removal of silver from photographic and other solutions using a non-carbon halogen impregnated adsorbent is described.

Abstract: The removal of silver from photographic and other solutions using halogen impregnated activated carbon is described.

Abstract: The invention relates to a process for separating seminoble and/or noble metals from an aqueous solution having compounds of these metals dissolved therein by subjecting the solution to reaction with red phosphorus. More particularly, the solution is conveyed through a zone containing a layer of granular red phosphorus particles with a size of 0.01 to 10 mm, which may be used in admixture with active carbon.

Abstract: A method of treating pyrite bearing polymetallic material comprises heating the material in an atmosphere of reducing gases at a temperature of 450.degree. to 500.degree. C. for a period of 30 to 60 min.Gases such as hydrogen, or products of conversion of natural gas or mazut can be used to provide the reducing atmosphere.The roasted copper-containing material is cooled at a rate of 2 to 4 deg. per min and is then subjected to magnetic separation.The operation of magnetic separation is carried out in two stages with the intensity of the magnetic field ranging from 1000 to 2000 oersted, whereafter copper sulphides are removed from the roast, with a magnetic field intensity ranging from 4500 to 6000 oersted.

Abstract: A method comprises heating the material to be treated without access of air at a temperature of 700.degree. to 800.degree. C. for a period of 1-2 hours, and then subjecting this material to subsequent magnetic separation.It is advisable that the furnace walls surrounding the material under treatment be heated to a temperature which is 100.degree. C. to 200.degree. C. higher than the boiling temperature of the volatile components of the material. Upon completion of the heating operation, the material being treated is cooled at a rate of 2 to 4 deg. per minute, whereafter iron sulphides are removed therefrom by means of magnetic separation, the intensity of magnetic field ranging from 1000 to 2000 oersted, and then copper sulphides are separated, with the field intensity ranging from 4500 to 6000 oersted.

Abstract: This disclosure concerns primarily the recovery of hydrogen-reduced metals from aqueous solutions of salts thereof, by hydrogen reduction at a porous hydrophobic catalytic barrier, at ordinary temperatures, in an apparatus provided with means to supply hydrogen to one face and aqueous solution to the other face of said barrier.

Abstract: Symmetrical quaternary ammonium compounds of the formula ##STR1## are disclosed, wherein each Ar is identical and is phenyl or a condensed polynuclear aryl group having 2 to 4 aryl nuclei, each R is identical and is alkyl of 1 to 4 carbon atoms, X.sup..crclbar. is a salt-forming anion of valence 1 or 2 and n is 1 or 2 depending on the choice of X. Also disclosed are apparatus and processes for the recovery of heavy metals such as silver, gold and other precious metals from solution in water. The disclosed quaternary ammonium compounds are adsorbed to a suitable substrate, preferably alumina, and the treatment water is passed therethrough. A second bed of divided metal such as aluminum is disclosed for use in series with the bed incorporating the quaternary ammonium compounds.

Abstract: The recovery of gold from refractory carbonaceous gold-containing ores by cyanidation techniques is improved by subjecting an oxidized slurry of this type of ores to simultaneous cyanidation and countercurrent granular activated carbon adsorption in two or more stages. The gold transfers to the carbon and may be separated from it by conventional methods.

Abstract: A method of regenerating an activated carbon which has had its collecting capacity for gold adsorption reduced through use which includes the step of contacting the carbon with an aqueous copper salt solution having a pH of less than 6. The regeneration is improved if the solution contains carbonic acid or if the copper salt solution treatment is followed by treatment with a carbonate or bicarbonate solution.

Abstract: To a coal-fired furnace that uses electrostatic precipitation or a mechanical collector to collect fly ash, a mix of magnesia-alumina or magnesia-talc is added above the fireball (2600.degree.-3300.degree. F.). The additive increases the mean particle size of the fly ash and reduces its surface resistivity, thereby causing improved collection in the electrostatic precipitators or mechanical collector. Fine particulates containing heavy metals tend to be agglomerated; thus the invention permits recovery of substantial amounts of heavy metal contaminants that would otherwise be lost as stack emission.

Abstract: Gold is desorbed from activated carbon by contacting, at a temperature of about 70.degree. to 160.degree. C., with a solution comprising about 20 to 30 percent by volume of a water soluble alcohol and about 80 to 70 percent by volume of an aqueous solution of a strong base.

Abstract: A process for the removal of heavy metals uranium and transition metals other than noble transition metals from solution by contacting the solution with the product obtained by reacting an inorganic solid eg. silica gel containing surface hydroxyl groups with a silicon compound of defined formula containing a free thiol group or a free amino group and either an --OR group or a halogen atom under conditions which effect reaction between the hydroxyl group and the --OR group or halogen atom thereby bonding the silicon compound to the inorganic solid.

Abstract: When certain sedimentary gold ores containing indigenous organic carbonaceous materials are slurried with an aqueous solution containing an alkali metal cyanide, the aurocyanide complex which is formed is adsorbed by an adsorptive carbon component of the ore. Dissolution of the gold proceeds until chemical equilibrium is attained between the aurocyanide complex in solution and the aurocyanide complex adsorbed by the ore. In the process of the invention, the gold is dissolved from the ore by using (1) much higher strengths of cyanide solution, and (2) much higher temperatures than are normally used in the standard cyanidation process, allowing higher extractions of gold to take place. Because the concentration of aurocyanide in solution is limited by chemical equilibrium, the dissolution of gold must be done in stages.

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: Process for selectively separating precious metal such as silver and gold from a chloride solution of the precious metals and other heavy metals which involves:(a) adding finely divided activated carbon to the solution for reduction of gold to gold metal and absorption of the gold metal by the carbon,(b) adding an aqueous solution of an iodine compound for selective precipitation of further precious metal including the silver, if present.During steps (a) and (b) the pH is below 3 so that hydrolysis with the metal ions does not occur, and the potential of the solution during step (b) is such that no substantial decomposition of the iodine compound occurs. The precipitated precious metal and active carbon are separated, dried, and admixed with an iodine binder, and the resulting admixture is subjected to reduction for formation of a regulus containing the precious metal.

Abstract: The present invention relates to a process for treating aqueous waste solutions containing complexing or oxidizing agents and dissolved metallic elements or compounds of copper, chromium, nickel, lead or tin. The waste solution is treated with finely divided magnetized ferrous particles, continuing such treatment to allow for homogeneous stirring promoting substantial ion exchange between the solute and ferrous particles, and providing a post-treatment step using an agent to promote precipitation of metallic hydroxides. The precipitates are separated from the solution by deposition in a settling tank and/or filtration.

Abstract: A novel continuous reduction process is disclosed for recovering values of metals having a more positive reduction potential than hydrogen from an aqeuous solution. The process includes the steps of contacting the aqueous solution containing metal value in a reactor with a metal catalyst consisting essentially of Pt or Pd metal dispersed on an inert catalyst support in the presence of a stoichiometric excess of hydrogen substantially dissolved in the aqueous solution to reduce the metal value and deposit free metal on the catalyst, and separating recovered metal value from the catalyst.The catalyst support may comprise electrically conductive particles. In the preferred embodiments, the catalyst consists essentially of about 0.02 to 1 Wt % Pt on a porous carbon support and the aqueous solution contains gold or copper values.