Abstract: The present invention relates to microbiological processes for the oxidative treatment of refractory gold and base metal ores and concentrates, and specifically, to bacterial inoculums for use in such processes that are strongly resistant to thiocyanate toxicity. The present invention also relates to methods of developing and using these bacteria. The use of a bacterial inoculum with high thiocyanate resistance confers a number of technological advantages on biooxidation processes including improvements in operating flexibility, operation costs and environmental acceptability.

Abstract: Process and apparatus for regenerating spent acid liquor includes a primary roasting furnace for evaporating a substantial portion of the liquid from the spent acid to produce acid vapors and partially roasted metal salts. The partially roasted metal salts are transferred to a secondary roasting chamber where the acids adhering to the surface of the metal salts is vaporized and the metal salts are oxidized. The acid vapors from the primary roasting furnace are then transferred to an absorption column to regenerate the acid. The primary roasting furnace is operated at a different temperature from the secondary roasting chamber and has different retention times for the metal salts. The secondary roasting chamber includes a raking device to mix and convey the metal salts during the secondary roasting step to produce a uniformly roasted metal oxide.

Abstract: A method for the total precipitation of valuable metals, such as copper, nickel, zinc, cobalt, etc., from a leaching solution that has been acidified with sulphuric acid and that is substantially free from impurities, by neutralizing the solution with lime and/or limestone. Neutralization is effected in at least two stages, wherewith only partial precipitation is effected in the first stage, and wherewith full precipitation of remaining valuable metal content is effected in the last stage, by adding a surplus of neutralization agent. Slurry containing precipitates and remaining solid neutralization agent formed in the last stage in the neutralization process is returned to the first neutralization stage, possibly after re-dissolving the slurry in the incoming acid leaching solution. The amount of slurry returned together with any further neutralizing agent added promotes the partial precipitation of the valuable metal content.

Abstract: A new, cost effective process for the production of ultrafine particles which is based on mechanically activated chemical reaction of a metal compound with a suitable reagent. The process involves subjecting a mixture of a metal compound and a suitable reagent to mechanical activation to increase the chemical reactivity of the reactants and/or reaction kinetics such that a chemical reaction can occur which produces a solid nano-phase substance. Concomitantly, a by-product phase is also formed. This by-product phase is removed so that the solid nano-phase substance is left behind in the form of ultrafine particles. During mechanical activation a composite structure is formed which consists of an intimate mixture of nano-sized grains of the nano-phase substance and the reaction by-product phase.

Abstract: Besides a synthesis gas, a metallurgical raw material is to be produced from an oil containing heavy metals. To do this, the oil is partially oxidized and the heavy metal-containing soot is separated and burnt and the heavy metals thus occurring as ash can be taken to further processing, e.g. washing from the synthesis gas produced, using an aqueous washing solution.

Abstract: A method for reclaiming a metallic material from a article including a non-metallic friable substrate. The method comprising crushing the article into a plurality of pieces. An acidic solution capable of dissolving the metallic material is provided dissolving the metallic material in the acidic material to form an etchant effluent. The etchant effluent is separated from the friable substrate. A precipitation agent, capable of precipitating the metallic material, is added to the etchant effluent to precipitate out the metallic material from the etchant effluent. The metallic material is then recovered.

Abstract: A process for removing impurities contained in the crystal lattice of minerals, comprising the steps of forming a mixture of a mineral capable of structurally reorganizing its crystal lattice which contains an impurity in its crystal lattice and a halogen anion, and water; heating the mixture to the mineral's structural reorganization transition temperature; holding the mixture at the structural reorganization transition temperature for a sufficient period of time to allow the impurity to freely migrate from the lattice to combine with the halogen anion; and separating the combined impurity and anion from the mixture to render the mineral essentially free of the impurity. The process is applicable to numerous minerals and impurities, but is especially useful to remove arsenic from fluorspar. Numerous halogen anions can be employed, such as chlorides, fluorides, bromides and iodides, but the preferred halogen anion is a metal chloride such as calcium chloride.

Abstract: A method for the preparation of sodium tungstate by the oxidation of hard metal scrap and/or heavy metal scrap in a molten salt mixture of hydroxide and sodium sulfate.

Abstract: A cellulosic cationic ion-exchange composition is formed by sulfonation of activated cellulose having of high surface area characteristics, using an acid such as concentrated H.sub.2 SO.sub.4. The sulfonated material is convertible into different forms, viz., H-form, Na-form, K-form, NH.sub.4.sup.+ form, Ba-form, Ca-form, and Cu-form by appropriate reaction. The cation-exchanger has been found useful to treat industrial effluents for the removal of heavy metals, to achieve recovery of precious metals, to carry out water-softening, and the like.

Abstract: Heavy metals are efficiently removed from contaminated soil by a process which comprises leaching or washing the soil with a mild leachant solution. The leachant solution is comprised of an aqueous solution of an acid and a salt. The anion of the acid forms a water-soluble salt with the heavy metals which contaminate the soil. The salt component is comprised of at least one alkali metal, alkaline earth metal, or an ammonium salt having one or more anions which also form a water-soluble salt with the heavy metals leached from the contaminated soil.

Abstract: A process for producing a sintered body from untra-fine superconductive particles. In the first step of this process, a ceramic precursor material containing yttrium, barium and copper cations, a nitrogen-containing material, a solvent, and an anion capable of participating in an anionic oxidation-reduction reaction with the nitrogen-containing material, is provided; the nitrogen-containing material contains at least three nitrogen atoms, at least one oxygen atom, and at least one carbon atom. In the second step of the process, droplets of such ceramic precursor material are formed. In the third step of the process, the droplets are dried until particles which contain less than about 15 weight percent of solvent are produced. In the fourth step of this process, such particles are ignited in an atmosphere which contains substantially less than about 60 weight percent of the solvent's saturation value in such atmosphere.

Abstract: A novel method for the production of titanium dioxide slurries having a high solids content comprises subjecting an aqueous slurry of titanium dioxide to cross-flow filtration to produce a slurry containing at least 50%, preferably 60 to 80% titanium dioxide by weight. The slurry can be washed during filtration to reduce the concentration of soluble ions. The process can produce concentrated slurries of titanium dioxide having remarkably low viscosities.

Abstract: Heavy metals are efficiently removed from contaminated soil by a process which comprises leaching or washing the soil with a mild leachant solution comprised of an aqueous solution of an acid and a salt. Heavy metals are also efficiently removed from paint chips by washing with an aqueous acid. The heavy metals are recovered from the leachant be cementation.

Abstract: In a continuous process for reacting particulate ore with a liquid reagent in a counter-current vertical column the improvement comprising:(a) providing an upper and lower chamber for the vertical column;(b) maintaining sufficient upward flow of liquid reagent in The upper chamber so that the particulate ore is wetted and deaerated, at least some fine particles thereof are carried overhead for removal, and the remainder thereof settle and enter the lower chamber; and(c) maintaining sufficient fluidization and retention time in the lower chamber so that the desired amount of reaction with the ore takes place, at least some of the fine ore particles which are generated from the reaction process and/or which are introduced with the particulate ore are entrained and carried upward for removal, and the reacted particulate ore exits the lower chamber.

Abstract: An agglomerating agent for use in the heap leaching of mineral bearing ores is disclosed. The agglomerating agent is a polyvinyl alcohol of moderate to high molecular weight which is partially or fully hydrolyzed. The polyvinyl alcohol agglomerating agent can be used alone or in combination with cement or lime in acidic or alkaline heap leaching operations.

Abstract: A process for producing ultra-fine ceramic particles in which droplets are formed from a ceramic precursor mixture containing a metal cation, a nitrogen-containing fuel, a solvent, and an anion capable of participating in an anionic oxidation-reduction reaction with the nitrogen containing fuel. The nitrogen-containing fuel contains at least three nitrogen atoms, at least one oxygen atom, and at least one carbon atom. The ceramic precursor mixture is dried to remove at least 85 weight percent of the solvent, and the dried mixture is then ignited to form a combusted powder.

Abstract: A process for the recovery of a metal, in particular, cadmium contained in scrap, in a stable form. The process comprises the steps of mixing the cadmium-containing scrap with an ammonium carbonate solution, preferably at least a stoichiometric amount of ammonium carbonate, and/or free ammonia, and an oxidizing agent to form a first mixture so that the cadmium will react with the ammonium carbonate to form a water-soluble ammine complex; evaporating the first mixture so that ammine complex dissociates from the first mixture leaving carbonate ions to react with the cadmium and form a second mixture that includes cadmium carbonate; optionally adding water to the second mixture to form a third mixture; adjusting the pH of the third mixture to the acid range whereby the cadmium carbonate will dissolve; and adding at least a stoichiometric amount of sulfide, preferably in the form of hydrogen sulfide or an aqueous ammonium sulfide solution, to the third mixture to precipitate cadmium sulfide.

Abstract: A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed, The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts, For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates.

Abstract: Apparatus and process for extracting simultaneously metal values from foundry sands, said apparatus comprising a thermostated column which is in flow communication with a controlled air supply source and with a heating system arranged to keep said column at a predetermined temperature; said column is adapted to receive the necessary components to form an aqueous pulp from which the metal values are to be extracted, and has a device for finely dividing the airflow coming from the supply source in order to obtain a suitable suspension and homogenization of said pulp.

Abstract: A process is provided for solubilizing coprecipitated metals. Metals in wastestreams are concentrated by treatment with an iron oxide coprecipitating agent. The coprecipitated metals are solubilized by contacting the coprecipitate with a bacterial culture of a Clostridium species ATCC 53464. The remobilized metals can then be recovered and recycled.

Abstract: It has been discovered that relatively large cyclic and open chain carbonates are extremely efficient in the selective extraction of metal ions, such as gold, silver, platinum and mercury from aqueous solution without the need for a potentially hazardous, organic solvent or use of a corrosive salt, such as NaCl. For example, 1,2-decane carbonate extracted >99.9% mercury, 99.76% gold, 97.5% silver and 79.0% platinum. The homologous 1,2-dodecane carbonate was found to extract 99.9% gold and silver from aqueous solution and 95.8% platinum. Didecyl carbonate extracted 77% gold from aqueous solution. The method of this invention is simpler than prior techniques and eliminates the need for potentially hazardous solvents (toxic, flammable and environmentally unfavorable) and corrosive additives, such as salt, NaCl, used as a salting agent in prior methods.

Abstract: In order to treat metal chlorides obtained in the form of dust collector solids in the production of titanium dioxide by the chloride process, the inert constituents, especially particulate coke, is separated then the metals are selectively precipitated and a maturing phase under oxidative conditions is provided for. The residue consisting of metal hydroxides is also not thixotropic in the absence of inerts. As a result, the material to be deposited has been cut in half.

Abstract: A process and apparatus for the separation of vaporous heavy metal compounds from a carrier gas wherein the heavy metal compounds are cooled and desublimed. An apparatus for carrying out this process has a melting furnace with a discharge opening for a gas/ vapor mixture, which leads to a cooling device.Vaporous heavy metal compounds can be separated from a carrier gas on a large industrial scale. In addition, the apparatus for carrying out this process is easy to operate. The gas/vapor mixture is turbulently mixed immediately after the discharge from the furnace in a mixing section with cold air and is thus cooled. During this cooling, the vaporous heavy metal compounds desublime and are filtered as particles in a filter.

Abstract: A process for removing and recovering cyanide from a cyanide-containing mixture. The process includes the steps of adjusting the pH of the cyanide-containing mixture to between about 6 to about 9.5, volatilizing the HCN contained in the pH adjusted mixture and contacting the volatilized HCN with basic material. Preferably, the cyanide recovery process is performed on tailings slurries resulting from metal recovery processes.

Abstract: Sodium silicate (waterglass) is added to a waste process stream containing metal to form a waterglass sludge containing the metal contaminants. The waterglass sludge matrixed with the metal is removed from the stream. Thereafter, a caustic is added to the separated waterglass sludge which dissolves the sodium silicate, leaving a metal solid in suspension. The sodium silicate solution is filtered off and recycled for use in the waterglass precipitation process. The metal solid remains and concentrated acid is added to form a metallic acid solution which is substantially free of silicates. This solution may then be treated by solvent extraction or other means to recover the metal. The process provides substantial metal recovery from the process waste stream and eliminates the need for burial of the waste, thereby eliminating burial costs.

Abstract: In the treatment of solid residues containing heavy metals from combustion plants, the heavy-metal compounds dissolved after washing-out and subsequently precipitated are separated from the solvent, usually water or slightly acid aqueous solutions by cross-current diaphragm filtration. The sludge obtained during filtration and comprising precipitated insoluble heavy-metal compounds is dewatered together with the remaining solid residues and made suitable for dumping, e.g. by using binders. The cross-current diaphragm filter improves the washing of heavy metals out of the washing or waste water, and the method and the associated plant are simplified by the joint processing of the sludges containing solids.

Abstract: Precipitation (conversion) of dissolved heavy metals in waste effluents is achieved with the addition and mixing of a solution of sodium polythiocarbonate with a solution containing dissolved heavy metals. The solution of sodium polythiocarbonate has been pH buffered to a pH of 12.5 or less in the manufacturing process. Precipitation of the dissolved heavy metals with the buffered sodium polythiocarbonate is complete by the formation of a stable, unleachable [as defined in 40 CFR 190.01, Part 261 Appendix II (Code of Federal Regulations)], extremely insoluble metallic polythiocarbonate particle.

Abstract: An elastic bar member is coupled to an orbiting mass oscillator and the entire assembly is suspended from a cable or the like such that the bar member has freedom of lateral motion and is nakedly immersed in a slurry having particulate material contained therein such as a mineral ore reject from which metal has been extracted. The rotor of the orbiting mass oscillator is driven at a speed such as to generate cycloidal sonic energy in the bar preferably at a frequency such as to set up resonant standing wave vibration of the bar in a cycloidal quadrature pattern. The cycloidal vibrational energy tends to set the surrounding fluid material into a whirling rotation or rotary traveling wave which facilitates the agglomeration or coagulation of the particles in the material and enhances the settling operation to make for more complete separation of the particles from the liquid.

Abstract: An elastic bar member is clamped to an orbiting mass oscillator and the entire assembly is suspended from a cable or the like such that the bar member has freedom of lateral motion and is nakedly immersed in a leachant having a material contained therein such as a mineral ore from which metal is to be extracted. The rotor of the orbiting mass oscillator is driven at a speed such as to generate cycloidal sonic energy in the bar preferably at a frequency such as to set up resonant standing wave vibration of the bar in a cycloidal nutating pattern. The cycloidal vibrational energy tends to set the surrounding fluid material into a whirling rotation or rotary traveling wave which facilitates the mixing of the ore and leachant and enhances the leaching operation to make for more complete separation of the mineral from the ore.

Abstract: This invention can treat a uranium-containing solution of high or low concentration and/or the waste generated from uranium conversion processes, etc. It is characterized by the use of acorns, nuts of oak tree, which can be easily obtained in our botanical system. By coprecipitating the uranium or other heavy metal elements with the extract of acorns, this invention can not only recover the uranium of other heavy metal elements but also can reduce them before being discharged to the environmental radioactivity level.

Abstract: A method of processing waste solutions containing metal salts or complex involves applying ultra-sonic vibrations to a container in which the solution is placed and treating the solution or the generated misting therefrom to insure that the metallic ions remain behind and then finally exhausting the vapor through an activated charcoal filter to remove any organic contaminants and insure that the discharge is environmentally safe.

Abstract: Hazardous waste containing inorganic compounds which contain heavy metals or particular hazardous anionic groups or which are hazardous halides or non-metal oxides or sulfides is contacted with molten aluminum to provide reduction to lower less hazardous oxidation state.

Abstract: Metal ions are reduced from a higher to a lower oxidation stage using ferrophosphorus as the reductant.

Abstract: A process and device for recovering polymetal compounds discharge from a submarine hydrothermal source comprises the use of a device comprising a bell-shaped collector member provided with a flexible skirt and placed just above the hydrothermal source to cover it substantially tightly. Means are connected to said collector for withdrawing hydrothermal fluid from the source and means are provided for concentrating the polymetal compounds thereof by settling or by centrifugation with a pipe for raising the so-concentrated flow to a surface installation associated with a bottom turbine energized by power derived from the hydrothermal fluid energy.

Abstract: Molten alkaline earth metal halides are used to convert highly stable oxides into the corresponding anhydrous halides. Usually a third reactant, such as silica, is added in order to bind the basic oxide thus formed. The solid oxide compounds (e.g. silicates) which result are wellknown ceramic phases of a high degree of purity.

Abstract: A process for purifying an acid aqueous solution containing heavy metals by adding sulfide ions to said acid aqueous solution at a first pH lower than 3.4, precipitating a first heavy metal, adding sulfide ions again to said first precipitate containing acid aqueous solution, after adjusting to a pH of higher than 4, to precipitate a second heavy metal, and then removing the resultant first and second precipitates from the acid aqueous solution.

Abstract: The invention relates to a process for the recovery of valuable metals from sulfidic, silicate-containing raw materials by slurrying the raw material in water, by subjecting the slurry to a selective leach under atmospheric conditions and in an acidic milieu, and by separating the valuable-metal containing solution from the solid leach residue.When the leach is carried out by introducing an oxygen-bearing gas into the slurry which contains finely-divided sulfide and carbon, the acidity of the slurry drops in a controlled manner so that a high efficiency of oxygen, and a high selectivity of the leach as regards valuable metals, are obtained. Owing to the presence of carbon the oxygen is reduced very easily and so oxygen efficiency is high and the rate of dissolving of the valuable metals increases in the slurry mixture.

Abstract: A process of leaching ores, ore concentrates, intermediate metallurgical products and the like, which contain acid-soluble constituents, by a treatment in an acid aqueous solution under pressure in a tubular reactor. The slurry contains suitably 300 to 1100 g starting material per liter of water and a velocity of flow of 0.5 to 4.0 m/sec. is suitably maintained throughout the flow path in the tubular reactor of the slurry and of the leached suspension.

Abstract: A process for the recovery of valuable metals from metallic alloys having iron as their principal constituent is disclosed in which the metal is leached by means of a sulfuric acid solution having such a concentration that a nearly saturated salt solution is obtained, and after the separation of a possible leach residue the solution is heated close to the boiling point, at which time an acid solution is added in an amount corresponding to the salt which has passed out of the solution, in order to crystallize the salt mixture, the crystallized material is separated from the solution and is decomposed under sulfating conditions, whereafter the metal salts are leached out from the iron oxide by means of water.

Abstract: A process for the purification of solutions containing sodium or potassium carbonate, sulphate, hydroxide or hydrogen carbonate, and mainly at least one of the metals belonging to the group formed by vanadium, uranium or molybdenum, in the form of sodium or potassium salts, and inorganic and/or organic impurities, wherein the above-mentioned solutions are completely or partially caustified by the addition of an adequate amount of lime, whereby a first precipitate essentially containing calcium carbonate is separated, and the separated liquor is concentrated by evaporation until the hydroxide content is at most equal to 50%, to cause the production of a second precipitate which essentially comprises sodium or potassium sulphate, then, after separation thereof, a hydroxide-rich liquor is collected.This process is more particularly adapted for treatments of liquors resulting from the alkaline attach of vanadiferous and uraniferous ores.

Abstract: A process for recovering metallic values by putting the values into solution and separating undesired mineral matter from the solution using countercurrent flotation is provided. The process involves leaching metallic values from host rock, conditioning the resultant ore pulp with the required reagents to achieve selective flotation of mineral matter in the metallic values solution, introducing the conditioned ore pulp into flotation cells, along with counterflow of solution from an immediately subsequent flotation step, wherein simultaneous washing and flotation is achieved, and the mineral matter is removed leaving a solution of the metallic values. The resultant mineral matter froth product is subjected to subsequent stages of flotation and simultaneous washing with counterflow of solution removed from each subsequent stage of flotation, water and/or barren solution being used for washing in the final flotation stage.

Abstract: There is disclosed a method for the treatment of aluminum dross oxides which contain aluminum metal, aluminum carbide, aluminum nitride and salts such as potassium and sodium chloride. The method comprises the thermal treatment of an aqueous suspension of the dross oxides with agitation in the presence of a particulate grinding medium. The method is practiced in a stirred reactor vessel which contains a bed of refractory, ceramic balls that are agitated with a slurry to provide a sufficient abrading action on the aluminum metal particles to remove the aluminum hydroxide coating and continually expose the aluminum metal for reaction with the water. This invention comprises the introduction of a purge gas into the suspension, preferably air, during its thermal treatment to reduce the formation of foam during the treatment and to assist in liberation of ammonia formed by the decomposition of the aluminum nitride.

Abstract: The method for extraction of precious metals from leachable ores and forming a building materials which includes the steps of crushing a quantity of leachable ore into a powder of substantially uniform particle size, mixing with a quantity of a binding material and mixing with a leaching material. The materials are then formed into a masonry building construction article having at least one passage therein. A plurality of the masonry building construction articles are stacked with at least some of the passages disposed therein in generally parallel flow paths and a solvent is passed through the passages of the masonry building construction articles.

Abstract: Metal values, such as copper, lead and zinc, are recovered from complex sulfides, e.g., ores or smelter flue dusts, by means of aqueous leaching in the presence of oxygen and CaCl.sub.2 or BaCl.sub.2 at elevated temperature.

Abstract: A process for the treating of zircon to remove a coating which contains iron from the surface of individual grains to make them move amenable to electrostatic and magnetic separation, wherein the method comprises coating the zircon grains with a strong basic reagent, calcining the coated grains and treating the calcined grains to remove the calcined impurities.

Abstract: A method and an apparatus for treating a gravel type solid material with a liquid in a bath are described. The apparatus comprises means for supplying the solid material, means for transporting it through the bath and means for removing the processed solid material from the bath. The apparatus comprises further means for supply of liquid and tapping off of the liquor. The method comprises introduction of the gravel type solid material into the bath at its lower end and removal of the processed solid material at the upper end, the gravel type solid material being gradually transported upwards through the bath by means of rotating lifting members while liquid is introduced into the bath at its upper half while liquor is drained off at the lower half. The lifting member comprises at least one inclined plate which is rigidly fixed to a vertical tube through which the solid material is introduced into the bath or the tank.

Abstract: A process for the recovery of selected metal values from silica containing sludges including incineration of the sludge to degrade organic components, followed by acid leaching of the ash, followed by hydrometallurgical recovery of metal values from the remaining solid and liquid residues, wherein the incineration step is carried out at a temperature below the slagging temperature of silicates, whereby to avoid the occluding of metal values in glass matrices which are not attacked by subsequent acid leaching and hydrometallurgical steps.

Abstract: Uranium ore is crushed and formed into a slurry. The slurry is pumped into a leaching tank and classified by a sparge tube projecting water at teeter velocity at the bottom of the ore bed. Thereafter, a second ore bed is pumped by the slurry into the tank and the second bed classified. This is repeated until there are four or five ore beds in the tank.Thereafter, the ore is leached by passing liquid up from the bottom of the tank at velocities less than teeter velocities so that the bed remains classified.After leaching, the ore is formed into a slurry and the slurry pumped from the tanks to disposal.

Abstract: A process for the recovery of selected metal values from silica containing sludges including incineration of the sludge to degrade organic components, followed by acid leaching of the ash, followed by hydrometallurgical recovery of metal values from the remaining solid and liquid residues, wherein prior to incineration of the sludge a quantity of soluble sodium and/or potassium salts are mixed with the sludge, the quantity being in excess by weight of the silica content of the sludge, and then the incineration step is carried out on this mixture so that silicates which form during such incineration are predominantly soluble in water and in the leaching acid, whereby to avoid the occluding of metal values in insoluble glass matrices which would not be attacked by subsequent acid leaching and hydrometallurgical steps.

Abstract: A novel process for enhancing the leaching rate of a mineral wherein the mineral is characterized by the tendency to form a reaction product layer during leaching. A suitable particulate modifier such as carbon is mixed with the mineral prior to leaching and selectively alters the characteristics of the reaction product layer. The process is particularly useful for leaching chalcopyrite, sphalerite and galena.