Hazen Research, Inc.

Cyprus Metallurgical Processes Corporation

Resource Technology Associates

Technology Management Advisors LLC

Kennecott Utah Copper Corporation

Tajima Roofing Co., Ltd.

Cyprus Power Company

Equity Mining Corporation

Enzo L Coltrinari

Wayne C Hazen

James E Reynolds

Paul B Queneau

Jerome P Downey

Patrick M Brown

John E Litz

Jerry Dobson

Wayne W Hazen

Robert K Johnson

David L Thompson

Eugenio Iasillo

Victor J Ketcham

Molybdenum trioxide is produced from molybdenite by a pressure oxidation process comprising of the steps of forming an aqueous slurry of molybdenite, pressure oxidizing the slurry to form soluble and insoluble molybdenum species, converting the insoluble molybdenum species to soluble molybdenum species by alkaline digestion, separating the soluble molybdenum species from insoluble residue contaminants (if present), removing the molybdenum species from the aqueous media through solvent extraction, and recovering the molybdenum values as molybdenum trioxide from the organic solvent. Low grade molybdenite concentrates, including concentrator slimes containing talc and sericite, can be used as a feed. The process produces technical grade molybdenum trioxide.

Pressure oxidation process for the production of molybdenum trioxide

A copper alloy plumbing fixture containing interdispersed lead particles coated non-continuously on a water contact surface to resist the leaching of lead into potable water systems. The leach resistant fixture is prepared by immersing conventional copper alloys in a bismuth nitrate solution, selectively and non-continuously coating the lead dispersoid particles on the water contact surface with bismuth, tin or copper.

Apparatus and method for inhibiting the leaching of lead in water

The present invention is a method to remove metals from solutions by precipitating the metals and adding cellulosic fiber to the solution. The precipitates attach to the cellulosic fibers to form products. The products may be removed from the solution by gravity separation techniques or by filtration. The removed products may be dewatered and incinerated. The method provides a simple and effective technique for removing low concentrations of metals from high volume solution streams.

Method for removing metals from waste solutions

A copper alloy plumbing fixture containing interdispersed lead particles coated noncontinuously on a water contact surface to resist the leaching of lead into potable water systems. The leach resistant fixture is prepared by immersing conventional copper alloys in a bismuth nitrate solution, selectively and noncontinuously coating the lead dispersoid particles on the water contact surface with bismuth. Tin may be substituted for bismuth to obtain similar results.

Method for removing metals from a solution

Discussed is a process for recovering metals and metal-containing products, such as a nickel sulfate product, from aqueous feed solutions comprising two or more dissolved metals. A selected metal is isolated and in a purified form in an aqueous raffinate phase from solvent extraction of nonselected metals using an organic phase containing a salt of an organic acid and the selected metal. Aqueous feed solution may result from leaching operations, including leaching of nickel-containing catalyst, such as catalyst used in hydrogenation of vegetable oils.

Selective recovery of dissolved metals and preparation of metal salt

The present invention provides a novel method of extracting zinc from geothermal brines and synthetic brines which can be performed in a continuous, in-line process.

Method of extracting zinc from brines

A process for selectively recovering dissolved heavy metals from a solution is disclosed that involves selectively reacting a xanthate with such dissolved heavy metals. Selective reaction of a xanthate with selected dissolved heavy metals is accomplished by conducting the reaction under conditions such that only some of the heavy metals react with the xanthate, to the exclusion of reaction with other dissolved heavy metals. Selectivity of the reaction is particularly influenced by the pH at which the reaction occurs. Typically, the reaction should occur at a pH below about 4.0. Xanthates, once reacted, can be separated from the heavy metal xanthate reaction product and recycled for use within the process. Purified heavy metal product can be produced if desired.

Selective recovery of heavy metals using xanthates

A process is provided for removing cyanide from a dilute cyanide solution. The solution is passed through a weak base anion exchange resin to absorb cyanide complexes. The resin is eluted with a weakly basic Ca(OH).sub.2 solution, to produce a cyanide-rich eluate. Elution is accomplished by recycling the eluting fluid past a bed of solid Ca(OH).sub.2, to maintain the eluting fluid in Ca(OH).sub.2 saturation. Recycling in this manner produces an eluate with relatively high cyanide concentration using economical reagents. The eluate is subjected to an acidification/volatilization process including acidification, preferably with H.sub.2 SO.sub.4, heating by introduction of steam and removal of volatilized HCN by an air sparge. The HCN-rich off-gas and slats produced therefrom may be recycled in the process. The cyanide-depleted waste streams may be disposed of in, for example, tailings ponds.

Method for recovery of cyanide from waste streams

The invention comprises the treatment of metal oxides and mixed metal oxides and metal sulfides in a vertical tube reactor system having a downcomer section and a riser section in order to oxidize and dissolve the metal values in aqueous slurry primarily in the downcomer section and introducing a reducing agent comprising a formate species and reducing the dissolved metal values in the riser section. The reduced metal values are then separated with the gangue values from the product solution downstream from the vertical tube reactor system. The reduced metal values may then be separated from the gangue material by conventional solid separation techniques, such as flotation.

Method of recovering metals from ores using a formate reducing agent

An improvement in the hydrometallurgical recovery of metals, such as, lead, silver, gold, antimony, and bismuth from materials such as flue dust in the presence of arsenic, comprising precipitating arsenic as an insoluble ferric-arsenic compound in the first processing step, carrying the insoluble arsenic compound through a chloride leach step, in which it is insoluble, to recover the metals, and disposing of the residue in which the arsenic has been fixed with ferric ions to render it non-polluting, or alternatively, recovering the arsenic by caustic leach and crystallization.

Chloride leach process for recovering metal values in the presence of

An arsenic-recovery process primarily for use in conjunction with the hydrometallurgical processing of arsenic-containing materials for metal recovery. Arsenic is recovered from ferric arsenate by reaction with sodium hydroxide in accordance with the following general reaction:

Process for recovering arsenic compounds by sodium hydroxide leaching

An improvement in hydrometallurgical recovery of metals, i.e. copper, zinc, cadmium, germanium, indium, lead, silver, gold, antimony and bismuth from materials such as flue dust containing arsenic in which the metals are selectively separated in successive process steps for final recovery, the improvement comprising precipitating arsenic as an insoluble ferric-arsenic compound in the first processing step, carrying the insoluble arsenic compound through subsequent processing steps in which it is insoluble until the other metals have been recovered leaving the ferric-arsenic compound as the final residue which can be disposed of without violating pollution requirements or converted to soluble sodium arsenate and recovered from solution by crystallization.

Process for recovering metal values from materials containing arsenic

A process is disclosed for treating mixed metal sulfides containing trivalent antimony sulfide wherein the sulfide concentrates are leached with an excess of sodium sulfide in order to isolate copper sulfide and other insolubles in solid form while solubilizing the remaining metal sulfides and producing sodium thioantimonite, separating the insoluble sulfides from the solution; oxidizing the sodium thioantimonite with elemental sulfur to produce sodium thioantimonate in solution; crystallizing a portion of the sodium thioantimonate along with other available metal sulfides from solution; and recirculating the remainder of the solution to the sodium sulfide leach stage. The crystallized metal sulfides may be further treated, isolated, and recovered as desired.

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Golden, CO, United States of America

Enzo L Coltrinari