Freeport Minerals Corporation

Freeport-mcmoran Corporation

Freeport Minerals Company

Freeport-mcmoran Sulphur LLC

Jay Charles Smith

Wayne Werneke Hazen

David R Baughman

Joanna M Robertson

Thomas R Bolles

Thomas H McCord

Robin W Strickland

Lawrence D May

Gregory R O'Neil

James E McAllister

Ronald J Manuel

Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, and leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution.

Systems and methods for copper recovery via roasting and leaching

Systems and methods for metal recovery

Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, leaching the roasted metal hearing material in a basic medium to yield a pregnant leach solution, conditioning the pregnant leach solution to thrill a preprocessed metal bearing material; and leaching the preprocessed metal bearing material in acid medium.

A sulfur purification process is provided. Ash-containing molten sulfur is fed to a centrifuge and subjected to centrifugation under controlled conditions at G forces at least about 4,000 times that of gravity. The centrifugation generates a purified sulfur product and a high-solids sulfur waste stream. A solid bowl disc centrifuge provided with conical discs is used to effect the centrifugal separation of solids from liquids at G forces of at least about 4,000. The centrifuge and related piping system are equipped with heating means so as to maintain the temperature of the sulfur above about 250&deg; F. If large volumes of sulfur are to be treated, e.g., 40 or more long tons per hour, a pretreatment step, where the molten sulfur is first subjected to centrifugation at G forces at least about 4,000 times that of gravity in one or more nozzle bowl centrifuges, is added in order to obtain satisfactory results. In another aspect of the sulfur purification process, the nozzle bowl centrifuge underflow waste stream is further processed in a cyclone-thickener arrangement to obtain a high-solids sulfur waste stream and a moderate-solids sulfur stream which is then mixed with the low-solids sulfur product stream from the nozzle bowl centrifuge(s), or recycled to the feed of the nozzle bowl centrifuge(s).

Purification of sulfur by means of centrifugation

A process and apparatus for removing SO.sub.2 from low-volume gas streams containing high concentrations of SO.sub.2 includes a tank scrubber containing an aqueous SO.sub.2 absorbent and an impeller. The tank scrubber has an unpartitioned vessel. The impeller includes a vertical rotating shaft having an upper and lower impeller. The lower impeller serves to agitate the SO.sub.2 absorbent. The upper impeller includes a shroud thereby directing the absorbent and gas outwardly toward the wall of the scrubber. The gas is injected into the absorbent at a point below the shrouded impeller. The shroud prevents gas bypass and thereby promotes gas-liquid mixing and, consequently, markedly improves SO.sub.2 removal efficiency.

Method and apparatus for removing sulfur dioxide from gas streams

A process and apparatus for removing SO.sub.2 from low-volume gas streams containing high concentrations of SO.sub.2 includes a tank scrubber containing an aqueous SO.sub.2 absorbent and an impeller. The impeller includes a vertical rotating shaft having an upper and lower impeller. The lower impeller serves to agitate the SO.sub.2 absorbent. The upper impeller includes a shroud thereby directing the absorbent and gas outwardly toward the wall of the scrubber. The gas is injected into the absorbent at a point below the shrouded impeller. The shroud prevents gas bypass and thereby promotes gas-liquid mixing and, consequently, markedly improves SO.sub.2 removal efficiency.

Method for removing sulfur dioxide from gas streams

Gold-containing ores, having refractory sulfidic matter or a combination of refractory sulfidic matter and refractory carbonaceous matter, are processed to recover their gold values. The process uses an ore roasting procedure that utilizes a two-state, fluidized bed roaster. The process also employs a pure oxygen atmosphere during roasting. A carbon-in-leach step is desirably used to extract gold values from the roasted ore.

Treating refractory gold ores via oxygen-enriched roasting

A method for pretreating phosphoric acid to prevent the formation of a mass of suspended solids (i.e., 'crud') during solvent extraction of the acid is described. Prior to solvent extraction, the acid is contacted with a liquid hydrocarbon such as kerosene which collects the crud-forming agents. The mixture of liquid hydrocarbon and collected crud-forming agents is separated from the acid and the liquid hydrocarbon is regenerated for reuse in the first step of the method.

Method of treating phosphoric acid to prevent crud formation during

A method for handling the problem of crud formation in the solvent extraction of wet-process phosphoric acid is described. Crud is the name ordinarily given to the thick interfacial layer of semi-floatable material which tends to form and accumulate, and which interferes with many of the extraction processes and, in particular, with the solvent extraction of wet-process phosphoric acid. The method described provides for the operation of the solvent extraction stages in a manner that allows the formation and temporary accumulation of crud in those stages whereupon the solvent and the crud are then removed from the extraction stages and treated in a series of operations which include a clarification step, an acid removal step, a water wash step and a caustic treatment step, which steps effectively separate the solvent from the crud, and remove the crud components from the system and regenerate otherwise unusable solvent. The invention is particularly applicable to the solvent extraction of wet-process phosphoric acid for the recovery of uranium by the reductive stripping technique.

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Pearl River, LA, United States of America

Jay Charles Smith