Reduction leaching of raw sea nodules with sulfides
AssigneeThe International Nickel Company, Inc.
InventorsKohur Nagaraja Subramanian, Gerald Vernon Glaum
Life of this patent
Estimating the term…
Abstract
A process for extracting metal values from sea nodules is provided in which nickel, cobalt and copper values are selectively extracted by leaching raw sea nodules in an aqueous ammoniacal medium in the presence of a reducing agent for tetravalent manganese and carbonate to precipitate the reduced manganese as manganous carbonate.
Claims11
A process for extracting nickel, cobalt, copper and molybdenum values from raw sea nodules containing a major amount of manganese and iron, manganese being present in tetravalent state and a lesser amount of at least one of the nonferrous metals nickel, cobalt, copper and molybdenum comprising leaching said raw nodules in an aqueous ammoniacal medium at a pH of not less than about 8 in the presence of a reducing agent for tetravalent manganese selected from the group consisting of H.sub.2 S, (NH.sub.4).sub.2 S, ammonium polysulfide, and combinations thereof and in the presence of a manganous carbonate precipitant selected from the group consisting of CO.sub.2, (NH.sub.4).sub.2 CO.sub.3, and an alkali metal carbonate, at a temperature in the range of about 50.degree. C to about 125.degree. C and pressure of atmospheric to about 100 psig, to convert tetravalent manganese to the divalent state, extract nickel, cobalt, copper and molybdenum values into the leach solution and to separate manganese and iron values into the leach residue, said leaching reaction condition being maintained for a period of time sufficient to maximize said extraction of nickel, cobalt, copper and molybdenum values into solution and separation of manganese and iron values into the leach residue.
A process for extracting nickel, cobalt, copper and molybdenum values from a manganiferous ore containing a major amount of manganese and iron, manganese being present in tetravalent form, and a lesser amount of at least one of the nonferrous metals nickel, cobalt, copper and molybdenum comprising leaching said ore in an aqueous ammoniacal medium at a pH of not less than about 8 in the presence of a reducing agent comprising a sulfide, said sulfide being selected from the group consisting of H.sub.2 S, (NH.sub.4).sub.2 S and ammonium polysulfide, at reaction conditions to convert tetravalent manganese to the divalent state and in the presence of a carbonate capable of forming substantially insoluble manganous carbonate in the ammoniacal medium, whereby at least one of the nonferrous metal values nickel, cobalt, copper and molybdenum is extracted into the leach solution and the manganese and iron values are separated into the leach residue.
A process for extracting nickel, cobalt, copper and molybdenum values from a manganiferous ore containing a major amount of manganese and iron, maganese being present in tetravalent form and a lesser amount of at least one of the nonferrous metals nickel, cobalt, copper and molybdenum comprising leaching said ore in an aqueous ammoniacal medium at a pH of not less than about 8 in the presence of a reducing agent comprising a sulfide soluble in said ammoniacal medium at reaction conditions to convert tetravalent manganese to the divalent state and in the presence of a carbonate capable of forming substantially insoluble manganous carbonate in the ammoniacal medium, whereby at least one of the nonferrous metal values nickel, cobalt, copper and molybdenum is extracted into the leach solution and the manganese and iron values are separated into the leach residue.
Dependencies are inferred from the claim text.