Kennecott Copper Corporation

Lester J Szabo

Robert E Lueders

Roger N Kust

David S Davies

Herbert E Barner

Process in which manganese nodules are treated to enable metal values to be recovered. Manganese ore nodules are treated in a two-stage fluid bed process to produce a leachable product. In the first stage, dried nodules are calcined using direct fuel injection under a neutral or slightly oxidizing atmosphere to remove about one-half of the oxygen content. Subsequently, in the second stage, the calcined nodules are reduced with synthesis gas to render the metal values leachable. The metal values such as copper and nickel are leached from the reduced nodules with an ammonia-ammonium carbonate leach solution.

Two-stage fluid bed reduction of manganese nodules

A metal recovery process in which copper, nickel, cobalt and molybdenum are recovered by reducing comminuted raw manganese nodules and leaching the reduced nodules with an aqueous ammoniacal solution to obtain a leach solution containing these metal values. In order to recover copper from leach solutions by techniques such as ion exchange extraction, it is desirable to oxidize the copper to the cupric state. In another embodiment, oxidation is required to bring about the solution of reduced metallic metal values of copper, nickel and cobalt or to convert lower valence ions of these metals to a more highly oxidized state. The present invention is an improvement in the foregoing metal recovery processes. In the present invention manganese nodules are used as the oxidizing agent to oxidize slurries containing pre-reduced manganese nodules which have lower valence ions of metals such as copper or the metal itself. In the process of this oxidation reaction, the manganese nodule used as an oxidizing agent is itself reduced and its metal values are added to the leach solution.

Use of raw manganese nodules for oxidation leaching of reductively

A process in which copper, nickel, cobalt and molybdenum are recovered by direct leaching of comminuted raw manganese nodules after the nodules are reduced in a reduction circuit with an aqueous ammoniacal leach solution containing cuprous ions. An improvement is disclosed which results from recycling a portion of the metal values recovered back to the reduction circuit as a solid basic metal carbonate. The metal carbonate recycle enables the size of the reactors in the reduction circuit to be reduced. The recycle also increases the efficiency of the process by facilitating the solubilization of copper. Another aspect of the invention resides in the advantages of maintaining solubilized copper in amounts between 10 grams per liter and the solubility limit in the reduction circuit.

Metal carbonate recycle to reduction circuit in the cuprion process

A process in which copper, nickel, cobalt and molybdenum are recovered by direct leaching of comminuted raw manganese nodules with an aqueous ammoniacal leach solution containing cuprous ions. During the process cuprous ions reduce the nodules, are consumed, and are oxidized to cupric ions. The cuprous ions are regenerated by reducing the cupric ions with a reducing gas.

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Lester J Szabo