Kennecott Copper Corporation

Roger N Kust

Robert E Lueders

J Paul Pemsler

Robert Powers Cox

David L Natwig

Lester J Szabo

David S Davies

Gale L Hubred

Herbert E Barner

A process for winning copper and zinc from brass mill waste products containing oxidic copper and zinc, iron, nickel, or cobalt. The feed material is leached in sulfuric acid, neutralized to a pH between about 2.5 and 3.0, and treated with zinc metal to precipitate copper. After separation of the copper product, residual copper as well as iron and cobalt are removed in a second, oxygen-free, cementation on zinc metal. The liquor is then raised to about pH 4.0 or greater and flushed with oxygen to precipitate iron. Lastly, the purified electrolyte is subjected to zinc electrowinning wherein acceptably pure zinc cathode is produced and sulfuric acid is regenerated.

Hydrometallurgical brass dust reclamation

A process in which copper, nickel, cobalt and molybdenum are recovered by reducing comminuted raw manganese nodules with an aqueous solution containing cuprous ions. An improvement is disclosed in which copper is oxidized to provide a starting solution of cuprous ions for the process. In one important embodiment of the invention wet copper cement is added to a solution of carbon dioxide and ammonia and ground manganese nodules are then added to the mixture. As a result, a starting solution containing cuprous ions is produced. A major advantage gained from utilizing manganese nodules as an oxidizing agent is that the manganese nodule is itself reduced and its metal values are added to the reaction solution.

Cuprion process start-up control

After the non-cobalt values are stripped from the co-loaded organic, the cobalt ions on the organic are reduced to the divalent state. The organic loaded with divalent cobalt ions is easily stripped with a dilute acid to render the organic recyclable. In another embodiment of the invention simultaneous reduction and 'crowding' is utilized to strip cobalt from the organic. In this embodiment, a convenient source of both reductant Cu.sup.+ and of copper and/or nickel such as pregnant leach liquor is used to crowd the reduced cobalt from the organic.

Cobalt stripping process

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 with an aqueous ammoniacal leach solution containing cuprous ions. During the process cuprous ions are consumed and are oxidized to cupric ions. The cuprous ions are regenerated by reducing the cupric ions with a reducing gas. An improvement is disclosed which results from increasing the pressure of the reducing gas. This increased pressure facilitates maintaining a high cuprous ion concentration in each reaction vessel, by increasing the rate at which the cuprous ions are regenerated from the cupric ions without affecting the rate at which the metal values are recovered from the nodules, which in turn, increases the efficiency of each reactor thus enabling the size of reactors to be reduced. In one important embodiment of the invention, the reducing gas is sparged into a series of reaction vessels at increased pressure while the manganese nodules are injected into several vessels simultaneously. This increased pressure of the reducing gas together with the multiple point injection of the manganese nodules greatly increases the efficiency of the process. In another important embodiment of the invention as the reducing gas is sparged into the reaction vessels under increased pressure sufficient heat is removed from the slurry leaving each reaction vessel so that all reaction vessels operate at substantially the same temperature within the range of 35.degree.-55.degree. C. By operating within this temperature range, nickel and cobalt solubilization within the reaction vessels is improved.

Growing community of inventors

Acton, MA, United States of America

Roger N Kust