Richard T Um

US Patent:

41244575, Nov 7, 1978

Filed:

Sep 16, 1977

Appl. No.:

5/833847

Inventors:

John C. Stauter - Streamwood IL
Richard T. Um - Tucson AZ

Assignee:

UOP Inc. - Des Plaines IL

International Classification:

C25C 334

US Classification:

204 66

Abstract:

Metallic lead is obtained from lead sulfide ores or concentrates by subjecting the concentrate to a drying step followed by halogenating the dried concentrate in a dry atmosphere at a temperature in the range of 90. degree. to about 120. degree. C. Thereafter the halogenated mixture is subjected to a water wash and leached with a brine solution. The brine solution is then filtered to separate elemental sulfur and residue from the solubilized lead halide, the latter being then crystallized and subjected to fused salt electrolysis to recover metallic lead.

US Patent:

42617375, Apr 14, 1981

Filed:

Oct 31, 1979

Appl. No.:

6/089837

Inventors:

James A. Bradbury - Tucson AZ
Richard T. Um - Tucson AZ

Assignee:

UOP Inc. - Des Plaines IL

International Classification:

C22B 2304

US Classification:

75101BE

Abstract:

The present process involves an improvement in the hydrometallurgical recovery of metal values from metal bearing sources such as ores and the like. The desired metal values are recovered by subjecting a metal bearing source to a reductive roast in a reducing atmosphere after having treated said source with at least one additive. Following the reductive roast the reduced metal bearing source is cooled and extracted by a leaching operation. The separation of various metal values in the metal bearing source may be effected by adding a solid adsorbent to the leach solution whereby selective metal ions are adsorbed thereon. The improvement in the present process comprises pretreating the solid adsorbent prior to use thereof with an acid thereby increasing the loading capacity of the metal ions in the adsorbents as well as kinetics of metal adsorption.