Andrew S Larson

US Patent:

44251602, Jan 10, 1984

Filed:

Nov 23, 1982

Appl. No.:

6/444258

Inventors:

Jitesh R. Mehta - Eagan MN
Andrew H. Larson - Eagan MN

Assignee:

GNB Batteries Inc. - Mendota Heights MN

International Classification:

C22B 1306

US Classification:

75 63

Abstract:

An improved process for refining lead bullion containing antimony, in which the bullion is initially heated in a refining vessel to about 25. degree. F. (14. degree. C. ) above the bullion melting point, and is thereafter kept molten primarily by exothermic process reactions. The process includes the steps of melting the lead-antimony bullion, agitating the bullion, adding caustic soda and metallic sodium to form an antimony-rich skimmable refining dross comprising a sodium-antimony intermetallic and separating the dross from the refined bullion. Along with antimony, other elements, such as arsenic, cadmium, copper, nickel, silver, sulfur, selenium, tellurium and zinc, if present in the bullion, are also removed in the dross by the sodium. The antimony-rich dross is accumulated for subsequent use. The process further comprises a cleansing operation wherein sodium present in solution in the refined bullion is removed using cleansing agents.

US Patent:

44276290, Jan 24, 1984

Filed:

Nov 23, 1982

Appl. No.:

6/444259

Inventors:

Jitesh R. Mehta - Eagan MN
Andrew H. Larson - Eagan MN

Assignee:

GNB Batteries Inc. - Mendota Heights MN

International Classification:

C22C 1100
C22C 1104
C22C 1106
C22C 1108

US Classification:

420563

Abstract:

A process for metal-enrichment of lead bullion, wherein an alkali metal-desired metal intermetallic, such as sodium-antimony intermetallic, is added as a refining dross to the bullion and the desired metal is stripped from the dross and recovered as an enriched bullion. The process includes the steps of heating the lead bullion, in which the desired metal is to be recovered, to a temperature between 650. degree. F. and 900. degree. F. ; agitating the molten bullion; adding said alkali metal-desired metal intermetallic to said bullion; mixing said intermetallic into said bullion; adding a stripping reagent for stripping said desired metal from said intermetallic; forming a desired metal-enriched lead bullion and a residue dross substantially void of said desired metal; and separating said enriched bullion from said residue dross. The process may also require a cleansing step to cleanse said enriched lead bullion of any said alkali metal in solution. Through the control of temperature, additions of stripping and cleansing reagents and agitation, the process provides economies of materials, energy, time and labor over conventional metal recovery processes.