The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 1984
Filed:
Nov. 23, 1982
Jitesh R Mehta, Eagan, MN (US);
Andrew H Larson, Eagan, MN (US);
GNB Batteries Inc., Mendota Heights, MN (US);
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. This refining process is performed at a temperature between 600.degree. F. (316.degree. C.) and 800.degree. F. (427.degree. C.). Through the control of temperature, reagent addition and agitation, the process provides an environmentally nonpolluting and controlled process in which economies of materials, energy, time and labor are realized over conventional refining processes.