Refining process for removing antimony from lead bullion
US4425160A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1982 |
| Grant date | Jan 10, 1984 |
| Priority date | — |
| Expiry date | Nov 23, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
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…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.