ABSTRACT OF THE DISCLOSURE"An Improved Refining Process for RemovingAntimony from Lead Bullion"An improved process for refining lead bullioncontaining antimony, in which the bullion is initiallyheated in a refining vessel to about 25°F (14°C) abovethe bullion melting point, and is thereafter keptmolten primarily by exothermic process reactions. Theprocess includes the steps of melting the lead-antimonybullion, agitating the bullion, adding caustic soda andmetallic sodium to form an antimony-rich skimmablerefining dross comprising a sodium-antimony inter-metallic and separating the dross from the refinedbullion. Along with the antimony, other elements, suchas arsenic, cadmium, copper, nickel, silver, sulfur,selenium, tellurium and zinc, if present in thebullion, are also removed in the dross by the sodium.The antimony-rich dross is accumulated for subsequentuse. The process further comprises a cleansingoperation wherein sodium present in solution in therefined bullion is removed using cleansing agents.This refining process is performed at a temperaturebetween 600°F (316°C) and 800°F (427°C). Through thecontrol of temperature, reagent addition and agitation,the process provides an environmentally nonpollutingand controlled process in which economies of materials,energy, time and labor are realized over conventionalrefining processes.
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