Asarco LLC

Leo J Bulvanoski

William Lafayette Scott

Carl R Di Martini

Herbert E Howe

Carl Richard DiMartini

Lead is separated from material containing lead sulfide, e.g., galena ore concentrate, by a substantially autogenous process involving establishing a pool of molten lead in a kettle, adding a metallic alkali metal, e.g., metallic sodium, to the molten lead in an amount sufficient to reduce the combined lead of the lead sulfide to metallic lead, adding the ore concentrate to the molten lead pool, and mixing together the metallic sodium, molten lead and ore concentrate. The sodium reacts rapidly and exothermically with the lead sulfide to reduce the combined lead of the lead sulfide to metallic lead and form sodium sulfide. The thus-liberated metallic lead reports in the molten lead pool, and a matte phase containing the sodium sulfide separates from the molten lead and forms on the surface of the molten lead pool. Lead sulfide from an excess of the ore concentrate, or other suitable added flux, which is usually added to the molten lead pool, serves to flux the sodium sulfide-containing matte phase to attain desired fluid and low melting characteristics of the matte phase. The process herein employs a kettle as the reactor, ordinarily the steel refining kettle of a lead refinery, is a low temperature process requiring temperatures above the melting point of lead but ordinarily not above 650.degree. C., and does not discharge polluting SO.sub.2 into the atmosphere.

Low temperature, non-SO.sub.2 polluting, kettle process for separation

Lead is separated from material containing lead sulfide, e.g. galena ore concentrate, by a substantially autogenous process involving establishing a pool of molten lead in a kettle, adding a metallic alkali metal, e.g. metallic sodium, to the molten lead in an amount sufficient to reduce the combined lead of the lead sulfide to metallic lead, adding the ore concentrate to the molten lead pool, and mixing together the metallic sodium, molten lead and ore concentrate. The sodium reacts rapidly and exothermically with the lead sulfide to reduce the combined lead of the lead sulfide to metallic lead and form sodium sulfide. The thus-liberated metallic lead reports in the molten lead pool, and a matte phase containing the sodium sulfide separates from the molten lead and forms on the surface of the molten lead pool. Lead sulfide from an excess of the ore concentrate, or other suitable added flux, which is usually added to the molten lead pool, serves to flux the sodium sulfide-containing matte phase to attain desired fluid and low melting characteristics of the matte phase. The process herein employs a kettle as the reactor, ordinarily the steel refining kettle of a lead refinery, is a low temperature process requiring temperatures above the melting point of lead but ordinarily not above 650.degree. C., and does not discharge polluting SO.sub.2 into the atmosphere.

Antimony values are separated from a material containing a sulfo-antimony compound of copper, e.g. tetrahedrite ore concentrate, by a process involving establishing a pool of molten lead, adding a metallic alkali metal, e.g. metallic sodium, to the molten lead in an amount which is sufficient to reduce the combined antimony of the sulfo-antimony compound or compounds of copper of the tetrahedrite to metallic antimony, adding the tetrahedrite ore concentrate to the molten lead, and mixing together the alkali metal, molten lead, and tetrahedrite ore concentrate. The alkali metal and sulfo-antimony compound of copper are reacted together in the presence of the molten lead for a period which is sufficient to reduce the antimony of the sulfo-antimony compound of copper to metallic antimony and to form one or more sulfo-alkali metal compounds of copper, and a matte phase which separates from the molten lead. The reduced, metallic antimony passes into the molten lead pool, and the sulfo-alkali metal compound or compounds of copper report in the matte phase on the surface of the molten lead pool. The matte phase is separated from the molten lead. The metallic antimony is then recovered from the lead. Alternatively, if lead- and antimony-containing alloy is desired as a product, the antimony is retained in the lead, and additional antimony and/or lead may or may not be incorporated into the alloy, as desired or required, to obtain the desired alloy composition. Should the alloy product be a desired product, the starting lead of the molten pool will ordinarily not be a liquated, rough drossed lead bullion, but instead another lead such as, for example pure lead or antimonial lead. The process herein is a relatively low temperature process employing temperatures of the molten lead pool above the melting point of lead but ordinarily not in excess of 650.degree. C. Further, the instant process does not require a smelting furnace but is ordinarily carried out in a kettle.

Low temperature, non-SO.sub.2 polluting, kettle process for the

Copper sulfide in the presence or absence of metallic copper contained in a dross obtained from the copper drossing of lead bullion is separated from metallic lead entrained or occluded in the dross by introducing the dross into a vessel other than a reverberatory furnace, usually a kettle, also introducing an alkali metal sulfide, preferably sodium sulfide, into the kettle, and heating the dross and alkali metal sulfide together in the kettle at an elevated temperature not in excess of 1200.degree. F. and for a time sufficient to melt together the dross and alkali metal sulfide. The thus-obtained molten dross releases the entrained molten lead which falls to the bottom of the kettle. The molten dross and molten alkali metal sulfide form a low melting copper sulfide-alkali metal sulfide matte on the surface of the resulting pool of the released molten lead, and the matte is separated from the molten lead pool, for instance by being lifted off the pool by means of a hook positioned in the matte layer while molten and retained in the matte layer while the matte layer is permitted to solidify on the molten lead pool surface. Copper sulfide in the presence of metallic copper can also be separated from metallic lead and tin contained in solder drosses, e.g. high tin-bearing solder drosses, or in other drosses in accordance with this invention.

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Fords, NJ, United States of America

Leo J Bulvanoski