Process for debismuthizing lead

Abstract

A continuous process for debismuthising lead containing one or more alkaline earth metals or alloys thereof, comprising continuously adding thereto a reagent selected from the group consisting of antimony, arsenic and alloys containing antimony and/or arsenic, so as to form a crust/bullion mixture, continuously introducing the crust/bullion mixture into the lower separation zone of a separation vessel having an upper liquation zone and a lower separation zone, maintaining the temperature in the upper liquation zone between 330.degree. and 480.degree. C and maintaining the temperature in the lower separation zone between the freezing point of lead and 350.degree. C, the average temperature in the upper liquation zone being at least 15.degree. C higher than the average temperature in the lower separation zone, separating crust particles from the bullion in the lower separation zone, causing the crust particles to move upwardly in the vessel and the bullion to move downwardly in the vessel, separating entrained lead from the crust particles in the upper liquation zone so as to form enriched crusts, removing the enriched crusts continuously or intermittently from the upper surface of the material in the vessel, and withdrawing debismuthised product lead continuously from at or near the lower end of the lower separation zone.

Dependencies are inferred from the claim text.