| 摘要 |
470,847. Refining metals; alloys. AMERICAN METAL CO. (Ltd.). Dec. 21, 1935, No. 35451. Convention date, Jan. 5. [Class 82 (i)] Alloys of antimony with lead or tin or lead and tin are treated with an alkali or alkaline earth metal to separate and remove antimony, the alkali or alkaline earth metal being floated on the surface of the molten alloy and relative movement being produced between the metal and the alloy surface. Such relative movement is produced by the formation of a vortex by means of an agitator 7, rotated in the kettle T. Oil-coated sodium may be added to the alloy, maintained at a temperature of 500-600‹ F., in the forms of small ingots, added successively adjacent the container wall. Prior to this treatment, the alloy may be treated with a drying agent, e.g. rosin or rosin and sulphur, and the dross removed. The alkali or alkaline earth dross is treated with high boiling oil stirred into the alloy and then burned by raising the temperature of the alloy : the coke-like substance produced is removed and, after cooling, a further wet dross is also removed : the alloy is then sprayed with water and treated with sulphur to remove any residual alkali or alkaline earth metal and any copper that may be present, the excess sulphur being removed by poling or steaming. Arsenic and zinc, if present, are removed along with the antimony. The Specification as open to inspection under Sect. 91 comprises also the subject-matter of Specification 469,519. This does not appear in the Specification as accepted. |
