Improvements in and relating to the treatment of metals or alloys containing tin

摘要

In a process for treating tin-bearing metal such as tin-lead or tin-antimonial lead, a molten bath of such metal is treated with an oxidizing agent in the presence of lead chloride, the tin being oxidized and concentrated in the slag. The oxidizing agent used may be air which is introduced through a pipe into the bath or a solid substance such as litharge nitre or lead oxide-lead sulphate. The lead chloride may be used alone or mixed with other salts such as sodium chloride. The lead chloride is recovered from the slag either by fuming or by leaching the slag with a not concentrated brine solution and recovering it from the leach solution.ALSO:In a process for treating tin bearing metal such as tin-lead or tin-antimonal lead, a molten bath of such metal is treated with an oxidizing agent in the presence of lead chloride, the tin being oxidized and concentrated in the slag. The oxidizing agent used may be air which is introduced through a pipe into the bath or a solid substance such as litharge, nitre or lead oxide-lead sulphate. The lead chloride may be used alone or mixed with other salts such as sodium chloride. The lead chloride is recovered from the slag either by fuming or by leaching the slag with a hot concentrated brine solution and recovering it from the leach solution. The residue containing the tin may be reduced with coke to produce metal of high tin content. In an example, an alloy containing 72,2 per cent of lead, 4 of tin, 22,1 of antimony, 0,28 of arsenic and 0,89 of copper was treated with an eutectic mixture of lead and sodium chlorides and then litharge added, the bath being stirred for an hour at 950-1000 DEG F. The tin slag was skimmed off and the process repeated. The final metal container 76,1 of lead, 0,1 of tin, 21,9 of antimony, 0,73 of arsenic, and 0,62 of copper.