VACUUM REFINING ANTIMONY MELTS TO REMOVE LEAD

Experiments were carried out over temperatures of 873 to 1073 k and re sidual gas pressure ranges of 6 to 150 Pa, respectively During vacuum refining, lead from antimony melts was left behind in tile destilland and antimony was evaporated in the distillate. The experimental result s showed that lead content in the refined antimony could be lowered fr om 0.88 % to 0.010-0.036 % ender the following experimental conditions : temperatures of 923 to 973 K, vacuum treatment time of 20 to 30 minu tes and residual gaspressure of lower than 150 Pa. If is concluded tha t fine removal of lead impurity from antimony melts by vacuum refining is not a problem. Moreover, vacuum treatment eliminates much of the a ir pollution and metal losses associated with other conventional refin ing methods.