Among the following statements, the inocorrect one is :
A. cassiterite ore of tin contains the impurities of Wol-framite which are separted by electromagnetic separtor.
B. tin metal is obtained by the carbone reduction of black tin.
C. in the extraction of lead from galena, th roasting and self-reduction are carried out in the same furnance at different temperature.
D. The copper obtained from Bessomer converter is called as blister copper.
