Which of the following statements is incorrect ?

Options

A. Cassiterite is an oxide ore of tin
B. Tin metal is obtained by the carbon reduction of black tin
(purified ore of tin)
C. In the extraction of lead from galena, the roasting and self-
reduction are carried out in the same furnance at different temperature.
D. Reducing agent of haematite in blast furnace is coke in upper
part and CO in lower part of furnace

Answer

D

Explanation

(A)Cassiterite contains iron and manganese tungstate, called as Wol-framite.They have magnetic properties.
(B)Purified ore that contains 70% `SnO_2` is called black tin.
`SnO_2+2CtoSn+2CO` (carbon reduction)
(C )Roasting is done at moderater temperature in presence of air in reverberatory furnace.Then air supply is stopped and temperature is increased to melt the mass when self-reduction takes place.
(D)At 500-800 K(lower temperature range in the upper part of blast furnace)
`3Fe_2O_3+COto2Fe_3O_4+CO_2`
`Fe_3O_4+COto3Fe+4CO_2`
`Fe_2O_3+CO to 2FeO+CO_2`
At 900-1500 K (higher temperature range in the lower part of blast furnace):
`C+CO_2to2CO, FeO+COtoFe+CO_2`