19
MCQ (Multiple Correct Answer)
Common impurities present in bauxite are ............. .
A
CuO
B
ZnO
C
$\mathrm{Fe}_2 \mathrm{O}_3$
D
$\mathrm{SiO}_2$
20
MCQ (Multiple Correct Answer)
Which of the following ores are concentrated by froth floatation?
A
Haematite
B
Galena
C
Copper pyrites
D
Magnetite
21
MCQ (Multiple Correct Answer)
Which of the following reactions occur during calcination?
A
$\mathrm{CaCO}_3 \longrightarrow \mathrm{CaO}+\mathrm{CO}_2$
B
$2 \mathrm{FeS}_2+\frac{11}{2} \mathrm{O}_2 \longrightarrow \mathrm{Fe}_2 \mathrm{O}_3+4 \mathrm{SO}_2$
C
$\mathrm{Al}_2 \mathrm{O}_3 \cdot x \mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{Al}_2 \mathrm{O}_3+x \mathrm{H}_2 \mathrm{O}$
D
$\mathrm{ZnS}+\frac{3}{2} \mathrm{O}_2 \longrightarrow \mathrm{ZnO}+\mathrm{SO}_2$
22
MCQ (Multiple Correct Answer)
For the metallurgical process of which of the ores calcined ore can be reduced by carbon?
A
Haematite
B
Calamine
C
Iron pyrites
D
Sphalerite
23
MCQ (Multiple Correct Answer)
The main reactions occurring in blast furnace during extraction of iron from haematite ore ............. .
A
$\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{CO} \longrightarrow 2 \mathrm{Fe}+3 \mathrm{CO}_2$
B
$\mathrm{FeO}+\mathrm{SiO}_2 \longrightarrow \mathrm{FeSiO}_3$
C
$\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{C} \longrightarrow 2 \mathrm{Fe}+3 \mathrm{CO}$
D
$\mathrm{CaO}+\mathrm{SiO}_2 \longrightarrow \mathrm{CaSiO}_3$