Question

Which of the following statements is/are correct about slag?

• A. slag is lighter than molten metal.
• B. calcium silicate, $CaSi{O}_3$ is obtained in slag formation zone in the extraction of iron from haematite ore.
• C. in blast furnace/Bessemer converter, the upper layer of molten liquid (i.e. molten metal) is of slag.
• D. slag of fusible matter.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A slag is lighter than molten metal.
B calcium silicate, $CaSi{O}_3$ is obtained in slag formation zone in the extraction of iron from haematite ore.
C in blast furnace/Bessemer converter, the upper layer of molten liquid (i.e. molten metal) is of slag.
D slag of fusible matter.

(A) Slag is lighter than molten metal is a true statement.
(B) $CaC{O}_3\stackrel{\Delta }{\to }CaO+C{O}_2$
$CaO+Si{O}_2\to CaSi{O}_3$.
These reactions take place in slag formation zone at temperature $\approx 1275K$.
(C) As slag is lighter than molten metal so in blast furnace/Bessemer converter, the upper layer of molten liquid (i.e. molten metal) is of slag.
(D) Infusible matter + Flux = Fusible matter (slag).