Question

Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores of iron is ______

Answer 1

The principal ores of iron are :
Siderite, Haematite, Magnetite, Limonite.

$\begin{array}{ccc}\text{Bauxite}& -& {\text{AlO}}_{\text{x}}\left(\text{OH}{)}_{3-2\text{x}}\right(\text{where 0 < x<1})\\ ✓\text{Siderite}& -& {\text{FeCO}}_3\\ \text{Cuprite}& -& {\text{Cu}}_2\text{O}\\ \text{Calamine}& -& {\text{ZnCO}}_3\\ ✓\text{Haematite}& -& {\text{Fe}}_2{\text{O}}_3\\ \text{Kaolinite}& -& {\text{Al}}_2(\text{OH}{)}_4{\text{Si}}_2{\text{O}}_5\\ \text{Malachite}& -& {\text{CuCO}}_3\cdot \text{Cu}(\text{OH}{)}_2\\ ✓\text{Magnetite}& -& {\text{Fe}}_3{\text{O}}_4\\ \text{Sphalerite}& -& \text{ZnS}\\ ✓\text{Limonite}& -& {\text{Fe}}_2{\text{O}}_3\cdot 3{\text{H}}_2\text{O}\\ \text{Cryolite}& -& {\text{Na}}_3{\text{AlF}}_6\end{array}$