Question

Gravity separation process is used for the concentration of ______.
A) Calamine
B) Hematite
C) Chalcopyrites
D) Bauxite

Answer 1

Hint:We know that the gravity separation process is used in metallurgy. The gravity separation process is also known as hydraulic method or levigation. The gravity separation process is based on the differences in the gravity of the ore and the gangue particles that are present in the ore.

 Complete step by step answer:
We know that the gravity separation process is used for the concentration of ore. The gravity separation process is based on the differences in the gravity of the ore and the gangue particles that are present in the ore.
-The ores of metals are generally heavier than the gangue particles. The gravity separation process uses this property for the concentration of ore.
-Hematite ore is concentrated using the gravity separation process. Hematite is a common ore of iron oxide. The chemical formula for hematite is ${\text{F}}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{3}}}$. Hematite ore is black or silver-grey in colour.
-The particles of hematite ore are first crushed to fine powder and then concentrated using the gravity separation process.
-During the gravity separation process, the powdered hematite ore is washed by an upward stream of running water. The lighter particles of gangue get washed away with water. The heavier ore particles are left behind.
Thus, the gravity separation process is used for the concentration of hematite.

Thus, the correct option is (B) hematite.

Note: Calamine is an ore of zinc, chalcopyrite is an ore of copper and bauxite is an ore of aluminium. The gravity separation process is used for the concentration of heavier ores of iron, lead or tin. Thus, these ores cannot be concentrated using the gravity separation process.