Question

Haematite ore is concentrated by
A. Gravity separation method
B. froth floatation method
C. Amalgamation
D. Hand picking

Answer 1

Hint: Haematite ore is one of the important ore of Iron. The question is about concentration of ore. Ore is a naturally occurring material from which we can extract a mineral. Along with the mineral,many other impurities are also associated with it, which should be removed. The process where these impurities are removed in order to get pure minerals is called concentration.

Complete answer:
There are different methods of concentration that include leaching,froth flotation,gravity separation etc. Let us discuss one after the other. Gravity separation method is used when there is huge difference in the specific gravities of ore and associated impurities. Hence used for concentrating heavy oxide ore. Froth floatation is mainly used for sulphide minerals,so you can eliminate this option. Amalgamation is done using mercury where you combine two or more entities into a new one. Hand picking is done where the impurities can be seen with the naked eye such as separation stones from rice. Haematite ore is a combination of Iron and oxide and also it is a heavy mineral oxide. Hence, gravity separation is used.

$\therefore $ Haematite ore is concentrated by “Gravity separation method”. The correct option is (A).

Note:
Carbonate ores can also be concentrated by gravity separation methods. It is also called hydraulic washing. It is of two types which include Jigging and Tabling. In jigging, lighter portions of ore are removed using a stream of air or water and in tabling, a mixture of ore and water is passed over an inclined vibrating table,hence the name tabling.