Question

Gravity separation method is based upon

• A. preferential washing of ore and gangue particles.
• B. difference in the densities of ore particles and impurities.
• C. difference in the chemical property of ore particles and impurities.
• D. none of these

Answer 1

The correct option is B

difference in the densities of ore particles and impurities.

The explanation for the correct option B:

• The mineral that contains either metal or metal compounds in enough quantity that can be extracted easily and profitability is termed as ore.
• Impurities like sand and soil particles existing in any ore are termed as gangue or matrix. Elimination of these impurities from ore is termed as enrichment of ore or concentration of ore.
• Gravity separation is one of the methods to eliminate the unwanted substances from ore on the basis of their densities. It is one of the processes utilized to concentrate the ore.
• Generally, ores are heavier while gangue or matrix are lighter.
• When gangue or matrix and ore particles are treated with a stream of water moving in the opposite direction then gangue particles are eliminated with water and ore particles are left behind.

The explanation for the incorrect option:

A

• Since ore and gangue particles are not washed separately but together, the given option is incorrect.

C

• Since no chemical reagent is involved in gravity separation, the chemical nature of ore and gangue particles is not considered. Hence, this option is incorrect.

D

• Since the correct option is B, this option is incorrect.

Final Answer: Hence, option B is correct. Gravity separation method is based upon differences in the densities of ore particles and impurities.