Question

The process of removing lighter gangue particles by washing in a current of water is called

• A. levigation
• B. liquation
• C. leaching
• D. cupellation

Answer 1

The correct option is A

levigation

A

• Impurities like sand and soil particles existing in any ore are termed as gangue. Elimination of these impurities from ore to extract the metal is termed as enrichment of ore or concentration of ore.
• 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 obtained behind. This process is termed as levigation.

B

• The process in which a mixture of metals is separated from the ore on the basis of differences in melting point is termed as liquation.
• Since water current is not associated with liquation, this option is incorrect.

C

• The process in gangue or matrix particles are separated from the ore by reacting with a suitable chemical species is termed as leaching.
• In this process, the metal is converted into soluble salt by the chemical species while gangue particles remain insoluble. Since water current is not associated with leaching, this option is incorrect.

D

• The process in which noble metals like Silver $\left(\mathrm{Ag}\right)$ in the presence of high temperature and modulated conditions is termed as cupellation.
• Since water current is not associated with cupellation, this option is incorrect.

Hence, option A is correct. The process of removing lighter gangue particles by washing in a current of water is called levigation.