The methods NOT involved in concentration of ore are
(A) Liquation
(B) Leaching
(C) Electrolysis
(D) Hydraulic washing
(E) Froth floatation
Choose the correct answer from the options given below:

Concentration of ore involves separating the ore from gangue (impurities). The common methods include:

- Hydraulic washing (gravity separation) ✔

- Froth flotation ✔

- Leaching (chemical method of concentration) ✔

- Magnetic separation ✔

Methods NOT used for concentration of ore:

(A) Liquation: This is a refining technique (used to purify metals with low melting points like tin, bismuth, lead). It is NOT a concentration method. ✘

(C) Electrolysis: This is a refining technique (electrolytic refining). It is NOT a concentration method. ✘

Therefore, the methods NOT involved in concentration of ore are A and C only.