Question

Removal of impurities from ore is known as:
A. Crushing
B. Concentration of ore
C. Washing
D. Grinding

Answer 1

To know the process of removing impurities from ore, we should go through the meaning of every given option. And we will also discuss the various methods of removing impurities from the ore that is based on the properties of the ore.

Complete step-by-step answer: The removal of gangue or the impurities present in the ore is known as concentration of ore.
There are numerous methods of concentration and the methods are chosen based on the properties of the ore:
$*$ Hydraulic Washing: This technique concentrates the ore by going it through an upward stream of water whereby all the lighter particles of impurities are isolated or separated from the heavier metal ore. This is a kind of gravity partition.
$*$ Magnetic Separation: This includes the utilization of magnetic properties of either the ore or the impurities to separate them. The ore is first ground to fine pieces and afterward passed on a transport line ignoring a magnetic roller. The magnetic ore remaining parts on the belt and the gangue falls off the belt.
$*$ Froth Flotation Method: This technique is mainly used to eliminate gangue from sulphide ores. The metal is powdered and a suspension is made in water. To this are added, Collectors and Froth Stabilizers. Authorities (pine oils, unsaturated fats and so forth) increment the non-wettability of the metal piece of the ore and permits it to frame a foam. Foam Stabilizers (cresols, aniline and so forth) support the foam. The oil wets the metal and the water wets the gangue. Oars and air continually work up the suspension to make the foam. This foamy metal is skimmed off the top and dried, to recover the metal.
$*$ Leaching: Filtering is utilized when the metal is dissolvable in a dissolvable. The powdered metal is broken up in a substance, ordinarily a solid arrangement of $NaOH$ . The compound arrangement breaks down the metal in the metal and it tends to be removed and isolated from the gangue by separating the substance arrangement. Extraction of the Aluminium metal from Bauxite metal is finished utilizing this cycle.

Hence, the correct option is (B.) Concentration of ore.

Note: Crushing and grinding are the two essential comminution measures. squashing) might be directed on dry or slurried material. In comminution, the size decrease of particles is finished by three sorts of powers: pressure, effect and steady loss, predominant power in grinding.