Some metals like gold, silver, platinum etc are found in the free state in the earth’s crust because they are least reactive. Most metals are found as oxides, carbonates, sulphides, halides etc.
Minerals :- are elements or compounds which occur naturally inside the earth’s crust.
Ore :- is a mineral from which metals can be extracted profitably.
Gangue :- is the impurities present in the ore like rock particles, sand particles, clay particles etc.
Metals are extracted from their ores in three main steps. They are :-
i) Concentration of the ore (Enrichment of the ore).
ii) Reduction to the metal.
iii) Refining (Purification of the metal).
Concentration of the ore :-
is the removal of gangue (impurities) from the ore by different methods.