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JEE Main levelSingle correct optionDifficulty 2 of 3mt081

In copper extraction, silica is added during smelting of roasted pyrites to remove iron(II) oxide. The flux, its nature and the slag formed are

A $CaO$ , acidic flux, $FeSiO X_{3}$
B $CaO$ , basic flux, $CaSiO X_{3}$
C $SiO X_{2}$ , basic flux, $FeSiO X_{3}$
D $SiO X_{2}$ , acidic flux, $FeSiO X_{3}$

Answer: D

FeO

is a basic gangue, so an acidic flux, silica, is used:

FeO + SiO X_{2} FeSiO X_{3}

. The iron(II) silicate floats as slag over the copper matte.

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