JEE Advanced 2016 · Paper 2 · Chemistry Q28

ChemistryMultiple correct+4 / -2Question 28 of 54

Extraction of copper from copper pyrite $(\ce{CuFeS2})$ involves

crushing followed by concentration of the ore by froth-flotation

removal of iron as slag

self-reduction step to produce 'blister copper' following evolution of

\ce{SO2}

refining of 'blister copper' by carbon reduction

Answer and worked solution

Official answer: A, B, C

(A) The sulphide ore is crushed and concentrated by froth flotation. True.
(B) After roasting, FeO is removed with silica as $\ce{FeSiO3}$ slag. True.
(C) In the Bessemer converter, $\ce{Cu2S}$ and $\ce{Cu2O}$ react, $\ce{2Cu2O + Cu2S -> 6Cu + SO2}$ (self-reduction), and escaping SO₂ gives "blister copper". True.
(D) Blister copper is refined by poling and electrolysis, not by carbon reduction. False.

(A), (B), (C)

JEE Advanced 2016 · Paper 2, Chemistry question 28