Consider the following statements:
Statement I: Studies indicate that carbon dioxide emissions from cement industry account for more than 5% of global carbon emissions.
Statement II: Silica-bearing clay is mixed with limestone while manufacturing cement.
Statement III: Limestone is converted into lime during clinker production for cement manufacturing.
Which one of the following is correct in respect of the above statements?
A.Both Statement II and Statement III are correct and both of them explain Statement I
B.Both Statement II and Statement III are correct but only one of them explains Statement I✓ Correct
C.Only one of the Statements II and III is correct and that explains Statement I
D.Neither Statement II nor Statement III is correct
Explanation
Cement industry contributes approximately 7-8% of global CO2 emissions, so Statement I is correct. Statement II is correct — silica-bearing clay is indeed mixed with limestone in cement manufacturing. Statement III is also correct — during clinker production, limestone (CaCO3) is calcined to lime (CaO), releasing CO2. However, only Statement III explains the high carbon emissions of cement industry (calcination releases CO2 as a process emission). Mixing clay with limestone (Statement II) does not directly explain CO2 emissions. So both II and III are correct but only one explains Statement I.
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