Why is there a concern about copper smelting plants?
1. They may release lethal quantities of carbon monoxide into environment.
2. The copper slag can cause the leaching of some heavy metals into environment.
3. They may release sulphur dioxide as a pollutant.
Select the correct answer using the code given below:
Explanation
Statement 1 is incorrect: In primary copper pyrometallurgy, carbon acts as a reducing agent yielding carbon dioxide (CO₂), or off-gases are captured. Copper smelters do not release lethal quantities of carbon monoxide (CO) into the surrounding open atmosphere under normal operational standards.
Statement 2 is correct: Copper slag generated during extraction contains residual traces of toxic heavy metals such as arsenic, lead, cadmium, and nickel. If dumped unlined, rainwater causes the leaching of heavy metals into local groundwater reserves and soil systems.
Statement 3 is correct: Copper is extracted primarily from copper sulfide ores (such as chalcopyrite, CuFeS₂). The roasting and smelting processes generate substantial volumes of sulphur dioxide (SO₂), a hazardous gas contributing directly to atmospheric pollution and acid rain.
Therefore, statements 2 and 3 are correct — Option B.