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.

Copper smelting involves extracting copper from its ore using heat and a reducing agent.

Smelting can release air pollutants, including sulfur dioxide (SO2), due to the pyro-metallurgical processes involved.

Copper slag, a byproduct of smelting, can contain heavy metals like cobalt, zinc, arsenic, lead, cadmium, and barium. These metals can leach into the environment under natural weathering conditions, polluting soils, surface water, and groundwater.

While smelting can produce carbon monoxide (CO), lethal quantities are not a typical direct emission as stated in statement 1. CO is produced from secondary smelting roasting operations and fuel combustion and results in smog.

Statement 2 is correct: Copper slag can leach heavy metals. Statement 3 is correct: Smelting releases sulfur dioxide. Statement 1 is not correct: Lethal quantities of Carbon monoxide is not produced directly during smelting.

Hence, option b is the correct answer.