Which of the following are some important pollutants released by steel industry in India?
- 1.Oxides of sulphur
- 2.Oxides of nitrogen
- 3.Carbon monoxide
- 4.Carbon dioxide
Select the correct answer using the code given below.
Answer & explanation
Answer: (d) 1, 2, 3 and 4
All four gases are important steel-plant pollutants, so the answer is (d). Steelmaking burns large amounts of coal and coke in sinter plants, coke ovens and blast furnaces. These operations release sulphur oxides, nitrogen oxides, carbon monoxide and carbon dioxide.
- ✓ 1. Sulphur dioxide comes mainly from burning the sulphur compounds in the sinter feed, which enter chiefly through the coke breeze.
- ✓ 2. Nitrogen oxides are emitted mainly from sintering and heating operations, at about 1.2 kg per tonne of steel.
- ✓ 3. Carbon monoxide is listed among the air emissions of iron and steel plants. The gases produced in blast furnaces and coke ovens contain carbon monoxide.
- ✓ 4. Steel plants are energy intensive and can emit significant amounts of carbon dioxide, because they burn coal and coke to heat and reduce iron ore.
Remember · Coal and coke combustion in sinter plants, coke ovens and blast furnaces makes steel plants emitters of SOx, NOx, CO and CO2, so all four are correct.
Sources
- IFC/World Bank Group EHS Guidelines for Integrated Steel Mills (2007) ↗ · reference work “Sulfur dioxide (SO2) emissions are mainly associated with combustion of sulfur compounds in the sinter feed, primarily introduced through the coke breeze … Steel manufacturing facilities are energy intensive and may emit significant amounts of carbon dioxide (CO2).”
- World Bank/IFC Pollution Prevention and Abatement Handbook: Iron and Steel Manufacturing ↗ · reference work “nitrogen oxides (NOx), mainly from sintering and heating (1.2 kg/t of steel); hydrocarbons; carbon monoxide; in some cases dioxins (mostly from sintering op- erations); and hydrogen fluoride.”
Question: UPSC Civil Services (Preliminary) 2014, General Studies Paper I. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·
