Steel slag can be the material for which of the following ? 1. Construction of base road 2. Improvement of agricultural soil 3. Production of cement Select the correct answer using the code given below :
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• Steel slag, the by-product of steel-making, is increasingly reused rather than dumped.
• Processed slag aggregates are used in road base and sub-base layers (1); India's first steel-slag road was built at Hazira, Surat in 2022 by CRRI and AMNS.
• Slag is rich in calcium, silicon and micronutrients and is used as a soil conditioner and liming agent to improve acidic agricultural soils (2).
• Granulated blast-furnace/steel slag is blended into cement (Portland slag cement) (3).
• Hence 1, 2 and 3, option (d).
Why the other options are wrong
- (a) 1 and 2 only
- Slag is also used in cement production.
- (b) 2 and 3 only
- Slag is also used in road base construction.
- (c) 1 and 3 only
- Slag also improves agricultural soil.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2020, held on 4 October 2020. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.