Which one of the following industries uses limestone as a raw material?

Category: Miscellaneous Indian Gk

Correct Answer: B) Cement

Exam Relevance: UPSC, SSC, Bank PO, CLAT

Difficulty: Easy

Explanations:

Raw Material Preparation: Limestone is quarried and crushed into small pieces. It is then mixed with other raw materials such as clay, sand, and iron ore. The proportions of these materials are carefully controlled to ensure the desired chemical composition of the final product.

Preheating: The raw material mixture is preheated in a kiln to a high temperature, which begins the chemical reactions that will form the cement clinker.

Calcination: The preheated mixture is then subjected to a high-temperature process called calcination, where the calcium carbonate in the limestone decomposes into calcium oxide (CaO) and carbon dioxide (CO₂). This step is crucial for the formation of the clinker, which is the intermediate product in cement production.

Clinker Formation: The clinker is formed through a series of chemical reactions that occur at high temperatures. The clinker is then cooled and ground into a fine powder, which is the final cement product.

Option Analysis:

Option A: Aluminium production primarily uses bauxite as a raw material, not limestone. The misconception might arise from the idea that all metals use similar raw materials.
Option B: Cement production uses limestone as a key raw material. Limestone is essential for the chemical reactions that occur during the production process, making this the correct answer.
Option C: Steel production primarily uses iron ore and coke, not limestone. The misconception might arise from the idea that all construction materials use similar raw materials.
Option D: Jute production involves the processing of jute plants, which are a type of fiber crop. Limestone is not a raw material used in jute production, leading to this being an incorrect option.

Mnemonic: Limestone is a key ingredient in cement, think "Lime" in "Cement".

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