ANS:B - coal

A widely used size reduction equipment for coal is the Bradford breaker. Bradford breaker is specifically designed to break coal into smaller sizes and remove rock and other debris from coal. It is commonly used in coal processing plants to prepare coal for further processing or transportation. The Bradford breaker operates by rotating at low speeds and breaking the coal by impact and crushing actions, separating the coal from impurities. "Coal" refers to a combustible black or brownish-black sedimentary rock that forms from organic matter over millions of years. It is primarily composed of carbon along with various other elements, including hydrogen, sulfur, oxygen, and nitrogen. Coal is formed from the remains of plants that lived and died in swamps and peat bogs, and through geological processes, these organic materials were buried, compacted, and transformed into coal under high pressure and heat over geological time scales.

Types of Coal

1. Anthracite:
   • This is the highest quality coal, known for its high carbon content and low moisture and impurities. It burns cleanly and efficiently, making it ideal for heating and energy generation.
2. Bituminous Coal:
   • Bituminous coal is the most abundant type of coal. It has a high heat and energy content, making it suitable for electricity generation and industrial use. It varies in carbon content and can range from soft to hard varieties.
3. Sub-bituminous Coal:
   • Sub-bituminous coal has a lower carbon content than bituminous coal and higher moisture content. It is mainly used for electricity generation.
4. Lignite (Brown Coal):
   • Lignite is the lowest quality and youngest form of coal. It has high moisture content and low carbon content. It is used primarily for electricity generation in power plants located near the coal mines due to its low energy content.

Uses of Coal

1. Electricity Generation: Coal is burned in power plants to produce electricity. It remains a significant source of electricity globally, particularly in countries with abundant coal reserves.
2. Industrial Use: Coal is used in various industries such as steel production, cement manufacturing, and chemical industries.
3. Heating: Historically, coal has been used for residential and commercial heating purposes, although its use in this regard has declined in many parts of the world due to environmental concerns.
4. Other Uses: Coal tar and coke (derived from coal) are used in the manufacture of various products such as chemicals, dyes, and synthetic materials.

Environmental Impact

• Burning coal releases carbon dioxide (CO2) and other pollutants such as sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter. These emissions contribute to air pollution and are associated with environmental and health concerns, including climate change.
• Efforts are underway globally to reduce the environmental impact of coal use through technologies like clean coal technologies (e.g., carbon capture and storage) and transitioning to cleaner energy sources.

In summary, coal is a fossil fuel that has been a crucial energy source for centuries, playing a significant role in industrialization and electricity generation. However, its environmental impact and contribution to climate change have spurred efforts to develop cleaner alternatives and technologies.