ANS:B - hammer crusher

Run of mine (ROM) coal is typically crushed by a hammer crusher for use in domestic ovens. Here’s why:

1. Hammer Crusher:
   • A hammer crusher (also known as a hammer mill) is a type of crusher that uses mechanical impact to break coal and other materials into smaller particles.
   • In a hammer crusher, the coal is crushed between the rotating hammer heads and anvils.
   • Hammer crushers are suitable for crushing brittle and abrasive materials, such as coal, limestone, gypsum, and other similar minerals.
2. Suitability for ROM Coal:
   • ROM coal refers to coal directly from the mine that has not been processed or sized further.
   • Hammer crushers are effective for crushing ROM coal into smaller sizes suitable for domestic use, such as in coal-fired ovens or for household heating purposes.
   • The hammer crusher’s design allows it to handle varying sizes of feed material and produce uniform output sizes suitable for combustion.
3. Other Equipment Mentioned:
   • Jaw Crusher: While also capable of crushing coal, jaw crushers are generally used for primary crushing in larger mining operations and industrial applications rather than for domestic purposes.
   • Ball Mill and Tube Mill: These are not typically used for crushing coal into smaller sizes suitable for domestic ovens. Ball mills and tube mills are used for grinding and pulverizing materials rather than crushing them.