Activated coal gangue is a byproduct derived from the coal mining and washing process, which traditionally posed a significant environmental burden due to its disposal issues. However, recent technological advancements have transformed coal gangue into a valuable secondary raw material for the construction industry. Activated coal gangue undergoes a physical or chemical activation process, enhancing its pozzolanic properties, making it suitable for use in cement and concrete production. This activation typically involves thermal treatment or chemical alterations that increase its reactivity and bonding capabilities with cementitious materials.