Direct Answer: Toothed roller crushers process raw coal, cleaned coal, and gangue using low-speed shearing and extrusion mechanics. They significantly outperform high-speed hammer and impact crushers by minimizing over-crushing, preserving lump coal, lowering dust emissions, and preventing wet material blockages.

Advantage	Technical Feature	Coal Processing Benefit
Preserves Lump Coal	Low-speed shearing and extrusion	Prevents excessive fine powder generation and maximizes lump coal yield and market value.
Environmental Dust Control	Reduced rotational velocity (vs. impact crushers)	Dramatically reduces airborne dust emissions to meet strict plant environmental standards.
Wet Feed Handling	Specialized wolf-tooth roller profile	Firmly grips raw and wet coal to prevent material slippage, bridging, and chamber blockages.
Tramp Metal / Gangue Relief	Automated hydraulic overload system	Automatically retracts rollers when uncrushable tramp iron or hard gangue enters, protecting tooth wear elements.
Low Maintenance Overhead	Simple structural design with high-wear alloys	Features fewer wear parts, extended tooth service life, and lower overall energy consumption.

Summary: By delivering low over-grinding, effective wet-feed grip, low dust, and automatic overload protection, toothed roller crushers provide a durable, energy-efficient solution for modern coal preparation operations.