crushers

Crushers are machines designed to reduce large rocks or other materials into smaller pieces by applying compressive, impact, or shear forces. They are widely used in mining, quarrying, construction, and recycling to transform run-of-mine ore, blasted rock, or demolished concrete into sizes suitable for processing or end use.

Crushers are categorized by their mechanism and the stage of reduction they perform. Primary crushers handle large feed and high throughput, including jaw crushers and gyratory crushers. Secondary and tertiary crushers, such as cone crushers, impact crushers, and roll crushers, produce finer material and prepare it for screening or milling.

Jaw crushers use a fixed jaw and a moving jaw to compress material within a crushing chamber as the movable jaw approaches the fixed one. Gyratory crushers have a conical head that gyrates within a surrounding concave surface, providing continuous crushing. Cone crushers crush by compressing material between a mantle and a concave bowl; closed-side setting determines product size. Impact crushers break material by high-velocity impact from hammers or bars, often generating more fines. Roll crushers pass material between rotating cylinders to achieve a controlled size reduction.

Performance is described by capacity, reduction ratio, feed size, product size, and energy consumption. Selection depends on material hardness, moisture, desired product, and plant configuration. Crushers require regular maintenance, including replacement of wear parts such as jaw plates, cones, mantles, concaves, blow bars, and hammers, plus lubrication and routine inspections for wear, alignment, and cracks. Safety measures and dust control are integral to operation.

In modern plants, crushers are part of multi-stage systems with screening and, in some cases, closed-loop recycling to separate oversize material for recapture or further crushing.