EV hammer impact crusher - FLline by blasting. This produces many oversize boulders which often contain a lot of clay and sand. The crusher therefore has to handle feed containing.hammer crushers line,how hammermills crush rocks - Mine EngineerImpact Crushers - Hammermills . Finally, the material is forced over a discharge grate by the hammers, where crushed finer particles drop through the . They are used most in crushing coal, but are also common in line operations.