The answer might not be popular with competing salesmen of small crushers but it is our expert opinion that small crushers be used to reduce concrete and soft rock and that the concrete be reduced down to a size that the crusher can handle. Please remember that small crushers can range from 7,500 pounds up to 29,000 pound machines, so the feed size will increase as the size of the jaw increases.
A better answer to this question might be to say what materials we do NOT recommend a small jaw crusher for.
Asphalt: Regardless of the machine’s size, we do not recommend crushing asphalt with a jaw crusher. Jaw crushers have a tendency to compress the asphalt rather than fragmenting it resulting in a gradual buildup of pressure that could cause catastrophic damage.
We hear all of the time from commissioned salesmen: “Run the jaw backwards and you can use a jaw on asphalt”. Doing so might spare some of the damage, but it also decreases production tremendously. There are however, two exceptions for crushing asphalt with a jaw crusher.
Hard Rock: If a salesman says their small crusher can crush hard rock, they might not be lying. The question you should ask is “For How Long?” We frequently explain to customers that we will not sell our small crushers for applications to crush hard rock. The crushers are simply not heavy duty enough to handle it. We get numerous calls from customers saying that “X” brand claims they can crush granite, river rock or anything of the sort. Our response is, Buy it and make sure you get in writing that these materials are acceptable and that the warranty will apply in these cases. Be smart!
GrinderCrusherScreen’s policy is to sell you the machine you need, not just the machine we have. There are no small track mounted crushers on the market now that should be crushing 100% asphalt or hard rock.
If you need to crush asphalt, hard rock, or any other material, you can learn more with our article, “What Type of Crusher is Best for Recycling”, or by talking to our seasoned professionals that can recommend what’s best for your application.