Underground hard rock mining refers to various underground mining techniques used to excavate hard minerals, usually those containing metals such as ore containing gold, silver, iron, copper, zinc, nickel, tin and lead, but also involves using the same techniques for excavating ores of gems such as diamonds.
General, using jaw crusher to crush rock first, then using cone crusher to crush rock secondly. Grinding mill machine grind the crushed rock to powder. The final step is to separate glod from the rock. Jaw crushers is the most common gold mining equipment, and is designed to take big rocks and partially crush them down to a mrock workable .