Which Crusher Is Suitable for Your Hard Rock? | Fote
2021-10-28 · Protodyakonov rock classification is based on Protodyakonov scale to classify the hard rock and soft rock. f = 15-20: Extremely strong rocks, such as very strong granite, limestone, quartzite, etc. f = 8-10: Strong rocks, such as strong granite, strong sandstone, etc. f = 4-6: Medium strength rocks, such as common sandstone, iron ore, etc. f = 0.8-3: Soft rocks, such