Continuous Excavator for Surface Coal Mining

A forward- rotating bucket wheel excavator designed to continuously fragment and load unshot coal has been tested in an open pit mine. In principle, the excavating wheels rotate faster than required for rolling contact with the surface so the buckets excavate, carry away material, and provide a tractive effort to aid in pulling the vehicle forward. Production rates of over 1,080 tons per hour (1,000 cubic yards per hour) have been achieved utilizing 510 hp, verifying projected fragmenting and loading cost savings of 80 percent over conventional methods. Furthermore, due to the uniformly small size of the coal excavated, additional savings in preparation plant costs are possible.