Mechanical-Metallurgical Problems Associated with Mine Drilling Operations
Satisfactory mine drilling operations depend on the good performance of the drilling machine, and of what may be called the drill set, i.e., the following four elements: bit, attachment, drill rod, and shank end. The field performances of these four elements in the drill set are analysed and their service lives are compared. The most .common causes of service failure are reviewed and possibilities of increasing service life are discussed. The laboratory methods now employed for the simulated service testing of .. tungsten carbj.de bits, conical push-on and threaded .types of attachments, drill rods, and shank ends are described, and some results are discussed. The objectives of the research programme now being carried out on the above mentioned elements are outlined. A number of mines in British Columbia, northern Ontario, and northern Quebec have been visited, and, with the co-operation of the C.I.M. Branches in these areas, meetings with representatives of the mining and steel industries concerned :have been held. In this paper, the mechanical- metallurgical problems most frequently encountered and discussed during these visits and meetings are described and analysed.
Bits, Drill, Drill Stee, fatigue, shot peening, steel, tungsten carbide, Drilling, Drills, Failure, failures, Performance, steel, Steels