By Greg Fenrick

The type of drill bit used in the mining industry is dependent on the type of drilling being done. There are three types of drilling:

Percussion drilling – uses steel rock bits of various designs to break up the rock while drilling. Drill hole diameter can vary greatly, but is commonly about 7 centimetres. The bit is rotated and the hammer action of the drill is transmitted through a string of drill rods, which have a relatively small center hole through which compressed air (in the case of dry ground), or water (in the case of wet ground), is passed.

Reverse circulation – These drills produce rock cuttings at the bit which are blown up the hole by compressed air. The cuttings are separated from the air or water by a cyclone or cyclone-splitter combination.

Diamond drilling – using large machines is the preferred method of delineating mineralization. Diamond drills produce core which ranges from approximately one to two inches in diameter. Drill core is usually split in half by either a core splitter which produces samples of uneven size or by a diamond saw which produces halves of equal size. Half of the core is saved for geological examination and half is bagged and sent to the laboratory for analysis. Drill core is usually analyzed by assay methods.

Rotary Drill Bit Manufacturers

For a list of drill bit manufacturers and distributors, check InfoMine Buyer’s Guide

Related News & Articles: