Air Core Drilling
Air Core is an inexpensive method of exploration drilling that can used when safe removal of sample material is the top priority. It is preferred over RAB (Percussion rotary air blast drilling) drilling and compared with the diamond drilling method, air core drilling is much faster and more cost-effective.
Air core drilling relies on compressed air to flush cutting samples out of your drill holes. This enables safer collection of samples without added damage to the area. This therefore results in a more effective analysis sample. In first pass exploration drill programs, air core provides precise samples.
Reverse Circulation Drilling
RC drilling is similar to air core drilling, in that the drill cuttings are returned to the surface inside the rods. RC drilling is not only a quick cheap first pass exploration hole option, it achieves better penetration than air core drilling. It is also far cheaper than diamond coring. Consequently, this make RC drilling the ideal method for most mineral exploration work.
Reverse circulation is achieved by blowing air down the rods. The differential pressure creates air lift of the cuttings up the inner tube inside each rod. It reaches the bell at the top of the hole, then moves through a sample hose which is attached to the top of the cyclone. The drill cuttings travel around the inside of the cyclone before falling through an opening at the bottom. The cuttings are then collected in 1m intervals into a sample bag.