Air-core drilling

Air core drilling is a well-known and widely used method when it comes to soft rock and soil formations that don’t need heavy machinery in order to drill through to the desired depth. The standout feature of this drilling method is that it makes use of three blades that cut into the earth. The blades are attached to a hollow tube. This hollow tube takes up the materials which are loosened and is able to separate the samples from the materials. The samples are thus not damaged and can be easily analysed. This is one of the features that makes this method of exploratory drilling stand out from percussion rotary air blast drilling, which can sometimes cause damage to the samples that are being extracted. In order for the samples to be effectively removed from the created hole, air is compressed into the hole and the materials are blasted up and into the hollow tube.

Air core drilling has been known to reach depths of up to 300 metres which is great for mining companies looking for minerals that are well below the surface. When it comes to exploratory drilling the last thing you want is for your samples to be contaminated by other materials. Air core drilling ensures that this doesn’t happen. As the samples are blown right up into the hollow tube of the machine, the chances of the samples being contaminated are highly unlikely.

Unlike other exploratory drilling methods, air core drilling can take a bit longer as the process is more accurate and the process might also cost a bit more than percussion rotary air blast drilling. With air core drilling samples are protected from damage, so while percussion rotary air blast drilling may be quicker the samples collected could be damaged in the process. Air core drilling minimises damage and it ensures that the samples collected are as complete as possible.

What are the advantages and disadvantages of air core drilling?

Advantages

  1. The samples collected are a more accurate representation of what is below the surface and this exploratory mining process often yields large pieces of samples which are easier to analyse and to get an accurate representation of than the smaller pieces.
  2. Holes do not need to be cased.
  3. Great depths can be reached.
  4. When the machine needs to be moved between areas it can be done quickly and easily.

Disadvantages

  1. Air core drilling can take longer than other methods.
  2. Air core drilling can cost more.