By it is obvious nature, mineral exploration involves drilling to discover what is below the surface. While there are a lot of advantages of drilling technologies especially in the petroleum, geothermal sector and mineral sector for decades. Generally, mineral exploration includes percussion, rotary drilling, diamond drilling, etc. to produce, manufacture rock chips and samples of the core.
Drilling is a procedure to attain complete information and analysis about rocks types, minerals, rock texture and the relationship between rock layers and surface depth. Drilling is used to surface and in-depth areas to check detailed aspects based on geographical, geological and geochemical techniques. Not to forget, drilling is one of the most crucial, and can be the most costly, of all mineral exploration procedures.
There are three major techniques that can be used for mineral exploration. The selection of methods is basically based on types of equipment, cost, rock types, the environmental condition, and knowledge of those involved.
Types of Drilling Techniques one can use in mineral exploration
There are a large number of different drilling techniques out of which the important ones are described here. The below mentioned techniques are most commonly used drilling techniques in mineral exploration.
Rotary Air Blasting
Rotary Air Blasting is both affordable and the easiest technique for mineral exploration. In these types of techniques, you need minimum skills to acquire this equipment during construction. This is a conventional drilling method, so obvious, it has its own drawbacks. Constructors and engineers generally don’t prefer this technique or mining or mineral exploration, as it is unable to represent expected samples of core, it has been replaced by the diamond drilling method.
Rotary air blasting is a type of rotary drilling, where a blade bit or roller-cone bit is used to break or cut the rock with the simplest bit mounted at the end of the rotator (Drill stem). Once the bit breaks and removes the rock utilising either acrushing action or chipping-scraping action in order to supply it to the bit. Compression air is produced by the machine to cool the bit and flush the cutting back to the floor.
Reverse Circulation Drilling
Reverse Circulation Drilling or RC drilling is an exclusive, & costly than rotary air blasting method. This technique requires proper skills and knowledge to drive this method. However, RC drilling gives a greater sample accuracy to offer the best and appropriate form of mining exploration. It is a common drilling technique used for mineral exploration, especially in Australia & South America.
RC drilling is a form of percussion drilling which is used to crack rocks and slabs, & by which rocks are made to fail through the usage of a piston mounted over the drill stem. It delivers rapid influences to the drill stem by transferring energy to the drill bit. Drill bits feed high force when it comes into the contact of rock or surface. Compressed air is used to reduce or flush the drill cutting from the hole, and help the bit to advance the hole depth effectively.
Diamond Core Drilling
With RC drilling, completing every project demand and expectation becomes substantially impossible due to the high cost and potential requirements of high skilled equipment. Diamond core drilling needs less equipment compared to RC drilling. With diamond core drilling, a pipe is connected with diamond drilling bits to use and drill rock layers. The diamond drilling method helps to reach the center layers of rock known as a core, then it is recovered as a sample. This core is used to analyze and determine the composition, mineral fabrics and relationship between rock layers. Diamond core drilling requires a high rpm of 300-1500 to penetrate the rock and analyze the rock composition efficiently.
There are two ways to remove the sample from a diamond coring bit. This method is based on a conventional coring tactic to draw up a complete core barrel to the surface after pulling out the drill rods of the hole. This is an efficient method that gives authenticated results and project outcomes. Wire-line coring lifts the inner-tube to the surface and lower part to the barrel with the help of drill rods and winch.
Conclusion
For Mineral Exploration, different drilling techniques can be used to evaluate and determine facts and information about rock types, layers and mineral fabrics. There are a lot of aspects about drilling methods that should be weighed when to decide, use, etc. The rotary air blasting method is often utilized for site investigation, sampling and to obtain a fresh rock sample. Diamond Core Drilling Technique is the best drilling method out of the aforementioned points. It is the best-consolidated formation. Compared to rotary drills, diamond core drills are small and sharp in size and well-suited for remote sites and bad rock exploration processes. The aforementioned overview of methods provides starting points for mining companies to object and determine how to proceed with the mining exploration procedure.
