Exploration Drilling
Exploring Minerals in Africa
Africa’s mineral and oil wealth is enormous. The continent has 30 percent of the world’s minerals and proven oil reserves equivalent to 10 percent of global stock. Yet, much of the natural wealth of the continent remains unexplored. Properly harnessed and managed, Africa’s mineral wealth could be transformational for the continent’s future.
Exploration drilling is a procedure in which several test holes are drilled for the purpose of evaluating the contents of the ground in a particular area. Drilling is used to obtain detailed information about rock types, mineral content, rock fabric and the relationship between the rock layers close to the surface and at depth. It is conducted to find out whether or not materials of value are present, and to assess the quality of those materials.
Geologists use exploration drilling to learn more about geologic strata, without the specific goal of exploiting mineral resources. Samples can provide a great deal of information about a site’s geological composition and history.
Exploration Drilling Techniques
There are various techniques for mineral exploration drilling. Below are the drilling services we are specialized at:
- Auger Drilling
- Air Core Drilling
- Reverse Circulation Drilling
- Grade Control Drilling
Auger Drilling
Auger drilling uses an auger mounted on a 4×4 vehicle. The rock is cut and broken with a simple blade bit mounted on the end of a rotating string of rods. As the drill advances, extra rod sections are added to the top of the drill string. This drilling method is generally used for shallow boreholes and requires little site preparation.
We do have the Auger drill mounted on 4×4 tractor which is suitable to climb any kind of difficult terrains and mud areas. Our Auger drills are capable of drilling Ø 140mm to a maximum depth of 90 meters. Based on the geological formation, we use various cutter heads like toothed or Rock cutter heads to maximize the penetration and improve the production.
Air Core Drilling
Air-core drilling is a specialized reverse circulation drilling where a small, annular bit is used to cut a solid core of rock from relatively soft or easily broken material. The bit produces short sections of core which are recovered, along with broken rock chips, up the center of the drill stem in the manner of a standard reverse circulation rig. The system is often capable of penetrating and coring soft sticky clays with might bind a normal blade bit.
We do fabricate the steel or tungsten blades ourselves based on the experience we gained all through these years. Our team of experts with their vast experience pick the right blade to bore a hole into unconsolidated ground, thereby providing quality samples in short time.
Our Air-core rigs are capable of drilling Ø 75mm to optimal depths ranging from 60-120 meters and is performed using a Truck or Track mounted rig based on the client needs. When the need arises, we are ready to use hammer or tri-cone roller for drilling through surface cap rock at the top of the hole.
Reverse Circulation (RC) Drilling
Reverse circulation drilling is a form of percussion drilling, by which the rock is broken by use of a piston that delivers rapid impacts to the drill stem, transferring energy to the drill bit. These blows to the rock are delivered by the bit, while a rotational device makes sure that the bit hits a new rock surface with each blow. A feed force is applied to maintain rock/bit contact, and compressed air is used to remove or flush the drill cutting from the hole, advancing the hole depth efficiently.
Some of the benefits of Reverse Circulation drilling are,- Gives more accurate understanding of the soil composition at any given depth.
- This process allows for faster, deeper drilling. Meaning, the samples can be retrieved quicker when compared to other methods.
- Delivers uncontaminated samples. As the drill bit cuts into the surface, the debris travels up into the drill bits hollow inner tube. This prevents the sample from being exposed to other areas of drill hole, resulting in avoiding cross contamination.
Our rigs are capable of drilling depths of up to 400 meters with the hole size ranging from Ø 115mm to Ø 140mm. We do support both Truck and track mounted rigs based on the client requirements.
Grade Control Drilling
Grade control is the process of drilling holes in pit, usually in close proximity to check the quality & grade of the ore while mining is underway. This is commonly carried out to provide knowledge for mine planning and blasting. This information is critical to reduce waste rock (dilution) in concentrator feed as dilution can vary greatly. RC grade control is the most cost effective and accurate way to define boundaries between waste rock and ore bodies.
Our rigs can perform GC drill to optimal depths of 40 meters with the hole size ranging from Ø 125-140mm.
Splitting systems are setup to meet client and ore body requirements.
We understand the impact of downtime and cost management, so our teams are always focused on being productive without compromising the sample quality with the help of our modern equipment.