Gold Mining Diamond Core Drill Bits High Productivity Underground Diamond Drilling

Gold Mining Diamond Core Drill Bits High Productivity Underground Diamond Drilling



Roschen New Diamond Core Bits Put 23% More Core in the Box
 

Product: Roschen Bit
Location: Western Australia
Application: Higher productivity in underground diamond drilling

23% Increase in Meters Drilled/Hour

The Yilgarn Craton forms the bulk of Western Australia and is home to 30% of the world's gold deposits. Within in this region, the Laverton district is one of the most important gold producing regions.

Underground miners of these "nuggety" gold deposits are under significant pressure to reduce their all in sustaining costs (AISC) and improve their return. Combine each mine's sharp focus on costs with an extremely competitive diamond drilling market, and the result is the constant search for higher productivity in underground diamond drilling.

Using patented technology, the new Roschen bits have diamonds that are chemically bonded to the matrix creating a more versatile, faster penetrating, and a longer-lived bit. The new Longyear bits retain the smooth drilling characteristics drillers prefer, resulting in more core in the box on every shift for every crew. Available in 16mm more open, express geometry for even higher cutting speeds as well as 16mm Stage and 25mm Stage 3 configurations.

 

23% Increase in Meters Drilled/Hour
 

"Just some feedback… the other night I witnessed a bit cutting 24 inches a min … by far the fastest cutting bit Boart Longyear has made…" Roschen Site Supervisor, Western Territory.

 

THE CHALLENGE
 

On the surface, the Laverton district is a flat, hot, dry environment with scattered acacia trees only interrupted by dry, salt lake beds, and gypsum sand dunes. The high concentration of salt results in a very saline aquifer. While the high salinity is hard on equipment it does not factor heavily into bit selection and drilling performance.

 

Underground, the formation is a mesothermal, meaning deep extending, gold deposit typical in Western Australia, composed of greenstone, a rock type common to gold deposits globally, basalts, magnetite shales and banded iron formations (BIF).
 

Within this host rock, the gold is typically contained within intrusive dykes of quartz porphyry near the shear and fracture networks which supported gold-bearing hydrothermal flow. The greenstone, shale and even basalts are only of medium hardness and have the potential to be cut quite quickly, while the sections of BIF, quartz and fracture zones force slower penetration rates. The ideal bit would be versatile; free-cutting enough to easily handle the occasional BIF and quartz but tough enough to penetrate the greenstones quickly.
 

The underground portion of the mine is decline accessed and extends 900m below the original open pit. Due to its "nuggety" deposit, diamond drilling tends to underestimate grade, so the mine has adopted new techniques of grade control. RC drilling has been introduced underground to produce larger sample volumes, which match well with the bulk mining techniques being used. Considering that RC drilling is typically half the cost-per-meter and three times faster, and the industry-wide initiatives to drive down all in sustaining costs, a lot of scrutiny is paid to the productivity of remaining diamond drilling.
 

After optimizing drilling parameters, the incumbent product's (Hayden 9AA and KS5) average performance, maxed out at 180 meters/bit life and 22 centimeters/min of penetration rate over the three months of monitoring. While solid performance, a new solution was needed to continue improving productivity.

THE SOLUTION
 

The first step was to introduce the new Roschen Green Bit in a ROS 3 25mm configuration. The Roschen Green formula (Prototype P520) was selected to drill like the competitor's 9AA formula with Stage configuration to maximize life. Comparing performance in the three-month period after adoption, penetration rate increased to 26 centimeters/minute and bit life nearly doubled, increasing to 356 meters/bit. The ease of use and consistency across shifts was appreciated by the crews and helped produce the measurable gain. These improvements combined to noticeably increase core in the box by 6%. The Boart Longyear drill crews correctly observed that such long life was not driving a significant increase in productivity as reduced tripping time has less impact than improved penetration, so the decision was made to trial even more free-cutting formulas.
 

The next bit trialed was the Roschen Yellow again in the Stage 3 25mm configuration to line up against the competitor’s KS5 and even 12-14. The penetration rate jumped to an average of 35 centimeters per minute and life held at an impressive 300 meters per bit. Since the bits were still achieving much better life, Roschen Drilling Services moved one more step up to the Roschen Red bit. Since the goal was to maximize penetration rate, the Roschen Red bits were produced in the 16mm express configuration with a more open area for enhanced penetration.

The Roschen Red bits achieved an astonishing 60 centimeters per meter penetration rate and still lasted 120 meters. With the goal of maximizing productivity, the drill crews decided to use one Roschen Red at the top of the hole and finish it with a Roschen Yellow in 25mm Stage 3. The results speak for themselves. After 3 months of measurement, this two-bit strategy averaged 283 meters/bit, still a 60% improvement over the competition and 34 centimeters per minute, a full doubling of penetration rate. The combined result put 23% more core in the box.
 

After the promising initial results, trials were started using the new Roschen bits on all Roschen Drilling Services sites in Australia and select sites globally. Now, all sites in Australia have converted to great effect on productivity. Over the next six months, the new Roschen bits in the Roschen line will be launched, moving from prototype to full production. Roschen bits are now stocked in Australia and available to order.

Express Geometry
 

With the competitiveness of today's market, everyone is looking to cut faster, especially underground. To support higher penetration rates, we have combined the new Roschen formulas with a new, more open express geometry. Tapered intermediate waterways improving flushing and prevent accumulation of debris. Designed for fast cutting in competent ground, the new express geometry is available in our 16mm crown heights to maintain bit life at higher cutting speeds.

 

For more information, please contact:

ROSCHEN INC.
ROSCHEN GROUP LIMITED
ROSCHEN HOLDINGS LIMITED

Skype: ROSCHEN.TOOL , ROSCHEN_GROUP
 

WeChat: +86-137 6419 5009 ; +86-135 8585 5390
 

WhatsApp: +86-137 6419 5009 ; +86-135 8585 5390
 

Email: roschen@roschen.com ; roschen@roschen.net
 

Website: http://www.roschen.com ; http://www.roschen.net