DER and Ibbotson Drilling Services active in Scotland Granite Quarry
DER is working with our partner Ibbotson Drilling Services in a granite quarry in the Scotland currently drilling 102 mm or 4” diameter bore holes with T51 drill steel (51 mm diameter rods). These top hammer bits have parabolic inserts and 4 flushing holes for maximum rock fragmentation and hole cleaning. The IDS drill bits are made in the UK and are outperforming the competition by 20%. The ground conditions are extremely difficult with broken and fragmented rock. The design of the face of the bit and placement of the tungsten carbide inserts allow for larger root clearances between inserts. This allows better flow patterns and flushing of the broken rock chips while drilling. We are not only providing the drill bits but also the drilling expertise on location. Direct feedback from the drilling contractor is that IDS and DER are providing better expertise and hands on service to their drilling needs than Atlas Copco. The hydraulic crawler type rock drill being utilized in this quarry is an Atlas Copco FlexiROC T40. This drilling rig utilizes an Atlas Copco 2560 top hammer and is capable of drilling boreholes to 28 m. The air compressor delivers 145 l/s for hole flushing.
The IDS top hammer bit works perfectly with the auto drill features of the FlexiROC T40. The EN27 forging material that Ibbotson uses allows for a special heat treatment process known as carburizing. This achieves Rockwell hardness numbers between 50-56 and adds a toughness to the bit so that it wears less and more evenly in hard abrasive rock conditions. Many competitive bits will wear excessively on the outer gage rows and thus expose the carbide inserts to a potential early failure from body wear.
