The Diamond Button series – which enables percussive hard rock drilling with diamonds – was first announced last October and production started immediately. The first bits being produced are suitable for use in underground mining, open-pit mining and quarrying. Before the October announcement Robit had carried out testing and development on the diamond button bits for several years.
The diamond bits are designed to be suitable for customers whose use cases require longer bit lifetimes. The pilot cases have focused on customers using remote control drilling in top hammer applications, but Robit says there is also customer potential in tunnelling and DTH (down-the-hole) applications, and that development work has started for these use cases.
“Mines are pursuing innovative ways to improve safety and productivity and remote control drilling is part of that,” said Jorge Leal, head of offering at Robit.
The first bit sizes are 89mm and 102mm production drill bits. Leal says that other sizes could be produced depending on the specific demand from customers. He adds that the availability is not constrained by bit size, and that Robit is currently testing bits in the field starting from 48mm size.
Robit says the technological answer for customer needs is a highly developed coating of diamond added on the typical tungsten carbide buttons. The Diamond range is designed to drill for a greater period of time and depth without interruption or the need for downtime due to bit change.
Niko Ojala, R&D engineer and materials specialist at Robit, said that when drilling hard Finnish granite it is quite usual to have to change a normal tungsten carbide button bit after 80m, while with diamond bits over 1,000m has been achieved. During the extensive field-testing the hardest drilling conditions reduced the normal bit life down to 15m. “Even in those conditions the diamond bit lasted 15 times longer,” according to Ojala.
“Moreover, as the diamond buttons practically don’t wear like normal buttons, the drilling speed remains the same throughout the bit’s lifetime,” he added. “Similarly, the diameter of the borehole does not decrease as the bit ages, resulting in a more consistent and predictable end result in production drilling. The many-times-longer change interval of the bit saves time and is particularly important for remote-controlled drill rigs in fully automated mining environments where people are not present during the process.”
Robit is planning an official launch of the Diamond Button series family in September this year at MINExpo in Las Vegas.