What are the common tools and equipment used in drilling and blasting?

A wide range of tools and equipment are used in drill and blast activities to achieve deliverables during and after drill and blast operations. Drilling operations use bench and production rock drilling tools, shank adapters, down the hole equipment, grinding equipment. Blasting is performed using explosives. There are substances that detonate to produce a high-intensity shock wave and large volumes of gas which, being confined in a hole, expand rapidly, entering existing minor cracks in the rock and create new cracks to break the rock. The drill and blasting tools fulfil the drilling and blasting operations but prior to their use drill and blast design and planning is performed to ensure safety and efficiency. Prior to the blast hole drilling the site is inspected and certain decisions need to be made with regards to hole size, type of drill or drills to be used based on the initial site survey. Raw data from the surveying process is used by researchers to plan effective and safe drilling patterns. The project manager takes over from the researchers and draws up the drilling plans. Drilling of the blast holes commences on-site based on recommendations from the team. Once the blast holes have been drilled, they will be packed with explosives that are remote-detonated to break up the rock. The nature and amount of explosives used are based on the research conducted. This article highlights drill and blasting tools through a separate assessment of tools used in drilling and blasting. It also looks at measuring equipment used before and after drill and blasting operations. 

What tools are used in drilling?

There are various tools used in drilling. Most drilling occurs using mechanical rockdrills which are rotary-percussive, imitating hand-drilling in which the chisel is stuck with a hammer and turned in the hole. Jackhammers are compressed air-powered, hand-held machines. They are used to drill holes up to 3m in length in both development and stoping. Coal drills or electric augers are electrically-powered, rotary machines with a spiral steel and used to carry out dry drilling in coal mining and soft rock. Drifters are similar to jackhammers but are mounted on bars. These tools drill up to 30 m in length and are used for stoping and developing large excavations. Mobile electrohydraulic rigs drill multiple rockdrills and are self-propelled either by diesel or electricity. They are extremely efficient and are capable of drilling many holes in a shift. Bench and production drilling tools include rope thread equipment designed to improve the drilling speed whilst ensuring that the automatic production line achieves quality stability. Reaming bits are used for second time drilling of the hole and are commonly applied to drill center hole of drifting. The shank adapter transmits rotation torque, feed force, impact energy, and flushing medium. It is made from specially selected material, to withstand the transmission of impact energy and rotation from the rock drill to the drill string and is hardened through carburizing. Extension and drifting rods transmit the impacting power and torque from shank to bit. Down the hole equipment gives the driller quality holes. These tools offer superb hole straightness within 1% deviation without guiding equipment, good hole cleaning, smooth, even walls for easy charging of explosives, deep hole drilling capacity and efficient energy transmission. 

What tools are used in blasting?

The tools used in blasting use different technologies based on the nature of the blasting operation. Blast initiation systems have evolved over time. Traditionally, explosives were initiated by fuse and ignitor cord which have a known range of burning speed, allowing miners to time the sequence of detonation of individual charges, which happened with very low accuracy. The latest technology in blast initiation uses radio controlled remote blast initiation system. They use a radio system signal that is digitally encoded. These tools have the capability to initiate non-electric shock tube, as well as standard electric blasting caps. Laser rock profiling systems are used to perform 3D rockface profiling to determine rockface geometry and blast hole burdens and thus reduce the incidents of fly rock, air blast and excessive vibration. There are various types of detonators. Instantaneous and delay electric detonators have been used for many years. They may be initiated by electric current from complex, mains firing devices or from small portable devices called shot exploders. Modern methods of initiation blasting use shock tubes, which are non-electric detonators capable of extremely accurate timing. Condenser blasting machines are used for firing medium and high power detonators in series. A nonel starter is a new generation electronic firing device for firing non-electric detonators. Electronic firing systems offer detonator firing and electronic programming for complex, high quality surface, underground or demolition blasting operations. Tampers are used for placing charges in the drilled holes.

Measuring equipment used before and after drilling and blasting. 

Regulations and requirements for drill and blasting are constantly changing as technology is evolving. Measuring equipment used before and after drilling and blasting is also catching the wave of change to the benefit of safety, health and risk management. Before drilling, there must be firing and drilling plan design support tools. The measuring devices used are laser rock profiling systems that perform 3D rockface profiling to determine rockface geometry and blast hole burdens and thus reduce the incidents of fly rock, air blast and excessive vibration. In addition laser profilers are utilized to calculate theoretical distances for the face hole and the drilling angles. After drilling the measuring devices used offer precise, quick means of checking the real deviation of the mining holes used before setting charges, which enables any firing incidents to be avoided. Laser profilers are also used in combination with software to create hole charge plans quickly and accurately on a hole-by-hole basis or for a whole row. Scattering risks are reduced considerably by using this measuring device. In addition 3D laser technology is used to provide information on total volume extracted, ore volume excavated, footwall waste dilution, hanging wall waste dilution, volume broken but not extracted (lockup), planned volume but not broken, ore development before stoping and stope extraction design. Moving forward the use of digital models contribute to the business model of the mining operation. 

The importance of quality in equipment and application

The discussion wraps up with emphasis on the benefits of choosing the down-the-hole drill bit correctly, which ultimately affects rock drilling, and the subsequent blasting to take place. Choice of down-the-hole drill bits should be done according to rock conditions (hardness, abrasiveness) and drill bit type (high wind pressure, low wind pressure). Installation of the down-the-hole drill must be done gently into the drill sleeve of the down-the-hill impactor, this avoids damage of the tail shank of the drill bit or the drill sleeve. Care must be given to ensure air pressure of the down-the-hole drilling is sufficient to avoid clogging of the blast-hole. It is key to pay attention to the size of the drilled blast hole when replacing the drill bit. The tools used in drill and blasting operations contribute immensely to the success of the operations. The integrated approach of technology and personnel can be utilized to achieve greater business success in drill and blasting operations. Choice of tools goes hand in hand with occupational health and safety. 

Improving health and safety in drill and blast is GRT’s focus. GRT provides GRT: 12X  for blast and drill dust control and GRT DC Binder for blast pattern dust control to complement the efforts in resource efficiency with worker safety and health. Dust should be eliminated at the source to save lives. 

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REFERENCES 

Blasting quality boosted by technology and data. In press. Retrieved 31/03/21

Blasting tools. In press. Retrieved 31/03/21

Drilling and blasting tools. In press. Retrieved 31/03/21

Equipment and accessories. In press. Retrieved 31/03/21

Overcoming operational challenges – post drill and pre-blast grade control. Retrieved 31/02/21

Technical aspects of mining. In press. Retrieved 31/03/21