Tag Archives: blasthole

iRing opens public database on explosives use in mining

iRing Inc has introduced what it says is an extensive, searchable, comprehensive Knowledge Base that provides answers to questions concerning the use of commercial explosives in mining and construction applications including the physics of the detonation reaction and how this is used in mining for fragmentation.

The iRing Knowledge Base provides in-depth analysis and descriptions of the use of commercial explosives under many topics including types of explosive products, priming, temperature, and pressure effects along with applications and use of explosives in mining and construction. The material has been collected over years of experience in explosive manufacturing and mining by Christopher Preston, Consulting Engineer and VP Research and Development for iRing.

The knowledge concerning the use of explosives as well as case histories and other notes are taken from a broad range of sources including authors skilled in the art as well as personal experience, according to iRing. These works are acknowledged where appropriate and are presented to provide answers to the world use of explosives in mining and construction for everyone.

“Many times, it is just handy to have a place to look up information without doing a rigorous search,” iRing says. “Hopefully, some of the information provided here will be useful. We have tried to acknowledge content that came from outside our realm of experience and we have acknowledged those authors who have provided input in the explosives technology public domain who are used as credible references.”

The Knowledge Base provided by iRing Inc is an extensive collection of information covering the years 1971 to the present. Over that period, commercial explosive products have changed drastically moving from dynamites and canned explosives such as Ammonal and Nitramon to ANFO, water gels and emulsions.

“Much work was completed by Dupont De Nemours and other large commercial manufacturers introducing the water-gel and emulsion families into a stream of safer commercial explosives,” the company said. “These could be used in a host of mining operations – from surface blasting, open-cast mining, and quarrying as well as construction to underground mining operations. Next followed dynamite’s replacement – emulsion explosives, which can be produced in both small and large diameters of charge for large mining operations and construction. Large quantities of bulk explosives can be delivered to the blasthole using pump or auger trucks with loading rates of hundreds of kilograms per minute.

“Delivery records are not only maintained on the trucks but also in the cloud for strategic data handling to arrive at the lowest cost of production. Extensive use of electronics in mining has affected production levels and, in particular, safety. Mine communications have improved to such an extent that normal operational activities can be handled by iPhones and/or tablets for production reports and foreman’s logs.”

iRing concluded: “Perhaps one of the best technologies introduced during the initial years of this century was the production of electronic blasting detonators giving timing accuracies that allow precision blasting methodologies surpassing traditional practices when blasting close to damageable structures.”

Boliden trials first automated electric drill at Aitik copper mine

Boliden says it has completed a world first with the trial of an autonomous electric Epiroc 351 Pit Viper drill at its Aitik copper mine in Sweden.

The trial ran through the month of March and was part of a three-year staged approach to autonomous drilling in Aitik that started in April 2017, Boliden said. The first part entailed tele-remote drilling, with the results from that setting the stage for stage two; a trial of single line autonomous drilling. “The third stage will evaluate the extent to which a whole pattern can be drilled with an electric autonomous drill,” Boliden said.

The drill, an Epiroc Pit Viper 351, is currently running successfully and achieving 30% increase in productivity compared with the manned equipment (190 m/d), according to Boliden. With the success of the project and positive feedback from the operators, a trial of autonomous drilling on two single passes (as opposed to multi-pass drilling) was expected to be performed shortly. There will also be a test performed with the soon to be commissioned LTE network in Aitik.

The KPIs were to be reviewed at a steering group meeting on May 7 when a decision was expected on whether to approve the investment to upgrade the remaining fleet, which could start as early as October. It is not yet known what the results were.

Shane Leighton, Senior Engineer Technology/Mine Automation at Boliden, said the trial represented a world first using an autonomous electric Pit Viper drill.

“There are a quite a few mines in the world running diesel-powered automated drills; this is the first automated electric 351 Pit Vipers. What we have learned from the trial in Aitik will support an upgrade to the 4 x 271 Pit Viper fleet in Kevitsa to an automated fleet that is scheduled to start in 2020,” Leighton said.

The trial must achieve a number of key performance indicators covering three different areas – safety, production and arctic weather conditions – to move onto a full investment. Currently, only single line drilling uses autonomous mode, the company said.

“Since we have never used this type of technology before, we wanted to be 100% certain that we could be successful before deciding to upgrade our entire fleet of Pit Vipers. The trial addresses that,” Leighton explained.

With regard to the safety, the same call-up procedures will apply when approaching the autonomous drill as for a manned drill. In addition, overview cameras mounted at various locations around the pit will allow the operator to gain a full overview of what is happening around the drill with four cameras located on the drills, Boliden said. A laser-based system for obstacle detection and a proximity detection solution are also new features designed to detect personnel; these will require staff to wear a tag that vibrates when entering the drill pattern.

The project team includes Boliden Project Manager Peter Palo, Niklas Johansson, representing the drillers, Shane Leighton from Technology, and Fredrik Lindstrom, Product Manager for Automation at Epiroc, Boliden’s supplier for the drills and technology. The project was partially funded by Boliden’s Mine Automation department.

Mining3, Robit and CSIRO team up to tackle drillhole deviation

Mining3, in partnership with global drilling tools specialist Robit and CSIRO, has taken up the challenge to develop an underground percussive drillhole deviation measurement tool.

The new system, dubbed as U-sense, is an upgrade of Robit’s S-sense technology (pictured) licensed from Mining3’s Automated String Positioning System. The S-sense system measures the straightness of surface production holes bored by a percussive drilling process and is commercially available for purchase by Robit. U-sense will extend the technology to longhole underground percussive drilling with water flushing.

As Mining 3 Technology Leader Dr Sevda Dekhoda says: “Drilling is one of the critical elements in the process of rock breakage. The location (including length and orientation), explosives charge, and detonation sequence of blastholes are strategically selected to produce the most efficient and optimal rock fragmentation.

“The consequences of deviation in drillhole trajectories from the designed pattern include build-ups, hang-ups and poor rock fragmentation, and will normally lead to extra drilling, loss of drill strings, ore dilution, ore loss, increased explosive consumption, time wastage, and delays in the chain of production operations. Hence, the impact of blasthole deviations can be felt throughout the production cycle, excavating, hauling, and mineral processing.”

This is where U-sense, which is an easy to use capsule that sits within an adapter between the percussive drill bit and drilling tube, comes in handy. It measures the trajectories of the drilled borehole as the bit is retrieved from the hole, then communicates the information with a receiver system mounted on the drilling mast.

The measurement module is on standby during the percussive drilling process and commences measurement once the drilling is complete.

As the unit is pulled out of the hole, the sensors record inertial information for processing with onboard proprietary algorithms. Once the tool is completely out of the hole, the data are transferred wirelessly for presentation on a cockpit tablet. The plot of actual borehole trajectory information – with respect to the planned orientation – allows the decisionmakers to drill a remedy blast hole or revise the blast design.

“Early access to drillhole trajectory information can have a huge impact on reducing mining costs of freezing stopes, creating large oversize, and under-break or over-break caused by blasthole deviation,” Dekhoda said.

“In addition, data from the testing unit will be used to develop decision support systems for determining the best way for a production team to modify the pattern if excessive deviation is detected. The availability of hole deviation data – on every blasthole – will enable further research into optimisation of blast designs for different rock mass conditions.”

The project Mining3, Robit and CSIRO are working on has two main phases to develop:

  1. A validated pre-commercial test unit;
  2. Next generation upgrade and testing of the unit through various case studies.

Mining3 expects the unit will be available for priority clients (sponsors) in 12 months and can be purchased through Robit.