This month’s Spotlight Feature Article focuses on the chemical and concrete side of the rock reinforcement business, including the shotcrete, resin and fibre technology that supports bolting in many underground mining environments.
Tag Archives: rock reinforcement
Epiroc makes the ‘impossible possible’ with launch of Boltec ABR
Epiroc has taken another significant step forward in its rock reinforcement automation journey with the release of the Boltec Auto Bolt Reload (ABR).
Combining the company’s ground support nous with its mechanisation and automation knowledge has resulted in a solution able to remove operators from the front end of the bolter – where personnel are most at risk of rock falls from unsupported ground – and increase bolting productivity, especially in poor ground conditions.
With mining operations steadily going deeper as they develop existing and newly discovered orebodies, the rock stresses associated with mining these orebodies are typically increasing, too. This often results in more challenging rock conditions with fractured rock mass, rock burst and squeezing ground, requiring more regular rehabilitation work. The Boltec ABR, with improved operator safety, flexibility and productivity, is the obvious choice for such conditions, Epiroc says.
Epiroc claims the Boltec ABR is the first ever underground rock reinforcement drill rig designed in such a way that the bolt type and machine work together in synergy to deliver optimal safety, performance and quality. The machine can also be equipped with a mesh delivery system.
This synergy also leads to improved accuracy in bolt installations and a reduced need for re-bolting, according to Peter Bray, Global Product Manager, Rock Reinforcement at Epiroc’s Underground division.
“By using a Boltec ABR, you are better able to install bolts and mesh correctly with high quality, reducing the need for re-bolting, re-meshing…and rehab work in the future,” he told attendees of a webinar announcing the product launch today.
The mechanisation of the bolting process – in tandem with the use of self-drilling anchors (SDAs) and pumpable resin – should provide operations with the comfort to follow recommended bolting patterns, reducing the need for the installation of additional bolts that go above and beyond optimal industry practice.
The main design feature of the Boltec ABR is the fully mechanised bolt reloading system. The system automatically feeds bolts from a large carrier magazine – able to hold 44 bolts in 2.4-m or 3-m lengths – to the feed magazine – able to hold eight bolts – all while the operator remains safe inside the cabin. This innovation removes the need for manually reloading the feed magazine, thereby reducing the associated risk to the operator.
The fast auto reloading sequence speeds up the production cycle, with a total of 52 bolts able to be installed in a heading before manual reloading of the carrier magazine. The carrier magazine is mounted on a swing arm that lowers the magazine to ground level for easy reloading behind the machine’s front support jacks – where ground support should already be in place.
Productivity can be further boosted with the operator carrying out the reloading process when bolting is being carried out in multi-bolt auto mode, according to Bray.
The Boltec ABR opens the door to other safety and productivity-enhancing autonomous functionalities previously not compatible with underground bolting machines, according to Epiroc. Tele-remote control and the aforementioned multi-bolt auto are now available options that can provide bolting potential during shift changes or when conditions preclude having an operator physically on the machine. The machine is also available with a battery-electric driveline.
Bray said the development and integration of SDAs and pumpable resin on conventional Boltec machines have been integral to achieving this new functionality.
“If you think about our face drills and long hole production rigs, they have had automation for many years,” he said. “There hasn’t been a mechanical reason why we couldn’t automate a bolting machine; the stopping point has been the type of legacy rock bolts used.”
SDA bolts, which, according to Epiroc, offer faster bolting times and higher quality installation, are not sensitive to varying conditions and will achieve consistently fast installation. This provides easier scheduling accuracy for mine planning and forecasting.
The pumpable resin, developed to address inconsistent and unreliable bolt installations as mines go deeper and rocks become less competent under added pressure, offers fast setting times and full bolt encapsulation, ensuring speed and quality of installation, the OEM says. An added plus is the resin’s insensitivity to wet ground conditions, which can be a desirable characteristic for many deep underground operations.
“Given that it is much cleaner and easier to use than traditional cement, the pumpable resin reduces hours spent on cleaning the machine,” Bray said. “Hence, it is increasing productivity by providing more bolting time.”
Like other Boltecs in the range, the Boltec ABR comes with a boom-mounted bolting system, providing flexibility in terms of coverage and bolt installation angles, according to Bray.
“It’s very rare that you have perfect straight drive profiles in underground mining,” he said. “The boom-mounted bolting system offers the flexibility to address this.”
LKAB, along with the European Institute of Innovation & Technology, have been key partners in the development of this machine, with the prototype tested out at both the Kiruna and Malmberget mines in northern Sweden.
Kiruna suffered a significant seismic event during May 2020 where several areas underground were adversely affected, providing a good test case for the new machine.
These affected areas required rehabilitation with bolts and mesh to make them safe for production again, according to Bray – a process the iron ore miner is continuing to carry out at Kiruna with the prototype Boltec ABR unit.
“The Boltec ABR was the perfect machine for the challenge; it has proven to allow safer operation and significant productivity increases when compared to LKAB’s conventional bolting fleet,” he added.
Epiroc said that up to double productivity gains were achieved in a trial with the Boltec ABR in LKAB’s Malmberget mine when compared with the miner’s conventional bolting fleet.
Bray concluded: “This solution has made the impossible possible. We can now install bolts where it used to be extremely difficult. Giving some relief to the bottleneck that rock reinforcement had become.”
Orica sticks with growth predictions as it completes Minova sale
Orica has completed the sale of its Minova business to the Aurelius Group for A$180 million ($131 million), with A$149 million of cash received at completion factoring in debt and “debt-like items”, as well as confirmed expectations that its first half performance is likely to representing year-on-year growth.
The company announced the planned sale of its rock reinforcement business back in December 2021, with the deal completed on February 28.
Orica additionally said that its first-half 2022 financial year performance, as previously announced at the 2021 full year results in November 2021, was expected to be stronger than the prior corresponding period (pcp). This, it said, reflects the positive momentum leading into the year associated with improved global commodity markets, which will result in volume growth in line with global GDP growth.
“Pricing discipline in contract negotiations is expected to broadly mitigate rising input costs and pass-through lags,” it explained. “Security of supply for Orica’s customers remains a priority in a tightening global ammonium nitrate market due to geopolitical issues and supply chain disruptions, which will result in increased trade working capital.”
All continuous manufacturing plants have been operating to required available capacity as determined by market demand, Orica said, and two planned turnarounds had been completed in the half year to date, namely the Carseland site-wide turnaround, which commenced in September 2021, was completed in October 2021; and the Yarwun turnarounds for two nitric acid plants, one ammonium nitrate plant and the emulsion manufacturing plant were all successfully completed in November 2021.
Orica Managing Director and CEO, Sanjeev Gandhi, said: “We’ve been able to maintain the positive momentum from the second half last year and remain on track to deliver a stronger first half than the prior corresponding period.
“With our refreshed strategy firmly in place, we are focussed on progressing on our four key business verticals and are well placed to leverage our strengths and seize opportunities in a tightening global market, while continuing to streamline the business.”
Epiroc reinforces order book with Norilsk Nickel contract
Epiroc has won an order from Norilsk Nickel for underground mining equipment that, the OEM says, will strengthen safety at three of its mines in Russia while ensuring highly efficient mine development.
Norilsk Nickel, one of the world’s largest producers of nickel, palladium, platinum and copper, has been investing in automation and digitalisation for the past several years. This has seen it introduce advanced digital technology in mine engineering, as well as in planning and operational control of mining activities, through its Technology Breakthrough program.
As part of this order, the miner has secured Epiroc’s Boltec M (pictured with with pumpable resin option) and Cabletec M rigs for use in the Oktyabrskiy, Mayak and Komsomolskiy mines to reinforce the underground rock in the safest and most productive manner, Epiroc says.
Quality and productivity are key features of these machines, Epiroc says. “For example, several of the Boltec machines will be equipped with the new automated pumpable resin system, a key component in Epiroc’s automated bolting development. The pumpable resin system, when combined with self-drilling anchors, is particularly effective in difficult and unstable ground conditions.”
One of the more difficult rock reinforcement tasks in underground mining and tunnelling operations is how to install long-term rock bolts in poor rock conditions, Epiroc says. As a result of this difficulty, rock bolting traditionally has often been the bottleneck within the drill and blast cycle.
“To resolve this, Epiroc in 2019, launched a pumpable resin system for underground rock bolting, allowing for a faster, more reliable and cost-effective bolting alternative for long-term rock reinforcement in difficult ground conditions,” the company said.
The Norilsk Nickel order exceeds SEK100 million ($11 million) in value and was booked in the September quarter of 2020. The equipment will be delivered from the company’s Sweden operations in the December quarter, Epiroc said.
“Norilsk Nickel has been an Epiroc customer for many years,” Helena Hedblom, Epiroc’s President and CEO, said. “We are proud to play a key role as this forward-looking mining company now takes the next step in its commitment to safety and productivity with our latest technology.”
Epiroc pumps up rock reinforcement offering
Epiroc, together with LKAB, has developed a new solution for installing long-term rock bolts in poor rock conditions.
The pumpable resin system for underground rock bolting, designed for the mechanised bolting machines Boltec M and Boltec E models, is a result of the mining OEM and mining company’s collaboration within the EU-led Sustainable Intelligent Mining Systems (SIMS) project.
Epiroc says: “One of the more difficult rock reinforcement tasks in underground mining and tunnelling operations is how to install long-term rock bolts in poor rock conditions. Rock bolting, as a result, is often the bottleneck within the drill and blast cycle, leading to difficulties to predict work task scheduling.”
Blocky or friable ground often leaves drilled bolt holes blocked or partially blocked. This slows down, or in the worst case, prevents the introduction of bonding agents such as cement grout or resin cartridges into the bolt hole.
“The Epiroc and LKAB solution will allow a faster, more reliable and cost effective bolting alternative for long term rock reinforcement in difficult ground conditions,” Epiroc said.
Peter Bray, Global Product Manager, Epiroc, said: “An important factor to achieve a workable rock reinforcement solution is to have a system where the bolt design, bonding agent and bolting rig all work together to provide a robust and reliable bolt installation. To this end, Epiroc has worked hand in hand with a leading bolt and chemical supplier to create a bolting system that addressed the issues faced with long-term bolting in poor ground conditions.”
The result of this work is an integrated pumpable two-component resin system that can be used with a Self-Drilling Anchor style bolt in tougher ground conditions or, alternately, with a two-step hollow bolt in more moderate ground conditions.
“Having the ability to choose a long-term rock bolt that suits the ground conditions means that customers are able to achieve an optimal rock reinforcement regime in terms of function and budget,” concluded Bray.
Quaker Chemical highlights dust suppression, ground control and fluid expertise
Quaker Chemical Corp says its package of dust suppressants, ground control agents and longwall fluids address several of the mining industry’s ongoing needs.
High levels of respirable dust and quartz can cause visibility and other health and safety issues to mine workers, which is where its DUSTGRIP® dust suppressants come in.
These suppressants have been formulated, the company says, to:
- Reduce the generation of airborne particulate matter from mines, roads, stockpiles, rail hauls, construction sites, quarries and other areas where air-born dust is a problem;
- Increase site safety for workers by reducing levels of airborne dust and quartz, and;
- Have a cumulative effect so they are longer lasting with lower maintenance cost when compared with water alone.
On top of this, it has its MINETECH™ Ground Control Agents within its portfolio. Designed to consolidate and stabilise unstable ground, as well as seal against water ingress, these ground control agents provide good penetration into small cracks and fissures, high adhesive strength and “Outstanding mechanical properties and flexibility to be an effective ground consolidation and stabilisation tool”, it says.
Fluid instability, sticky soaps, bacteria and corrosion can all be a risk to mine equipment and workers, the company said. “QUINTOLUBRIC® 818-02 has been developed as a 100% synthetic true solution that triples filter life through superior fluid dynamics and improved system cleanliness; reduces bacteria, keeping systems free of corrosion and plugged filters, and; is compatible with all commonly used longwall fluids for easy conversion.”