Tag Archives: Fred Stanford

Muckahi monorail-based tech removed from Torex’s Media Luna plans

Torex Gold has decided to move forward with “conventional development and mining methods” for its planned Media Luna project in Mexico, following the outcome of various risk assessments, extensive comparative financial analyses, and the results to date of the Muckahi test program at El Limón Deep (ELD), the company said.

In the company’s June quarter results – which saw “solid operational performance” of 118,054 oz of gold produced, adjusted EBITDA of $122.1 million and generation of $21.9 million of free cash flow – Torex said the monorail-based technology would no longer be used in the Media Luna feasibility study currently being worked on and expected to be published in a technical report in the March quarter of 2022.

It explained: “After an analysis of the results to date of the Muckahi test program at ELD and an assessment of business risks, the board has approved a decision to pursue the Media Luna feasibility study on a conventional mining basis. While the monorail-based technology has progressed since the beginning of the ELD test program, testing to date of the individual components operating as an integrated system demonstrates that additional process and equipment engineering is required to achieve desired advance rates, cycle times, and associated cost efficiencies, and that there is insufficient available upside in using the technology as it relates to financial or schedule considerations for Media Luna.”

The use of the Muckahi technology, invented by former President and CEO Fred Stanford, would also leave the company with “no alternative readily available once the decision is taken to drive the two steep ramps at Media Luna, since there would be no access to the ore via any other method without considerable investment and schedule disruption associated with driving conventional ramps”.

Apart from the technical risks, there are additional business risks that require time and consideration such as permitting and regulatory compliance given there is no precedent for the technology, Torex added.

The company believes the use of a conventional mining process is a more prudent approach to mitigate operational and financial risk to the business given Media Luna will be its primary source of feed at the Morelos property after mid-2024.

It did leave the door open for use of the Muckahi technology in the future, saying aspects of the monorail-based technology were currently being deployed for development of the Guajes Tunnel.

“Management will consider including a preliminary economic assessment-level study to utilise monorail-based equipment to develop the smaller EPO deposit near Media Luna as part of the overall technical report to be released in Q1 (March quarter) 2022,” it said.

Potential deployment of the technology at EPO, which hosts an inferred resource of 1.01 Moz of gold-equivalent, would allow for additional testing of the integrated system within a live production environment.

The Muckahi system was engineered by MEDATech in close collaboration with Stanford.

The monorail mining system is billed as providing a surgical way to mine narrower orebodies more efficiently. It involves three logistical paradigm shifts: steep ramps (a quarter of the length of conventional ramps), roof-mounted monorails and equipment to run on them and minimal underground infrastructure.

The technology is expected to significantly reduce capital expenditure, operating expenditure and cut time-to-revenue by as much as 80%, according to Stanford. It will also produce 95% fewer underground greenhouse gas emissions.

The Muckahi technology was included in the Media Luna preliminary economic assessment, but the company always noted that it was experimental in nature and had not yet been tested in an operating mine.

When publishing its 2020 financial results in February 2021, Torex noted: “Since the date of the technical report, the majority of the components of the Muckahi system have been tested by Torex and their functionality demonstrated. Although, the components have not yet been tested together as a system to demonstrate the rates per day in which tunnels can be excavated and material removed from long hole open stopes.

“Testing of the integrated system will continue and is expected to be completed in the second (June) quarter of 2021. Drill and blast fundamentals, standards and best practices for underground hard-rock mining are applied in the Muckahi system as described in of the technical report, where applicable. The proposed application of a monorail system for underground transportation for mine development and production mining is unique to underground mining. There are existing underground mines that use a monorail system for transportation of materials and equipment, however not in the capacity of Muckahi which is described in detail in the technical report. The mine design, equipment performance and cost estimations involving Muckahi in the technical report are conceptual in nature, and do not demonstrate technical or economic viability.”

At the same time as updating the market on its plans to use conventional development and mining methods at Media Luna, Torex said its Board had approved a pushback of the El Limón open pit, which is anticipated to add around 150,000 oz of gold production and extend open-pit mining to mid-2024. This would align with first production from Media Luna in 2024.

Torex’s Stanford looks forward to big year with advancement of Muckahi Mining system

It was a year of milestones for Torex Gold in 2019, with the Mexico-focused gold miner posting record operational and safety performance, alongside record EBITDA and free cash flow.

The company produced 454,800 oz of gold in 2019 and is guiding for 420,000-480,000 ounces in 2020.

From a technology perspective, the company also made significant progress on advancing its Muckahi Mining System, an alternative to established underground mining processes that, Torex says, can create a more continuous mining process able to accelerate return on investment.

The benefits of the technology include an up to 30% reduction in underground mining capital expenditure, an up to 80% reduction in time between investment and revenue, up to 30% reduction in mining operating expenses and an up to 95% reduction in underground greenhouse gas emissions, Torex says.

President & CEO, Fred Stanford, said: “On the Muckahi front, we successfully demonstrated the viability of the most innovative aspects of the mining system in 2019. We are now excavating our second 30° down ramp and are continuously improving the technique.”

The company is currently testing out the technology at the El Limón Deep zone (ELD) at its El Limón Guajes mining complex (ELG), in southwest Mexico.

Incorporating 30° ramps into mine designs will be a “game changer” for the industry, according to Stanford.

“Moving beyond tunneling to ore production, we demonstrated we could achieve ‘conveyable fragmentation’ when blasting a long hole open stope. The team then demonstrated they could completely ‘muck out’ the long hole open stope with a low cost electric slusher,” he said.

With the major innovations demonstrated as viable in 2019, 2020 will focus on optimising the processes tested in 2019, and initiating testing of the various conveyor applications in the Muckahi Mining System, Stanford said.

“A conveyor for the 30°-ramp has been designed, manufactured, and is currently in transit to the mine,” he said, adding that it will be installed in the ELD deposit in the June quarter.

“We all look forward to getting the conveyor installed and demonstrating the potential,” he said.

Torex breaking records and innovating underground mining space

It was quarter of milestones for Torex Gold Resources in the three months to the end of June, with a record production number from the company’s ELG complex, in Mexico, and more progress on the company’s innovative Muckahi underground mining system.

The June quarter saw gold production of 113,600 oz, around 12% higher than the previous quarterly production record set in the September quarter of 2018. This saw plant throughput averaging at 11,670 t/d, average underground ore production of 1,280 t/d, average open-pit ore production of 18,600 t/d and an open-pit strip ratio of 6.8:1.

With the quarterly production result, the company reiterates full-year sales guidance of 430,000 oz (+/- 7%), which is weighted towards the second half of 2019.

Fred Stanford, President and CEO of Torex, said: “Q2 was a notable quarter from a number of perspectives. Record total ounce production has been highlighted already. The 1 Moz was also surpassed in the quarter.

“The mining team produced at record levels, both in ore mined in the open pits and underground. Throughout the quarter the processing team made progress in reducing reagent consumption and, late in the quarter, they made improvements in throughput rates per hour.

“Overall, quarterly throughput was hampered by unrelated unplanned downtime in late June. The team has work to do to increase the predictive and preventative aspects of maintenance.”

The Muckahi team also had an excellent quarter, according to Stanford.

“They demonstrated the effectiveness of the drilling system (Jumbo) on the level and have now turned their attention to demonstrating that the system is effective on a -30 degree down ramp,” he said.

“In five rounds, they have completed the transition from a level tunnel to a -30 degree down ramp. In July, they will push forward with the down ramp and initiate the testing of the slusher-based muck removal system. Interesting times!”

The Muckahi concept is an alternative to established underground mining processes that, Torex says, can create a more continuous mining process able to accelerate return on investment.

Learn more about the concept and technology by clicking here.

Torex makes Muckahi plans for newly declared gold reserve

Torex Gold Resources has announced a maiden underground reserve for the El Limón Deep zone (ELD) at its El Limón Guajes mining complex (ELG), in southwest Mexico, and revealed plans to mine it with its newest innovation, the Muckahi system.

The probable mineral reserve at ELD contains 86,000 oz of gold in 487,000 t of material at an average grade of 5.5 g/t Au (cutoff grade of 3.7 g/t). This is a subset of an indicated mineral resource at ELD that contains 141,000 oz in 797,000 t at an average grade of 5.52 g/t Au (cutoff grade of 2.5 g/t).

The mineral resource at ELD is the downdip extension of mineralisation in the El Limón open pit, some 400 m north-northwest of the Sub-Sill deposit (already being mined) and is open in three directions.

Fred Stanford, President and CEO of Torex, said, while small in comparison to the open-pit mineral reserves, the ELD provides a “nice sweetener to the open-pit production”.

He added: “It is also indicative of the potential to add further underground mineral resources. With ELD open in three directions, the Sub-Sill underground deposit still open at depth, and the potential for down dip extensions of Guajes, we are upbeat about the potential to further expand underground reserves and resources through multiple sources.”

ELD will be accessed through the existing underground development and will use the existing site infrastructure, according to Torex. This infrastructure includes, but is not limited to, electrical facilities, maintenance facilities, main ventilation exhaust fans and the backfill plant. Depending on material availability and geotechnical requirements, all mining areas at the ELD will be backfilled with either cemented aggregate fill or uncemented rockfill.

While the mineral reserves for the ELD deposit have been estimated using conventional mining techniques and costs, the intention is to mine the deposit with the Muckahi mining system, Stanford said.

“If as expected, the costs associated with Muckahi mining are lower than conventional mining costs, we may be able to lower the cut-off grade and increase the size of the mineral reserve.”

Excavation of the 30° down ramp to access the lower parts of the ELD deposit is underway, with four rounds taken, according to Stanford. “In the upper portions of the deposit, the excavations are nearly completed for the initial long hole stopes that will be mined utilising the production aspects of the Muckahi system.”

Stanford also provided an update on the Muckahi system, which is currently undergoing trials at ELG. The first tunnelling blast of the field trials was taken on March 26 and the round was successfully drilled from the monorail mounted Muckahi jumbo drill. The second piece of equipment, the Muckahi service platform, was at the Mexican border as of April 3 and was expected to be in service this by the end of June.

The goal of the trial is to demonstrate Muckahi’s capabilities over the full development cycle for tunnelling, including on a minus 30° gradient, and to demonstrate the capability of the system to lower costs in long hole open stope mining.

Stanford said on June 20: “To date the Muckahi system has performed as expected, we are all eager to progress through the next stages of the testing program and, if proven, then move forward with the strategic options it has the potential to unlock.”

The Muckahi concept is an alternative to established underground mining processes that, Torex says, can create a more continuous mining process able to accelerate return on investment.

Learn more about the concept and technology by clicking here.

First Muckahi mining system on site in Mexico, Torex Gold says

At the same time as reporting record gold production for 2018, Torex Gold has provided an update on its innovative in-development Muckahi underground mining system.

The company recovered from a blockade at its ELG mine, in Mexico, which affected operations earlier in the year, to produce 353,947 oz of gold in 2018, with 96,316 oz of that coming in the December quarter. Torex guided for production of 430,000 oz in 2019.

In tandem with these results, the company’s President and CEO, Fred Stanford, talked up the company’s Muckahi concept, an alternative to established underground mining processes that, Torex says, can create a more continuous mining process able to accelerate return on investment.

Stanford, who is credited as the originator of the technology, said in the company’s 2018 financial report: “If proven successful in 2019, the Muckahi technology will reduce the costs of future underground mining on the Morelos property (which includes the ELG and Media Luna assets) and will provide us with a competitive advantage when bidding on potential acquisitions and pursuing other options for commercial deployment.”

He said the testing programme for the Muckahi technology was expected to be completed in 2019, with the first of four Muckahi machines on site in Mexico. “We anticipate breaking rock with it in the next couple of months,” he said, adding that as the other machines arrive, the company would incorporate them into the test programme.

The planned use of the Muckahi system, which is also being developed with help from MEDATECH, in the most recent preliminary economic assessment for the Media Luna project saw the after-tax internal rate of return jump from 27% to 46%.

For 2019, Torex’s Muckahi plans include:
• Development on the level;
• Development on a 30° down-ramp;
• Long-hole open stope fragmentation to 95% passing 400 mm, and;
• Mucking a long hole open stope with a slusher.

Muckahi Mining System set for underground testing in Q1: Torex Gold

The new underground mining concept put forward by Torex Gold’s President and CEO Fred Stanford is gaining some traction at the company’s early-stage Media Luna project in Mexico, with the new technology potentially able to cut upfront capital requirements, reduce operating costs and decrease the time to commercial production.

IM reported on the highlights of the latest preliminary economic assessment in an earlier story, which showed the after-tax IRR going from 27% to 46% using the Muckahi Mining System (MMS) concept. But, the filing of the latest technical report has brought out some more details.

The report states on MMS: “The system challenges the status quo in many ways with the goal of establishing more efficient and cost effective alternatives to established mining processes.”

The MMS requires the use of a one-boom jumbo, service platform, mucking machine and tramming conveyor to create a more continuous mining process that can accelerate return on investment. It also significantly reduces the ventilation needs in underground mines by using conveyors as the main transport solution, playing into the mine electrification theme that is gaining traction.

Stanford, who is credited as the originator of the technology, explains the design rationale in the report:
“The production system in a mine is effectively a serial set of processes, with the ultimate objective of delivering rock, at specification, to the processing facilities. Each process step will have a primary design objective of either transformation, transport, or storage. In some processes there will also be inadvertent, non-design, transformation. This inadvertent transformation is generally not a desired outcome (ore pass slough, oxidation, etc).

“It is quite common for the ‘rates’ or ‘availability’ of processes in a serial set of processes to be out of alignment/coordination with each other. When this is the case, the productive capability of the entire system is reduced.

“To increase the productive capability of the system, designers frequently insert storage processes between transformation and/or transport (T&T) processes. These storage processes serve to reduce the inter-dependence between T&T processes and thereby increase throughput. This can be an effective design feature to maximise output, but it is expensive.

“In an underground mine these storage facilities, whether they are for rock or supplies, must be excavated and equipped, which consumes capital. They frequently also require re-handling, which consumes operating dollars. A design objective for Muckahi was to eliminate the need for storage processes by finding ways to bring into alignment the rates and availability of the entire set of T&T processes.”

He continues: “If the quality (size) of the rock product from the primary blast is not adequate for downstream processes, then a secondary sizing process will need to be added to the ‘set of processes’. Having ore-passes in the mine design will also force a requirement for a secondary sizing process. This is due to the uncontrolled size of the wall rock that, over time, will slough into, and dilute, the ore product.

“Secondary sizing processes, particularly underground crushers, are expensive and time consuming to build and expensive to operate. A design objective for Muckahi is to eliminate large size secondary size reduction processes and just deal with minor oversize management with mobile rocker breakers or ‘chunk’ blasting.”

To materially reduce the capital, operating cost, and mine build schedule, the MMS design approach sought ways to reduce the number of process steps and make the remaining process steps more efficient.

This involved eliminating secondary sizing processes that required ‘constructed’ facilities such as a crusher station – thereby eradicating the need for ore passes – cutting out all storage facilities, and replacing the current logistics model of one-way traffic in large tunnels, with two-way traffic in tunnels half of the size.

Stanford said the MMS has been able to achieve all of these requirements on a conceptual level by using five solutions:

  • Blasting rock down to a smaller size – if the rock is to go directly onto a conveyor, then the product of the primary blast must be in the range of 95% passing -400 mm. Achieving this specification is not a challenge for ‘short hole’ primary blasts, such as used in development or cut and fill production mining methods. For ‘long hole’ production methods, it will require much tighter control of drilling procedures, explosives placement, and detonator timing;
  • Twin roof (back) mounted monorails in all tunnels – this technology from the European coal industry solves several of the design challenges. It provides a stable platform for ‘long and skinny’ loads, allows climbs up steep 30° ramps and two-way traffic (one rail for inbound traffic and the other for outbound). SMT Scharf Group and Becker Mining Systems are two companies currently supplying these systems to the mining industry;
  • A new transport concept named a ‘Tramming Conveyor’ (pictured) – this machine deals with the ‘first mile’ from the face/drawpoint, when straight lines for conventional conveyors are not an option. The conveyor is end loaded at the drawpoint until the belt is fully loaded. The belt then stops ‘turning’ and the whole unit drives away on the outbound rail to the discharge point. At the discharge point, the belts starts turning again and discharges its load (conveyor-to-conveyor transfer). The unit then switches to the inbound rail and returns to the drawpoint. While it was away from the drawpoint, other units have been loaded – hence, one of the benefits of two-way traffic;
  • Ramps at 30° instead of the conventional 7.5° – the rubber tyres on conventional equipment lose traction on gradients that are much steeper than 7.5°. The back-mounted monorails remove the need for rubber tyres, hence the ability to steepen the ramps to the 30° gradient that can be handled by the cog drive system;
  • Twin tunnels in waste – the tunnels in a Muckahi mine are half the volume of the tunnels required for a 50 t truck in a conventional mine. Half the volume means less rock to remove, less ground support, fewer holes to drill and load in the face, etc. This means they can be driven much more quickly. In a Muckahi mine, there are also no muck bays to be driven, which reduces metres by approximately 20%. The net effect is that excavation rates in a 4 m x 4 m tunnel should be two to three times faster than in conventional tunnel of 5.5 m x 5.5 m.

Torex said the concept is now shifting to the underground testing phase, with manufacturing of the first of the prototype machines underway in partnership with Medatech Engineering Services out of Canada. This could see the first trials underground at the company’s ELG mine in the March quarter.

In summary, the key expected benefits of Muckahi are:

  • Continuous muck handling system and the elimination of re-handle and storage;
  • All-electric operation and significant reduction in ventilation requirements;
  • Ability to travel on ±30° (58%) slope and major reduction in both permanent and operating development;
  • Ability for bi-direction travel in 4m x 4m tunnel.

Torex Gold’s Media Luna PEA to feature innovative Muckahi transport option

Torex Gold is weighing up the use of an innovative technology that could provide an efficient and cost effective means of moving people, mining devices, and ore out of steep underground mines.

The company, which is back in action at its ELG gold mine in Mexico after a long strike at the operation that started in 2017, said in its June quarter results that it had recently come to an agreement with its CEO, Fred Stanford, to acquire his interests in ‘Muckahi’.

Stanford conceptualised and patented the Muckahi process and has been working with Canada-based engineering firm MEDATECH to develop his methods and come up with the necessary equipment to make his process work.

Muckahi makes use of overhead rails as an efficient and cost effective means of moving people, mining devices and ore out of steep underground mines. The modififed machinery also allows for increased production rates and less handling, moving the process towards continous production, according to MEDATECH.

The mining system is currently in the evaluation stage, but is being considered for use at Torex’s Media Luna gold project in Mexico. There is a revised preliminary economic assessment on Media Luna due soon that is expected to feature the use of this technology.

The 2015 PEA on Media Luna envisioned an underground operation with expected average annual production of 313,000 oz of gold-equivalent at an average all-in sustaining cost of $636/oz.

The recovery of the Media Luna resource was planned to be through underground mining methods at 7,000 t/d with the mineralised material transported via a hybrid underground/aerial/underground rope conveyor to the ELG processing plant. The conveyor belt would be 6.7 km in length with a 360 m vertical drop over its length.

Torex said it was planning to run a technical session for investors and analysts on the Muckahi process next month.