Tag Archives: Cozamin

NextOre’s in-pit sorting advances continue with development of mining truck sensor

NextOre and its magnetic resonance (MR) technology have made another advance in the ore sorting and material classification game with the development of a new “open geometry” sensor that could enable mines to scan mining truck loads.

The company, in the last year, has surpassed previous throughput highs using its on-conveyor belt solutions, accelerated the decision-making process associated with material sorting viability with its mobile bulk sorter and made strides to branch out into the in-pit sorting space via the development of these open geometry sensors.

NextOre’s MR technology is the culmination of decades of research and development by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), with the division spun out from the organisation in 2017. Since then, NextOre has gone on to demonstrate the technology’s viability across the globe.

NextOre’s MR analysers were first fitted on conveyor belts, yet interest in solutions for in-pit equipment predates the company’s inception.

“A significant portion of the time when CSIRO would show people the technology, they were working on for fitting on a conveyor belt, many would ask: ‘could you possibly put it around a truck somehow?’,” Chris Beal, CEO of NextOre, told IM.

After workshopping many ideas and developing increasingly large prototypes – commencing at the start with an antenna made up from a copper loop and a couple of capacitors – two in-pit solutions leveraging CSIRO’s open-geometry sensor have come to the fore.

The first – a 3-m-wide sensor – underwent static and dynamic tests using chalcopyrite copper ore grade samples in a material feeder setup in 2022, in Australia.

This test work, observed by several major mining companies, laid the groundwork for a bigger installation – a 7-m-wide ruggedised antenna that weighs about 5 t. This can be positioned over a haul truck and manoeuvred using a crane supplied by Eilbeck and guidance systems developed for NextOre by CSIRO and the University of Technology Sydney.

The advantage of MR in a truck load scanning scenario, just as with a conveyor, is the ability to make accurate, whole-of-sample grade measurements at high speeds. Yet, to operate effectively, this system requires significant amounts of power.

“The truck system we are building is between 120 kW and 200 kW,” Beal said. “For people in the radio frequency space, power of that magnitude is hard to comprehend; they’re used to dealing with solutions to power mobile phones.”

For reference, a NextOre on-conveyor system rated up to 5,000 t/h has around 30 kW of installed power. And conveyor systems above 5,000 t/h have 60 kW of installed power.

The idea is that this new MR truck sensor station would be positioned at an ex-pit scanning station to the side of the main haul road at a site and trucks will be directed to ore or waste as a result. The test rig constructed in NextOre’s facility has been built to suit the truck class of the initial customer, which is a major copper mine using 180-t-class and 140-t-class haul trucks.

The first prototype has now been built (as can be seen by the photo) and is awaiting of shipment to the mine where a one-year trial is set to commence.

While pursuing this development, NextOre has also been increasing the scale of its conveyor-based installations.

Around nine months ago, IM reported on a 2,800 t/h MR ore sorting installation at First Quantum Minerals’ Kansanshi copper mine in Zambia, which had just shifted from sensing to sorting with the commissioning of diversion hardware.

Now the company has an ore sensing installation up and running in Chile that has a capacity of 6,500 t/h – a little over 50% higher than the highest sensing rate (4,300 t/h) previously demonstrated by the company at Newcrest’s Cadia East mine in New South Wales, Australia.

Beal said the unit has been up and running since December, with the copper-focused client very happy with the results.

For those companies looking to test the waters of ore sorting and sensing, another big development coming out of NextOre in recent years has been the construction of a mobile bulk sorter.

Able to sort 100-400 t/h of material on a 900-mm-width conveyor belt while running at 0.3-1 m/s, these units – one of which has been operated in Australia – is able to compress the timeline normally associated with making a business case for ore sorting.

“As people can now hire such a machine, they are finding it either resolves a gap in proving out the technology or it can be used to solve urgent issues by providing an alternative source of process feed from historical dumps,” Beal said. “They want to bring a unit to site and, after an initial configuration period, get immediate results at what is a significant scale.”

Such testing has already taken place at Aeris Resources’ Tritton copper operations in New South Wales, where the unit took material on the first surface stockpile taken from an underground mine.

While this initial trial did not deliver the rejection rate anticipated by Aeris – due largely to rehandling of the material and, therefore, a reduction in ore heterogeneity ahead of feeding the conveyor – Aeris remains enthusiastic about the technology and Beal is expecting this unit to be redeployed shortly.

“We now know thanks to results from Kansanshi, Carmen Copper Corp/CD Processing, this new Chilean site and Cozamin (owned by Capstone Copper) that this in-situ grade variability can be preserved, and that mixing impacts directly on sorting performance,” Beal said. “Even so, we have seen really good heterogeneity persist in spite of the unavoidable levels of mixing inherent in mining.”

He concluded: “People want this type of equipment not in a year’s time, but next month. Capitalising the business to put more mobile units out in the world is a priority.”

Capstone prepares Cozamin for introduction of paste backfill, dry-stack tailings

An updated Technical Report on Capstone Mining’s Cozamin copper-silver mine in Zacatecas, Mexico, has shown the potential for a mine life extension to 2031, and a plan for dry-stack tailings and underground paste backfill. At the same time, the company says it is studying the use of “innovative mining techniques and enhanced pillar recovery” to make the most of existing reserves and resources.

The updated life of mine plan released outlined average annual copper production of 51.2 MIb (23,224 t) of copper and 1.6 Moz of silver production over 10 years at average C1 costs, including the 50% silver stream, of $1.02/Ib of payable copper. From 2021 to 2027, average annual production is slated to be 58.8 MIb of copper and 1.7 Moz of silver.

The company said a planned ramp-up to 3,780 t/d, or 1.38 Mt/y, by the end of March quarter is on track, with a new section of ramp to open the one-way traffic circuit to debottleneck the mine (pictured) completed in early December 2020, ahead of schedule.

Reserves increased by 39% and now stand at 14.1 Mt, relative to April 30, 2020. Contained copper and silver increased by 37% and 49%, respectively, with around half of this increase due to recovery of high-grade pillars using paste backfill, Capstone said.

The miner said “tailings management transformation” activities were progressing on schedule at site, including feasibility-level design and studies in support of permitting a filtered (dry stack) tailings storage facility.

“This conversion from a slurry tailings impoundment aligns with industry leading socio-environmental best practice for tailings management,” the company said.

Meanwhile, a prefeasibility study (PFS) for an underground paste backfill system was completed in December.

The study indicates a paste backfill system will allow ore extraction containing over 100 MIb of copper and 3.1 Moz of silver between 2023 and 2031, which would have otherwise been left as unmined pillars. The PFS design has a capital cost estimate ranging from $41-$45 million and an increase in operating costs of around $7.50/t of ore mined. Capstone says its management has approved the paste backfill project and work has commenced on procurement of long lead items.

The proposed paste backfill system includes a tailings filter plant, a paste mixing plant, twin boreholes to deliver paste underground and an underground distribution system. The system is expected to be commissioned starting in the December quarter of 2022, with ramp-up completed in the March quarter of 2023.

PFS design of these facilities was completed by Paterson & Cooke in December 2020 and a feasibility study is underway with completion expected in April 2021. Mine planning was completed by Cozamin, with design support provided by a geotechnical consultant, and paste backfill operational guidance provided by AMC Consultants.

Within the latest release, Capstone also flagged the initiation of its “Impact23 Growth” project, which has identified areas of exploration excellence, innovative mining techniques and enhanced pillar recovery at Cozamin.

“By 2023, the goal is to further extend mine life, increase environmental and safety standards, and improve operational efficiencies at Cozamin, utilising mineral resources already discovered in addition to testing new targets,” the company explained.

Included among the options are the innovative mining techniques for resource to reserve conversion flagged at the start of this story.

Capstone says a study will be initiated this year to assess alternative mining techniques with the objective of lowering costs and dilution to convert resources to reserves from the indicated resource base. The current mining methods are longitudinal longhole open stoping and AVOCA, with possible alternatives to be studied including cut-and-fill, drift-and-fill and longhole open stoping with ore sorting technology.

Brad Mercer, Capstone’s SVP and Chief Operating Officer, said: “The life of mine plan announced today maximises extraction of the orebody’s high-grade core by deferring stoping in this area until the paste backfill plant is in operation in 2023. Projected production averages nearly 60 MIb of copper per year for seven years at first quartile costs.

“The Impact23 Growth project that we are kickstarting today is aiming to demonstrate in a 2023 technical report how Cozamin can sustain these levels of performance well into the 2030s.”

Darren Pylot, Capstone’s President and CEO, added: “After 14 years in operation, the best years of Cozamin are ahead. The mine is world class with sustainable low costs and leading safety and environmental performance entrenched throughout the organisation. The growth initiatives are supported by an entrepreneurial fabric at Capstone, as we embrace innovation and technology to create high impact value for our shareholders.”