Tag Archives: ore sorting

Tungsten West cuts CAPEX with new Hemerdon feasibility study plan

An updated feasibility study on Tungsten West’s Hemerdon project in Devon, England, has brought with it a processing re-optimisation program that includes a complete redesign of the front-end crushing circuit at the mine, a process that, it says, will considerably reduce the capital expenditure associated with this development.

The new study outlined average annual production of 2,900 t of WO3 in concentrate and 310 t of tin in concentrate over a life of mine of 27 years, along with an average steady-state mining rate of 3.5 Mt/y.

The changes to the existing process flowsheet to be implemented at Hemerdon can be categorised into three areas, namely:

  • Front end upgrades – new crushing, screening and ore sorting circuit required for Phase 1 (average of 2.4 Mt/y of granite ore, years 1-2);
  • Existing minerals processing facility modifications – upgrades to existing plant to accommodate production requirements for Phase 1; and
  • Phase 2 (3.5 Mt/y of granite ore, year 3 onwards) crushing and process plant expansion – future upgrades to both crushing and processing plants required for increased production rates, envisaged from year three onwards.

The re-engineering has mainly reduced capital and operating expenses around reduced ore handling costs by the introduction of direct tipping at a newly sited run of mine pad, incorporating the introduction of new semi-mobile primary jaw and secondary cone crushers, new operating parameters for the ore sorting circuit, and, to a lesser extent, changes to the existing dense media separation and fine gravity dressing circuits.

The revised front-end design also includes a significant tactical advantage through the introduction of a secondary crushed ore stockpile ahead of the ore sorters, Tungsten West said. This provides up to circa-40 hours of redundancy capacity to the crushing circuit, thereby de-coupling the front end crushing circuit from the minerals processing facility (MPF) – minimising downtime and maximising availability of the concentrator circuit.

Tungsten West has maintained the ethos of the original feasibility study in continuing to engineer-out as many operational, mechanical, electrical or ESG issues associated with the previous operation as possible and to ensure MPF availability and operability remains a priority, it said.

Back in July, Tungsten West concluded a re-evaluation of the options for bringing the Hemerdon mine back into production, announcing a new development plan that would re-optimise the March 2021 Bankable Feasibility Study. The plan was developed in response to global crises in power and diesel prices and the general inflationary environment for construction materials faced by the company.

The new plan has resulted in a remaining capital expenditure, including EPCM fees, of £31.1 million ($38 million) as of October 1.

Mark Thompson, Executive Vice Chairman of Tungsten West, said: “The feasibility study provides solutions to the energy price challenges and will enable increased operating efficiencies at the project. Key highlights from this study include a revised ore delivery and waste mining strategy, a split-phase approach to operational ramp-up to the full design specification, a new primary and secondary crushing method and location, a re-optimisation of the operating strategy for the X-ray Transmission ore sorters, re-design and re-engineering of the feed preparation, ore sorter buildings and structures, and a re-evaluation of the operation of unit processes and expected recoveries.

“We are build-ready at Hemerdon and we look forward to continuing to work with our partners and stakeholders to bring Hemerdon back into production in the fourth (December) quarter of 2023.”

TOMRA Mining to present complete diamond recovery solution at Mining Indaba 2023

TOMRA Mining is to use the backdrop of the upcoming Mining Indaba 2023 event in Cape Town, South Africa, to highlight its complete sensor-based ore sorting diamond recovery solution.

Kai Bartram, Global Sales Director, Corné de Jager, Global Segment Manager Diamonds, and Helga van Lochem, Area Sales Manager, will be available from February 6-9 at the event to discuss the benefits of TOMRA’s portfolio of sorting solutions for the diamonds, metals and industrial minerals industry, as well as the advantages of its advanced digital products and services, like the TOMRA INSIGHT cloud-based platform, the company said.

Today, TOMRA Mining has more than 200 machines in operation across the world.

Bartram said: “Our sorting technologies effectively address key issues that mining companies face, such as decreasing average ore grades and rising energy costs. Not only do we offer a complete solution, unique in the market, for diamond recovery, but we have proven that our sensor-based ore sorting technologies are extremely effective in a wide variety of applications such as chrome, manganese, gold, lead and zinc. There is a big untapped potential for our technologies in mining and so far we have only scratched the surface. Our excellent results show that we are on the right track and we have ambitious objectives of growth for TOMRA Mining.”

Its latest innovation in diamond recovery, the COM XRT 300 /FR sorter, is a new-generation machine that represents an industry first in diamond sorting, according to the company.

Kai Bartram (Tomra Mining photo by Pepe Lange 2022)

It uses the company’s proprietary ultra-high-resolution sensor, advanced new image processing and high-precision ejector valve system to produce an ultra-high diamond-by-weight concentrate with an exceptionally low yield. The sorter offers 100% diamond detection within the specified size fraction and >99% guaranteed diamond recovery with appropriate feed material preparation, according to the company. It is also a dry process that doesn’t require water or chemical reagents.

“Our Final Recovery sorter has the potential to revolutionise diamond flowsheets,” de Jager said. “This user-friendly, compact and easy-to-operate sorter offers higher efficiency and better grade, with fewer sorting stages and a smaller footprint. It reduces complexity and operational costs.”

The TOMRA COM XRT 300 /FR completes TOMRA’s complete partnered diamond recovery solution, which covers the entire process, from Bulk Concentration to Final Recovery and Sort House applications.

“We are now able to offer our customers a full XRT solution to sort +2-100 mm particles: our bulk concentration sorters for +4-100 mm particles and the COM XRT 300 /FR in its Final Recovery, Sort House or small-capacity exploration applications for +2-32 mm particles,” de Jager added.

Weir preparing to trial proprietary ore sorting tech by the end of 2022

In the Weir Group Capital Markets Event presentation last week, Chris Carpenter revealed that the company was collaborating within its divisions on trials of ore sorting technology in an effort to move less rock at mine sites and optimise processing within the plant.

Carpenter, Vice President of Technology at Weir ESCO, said the company was combining Motion Metrics’ particle size distribution (PSD) capability with ore characterisation technology to explore “in-pit sorting” opportunities for its clients.

“Looking further out, we believe ore characterisation and in-pit ore sorting has the potential to transform mining by moving less rock, using less energy and creating less waste,” he said during his presentation. “Ore characterisation technology, which is underpinned by sophisticated sensing systems, captures critical data on properties and composition of rock, including rock hardness and mineral and moisture content.

“When coupled with Motion Metrics fragmentation analysis technology, it has the potential to be a game changer, giving miners a full picture of the size and characteristics of rocks.”

Motion Metrics, a developer of artificial intelligence (AI) and 3D rugged machine vision technology, was acquired by Weir almost a year ago, with the business incorporated into the Weir ESCO division. Its smart, rugged cameras monitor and provide data on equipment performance, faults, payloads and rock fragmentation. This data is then analysed using embedded and cloud-based AI to provide real-time feedback to the mining operation.

These technologies were initially developed for ground engaging tool applications but have recently been extended into a suite of products and solutions that can be applied from drill and blast through to primary processing.

Carpenter said the added PSD capability from Motion Metrics was expanding the company’s value presence across the mine to the processing plant, where Weir Minerals operates.

“Results from early adoption of Motion Metrics PSD solutions have been extremely encouraging,” he said. “Feedback from customers is positive; data sharing and collaboration have increased.

“Given this early progress, we are really excited about the opportunity and expect fragmentation analysis to be a key growth driver for Motion Metrics in the years to come.”

On the in-pit sorting potential, Carpenter said Weir ESCO had laboratory-validated equipment and field trials of its proprietary solution that were due to start at customer sites before the end of the year tied to these developments.

“If successful, this technology opens the door to in-pit sorting, where miners complete the first stage of crushing in the pit and analyse the outputs to make real-time decisions about which rocks have sufficient mineral content to be moved,” he said. “This is a step change from the current process, where energy is expended in transporting and processing all of the rocks, regardless of mineral content, and with significant waste generated from zero- and low-grade material.”

He concluded: “Our vision is to move less rock, moving only the rocks with sufficient mineral content and using the data that is captured on size and hardness to optimise processing. The natural evolution thereafter will be towards real-time automation control of processing equipment, ensuring the right rocks are processed in the most efficient way, using less energy and creating less waste.”

Caravel Minerals takes HPGR use forward to DFS

Caravel Minerals has issued a prefeasibility study update on its namesake project in Western Australia, which, among other things, outlines opportunities to incorporate high pressure grinding rolls (HPGRs) and coarse particle flotation (CPF).

The company only issued the original prefeasibility study in July of this year. This outlined a dual train plant and infrastructure build costing some A$1.2 billion ($806 million), with parallel development of two 13.9 Mt/y capacity trains for a total throughput capacity of 27.8 Mt/y.

Over an initial 28-year mine life, annual production was expected to come in around 62,000 t of copper in concentrate in this study.

The company said at this point that optimisation studies by Ausenco were already in progress for a single train circa-27 Mt/y design, with the pending results expected to show substantial reductions in capital expenditure and operating costs.

That study has now come out, with the company saying the single train design and the adoption of HGPR and CPF are forecast to reduce processing cash unit costs by up to A$1.23/t of ore and reduce capital costs by around A$100 million.

What’s more, the company is also anticipating reductions in both power demand and water consumption with the use of these new technologies.

After seeing such results, Caravel says it will take forward HPGR use over SAG mills in its definitive feasibility study.

It also said the inclusion of CPF in the process flowsheet had the potential to reduce capital and operating costs when compared with the original prefeasibility study flowsheet.

The original Caravel PFS mentioned the potential use of diesel-electric autonomous haulage trucks with electric trolley assist and electric power for drills and face shovels. Mining operation opportunities also included the use of shovel-grade sensors, with the company saying XRF-based bucket sampling was under consideration.

TOMRA XRT ore sorters providing Mt Carbine with tungsten upgrade, circular economy advantages

TOMRA X-Ray Transmission (XRT) sorters are providing a game-changing solution for the EQ Resources-owned Mt Carbine mine in Queensland, Australia, reducing costs and achieving high-purity tungsten ore for follow-on processing while contributing to a circular economy by producing green aggregates for sale, the ore sorting company says.

The Mt Carbine mine, northwest of Cairns, Queensland, was acquired by EQ Resources in 2019. The company entered a joint venture with Cronimet Group to set up tungsten extraction from the mine’s large waste dump and tailings. It is also planning to operate the open pit and underground mine, of which it has full ownership.

EQ Resources management has a long-standing relationship with TOMRA, having used its sorters with success on a variety of projects since 2011, TOMRA says. Based on this experience, the company turned to TOMRA once again for the Mt Carbine mine, with test work conducted at TOMRA’s Test Center in Wedel, Germany, confirming its XRT technology would provide the solution for the project.

“We were confident it would work, but we sent a small sample for testing to make sure,” Kevin MacNeill, CEO of Mt Carbine mine, EQ Resources, said. “The advantage of TOMRA’s sorters compared to others is in the image resolution: it is able to resolve the finer inclusions in the tungsten. This high resolution gives us better recovery and more control over the sorting process.”

Mt Carbine is currently mining the 12 Mt of low-grade historical stockpiles. The ore is crushed and screened at 6 mm and 40 mm. Two TOMRA XRT sorters are used to pre-concentrate the feed in the 6-40-mm-size range before processing in the wet plant. Approximately 10% of the sorters’ feed mass is ejected as product with a recovery of tungsten of well over 90%. This means only 10% of the mass is processed in the wet plant, dramatically cutting running costs, reducing the required size of the wet plant, as well as saving water and energy, TOMRA says.

“We let the technology do the work for us and take out all the rubbish and we’re left with just the pure tungsten to send to the processing plant – and we do that very cheaply using the sorters,” MacNeill says. “One of the best things about the TOMRA XRT is the cost savings to the operation. It costs approximately A$1.5/t ($1.02/t) to sort and then it costs A$14/t for wet processing: as we take out 90% of the sortable fraction mass, we only have to process 10% of the higher grade concentrate and natural -6 mm material while maintaining recovery, so our cost benefit is obvious.

“We couldn’t afford to run this waste dump if we had to crush everything to 6mm and process it through the wet plant, it would be too low grade and costly.”

EQ Resources is also taking advantage of the TOMRA XRT sorters to create an additional revenue stream from the waste material.

MacNeil explained: “Normally you would grind the waste down to 6 mm and put it through the jigs, but, by putting it through the TOMRA sorters, we are able to keep a whole range of aggregates on the coarser size fractions. The sorters remove any material containing acid-forming sulphides and the waste rock that comes out is incredibly clean. We are, therefore, able to use it in making all kinds of different quarry products – from road bases to concrete aggregates. It’s a perfect example of a circular economy.”

“Selling these green aggregates adds a significant portion to our business – about A$5 million a year – and that’s all because of the TOMRA sorters. In fact, we’ve probably paid for each machine from this revenue five times over.”

The TOMRA XRT sorters are delivering both environmental and business benefits to the Mt Carbine operation, to the satisfaction of MacNeill: “They’re dry, they create no water usage, they require very little power compared to what we use in the processing plant, so it’s a real advantage to us to have these, and we’re looking at purchasing a third one in the near future.

“From an environmental point of view, I think the TOMRA sorters will play a huge role in the future because of their capability of removing sulphides. If you remove sulphide before stockpiling waste rock, you will have the benefit of no acid creation and drainage – and it would reduce your footprint in your closure plans.”

Metso Outotec aims for higher capacities as ore sorting offering develops

The entry of Metso Outotec into the bulk ore sorting space arguably heralds the beginning of a new stage of market adoption – one that is focused on significant throughputs across multiple commodities.

In May, the mining OEM announced a collaboration agreement with Malvern Panalytical, a company that has been using Pulsed Fast Thermal Neutron Activation (PFTNA) technology onboard its cross-belt analysers to analyse and help divert ore and waste streams with improved accuracy.

Up until that announcement, Metso Outotec had mooted the benefits of bulk ore sorting in several industry articles. On the smaller scale, it had also renewed its ongoing agreement with particle ore sorting major player, TOMRA.

The company said its agreement with Malvern Panalytical, which has previously worked on bulk sorting projects with Anglo American among others, brought together its expertise in crushing and bulk material handling solutions with Malvern Panalytical’s ore analysis nous to offer an industry-leading portfolio of solutions for bulk ore sorting.

Rashmi Kasat, Vice President, Digital technologies at Metso Outotec, said in the press release that the pact with Malvern Panalytical would allow the company to meet the industry’s increasing sustainability and resource efficiency needs in an enhanced way in the early comminution stage.

“Sensor-based bulk ore sorting and data-driven analysis upgrades low grade or waste stockpiles, making them economical and far less energy-intensive to treat,” she said.

There are obvious positive benefits up- and down-stream of sensor-based sorting too, with the ability to carry out a low-cost mining method (upstream), as well as reduced capital investments in downstream equipment already shown with early-adopter projects.

That is before considering the relative energy and water reduction requirements that come with applying the technology.

Kasat later told IM that the company’s existing portfolio of material handling modules, crushing stations or mobile crushing equipment, as well as bulk material handling solutions, already “complement” the concept of bulk sorting.

“The addition of the bulk sensor is easily achieved,” she clarified. “The diversion mechanism will be included as well to be able to offer the whole plant out of one hand.”

With crushing stations – at least in the in-pit crushing and conveying (IPCC) space – that can go up to 15,000 t/h (see the company’s Foresight™ semi-mobile primary gyratory station), the prospect of Metso Outotec making a concerted effort to get into the bulk ore sorting space bodes well for the rising throughputs of projects.

NextOre recently claimed it had commissioned the world’s largest bulk ore sorting system at First Quantum Minerals’ Kansanshi copper mine in Zambia. This installation, which uses the company’s magnetic resonance technology, comes in at a 2,800 t/h-rated capacity.

Scantech, meanwhile, recently confirmed it has a GEOSCAN GOLD installation using prompt gamma neutron activation analysis technology for bulk sensing/sorting up and running that uses a diversion system at conveyed flow rates of more than 6,000 t/h.

Kasat, without naming a range, confirmed Metso Outotec was targeting “higher capacities” in line with the sensors available on the market. She also clarified that the agreement with Malvern Panalytical was “non-exclusive”.

“We will choose all our sensor/analyser partners strategically,” she explained. “Malvern Panalytical has a leading position and history in this field with proven technology for ore sensing. We will leverage our and their Tier 1 position in the industry for our bulk ore sorting offering.”

Malvern Panalytical uses Pulsed Fast Thermal Neutron Activation technology onboard its cross-belt analysers to analyse and help divert ore and waste streams with improved accuracy

As the type of sensor to be employed varies based on several factors including mineralogy, plant capacity, application of bulk ore sorting, etc, Metso Outotec will identify the right partners for the right need, she explained.

The major constraints for these sensors are often measurement times and sensor penetration, according to Kasat.

“There are very few sensors out there that can do sensing of a 500-mm-deep bed of rock on a conveyor belt, moving at 5-6 m/s,” she said. “But our current and future prospective partners are working on developing the technologies to reduce measurement times without compromising the accuracy of measurement.”

The mining OEM is looking to, in most cases, provide ‘plug and play’ flowsheets for bulk ore sorting and then carry out the required customisation per sensor.

This plan reinforces Kasat’s assertion that there is no ‘one-size-fits-all’ concept in bulk ore sorting applications.

For new projects, the process could see the company start with metallurgical testing, progress to mobile/fixed pilot plants in the “backyard” to test the accuracy of the sensors for the given application, and then find the right solution for the customer’s use case.

Renato Verdejo, Business Development Lead for Bulk Ore Sorting at Metso Outotec, added: “For existing plants, we will install the sensor over the belt conveyor and analyse the results after selecting the right sensor for this sorting application.”

Metso Outotec intends to focus on major commodities like copper, iron, nickel and gold, among others, with applications such as waste/ore sorting, low grade re-crushing and beneficiation process optimisation.

Within this wide remit – and in line with its non-exclusive agreements with Malvern Panalytical and TOMRA – the company is also considering the combination of both bulk and particle sorting in flowsheet designs.

Metso Outotec, in 2021, renewed its ongoing agreement with particle ore sorting major player, TOMRA

“The combination of the superior throughput of a bulk application with the selectivity of particle sorting in a rougher-scavenger setup is something that can bring sorting to high volume mines in the future,” Kasat said.

“Plant concepts and flowsheets have already been conceptualised and we expect the first deliveries to be in pilot stations to test the sensors on site,” she added, saying that the tonnage requirements for bulk ore sorting sensor validation meant a bulk sensor would have to be piloted in the field to get statistically meaningful data about the properties of the deposit.

Metso Outotec’s crushing system offering will form the “base” for these solutions, with ore sorting optionality available to all customers, she said.

This sensor-based optionality also overlaps with another in-demand part of Metso Outotec’s business: IPCC.

The company’s dedicated team in Germany are responsible for this area, developing projects backed by comprehensive studies.

They – like most of the industry – are aware of the potential application for sensor-based ore sorting in IPCC projects.

Markus Dammers, Senior Engineer of Mine Planning for Metso Outotec and one of the team members in Germany, said there were applications for both bulk and particle sorting in IPCC applications, with the former likely integrated after primary crushing and the latter after secondary/tertiary crushing.

“Bulk ore sorting in an IPCC application should be integrated after primary crushing in order to recover marginal material determined as waste in the block model, or reject waste from the ore stream,” he said.

Bulk ore sorting in an IPCC application should be integrated after primary crushing in order to recover marginal material determined as waste in the block model, or reject waste from the ore stream, according to Markus Dammers

If integrated after secondary or tertiary crushing, it becomes less effective, with the ore’s heterogeneity decreasing every time the ore is rehandled, transferred, crushed, blended, etc.

“In this manner one can take advantage of the natural variability in the deposit, rather than blending it out, with bulk ore sorting,” he said.

After secondary and tertiary crushing, particle sorting may be applied as a “standalone or subsequent ‘cleaner’ process step”, he added.

With Metso Outotec open to the inclusion of ore sorting in fully-mobile, semi-mobile and stationary crushing stations within an IPCC context, the company has many potential customers – existing and new – out there.

And that is just in IPCC applications.

The company also has hundreds of crushing stations on fixed plant installations that could represent potential sorting opportunities.

Metso Outotec, on top of this massive install base, has a few advantages over traditional ore sorting vendors in that it understands the plant that goes around the analysis and diversion process associated with ore sorting; knows how important uptime is to its customers; and, through sophisticated modelling, realises what impact changes in the flowsheet will have up- and down-stream of such equipment.

“The key point here is to have all the equipment to handle and process the ore to feed the sorter and, later, having the technology to divert the material and retain the availability of the plant without changes,” Kasat said.

Energised by its Planet Positive aims of responding to the sustainability requirements of its customers in the fields of energy or water efficiency, emissions, circularity and safety, the company is now ready to flex its processing plant muscles to increase the industry’s adoption of bulk and particle sorting technology.

Newcrest’s Brucejack mine set for full fleet battery-electric transition in Q4

Newcrest’s Brucejack gold-silver mine in British Columbia, Canada, is set for a full battery-electric fleet transition by the end of the year, the gold miner said in its financial year 2022 results.

Following a successful site trial, seven underground battery-electric trucks are being commissioned at Brucejack, replacing the existing diesel fleet and abating approximately 65,000 t of CO2 emissions through to 2030.

The new fleet will improve truck productivity, lower unit costs and enhance operational efficiency from planning to production, according to Newcrest. Three of the Sandvik 50-t-payload Z50 battery-electric trucks are already in production, with the full switch over expected to be completed in the December 2022 quarter, it noted.

Sandvik and Pretivm previously noted that seven Z50 haul trucks would be supplied to the operation as part of the planned fleet transition.

The project is being partly funded thanks to a C$7.95 million ($6.1 million) investment from The CleanBC Industry Fund.

Brucejack, which became wholly owned by Newcrest when the acquisition of previous owned Pretivm Resources completed earlier this year, is currently the subject of Newcrest’s EDGE program, which aims to drive a culture of innovation, high performance and continuous improvement. The program has identified additional opportunities of approximately C$15-$25 million/y, with improvements in stope turnaround time and more efficient mine operations as the initial focus areas, the company said.

Run-rate benefits from this effort are expected to be fully realised by the June 2024 quarter, Newcrest says.

Newcrest said in the financial results that it was also assessing ore sorting technology at the mine, which aims to classify and separate mineralised material from non-mineralised material to deliver more consistent mill feed grades and increase operational flexibility.

Atlas Copco VSD electric compressors help improve Autlán’s manganese ore sorting capacity

Atlas Copco’s E-Air V1100 Variable Speed Drive (VSD) electric compressors are helping Mexico-based manganese producer, Autlán, improve the effectiveness of its ore sorting process by providing clean, dry compressed air whose temperature doesn’t exceed 20°C above ambient, the company says.

Compressed air is an essential component in the production of manganese nodules, with one such area being the company’s mineral sorting machine, which helps to classify the manganese ore. It blasts air at stones deemed to be waste, separating them from stones with high manganese content.

To do this, it needs clean, dry compressed air whose temperature doesn’t exceed 20°C above ambient. The amount of free air (FAD) needed to do this task is 45 Nm3/min at 150 psi.

Atlas Copco Power Technique Mexico worked closely with Autlán to understand and define the optimum airflow for the process. It advised Autlán that a constant flow of air was not required because the air shots were not continuous (only when stones with low manganese grades needed to be separated). Because of this intermittent requirement, Autlán could specify a compressor that met its FAD requirements but saved energy and lowered costs.

The suggested solution was to install three E-Air V1100 VSD mobile compressors: two compressors for production and one for stand-by purposes. These electric mobile air compressors with VSD technology are built to operate in harsh and outdoor conditions. Because of their robustness, Autlán did not need any special installation or compressor room, saving money on civil works, Atlas Copco says.

Atlas Copco’s E-Air VSD comes with the standard spillage-free frame that offers 110% fluid containment, providing reassurance against possible spillages on site. This was a key feature for Autlán, avoiding the possibility of polluting the soil of the mine, which is strongly regulated.

Moreover, the compressors come equipped with potted motor windings to prevent dust and water ingress, an IP65-rated controller, an IP67-rated water-cooled drive, single-sheet steel, non-welded undercarriage, and a three-layer anti-corrosion paint system, the company explained.

As the compressed air quality is vital for this project, Atlas Copco recommended adding its UD+ filter after the cooler to ensure the air guns didn’t clog. The UD+ filter is a patented design, two-in-one coalescing filter that takes out oil aerosols, dust and water, providing clean compressed air with hardly any pressure drop or efficiency loss. Moreover, this system is a space-saving option compared with traditional filter packages, according to Atlas Copco.

Julio Ponce, Sales Engineer & Air Master for Atlas Copco in Mexico and Central America, says: “The E-Air VSD provides Autlán with a reliable flow of compressed air without any CO2 emissions.”

The E-Air’s integrated VSD-driven permanent magnet electric motor only requires low power for start-up, so there is no need to oversize the power supply. The VSD and permanent magnet motor also make an important contribution to efficiency. Combined, they offer the best-in-class efficiency at partial load and ensure that power consumption closely follows the air demand trend, according to Atlas Copco.

These electric mobile air compressors with VSD range include the Atlas Copco’s PACE system (Pressure Adjusted through Cognitive Electronics). This enables users to control the pressure between 5 and 12 bar, in precise 0.1 bar increments, thereby adjusting the flow to the optimal level for their application. Because of this, one compressor can handle various jobs that previously would have required multiple units.

The E-Air VSD features the Smart Air Xc4004 controller. This increases the efficiency of operations by providing insights and features in an easy-to-use interface that allows a simultaneous view of several parameters, including pressure and flow. Additionally, top structured alarm settings allow for operation monitoring.

The E-Air VSD range is also equipped as standard with an after-cooler, providing high-quality air for applications like sandblasting.

Futureproofing the world’s copper supply through technology use

Realising the vision of a world of clean energy brings the issue of metal supply into sharp focus, with major and sustained increases required to meet growing demands, Thermo Fisher Scientific’s Ellen Thomson* writes.

With copper, for example, there are predictions of a shortfall of 15 Mt per annum by 2034 based on the current output. Therefore, boosting the efficiency of mining operations has never been more important, and smarter technology is undoubtedly the way forward to achieve this. Real-time sampling and measurement right across the mineral processing value chain can arm miners with analytical data, enabling them to build a robust understanding of the performance of each plant and drive continuous improvement at every step of the process. This article takes a closer look at how several of these steps could be optimised, including ore grade measurement, sorting on the mill feed conveyor, particle size analysis in the grinding circuit, the addition of reagents in the flotation circuit and elemental analysis and impurity detection in the concentrate leaving the plant.

Copper miners face the challenge of satisfying the rising demand for metal, while hitting the industry’s 2050 net zero carbon target. This is likely to require significant changes in operations through processing low-grade ore more efficiently, fully exploiting existing deposits, and bringing new mines into production. Unfortunately, higher-grade ore – with a 2-3% metal concentration – has largely been depleted, and miners now often work with concentrations of just 0.5%, meaning greater quantities of ore must be processed to extract sufficient amounts of copper. Therefore, it is essential to seek fresh opportunities to improve processes across the entire mining value chain, so that the increasing demand for copper ore will be met well into the future.

Does your ore make the grade?

Enhancing mining efficiency begins as soon as raw material is extracted from the ground, and extends through the crushing process and the mill feed conveyor. It is important to accurately measure the grade of the plant feed as this will impact both the performance of the concentrator and the production costs of the final product. However, this can be challenging, as some deposits are highly heterogeneous and unpredictable. Bulk ore sensing and sorting are, therefore, crucial steps in improving the raw feed material consistency and concentrator efficiency, since they reduce the dilution of incoming feeds and redirect low or marginal grade material away from the concentrator at the first opportunity. These stages rely on highly accurate and precise analytical technologies to rapidly differentiate material grade and minimise the loss of valuable material, moving only economically viable ore further along in the process. A high spec analyser is vital to this part of the chain and enables small and lower-grade satellite deposits to be accessed more successfully, as well as increasing profits for established plants.

Cracking down on the grinding circuit

Grinding is an essential first step in mineral liberation, but there is often no clear understanding of what the target particle size should be for a given head grade. Producing finer particles liberates more metal, but also increases media and energy costs. More than 50% of the energy consumed at a mine goes into crushing and grinding, so over grinding has definite economic and environmental implications. It is crucial, therefore, for each mine to find a balance between particle size and circuit throughput that limits consumption of grinding media and energy, while still maximising metal yields.

Grinding just enough is critical – too fine means lower throughput and/or higher energy consumption; too coarse and recovery suffers

Once a target has been established, real-time analysis of particle size and head grade elemental composition – for example, by prompt gamma neutron activation analysis (PGNAA) using a cross-belt system such as the Thermo Scientific™ CB Omni™ Agile Online Elemental Analyzer – can have a significant impact on the efficiency of the grinding circuit. In addition, by standardising particle size and controlling composition through the plant feed and grinding stages, the stability in feed forward control is increased going into the next stage – the flotation circuit.

The CB Omni™ Agile Online Elemental Analyzer (Thermo Scientific) rapidly and accurately differentiates material that is at or below the cut-off grade for ore sorting, the company says

Fine-tuning flotation

Flotation is a complicated physicochemical process where reagents – such as frothers, collectors and pH modifiers – are introduced to promote separation. The flotation feed can vary in particle size and chemistry depending on how the grinding circuit is optimised, and may contain excess fines. Miners might choose to compensate by adding more reagents, which can sometimes be beneficial but can also incur greater financial and environmental costs. Therefore, it is important to tailor the dosages of the flotation reagents in response to the incoming ore grade and particle size.

Concentrating on monitoring impurities

Certain impurities compromise the value of a concentrate, but they are often overlooked. Detecting impurities in the concentrate ahead of shipping reduces the chance of rejection at the receiving site – and the subsequent financial losses – and has the potential to improve ore quality, strengthen a company’s reputation and reduce the risk of penalty charges. In fact, representative sampling throughout ore extraction to concentrate the production process should be considered, but this can be extremely challenging owing to concentrated slurries, high tonnages, long distances between sample and analysis, and the expense and complexity of tackling head constraints.

Multi-stream analysers – like the Thermo Scientific MSA 3300 Slurry XRF Analyzer – are commonly employed in the mining industry, and can seem like an excellent, cost-effective solution. However, multiple streams can reduce efficiencies and lengthen the time to results – leading to less responsive control – and so their low upfront cost should be carefully balanced with their long-term implications. Choosing high quality analytical equipment that requires minimal manual input and has a proven record of reliability could help overcome these challenges and offer a better long-term solution. For example, a dedicated online sampling and elemental analysis station, such as the AnStat-330, provides a versatile and compact solution for addressing issues related to the process control of critical streams, time to results, the distance from sampler to analyser and the requirement for a metallurgical accounting quality sample.

 

 

The MSA 3300 Slurry XRF Analyzer (Thermo Scientific) measures up to 12 streams, with full stream separation retained throughout, Thermo Fisher says
The Anstat-330 Slurry Online Sampling and Elemental Analysis Station (Thermo Scientific) comes with options for additional process functionality, including distribution and pebble screening

Future-ready mining technology

It is vital to detect and understand why mining processes may be operating sub-optimally to know how to improve them. Relevant, reliable digital information is the foundation of an efficient operation and investing in more effective and continuous analysis is a key strategy for increasing return on investment. Digital twins, for example, integrate and collect data from sensors into a cloud platform to construct a complete and fully representative digital version of the concentrator. This allows miners to model different scenarios – such as changing process parameters – without interrupting the real-world activities of the mine. They aid in decision making and help to prevent unnecessary expenditure, as well as identifying any operational bottlenecks. Mining companies could potentially achieve 20 times – with some estimates up to 40 times – return on their initial investment through implementing digital twins, and more easily establish advanced, automated process control, increasing efficiency and depopulating mines.

Digital innovations are undoubtedly going to transform the mining industry and will help to reduce resource consumption and meet future sustainability goals. Without reliable, timely feedback, process control will always be on a ‘trial and error’ basis, which is no longer sufficient if miners are to fulfil the increasing copper demand ahead of us. Thermo Fisher Scientific supports the mining industry in adopting such technologies to enable dependable, timely and, often, real-time measurements that provide the data that miners need to track metal values, all the way from exiting the mine through to concentrate shipping.

*Ellen Thomson is PGNAA & Minerals Senior Applications Specialist at Thermo Fisher Scientific

NextOre, First Quantum fully commission ‘world’s largest bulk ore sorting system’

A 2,800 t/h MRA ore sorting installation at First Quantum Minerals’ Kansanshi copper mine in Zambia is now fully commissioned and using diversion hardware, Chris Beal, CEO of NextOre, told RFC Ambrian and Stonegate Capital Partners’ Copper Pathway to 2030 webinar on Tuesday.

Presenting alongside speakers from RFC Ambrian, Oroco Resource Corp and First Quantum Minerals, Beal revealed that the diversion process on what he said was the highest capacity bulk ore sorting operation in the world had now commenced, some 16-17 months after the magnetic resonance (MR) based system was installed and testing commenced.

“After a one year sensing-only trial, Kansanshi has now gone forward and commissioned and tested diverting hardware in May that has allowed them to fully transform into an inline bulk sorting system,” he said.

“With the validation of that having just gone by, this now represents the highest capacity sorting plant in the world.”

NextOre was originally formed in 2017 as a joint venture between CSIRO, RFC Ambrian and Worley, with its MR technology representing a leap forward in mineral sensing that, it said, provides accurate, whole-of-sample grade measurements.

Demonstrated at mining rates of 4,300 t/h, per conveyor belt, the technology comes with no material preparation requirement and provides grade estimates in seconds, NextOre claims. This helps deliver run of mine grade readings in seconds, providing “complete transparency” for tracking downstream processing and allowing operations to selectively reject waste material.

The installation at Kansanshi is positioned on the sulphide circuit’s 2,800 t/h primary crushed conveyor belt, with the system taking precise measurements every four seconds for tonnages in the region of 2.5 t to a precision of +/- 0.028%.

“Magnetic resonance technology, in particular, is very well suited to high throughput grade measurement – it is measuring all of the material that is going through,” Beal explained. “And these sensors like to be filled with more material.

“We hope to go larger from here. And we, in fact, have projects ongoing to do that.”

This wasn’t the only reveal Beal provided during the webinar, with the other announcement slightly smaller in scale, yet no less significant.

Seeking to address the lower end of the bulk ore sorting market, the company has come up with a mobile bulk sorting plant that is powered by MR sensors.

This solution, coming with a capacity of up to 400 t/h, has now found its way to Aeris Resources’ Murrawombie mine in New South Wales, Australia, where it is being used for a trial.

At Murrawombie, the setup sees an excavator feed a mobile crusher, with the crushed material then passed to the mobile ore sorting installation (the conveyor, the sensor, the diverter and supporting equipment). The system, according to Beal, provides bulk ore sorting results in a cost- and time-efficient manner.

It has been designed to suit small mines and those seeking to monetise historical dumps, or to provide a rapid test method for bulk sorting to support a potentially much larger bulk sorting plant, Beal explained.

The fully-diesel setup is destined for copper operations globally and potentially some iron ore mines, he added.