Tag Archives: SRK Consulting

Pre-concentration: it’s worth asking the question

Comminution of minerals, Environmental, Mineral processing, Mining equipment, Mining services, Sustainable mining, , , , ,

We’ve reviewed a novel, vendor-agnostic pre-concentration screening test in part one and explained a comprehensive five-step pre-concentration evaluation in part two…now for part three in the three-part series with SRK Consulting (Canada) Inc’s Adrian Dance (Principal Metallurgist) and Bob McCarthy (Principal Consultant)

SRK Consulting’s Adrian Dance and Bob McCarthy have devoted years to ensuring the mining industry can make informed decisions about preconcentration within their flowsheets and are now able to screen the opportunities quickly, cost-effectively and without vendor prejudice.

“We have been carrying out the different parts of the five-step evaluation process over the years, refining them independently and sometimes together,” McCarthy tells IM. “It is only now that we can present them all in a holistic way.”

This five-step process – which includes heterogeneity analyses; “size the prize” economics; laboratory test work that involves X-ray Transmission (XRT) based sensor technology; mine planning; and mine economics – has been deliberately designed to allow mining companies to pause at the end of each phase to re-evaluate if there is a strong enough case to continue with a preconcentration investigation.

BobMcCarthy-SRK
Bob McCarthy, Principal Consultant), SRK Consulting (Canada) Inc

The importance of such an approach has grown in recent years as more projects that are “grade-challenged” or metallurgically complex are being considered for exploitation by mining companies as the demand for metal increases worldwide.

Sensing this (pun intended), sorting and sensing manufacturers have been on the mining charm offensive, proclaiming the benefits of their technology – benefits that include cost reductions, improved metallurgical recoveries, rationalised use of energy and water, and more.

These market dynamics have created a void that SRK is looking to fill by providing the tools for both sides to assess the options and carry out informed decision making on which routes to pursue.

“We were concerned that the manufacturers didn’t have the background needed to understand the mining industry’s requirements,” Dance said. “At the same time, mining companies had difficult projects and deposits where they saw pre-concentration potential but didn’t know where to initially go to explore that potential.

“We saw a space for industry representatives like ourselves at SRK to bridge that divide.”

The independent testing that SRK has been able to offer for the last six or so months through its partnership with Base Metallurgical Labs (BML) in British Columbia was the final piece of the puzzle in establishing this nowestablished five-step process.

Able to not only indicate pre-concentration amenability but also provide key inputs into the pre-concentration strategy selection and evaluation, this has been employed for some 36 samples (close to 2,000 particles) being tested using the XRT unit situated in BML’s facility in Western Canada.

Demystifying the tech

While this XRT testing may have only recently become available to SRK and BML customers, the outcomes of SRK’s pre-concentration evaluation have been described to investors and stakeholders trawling through NI 43-101 reports up to the prefeasibility study (PFS) level for some time now. Various parts of the five-step evaluation have come into sections on metallurgical test work, mineral reserves, mining methods, costs and economics.

“Where the results feature is tied to what study stage the company is at and where people feel comfortable with pre-concentration,” McCarthy explains.

Providing comfort to mining companies and their investors is always difficult when examining any new flowsheet addition, hence the reason why many companies are initially pursuing pre-concentration or ore sorting in a ‘recovering ore out of waste’ scenario from material already deemed to be waste and having no economic value.

As a result, SRK has been very deliberate in the protocols it is pursuing.

Dance explains: “Because there is still a perceived ‘magical’ nature to preconcentration in that it can provide reserve upgrades and higher recoveries, we need to do more detailed evaluations at a preliminary economic assessment or PFS level than would be expected for other types of processing technology.”

For instance, the company is currently engaged on a gold operation where it has tested upwards of 22 samples (1,320 particles) for validation. “At this level of study, if you were working on comminution or leaching, the same process validation would be carried out with two or three tests,” Dance said.

McCarthy added: “We firmly believe that this five-step evaluation will allow people to sign off, at least at a PFS level, on whether pre-concentration is a viable route for them to take. Our process will prove this through testing and pulling different economic levers in the economic evaluation to quickly see where the value is, and where it isn’t.

“If pre-concentration is viable, you would then likely see clients moving on to performance testing with some of the sensing/sorting vendors at the feasibility study stage.”

Welcoming the independence

Those who understand the pre-concentration space have welcomed the involvement of SRK through its five-step process and, in particular, have highlighted the industry need for standardised and independent testing.

“They see where we are inserting ourselves into stages of the client and vendor relationship,” Dance said. “In no way are we competing with vendors – we are not suggesting we have the expertise they have. Rather, we are looking at the characteristics and amenability elements for the vendors to then truly apply their expertise, knowledge and sensor selection understanding.”

Adrian Dance, Principal Metallurgist, SRK Consulting (Canada) Inc

At the same time, Dance and McCarthy are looking to arm mining companies with relevant knowledge about pre-concentration principles, where the process could provide a grade uplift and what losses might be associated with the implementation. This is being done through gaining a better understand of their orebody through the testing.

It should result in mining companies providing a more representative sample to the pre-concentration vendors for the performance testing many of them offer. “Mining companies can then understand these pilot test results more broadly and ask more questions, if needed,” Dance said. At the same time, the vendors have a ‘pre-qualification’ check in hand: they would know from the SRK process if there is a strong basis for carrying out the performance test in the first place.

And, of course, SRK can get involved after the five steps are complete, carrying out small-scale work and integrating these results with the larger
scale performance testing that could eventually underpin a flowsheet developed by a third-party engineering company.

“We view pre-concentration as another aspect of geometallurgy that needs to be interrogated just like comminution and flotation,” Dance said.

The future focus

It is potential changes to both of those processes that could have positive implications for pre-concentration in the mining sector.

“We’re now seeing more flowsheets designed with a multi-stage comminution flowsheet that, at every stage, asks: ‘do I need to process the oversize material again?’” Dance said. “There is an opportunity for the right sensors to answer those questions. That is being highlighted in the design of some of this technology; some newer ore sorting units are reminiscent of cone crushers in size and shape, which means they can be inserted into this flowsheet with ease.

And, of course, some pre-concentration-focused companies have gone upstream of the plant to the pit to provide these readings: an area Dance sees as representing the future.

“Heterogeneity is better preserved the further upstream of the plant you go, so it is obvious to think that pre-concentration technology – which feeds off this heterogeneity – should be placed here,” he said. “The issue comes with getting a representative sample to test – whether that is a shovel load, or the equivalent of what a 200-t payload truck can carry. Ultimately the mining industry is at a ‘prove it’ stage when it comes to pre-concentration technology. The mining companies want to see results on paper or on a screen before they sign off on this technology and process. At the scale of a truck or shovel, this is very challenging.”

McCarthy added: “The Heterogeneity and Scale analysis we are doing in step one of the evaluation will identify some of these opportunities within the selective mining unit sizing, but it is still early days on factoring that into sorting at a truck or bucket scale.”

This work will require closer examination of the drill core than the typical 1-m assayed intervals, as well as a way to estimate the level of mixing that occurs between vertical blast holes, post-blasting, post-loading and post-conveying.

This comprehensive plan is broadening too, factoring in more than just economics.

For instance, SRK has made a case for carrying out the same sizing and XRT analysis included in the five-step evaluation for mill pebbles – which can represent up to 30% of the entire plant feed in some cases – to assess their true value.

This obviously has a cost benefit, as well as an energy benefit – avoiding recirculation of pebbles avoids excess energy use. This same testing is indicating there could be further energy benefits to be had by using preconcentration, too.

In addition, “We have recently expanded our testing protocol to now measure specific energy requirements of the concentrated material compared with the original feed,” Dance said. “This has shown (at times) a softening effect of pre-concentration that can produce measurable savings in power.”

And the impacts on water and energy use are another avenue that could come into the ‘size the prize’ economics McCarthy uses in step two of the five-step evaluation process. “There is no reason to think this could not be included in the analysis in the future; all we would need are the metrics for the existing proposed operation – the amount of water and energy used for the number of tonnes in the mill feed,” he said. “It will then just be a simple case of amending the two inputs based on the pre-concentration work.”

Against a backdrop of falling grades, increasing metallurgical complexity and perceived future demand for commodities, the pre-concentration question needs to be asked by all companies.

For more information on the XRT pre-concentration screening test SRK and Base Metallurgical Labs can provide, as well as the five-step evaluation process for pre-concentration amenability, click the link here

SRK’s stepwise approach to pre-concentration analysis

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Having outlined a new vendor-agnostic, lab-based “pre concentration screening test” for mining in part one of this three-part series, SRK is back for part two, discussing the wider pre-concentration evaluation process that this testing fits into

“With any pre-concentration analysis, we need to, first, understand the heterogeneity of the deposit; simply put, if you don’t have heterogeneity, you don’t have the ability to separate the good stuff from the bad stuff and carry out pre-concentration,” Bob McCarthy, Principal Consultant, SRK Consulting (Canada) Inc, says.

With this baseline in mind, SRK Consulting has devised a pathway for companies with drill core at their disposal to analyse whether pre-concentration is a viable option for their flowsheet.

Made up of five steps, this staged approach is deliberately designed to allow companies to pause at the end of each phase to re-evaluate if there is a strong enough case to continue investing the time and finances required.

The heterogeneity analysis is first up, which, under SRK’s evaluation, includes two different approaches based off drill hole analysis: Heterogeneity and Scale and Composite-Sample Relationship Analysis.

“Heterogeneity and Scale involves a process of looking up and down the bore hole at different aggregation distances from every sample and interrogating the sample grade – or net smelter return – against the aggregations above and below that individual sample,” he explains. “We then increase the size of the aggregation to see how that relationship changes.”

Such analysis enables SRK experts to derive the heterogeneity measures typically dubbed ‘waste in ore’ (mineralisation below the cutoff grade within an above cutoff grade zone) or ‘ore in waste’ (mineralisation above the cutoff grade within a waste or marginally below cutoff grade zone). Using a cutoff grade derived from industry benchmarking, the consultants assess the aggregation distance, as resolved in the vertical direction, with the “selective mining unit” (SMU), which typically relates to equipment sizing for mining.

“Heterogeneity and Scale involves a process of looking up and down the bore hole at different aggregation distances from every sample and interrogating the sample grade – or net smelter return – against the aggregations above and below that individual sample,” Bob McCarthy says

“The pitfall some companies go down is picking your SMU to match an equipment size and production rate typically aligned to a corporate or strategic objective,” McCarthy says. “This could mean generating a 12-14-year mine life for a gold operation, or some other investor-led metric that doesn’t necessarily respect the deposit’s heterogeneity.”

The second approach – Composite-Sample Relationship Analysis – allows consultants to further quantitatively assess those waste in ore/ore in waste heterogeneity measures.

“Those parameters have multiple uses after being determined,” McCarthy says. “For example, they help guide in the sample selection – you can even visualise them in 3D with something like Leapfrog. You can also see contiguous lengths of above or below cutoff grade material in ore zones or marginal waste zones, representing what an ore sorter may see. These would be targeted for testing.”

Responding to industry calls, SRK now offers a step between this fundamental heterogeneity analysis and the test work it can conduct at Base Metallurgical Labs’ Kamloops facility in British Columbia, with what McCarthy calls “size the prize” economics. It provides insight into possible pre-concentration strategy outcomes and, just as important, justification to continue to the next step of lab test work.

This process – carried out by SRK on several projects in the past – is designed to allow the mining company and consultant to test pre-concentration strategies from an economic perspective, assessing if an operation should be removing waste from ore or looking to recover above cut-off grade material from “marginal waste”.

McCarthy added: “It is about answering these questions: is it best to remove waste from mill feed, and to what maximum grade of feed, or to extract mineralised material from marginal, below cut-off grade material that increases the mineral reserve? And, of course, do the expected results of this process look promising?”

Gold is a good example here as the economic case study for pre-concentration often only stacks up when a “cap” is applied to the grade of ore subjected to pre-concentration. In other words, the highest-grade material should not be targeted. Even high-efficiency pre-concentration methods incur some metal loss, and any amount of “loss” that occurs in a gold project is difficult to make-up within a conventional flowsheet.

Example of drill core intervals showing waste in ore percentages of up to 80%

The third step in this five-step process is the lab test work McCarthy’s colleague, Adrian Dance (Principal Metallurgist at SRK Consulting), previously outlined in detail in the first article in this three-part series.

The “pre-concentration screening test” leveraging X-ray Transmission based sensor technology can not only indicate pre-concentration amenability, but also provide key inputs into the pre-concentration strategy selection and evaluation, Dance says. He says the testing offers an assessment of pre-concentration potential, as well as an estimate of material bypass and metal upgrade from samples as small as half cores.

Used in conjunction with crushing and screening, this testing rapidly – and cost effectively – assesses the potential for pre-concentration, which can then be applied to scoping or pre-feasibility studies, according to SRK and Base Metallurgical Labs.

Which is where steps four and five of the SRK evaluation – mine planning and mine economics – come in.

“With the heterogeneity measures assigning the distribution of waste in ore, ore in ore, and ore in marginal material in mining block models, the test results reflecting these conditions can be populated into those same models for mine planning,” McCarthy explains.

Typical mine planning steps of pit/stope optimisation, mine design and scheduling can proceed on the assumption of one or more pre concentration strategies, with different versions of mine schedules, reflecting different pre concentration strategies, evaluated.

This type of analysis typically works for a project in pre-feasibility study stage, where engineers can go into the existing block model, bringing the results from the heterogeneity and lab tests into the mine optimisation, design and scheduling process that takes place.

“The challenge is that the scheduling needs to assume a certain strategy – maybe you have determined what that strategy is close enough with the ‘size the prize’, but there are always a few elements you may want to tweak,” McCarthy says. “This could be the mass pull, or waste rejection targets, for instance.”

As a result, sensitivity analyses – mostly numerical tweaks – are embedded in the process.

When not dealing with a pre-feasibility-level project, the SRK team typically rely on an existing schedule that has been run during a scoping study or preliminary economic assessment. This model is modified and tested with different schedule scenarios and pre-concentration strategies based on the heterogeneity measures (step 1) integrated with the lab test results (step 3).

Out of the mine planning step comes a schedule that would go onto the next step: mine economics modelling.

“The model is configured to take in the heterogeneity measures, recovery curves, etc to change the amount of metal reporting to revenue and so forth,” McCarthy says. “Once I get schedules – based on the upgraded block models or it may be a pre-existing schedule – I would then put them into an economic model that has all the levers to pull for different pre-concentration strategies.”

Such a stepwise approach is indicative of where the mining industry is at the moment with vendor-agnostic pre-concentration analysis, enabling companies to get comfortable with the data and assessments as their understanding of their deposit’s heterogeneity grows.

There are potential refinements and fine-tuning opportunities too.

For example, if SRK was gifted with drill core or assay data that was more granular than the 1-2 m intervals typically taken at the exploration stage, it could indicate with greater certainty how particle sorting – typically analysing grades at intervals around a few centimetres – could benefit the deposit in question.

Also, if mine modelling software had matured to the point where block models could be tailored specifically to these waste-in-ore and ore-in-waste characteristics, SRK could segregate the areas in question, instead of applying the type of dilution factors they currently have in place to account for the grade-based realities. This would more clearly communicate the deposit’s heterogeneity to all stakeholders.

Yet, McCarthy and Dance know this will come in time, and are happy to work within the current confines to continue the industry’s education process and identify where the pre-concentration opportunities are

Further discussion on this and what SRK’s pre concentration analysis evaluation – with that embedded pre-concentration screening test – means within the broader mining industry context will follow in the final article in this three-part series later this year

SRK Consulting, Base Metallurgical Labs tackling pre-concentration amenability

Base metals, Mineral processing, Mining services, Mining software, Sustainable mining, , , , , , , , ,

In this first of a three-part series of articles on pre-concentration in the mining space, SRK’s Adrian Dance outlines a new vendor-agnostic, lab-based testing process that could have huge ramifications for a sector in need of guidance and strategy.

Stay tuned for part two in the series, which will see SRK’s Bob McCarthy explain how results of such testing can be used by the mining community.

The need to expand the values or lives of assets while reducing both energy and water use is leading to a flood of new enquiries landing on the doorsteps of the pre-concentration and ore sorting company fraternity.

Anybody that takes a passing interest in the junior mining sector has seen the TOMRAs and Steinerts referenced in numerous TSX-V, ASX and AIM releases, with early-stage test work often detailing results from particle sorting trials.

On the bulk sorting side of the business, more sensor-based solutions are emerging to cope with the need to build or expand copper assets in the most sustainable ways possible. Some progressive companies are including such innovations in initial flowsheet plans.

The bottleneck in the current environment is testing, according to Adrian Dance, Principal Metallurgist at SRK Consulting, with many of the vendors simply overrun with requests to test material or provide modular pilot plants that can be re-located after samples are processed.

At the same time as demand is outpacing supply, there is an argument that a standardised, vendor-agnostic test should be devised to screen for ore sorting or pre-concentration amenability before any vendors are even engaged.

SRK is one company arguing for this.

“At the moment, the manufacturers are driving the action, dictating what the sample has to look like for something that resembles a pilot plant trial,” Dance told IM. “Like any pilot plant run, these trials often give you an excellent result on that specific sample, but the question is: is that sample truly representative of the orebody? Or, is it representative of what a sorter would actually see in operation?”

An increase in available data and transfer of said data across the mine site is going some way to disproving the idea of mass homogeneity at many bulk mining operations – at copper porphyries, for example.

Dance believes this same thought process should be applied to pre-concentration.

This is where SRK Vancouver and Base Metallurgical Labs, both in British Columbia Canada, are looking to provide a “pre-concentration screening test” using X-ray Transmission (XRT) based sensor technology that can not only indicate pre-concentration amenability, but also provides key inputs into the pre-concentration strategy selection and evaluation.

The two companies are offering an assessment of pre-concentration potential, as well as an estimate of material bypass and metal upgrade from samples as small as half cores.

The XRT sensor lab unit

Used in conjunction with crushing and screening, this testing rapidly – and cost effectively – assesses the potential for pre-concentration, which can then be applied to scoping or prefeasibility studies, according to the companies.

“The testing has two parts to it,” Dance explains. “It was originally designed to see what the grade distribution of fines is after crushing and to see how that grade distribution varies depending on the amount of crushing energy applied to the material.

“The second part is looking to see if the material is amenable to pre-concentration when it is coarse and dry – ie conveyable.”

According to the companies, the XRT-based test can provide this within 24 hours of a sample arriving at the lab.

All of this helps characterise deposits (or low-grade stockpiles) using small samples, cutting down sample mass requirements, and potentially running multiple scenarios to obtain what Dance refers to as the “optimal sort”.

The two companies are not looking to replicate what may be done at one of the sorting vendors’ testing facilities. Instead, they are looking at whether the material wants to respond to this type of particle sorting exercise in the first place and at what size fractions pre-concentration would make sense.

Should the indications prove positive, the information on what appears to be the optimal sort can be passed onto the vendors for more accurate follow-on testing of a bulk sample.

“In this way, we are qualifying the opportunity ahead of the vendors getting samples,” Dance said. “The vendors also have knowledge about how a sample has responded to amenability testing in the first place and what other tests were conducted concurrently.

“We will be providing complementary testing that will, ultimately, benefit the project in question.”

Dance says the aim is to create an industry standard test for pre-concentration that can be replicated by commercial laboratories all over the globe and is carried out routinely with hardness and crushing and grinding testing.

“One of the samples we have already tested was being assessed for rock hardness and we were able to offer them pre-concentration amenability results at the same time,” he said. “We’re not trying to provide the ultimate or ‘perfect’ test; it just needs to be a standard test that can be benchmarked and easily replicated across the industry.

“The value is in the data shared. People want to know how their sample compares with other operations, but this will only come with a large volume of testing.”

XRT scan results of particles
XRT scan results of particles

While XRT is first up, Dance says the company could soon add an X-ray Fluorescence option to the unit.

And, further out, he is confident this type of testing will open the door to more sensors coming into the mining sector outside of the ones already on offer.

“When we show the electronics industry that we have a viable market by dictating the terms of how we want to sort material through knowledge of such testing, the sensors will come,” he said.

“I’m not saying everyone should implement pre-concentration; far from it, as I expect a minority of the tests will show strong amenability. What I am saying is that everyone should test for it.

“By providing a no licence fee test that has no bias towards any vendor, we are allowing mining companies to scope that out.”

The venture is also part of Dance’s own ambitions to educate the mining sector on its waste-generating ways, he says.

“In the grinding space there is so much material that is recycled throughout the plant inefficiently,” he said. “We must question why we are putting things back in the mill to ultimately take it to tailings.

“There is simply no way we can carry on pursuing the economies of scale argument to reduce our energy consumption and water use. We need to embrace new technology in the right way – not running towards it but walking with purpose and data-backed decisions.”

NMG to refine Matawinie Mine, Bécancour battery plant plan with Pomerleau

Energy minerals, Mineral project development, Mining services, Sustainable mining, , , , , , , , , ,

Nouveau Monde Graphite Inc says it has furthered its execution readiness for the construction of its Phase-2 commercial facilities, the Matawinie Mine and the Bécancour Battery Material Plant, in Quebec, with the appointment of Pomerleau as Construction Manager for the pre-construction stage.

With sustained engagement from Tier-1 battery manufacturers to sign offtake agreements and confirmed interest from lenders and strategic investors to participate in NMG’s project financing, the company says it is accelerating efforts to refine its execution plan for cost optimisation, procurement and construction at each site ahead of the final investment decision (FID).

Arne H Frandsen, Chair of NMG, declared: “Our strong owner’s team in engineering and project management now paired with experienced construction firm Pomerleau provides depth and technical expertise for refining our execution strategy. Amidst challenging economic conditions, we are seeking strategies to mitigate the expenses and uncertainties associated with complex construction projects to execute our projects responsibly while delivering on our commitment to our customers, community, and shareholders.”

Eric Desaulniers, Founder, President and CEO of NMG, said: “As battery production capacity continues to expand in Québec, North America and Europe, our commercial engagement is shifting from product qualification to execution and operation readiness to optimise our time-to-market window. Potential customers have tested our carbon-neutral active anode material produced at our Phase-1 facilities and are eager to access sizeable volumes to support their manufacturing and growth. Contemplated anchor customers, lenders and investors alike are seeking reassurance on our timeline and flawless execution with safety, environment, and quality as top priorities. We have found in Pomerleau a construction partner that shares our values and is keen to help us bring our vision to reality.”

Pomerleau is a prominent Canada-based construction company specialised in the building, infrastructure and civil, and construction sectors. With a rich history spanning early six decades, Pomerleau boasts a workforce of over 4,000 dedicated employees and operates across more than 200 job sites across Canada with a strong focus on safety, innovation, and sustainability.

Leveraging process development, continuous sample production at Phase-1 facilities, environmental monitoring and management, and extensive site and project studies, NMG has made steady progress over the years toward construction and financing of its Phase-2 Matawinie Mine and Bécancour Battery Material Plant.

The Matawinie Mine has already obtained governmental approval – the main permit for the mining operation – following an exhaustive environmental review and public consultation. Since securing this approval, NMG has carried out preparatory work to build the nearly 8-km access road, construct key environmental infrastructure and execute early civil works. Detailed engineering for the industrial, mining and environmental facilities is also well advanced thanks to continued work with specialised firms AtkinsRéalis, SRK Consulting, and key contractors and equipment vendors. The site is now ready for major civil works including excavation, underground utilities and concrete foundations once FID is reached.

Pomerleau’s mandate covers the pre-construction management of the industrial facilities, namely the concentrator, crusher and associated infrastructure. Pomerleau is working closely with NMG’s project team to prepare a detailed construction sequence and schedule, to develop the contracting strategy, to optimise worksite logistics, to expand the health and safety, environment, and quality programs, and to integrate planning and engineering into building information modelling (BIM), an advanced technology solution supporting enhanced project construction management for improved planning, tracking, project efficiency, productivity, and cost control.

At the Bécancour Battery Material Plant, the pre-construction mandate will build on the environmental studies completed thus far and active engineering work with BBA Inc. Pomerleau’s mandate includes construction scheduling, workforce planning, job site logistics, revision of the procurement strategy, and the development of health and safety, environment and quality programs.

Pomerleau is also contributing to the budget revision, cost optimisation and project control activities for both projects. NMG aims to refine capital expenditure estimates in light of advanced engineering and contemplated offtake agreements, and to reduce its exposure to market volatility and supply chain pressures. Considering that NMG’s integrated feasibility study for its Phase-2 operations was issued in July 2022 at the peak of inflation trends, the company anticipates optimisation of construction forecasts in light of stabilising material costs, technological enhancement to align with customers’ specifications, synergies between the two sites proactive procurement strategy plus Pomerleau’s current construction mandates in the Bécancour industrial work.

Having retained Pomerleau for both projects provides saving opportunities and a harmonised project execution across sites thanks to core team, programs and approach, NMG says, enhancing the integration of engineering, procurement and construction management. NMG will also benefit from Pomerleau’s established pool of workers and specialty subcontractors in preparation for the execution stage.

SRK and MTS to provide data-backed insights to mining customers

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SRK Consulting has announced a new partnership with Mine Tech Services (UK) Limited (MTS), a leading specialist in mining technology.

MTS is a team of world-class experts that provides consulting, training and specialised software development for continuous improvement in mining operations and asset health, SRK says. Its mission is to help clients better use their fleet management systems, turn their data into actionable information, deliver new insights and effectively manage what matters.

By joining forces, SRK says it and MTS will provide clients with unparalleled insights into their data, allowing them to radically improve the efficiency of their mining operations. This includes helping mines to:

  • Understand the root causes of inefficiencies through collecting and analysing data – then provide practical recommendations and supporting tools to enable the mine site team to implement solutions;
  • Review the effectiveness of operational policies, such as shift changes, as well as road design and management protocols, and then help mine sites develop more refined solutions;
  • Reduce fuel burn and CO2 emissions through highlighting underperforming trucks, high consumption road segments and operator performance inconsistencies;
  • Measure the effectiveness of mine-to-mill programs by monitoring the transportation of ore from the face through to the mill, as well as the impact of blasting on digging efficiency; and
  • Have confidence to forecast productivity improvements through modelling of opportunities.

SRK says it has a proud tradition of investing in emerging technologies.

Accordingly, SRK has co-invested in the development of Haul Road Explorer (HRE), a data visualisation software that leverages existing hardware and systems. A powerful feature of HRE is its ability to record the on-board health and link this to the geographic location as this can be used to show safety regulators that the proposed policies are robust, the company says. Another distinctive feature of HRE is its ability to merge data from multiple complementary sources to enable rapid, repeatable and more detailed diagnostics. The software processes vast volumes of data and presents it simply and clearly, giving decision makers the information they need to act swiftly and effectively.

Past SRK technology initiatives include forming Gemcom (now part of Geovia GEMS) and co-investing in Leapfrog to develop implicit modelling techniques. More recent initiatives include development of EasyMine to expedite field logging, EasyMineXR for collecting and visualising geological data, and several software programs for open pit berm-bench design and mine ventilation modelling.

SRK Consulting helps DRC miner with social development ‘first’

Environmental, Mining policy, Mining services, Sustainable mining, , , , , , , ,

A large mining company in the Democratic Republic of Congo (DRC) has – with assistance from SRK Consulting Congo – become the first to have its Cahier de Charge (Social Term Sheet) approved, the mining consultant says.

Regulations introduced in the DRC in 2018 require mines to set out a clear and financially-provisioned five-year plan for local social development – a Cahier de Charge – in consultation with local communities and stakeholders. According to Susa Maleba, Country Manager at SRK Consulting Congo, the key aspect of the new requirement was that effective consultation be conducted.

“Mines generally have community development plans but these are often designed by the mine, which historically had little formalised input from local communities or other stakeholders,” said Maleba. “This compulsory consultative process – as part of the Environmental and Social Impact Assessment – ensures that mine initiatives align with the real needs and preferences of those affected by the mine.”

The mining company contracted SRK Consulting Congo to work with its DRC mine on planning and implementing the consultation. This process began in 2018 and lasted four months. The final agreement between the communities and the company was signed off in March 2019.

Established a decade ago in Lubumbashi, the local SRK office appointed its stakeholder engagement specialist, Philippe Katuta, to guide the process.

Susa Maleba, Country Manager at SRK Consulting Congo

“As an experienced local expert who is well regarded by the mining communities, Phillipe supervised the process with the client – facilitating contact between the mine, three local communities, the ‘chefferies’ tribal structure and provincial government,” Maleba said.

He highlighted the importance of having the trust of all parties in the consultation, to ensure frank engagement and effective buy-in. This, in turn, helped ensure proper implementation of the agreed plan, so that the intended benefits would be achieved, according to SRK.

“Essential factors in the success of the process included our experience in stakeholder engagement and our local knowledge – from local language communication to the traditions and customs to be observed,” Maleba said. “Working with mining companies, we emphasise the social licence aspect of their strategy and operations – which prioritises close working relationships with partners, communities and government. It means applying the spirit – not just the letter – of the law.”

Among the social development imperatives highlighted by communities during the engagements were transformers to link with the country’s power grid, boreholes for access to water, agricultural extension programs and trade training for local youth.

Maleba acknowledged that it was seldom easy to balance the expectations of communities with the financial resources of the mining company, but this made the relationship of trust a vital foundation for collaboration.

He also noted that the new regulations provided for ongoing monitoring of mines’ community development plans – to ensure that what was promised was in fact delivered, in line with a predetermined schedule.

Condor Gold accelerates La India development with Metso Outotec SAG mill acquisition

Comminution of minerals, Mineral processing, Mineral project development, Mining equipment, Mining services, Precious metals, , , , , , , , , ,

Condor Gold has entered into an agreement to purchase a completely new Metso Outotec SAG mill package from First Majestic Silver to serve its La India project in Nicaragua.

The purchase consideration is around $6.5 million – made up of cash and shares – with the SAG mill representing a key item of the plant required to bring La India into production, Condor said.

The SAG mill is estimated by Metso Outotec’s technical support group to have a 2,300 t/d (800,000 t/y) throughput on a sustained basis, based on the metallurgical characteristics of the ore and mineralised material at La India. Based on internal technical studies and mining dilution studies conducted by SRK Consulting, initial production at La India is expected to be 80,000-100,000 oz/y of gold.

Condor says the SAG mill and parts are 90% ready to be shipped. The 2,300 t/d capacity forms “Stage 1 of production”, with capacity to be expanded materially after two to three years of production. Its delivery reduces the order time of this key long lead item by 12 months, fast tracking La India project into production. Condor said there is the possibility of increasing throughput by 22% to 2,850 t/d by installing a 4,100 kW motor (currently a 3,330 kW motor).

Mark Child, Chairman and CEO, said: “The key message is Condor has purchased and sized the mill at 2,300 t/d, significantly shortened the mill delivery time, set a trajectory for detailed project design and an accelerated path to production. What’s more, Condor has acquired a state-of-the-art, complete new SAG mill package with warrantees, manufactured and supplied by Metso Outotec, the premier manufacturer of grinding mills and entire grinding systems for the global mining industry.”

Condor plans to commence gold production at La India in 24 months.

The SAG mill agreement has come about as First Majestic ordered a complete new SAG mill package, which, Condor says, is now superfluous to its requirements.

The SAG mill has a mill diameter of 24 ft (7.3 m) and an effective grinding length of 18.5 ft and a structural charge mass of 315 t, Condor Gold said. The structural design ball charge is 11% with a structural design load volume of 35%. Specific gravity of the material is 2.55. The structural steel liner mass is 240 t; however, with the use of lighter composite liners, the weight and corresponding power requirement can be reduced significantly to 120 t.

The complete SAG mill package manufactured and supplied by Metso Outotec includes:

  • Mill shell fabricated in 8 x 90° segments;
  • Mill heads cast in 4 x 90° segments with demountable trunnions;
  • Ductile ring gear and carbonized pinion shaft;
  • Pinion shaft assembly equipment;
  • Erection cradles;
  • Bracket, coupling and guard;
  • Pinion bearings-2-pad polymer hydrostatic bearings;
  • Transformer for the mill;
  • Gear unit, steel guard and fasteners;
  • Allen Bradley variable speed drive;
  • Allen Bradley PLC mill local panel;
  • 3,300 kW WEG SCIM (motor);
  • Bearing housing;
  • Torque limiter and hubs;
  • Complete feed assembly. ‘Rock box’ feed chute with replaceable steel wear liners;
  • Complete discharge assembly. Fabricated discharge cone (no trommel screen) with replaceable rubber wear liners;
  • Discharge trunnion liner with replaceable rubber wear liners;
  • Installation materials and some spares;
  • Trunnion bearing;
  • Hydraulic torque wrench kit;
  • Liner handler; and
  • Howard Marten lubrication systems (trunnion oil lube, reducer/pinion oil lube, gear spray grease lube).

It is assumed that a pebble crusher will be used in the comminution circuit to provide some additional grinding power and to manage critical size fraction material, Condor said. The SAG mill is equipped with a variable speed drive to allow the mill to operate between 1,500 t/d and 2,300 t/d. Furthermore, it is possible to increase the daily throughput by increasing the motor size, as previously indicated. The 22% boost in throughput could potentially allow gold production to increase by a similar amount, the company said.

The SRK 2017 Technical Report on La India outlined an overall process flowsheet based on a single stage SAG comminution and conventional carbon-in-leach circuit.

SRK reflects on rock-related accidents in South Africa mining industry

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Rock-related accidents in South Africa’s mining sector have reduced significantly in recent decades, due in large part to incremental improvements in rock engineering practice, SRK Consulting explains.

According to William Joughin (pictured), Chairman of SRK Consulting and himself a rock engineering expert, the company’s contribution in this field has included assisting mines with reviews of safety practices, as well as providing safe rock engineering designs and detailed seismic hazard analysis.

Fall of ground (FOG) is the leading cause of fatalities in the sector, making up a third of mining fatalities in 2019, according to the Minerals Council South Africa. The organisation has reported recently that total FOG injuries have dropped from 1,121 in 2003 to 379 in 2019, while FOG fatalities are down from 131 to 20 over this period.

Joughin notes, however, that this reduction in the number of injuries and fatalities is also linked to the general decline in mining industry employment. There have been few major technological changes implemented in the last five years, in particular, which could help reduce injuries and fatalities. Instead, the focus has been on behavioural change.

“The industry is focusing its efforts on changing human behaviour, because the exposure of people remains high and workers have to manually implement safety measures,” Joughin said. “These efforts have had mixed results, but there is renewed research and development into mechanisation that could significantly reduce the exposure of workers to the more hazardous aspects of mining.”

Methods of seismic monitoring and hazard analysis continue to be developed as new technologies become available. Within its diverse range of projects conducted for the mining industry, SRK contributes to raising safety levels in South Africa mines in these and other ways, according to SRK Consulting Director and Principal Consultant, Andrew van Zyl.

“We have been involved in the Test Mine project and are currently involved with Mine Health and Safety Council projects on collision control and rock safety,” Van Zyl said. “We are also doing pioneering geotechnical work in both the open pit and underground environment.”

He added that the company’s work on water management and mine closure also contribute indirectly to the general levels of improved safety in mining, as do its contributions to tailings dam management in and around mines.

COVID-19 restrictions could lead to more ‘economical’ technical audits, SRK’s Dalgliesh says

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SRK Consulting’s Chris Dalgliesh believes the COVID-19 pandemic – specifically, the restrictions on movement – could change the way engineering projects are assessed now and in the future.

These projects face a growing range of audits, assessment, and monitoring, but will these restrictions make it difficult for consultants to carry out this vital work, he asks?

The answer lies in leveraging information systems and communication platforms and finding innovative ways of verifying information that used to be confirmed during a site visit (an example shown in the picture above, pre-COVID-19), according to Dalgliesh. While some audits monitor a range of project risks on behalf of financiers or investors, others are necessary to satisfy regulatory requirements.

“Meeting clients face-to-face on a project site has usually been considered by consultants as an integral part of conducting an audit or assessment,” Dalgliesh said. “But COVID-19 lockdown conditions have forced us to look at other ways of verifying information. This might include the sharing of satellite imagery online, or live data reviews with the client as part of the audit record.”

He highlighted that most audits require a combination of desktop work – analysing documentation and data from the client – and on-the-ground observation conducted during a site visit.

“In many of the larger, international projects where we monitor environmental and social performance against good international industry practice such as the Performance Standards of the International Finance Corporation, it is certainly very useful, even essential, to be physically present,” he said.

This is particularly the case where an audit needs to ascertain the capacity of health, safety and environment teams, and to assess whether something has been done to the required standard.

SRK Consulting Principal Environmental Scientist, Chris Dalgliesh

“Other types of audits require us to analyse past performance rather than current activities, and here the documentation is really the focus,” he said.

The amount of time required on site also depends on the phase of the project, according to Sharon Jones, also a Principal Environmental Scientist at SRK.

“For instance, the National Environmental Management Act requires statutory audits against Environmental Authorisations,” Jones said. “These focus in a fairly binary manner on whether the conditions of these authorisations are being implemented on site.”

Many of these are conducted when the project is already operational, so much of the work has already been undertaken and the project is either compliant or not.

“These kinds of audits lend themselves more to document review, where we scrutinise the systems in place and the documented evidence of action,” she said. “This aspect is usually more important than observing directly what is being done on site.”

Sharon Jones, Principal Environmental Scientist at SRK Consulting

She said the same usually applies to audits for Water Use Licences and Atmospheric Emissions Licences. Here, documented evidence must be supplied by the client, for the consultant to audit against local compliance limits and international standards. This data is provided in good faith that it is accurate and valid.

“In the past, there has generally been a ‘close out’ session with the client, in which the consultant returns to site following an audit, to report back,” she said. “Working remotely under COVID-19 lockdown conditions, it is clear that some of these interactions can be conducted remotely.”

However, she emphasised there are several minimum requirements for a remote audit to be an acceptable alternative to a site visit. For example, the consultant will generally have seen the site before, and on-site conditions must not change between seasons. Also, the consultant will have to be satisfied with the culture in place at the client’s operations – in terms of overall adherence to good international practice. This would provide assurance that audit data provided by the client is correct and reliable.

Under these conditions, there may be an opportunity for clients and consultants alike to save on the cost and time of travelling to site.

Dalgliesh noted that digital communication platforms are proving invaluable in making remote audits increasingly feasible.

“Meetings and conferencing using online platforms can often facilitate the iterative nature of our role, where we may need to be in close contact with a client over a period of time,” he said. “Doing this remotely can also make the process more focused and economical.”

Apart from the time and cost savings of not travelling to site – which may even involve regional or international travel – these online communication tools allow specific people within an organisation to be targeted for discussion as and when necessary, instead of having a large client team on standby.

A practical point not to be overlooked is that time is a scarce resource, and time spent travelling to site could often be better spent on the more detailed interrogation of existing documentation.

“A move towards doing more of our work remotely is likely to mean that we spend more time evaluating documented data,” Jones said. “This might even change our approach towards doing more desktop preparation and might be the new normal for certain categories of audit. The physical visits – which could be fewer and further between – would be for the purposes of verifying and corroborating, rather than discovery.”

Skeena Resources signs up Ausenco, SRK and AGP for Eskay Creek PFS

Mineral project development, Mining services, Precious metals, , , , , ,

Skeena Resources is to commence a prefeasibility study (PFS) on its Eskay Creek gold-silver project in the Golden Triangle of northwest British Columbia, Canada.

The goal of the PFS is to de-risk Eskay Creek, while developing an appropriate execution strategy to ensure fast-tracked development towards commercial production, Skeena says.

Given the success of the team that developed the preliminary economic assessment (PEA) for Eskay Creek, Skeena says it will once again partner with Ausenco Engineering Canada, SRK Consulting, and AGP Mining Consultants to complete the PFS. The target completion date for the PFS is summer 2021.

This PEA envisaged a high-grade open-pit mine producing a life of mine average of 236,000 oz/y of gold and 5.81 Moz of at all-in sustaining costs (including by products) of $615/oz gold recovered. It would involve a 6,850 t/d mill and flotation plant producing a saleable concentrate.

Shane Williams, Skeena’s new Chief Operating Officer, said: “I am very excited to be joining the Skeena team at this transitional stage in the company’s history. The PFS is the next step in the evolution of Eskay Creek as we move this high-grade, open-pit project towards development and through to commercial production.”

A key work program as part of the development of the PFS will be an extensive infill drilling program to convert a large portion of the inferred resources into the measured and indicated category and following completion of the PFS, declare maiden reserves for Eskay Creek, Skeena said.

The company said: “Following the completion of the Eskay Creek PEA in 2019, several areas were identified that could be optimised and enhanced with further work. This includes optimising the metallurgy and the concentrate quality and to better optimise the flowsheet.

“Another focus area will be to gain a better understanding of the geotechnical characteristics in the open pit, which will allow for further pit optimisation studies. Preparations and planning for these work programs are ongoing.”

Subject to the agreement with Barrick, upon exercise of the option to acquire a 100%-interest in Eskay Creek, the company will enter the permitting process for the expanded Eskay Creek project, it said.

Skeena has already begun the environmental studies that are required for permitting and has initiated community engagement and consultation with Indigenous Nations.