Tag Archives: tailings management

Decipher to help miners align with new tailings storage facility standards

Wesfarmers-owned software-as-a-service company, Decipher, says it has extended its successful TSF cloud platform to provide a solution to simplify the process of tailings storage facility (TSF) data disclosure as well as helping companies align with the new global tailings standard.

The recent Global Standard on Tailings Management was launched on the August 5, 2020. The historic agreement includes six topic areas, 15 principles and 77 auditable requirements, which covers the entire TSF lifecycle – from site selection, design and construction, management and monitoring, through to closure and post-closure.

With an ambition of zero harm to people and the environment, the standard significantly raises the bar for the industry to achieve strong social, environmental and technical outcomes by elevating accountability to the highest organisational levels and adds new requirements for independent oversight, Decipher says.

“These recent initiatives have encouraged mining companies to respond quickly to public demand for more transparency which has highlighted the need for a software solution which can improve tailings data management, reporting, monitoring, compliance and governance,” the company said.

This is where Decipher’s technology comes into play.

Decipher Chief Executive Officer, Anthony Walker, said the resources industry is actively seeking easily implemented, cost effective and globally accessible solutions.

“The early adoption from Tier 1 miners and general interest has been phenomenal indicating that there is a real need for a TSF data disclosure solution; it excites us that our technology platform can be leveraged to support better management and monitoring of tailings storage facilities,” he said.

Topic Area VI of the new standard requires operators to support public disclosure of information about tailings facilities, and participate in global initiatives to create standardised, independent, industry-wide and publicly accessible information about facilities. For example, the recent Investor Mining and Tailings Safety Initiative called upon 727 extractive mining companies to make public disclosures about their TSFs to form an independent global database – The Global Tailings Portal, developed by GRID-Arendal.

Due to manual processes, and often disparate and siloed datasets, mining operators have estimated it took them around six weeks per site to collate their tailings data, according to Decipher. “With many operators having well over 50 sites, this process is challenging and surfaced many inefficiencies,” it said.

After hearing these frustrations from the industry, Decipher designed a tailings database solution to help companies easily capture, manage and disclose tailings data, enabling them to meet data provision requests from industry groups such as the Investor Mining and Tailings Safety Initiative, it said.

Decipher has also been working closely with GRID-Arendal to create an API to facilitate automatic update of tailings data within the Decipher platform directly to the Global Tailings Portal.

“We believe this will significantly increase efficiency and provide a massive time savings for mining operators who choose to disclose regularly,” the company said.

Topic Area III of the standard aims to lift the performance bar for designing, constructing, operating, maintaining, monitoring, and closing facilities.

Recognising tailings facilities are dynamic engineered structures, this topic area requires the ongoing use of an updated knowledge base, consideration of alternative tailings technologies, and a comprehensive monitoring system.

“Decipher’s TSF solution is trusted by environmental, tailings, geotechnical and management teams globally to help improve monitoring, compliance, reporting, operational visibility and safety,” the company said. “The platform brings together data from laboratories, IoT devices, LiDAR, CCTV, drones, inspections and remotely-sensed platforms to serve users with up-to-date information to provide key data and insights, enabling teams to effectively monitor, govern and operate their TSFs.”

Armed with Decipher’s Tailings Database solution, Decipher says. customers can:

  • Comply and meet requests for data provision from industry groups such as COE, ICMM, UNEP, PRI, Global Tailings Review and more, with fields embedded for simple reporting and tracking;
  • Store an endless variety of tailings data in one location which is otherwise managed by a number of teams in disparate systems;
  • Operate with increased confidence knowing required data is being collected and monitored;
  • Easily visualise their operational TSF data on the map;
  • Cluster data into key areas such as safety, risk, compliance, construction, design, roles and responsibilities;
  • Assign actions and tasks for data collection with a register and audit trail of all actions and respective statuses to monitor progress, and reminder and escalation notifications;
  • View dam data across multiple sites in a single screen with the ability to easily export for reporting;
  • Facilitate automatic updates to databases and portals based on integration capabilities with third-party systems or public portals;
  • View spatial visualisation to display tailings dams in proximity to surrounding environment and communities;
  • Better align with standard such as the Global Tailings management; and
  • Access custom reports.

Weir Minerals mobilises team to take on tailings treatment challenge

Water requirements for intensive applications such as hard-rock mining and oil sands processing have historically been supplemented by local water sources. Today, these applications face new challenges as the focus shifts to how operations can minimise their environmental footprint but continue to improve productivity while also complying with new regulations. This global shift in focus reveals the need for increased sustainability in tailings processing, Weir Minerals says.

The way forward is not only installing energy-efficient products that offer improved reliability, but also working directly in partnership with companies such as Weir Minerals that can design engineered-to-order solutions tailored for optimised and sustainable results, the mining OEM explains.

One of the ongoing challenges for customers is tailings reclamation. The question of how best to reduce dependence on tailings ponds yet expedite reclamation of both water and product in the process, was top of mind for one Weir Minerals customer.

Pumping stations are a critical element of tailings management, providing the energy needed to drive the downstream processes. Static slurry pump houses have, until now, been the norm, but they are costly and present many limitations when considering alternate tailings processing techniques.

A new approach to tailings reclamation

When the customer approached the Weir Minerals Canada dewatering team with a vision to mobilise the pump system for their new tailings treatment process, initially they didn’t even know if it was even possible.

“The sheer size and energy requirements of the equipment needed for the application meant that this was a huge undertaking from the beginning. You don’t normally think of 3,500 hp (2,610 kW) pumps and 160 t of equipment as mobile,” Kris Kielar, Product Manager for Dewatering Engineered to Order Solutions at Weir Minerals Canada, explains.

The Weir Minerals team worked directly with the customer to design an innovative booster pumphouse, engineered especially to manage the non-segregating tailings on site. The proposed solution played an integral role in reducing the tailings pond footprint on site through accelerated fines capture and decreased fluid tailings production, thus releasing more water for recycling and reducing necessary water intake from local sources. This, in turn, would expedite reclamation to create landforms that support wetlands and self-sustaining forest ecosystems, according to Weir Minerals.

The standard tailings processing model takes time, but this solution dramatically reduced tailings residence time with a total solution realised through Weir Minerals equipment, it said.

Multiflo® pump barges mounted with Hazleton® submersible slurry pumps extract the target fluid tailings that feed high-powered, land-based Weir re-locatable pump houses. Inside the pump houses, Warman® slurry pumps boost recovered tails from the pond to drive the new tailings treatment process plant.

Kielar continued: “By working directly with the customer, we understood not only their desired outcome, but also the existing capabilities on site. We stayed close and were able to proactively tweak our design based on the customer’s needs, so when it was time to present, we were already prepared with the ideal solution.”

Engineering for extra value

The Weir Minerals dewatering team designs solutions using engineered and reliable equipment that is not just efficient, but also adds value to a customer’s site process, it says.

“For example, the entire module of the Weir mobile pump house can be built offsite at a much lower cost than traditional pump houses, which are built in-situ,” Weir Minerals said. “Building a pump house in-situ is time-consuming and expensive, as the method requires skilled trades to work for extended periods of time in remote locations.”

Peter Pavlin, Weir Minerals’ North America General Manager of Engineering, said: “Competitor pump houses built using in-situ construction methods can more than double the construction time and costs compared to the steel fabrication methods we have used. When faced with a complex problem from a customer, we always evaluate the situation holistically and strive to develop a new approach. That is the beauty of engineering, the possibilities are endless, and the Weir Engineering Team have the expertise and tenacity to go against the norm and develop novel and cost-effective solutions.”

The Weir mobile pump house provides a variety of pumping possibilities for intensive tailings applications, according to the company.

It is designed to relocate across the site using especially engineered, military-style skid and ‘jack-and-roll’ elements and a novel patent-pending pump/motor suspension system, providing a unique advantage in mobile pump house technology. These advances provide operators with distinct advantages over traditional fixed-in-place designs, creating a more agile and cost-effective solution, according to Weir Minerals.

Pavlin explained: “Our ground-breaking design sets a new standard for tailings management applications. Other pump houses in the market are static and often cause difficulties for operators when they wish to expand into new areas, as they must discontinue service, resulting in a large capital expenditure. Our solution has overcome these limitations by providing the customer with the tools to rapidly reconfigure a changing pumping network and move it to other sections of the tailings pond.”

The Weir mobile pump house incorporates an integral gland water supply system and a separate eHouse for power control and remote communication. A patent-pending, three-point pump base mounting system allows the base and skid to act independently, minimising the risk of pump and motor shaft misalignment during operation and the relocation process, according to Weir.

Filling the mineral processing flowsheet gaps

Crushing, grinding, flotation, solvent extraction, electro winning, tailings management…Metso Outotec covers it all.

The new mineral processing entity might be less than a week old, but many in the industry would have, no doubt, had some burning questions to ask since the planned merger was announced on July 4, 2019.

IM had a chance to put some of these questions to Stephan Kirsch, President Minerals business area, Metso Outotec, gaining an initial impression of what the combination of the two companies means for the Minerals business he heads up.

IM: What big mining industry challenge will the combined group be better placed to tackle? What equipment/solutions/expertise within the group are the most important in achieving these goals?

SK: One issue – although not technology-focused – is community engagement.

Some mining operations in the world face challenges in terms of engaging with local communities and returning benefits to them. There is a social responsibility for mining companies, as they are the operators, but also for mining industry supporters involved in such projects.

That said, the vast majority of the mining industry runs initiatives that ensure communities understand mining companies are not just there to extract the iron, copper or gold and make money from it. They give back to local stakeholders and help improve community standards.

Stephan Kirsch, President Minerals business area, Metso Outotec

From a technology perspective, an industry issue we are well equipped to tackle is tailings management. With our combined offering, we look very seriously into solutions that can involve dewatering, dry stacking, and the reprocessing of tailings.

You asked about the products involved in solving these challenges…that includes filtration technologies, bulk materials handling products for conveying and stacking, and then various ore sorting technologies for the reprocessing.

Another trend to highlight is the use of energy or, more specifically, the need to reduce power consumption. There is some work to do here.

When you go and buy a car, you tend to focus on the fuel consumption. The mining industry, however, aims for high installed power because there is a sentiment that more power in the mill means more product out of the mill, more fines and, as a result, better downstream recoveries. In a way that is true for technologies like horizontal mills, ball mills and SAG mills, but when you turn to different, newer technologies it is not always the case.

One of these technologies is HPGRs which were introduced in the minerals industry in the mid-80s. Today, HPGRs are used in high tonnage, competent, abrasive ore applications due to their lower specific power draw and other downstream benefits compared to conventional technologies.

One can add to this, conserving other natural resources such as water. Water scarcity is obviously a problem and we should look at the recycling of process water wherever possible (that is where the filtration technology comes into play again) at the same time as examining more energy-efficient flowsheets.

There is quite a bit we can do to solve some of these challenges from a mineral processing perspective, but, the problem is, the industry remains conservative and anything new takes time to be implemented sustainably.

IM: I know Metso has previously talked about creating a bulk ore sorting solution for industry. Considering this, do you as Metso Outotec expect to continue leveraging the agreement Outotec has in place with TOMRA to carry out more sensor-based ore sorting projects? Alongside this, will you continue with your own bulk sorting projects?

SK: Early removal of tailings/overburden from the processing plant feed has been the operator’s dream for probably a century! This concept of preconcentration has been a consideration for many years, but in the last 30 or so years, technologies with different sensors have been developed to help with this separation process.

It is the ability to use sensor technology to single out particles on a conveyor belt at an appropriate speed and quantity that is the industry challenge. After all, when it comes to mining, we are talking about bulk materials that must be processed, not single elements like you have in the recycling and food sectors where much of this sensor technology originated from.

You need to look at the operating economics of such plants. When I say economics, I am factoring in throughput and recovery rates: you want a high tonnage and you don’t want to waste your ore, which is already low grade compared with what was being mined, say, 30 years ago.

The answer to your question is that Metso has been looking into preconcentration technologies for some time – we have R&D projects and partners looking at it. The same is the case with Outotec. Going forward, we will analyse this and make a call on whatever is the best combination to continue with such work.

Personally, I am a big believer in segregating waste as early in the process as possible to save energy downstream. But there are technical challenges to this.

IM: Both companies have been expanding their modular offering in recent years (Metso with its flexible FIT™ stations and the smart Foresight™ stations/Outotec with its modular paste backfill plants and HIGmill): is a lot of your mining and metals R&D currently focused on reducing the footprint of your solutions?

SK: Our R&D budget – as you probably heard on the webcast last week – is quite significant when put together. As Metso Outotec committed to keep both of our budgets unchanged, the spend comes to about €100 million ($112 million). A market survey we carried out revealed that, in terms of R&D spend, we are at the top of the industry.

Then, we must spend this money wisely wherever we see it being applied most economically for the benefit of our customers and for Metso Outotec. The modular crushing stations you mention are an area of interest we started developing years ago. We see good potential for this modular offering and will continue to develop it.

As for the percentage of the budget we will dedicate to it, this will – like all R&D projects – be analysed alongside others for crushing, grinding and all separation technologies with a strong focus on product innovations, digitalisation and sustainability.

IM: As you hinted at earlier, do you see tailings management being one of the combined group’s core strengths?

SK: It is one big focus area for us, but only one.

Crushing and grinding, which I mentioned earlier, is another strong area. We are a market leader in some of the crushing technologies we offer, and high up the industry when it comes to grinding technologies. We plan to really expand on this side.

I mentioned HPGRs where we have brilliant, world-class technology, but are missing the installed base. With 20-25 years of HPGR experience, I know we have the technology to make a difference, we just need to effectively bring it to market.

The whole re-grind space is really a future area for us to pursue due to industry-wide issues of falling grades, the need to reduce power consumption and fine grinding requirements.

Back to the original question, I expect Metso Outotec to be a strong player for dewatering and tailings management solutions.

IM: Outotec has a much more developed downstream business in areas like hydrometallurgy and smelting, etc in mining than Metso – will this remain a core part of the combined group?

SK: The front-end strength of Metso for mineral processing plants and the wet processing business focus of Outotec shows how well both companies complement one another. From a technical perspective, this is one of the reasons why the merger of Metso and Outotec makes much sense.

IM: In what segments of the mining and metals market do you see the most complementary solutions within Metso and Outotec?

SK: When we brought these two companies together it is amazing how many renowned international mineral processing experts came with it. We can provide much more comprehensive services to the industry because we can look at the entire flowsheet – from run of mine ore, to metal.

Why is this so important for our customers? You can bundle equipment together to make tenders and dealing with OEMs more economical for mining companies. But, more than that, we can bring a much larger pool of experts to a project to interact and talk with each other to provide the right innovations. This is the ‘one plus one equals three’ effect.

We can also look at balancing the equipment so, for example, the primary crusher is appropriately configured to produce the right ore for the secondary crushing process and the screens are amply sized to effectively carry out their job. That then leads to finding the optimal operating point for the HPGRs and milling equipment and then the downstream processing segment. This type of equipment balancing is highly interesting for the market, creating win-win situations for customers and us as an OEM.

IM: Do you see your relationship with mining customers changing because of this holistic approach?

SK: Yes and no. There are companies that will appreciate this wider offering and there are others that will continue to come to us as part of a more traditional way of tendering for mineral processing equipment.

I see a trend where larger companies are coming back to reliable OEMs because the availability, sustainability and reliability of equipment is much more important than saving a dollar in capex in the first place. That is a trend we have seen strengthen even more recently with COVID; we all know when a plant is not running, it costs operators hundreds of thousands of dollars per day in lost revenue.

Yet, there are always customers that say capex is king. They will do everything they can to tender it most competitively from a capital expense perspective, regardless of the long-term total cost of ownership benefits choosing another solution will have.

IM: How will your digital offering be strengthened through the combination?

SK: At Metso, we started, especially in South America, with a strong operation and presence in terms of remote control and remote operating and maintenance support for processing plants.

The service solutions that have been developed and established in some countries, specifically for Metso and for Metso equipment, in the new company will, of course, be transferred into the installed base of Outotec (for example, a facility previous owned by Outotec in Espoo, Finland, is now a Metso Outotec Performance Center facility).

We often heard from customers: ‘We have great equipment from the Outotec side, but we have never experienced the great Metso services.’

What is so encouraging to see is that there is demand from the industry for such a combination of equipment and services.

IM: Where do you see an overlap of solutions (for instance, possibly crushing and grinding equipment (SAG/AG/ball mills), vertical crushing tech (Vertimill/HIG mill)) or flotation (Outotec has a greater market share but Metso supplies some interesting options like column flotation, plus is the leader in flotation camera monitoring with VisioFroth)? Historically, have you been competing against each other for contracts in these market segments?

SK: As you know, for 12 months or so, there was intense scrutiny from the regulatory authorities to find out if the companies could merge or not because of an overlap, and the answer that came back is yes.

From a regulatory authority perspective, there is no overlap, and, from a technical perspective, I view it in a similar way.

One prime example to give would be the Vertimill (below, left) and the HIGmill (below, right). If you look at both in detail and you talk to customers – which has happened when we have our project meetings and negotiations – you often find that the applications being examined are so specific that both mills, although close when it comes to operating process, have their own sweet spots.

                      

Most of the cases where we, as Metso and Outotec, won or lost a tender, the argument was not around price or sentiment; it was always technical where, for example, the feed was too coarse for the HIGmill, or the end product needed to be so fine that the Vertimill was ruled out.

We, therefore, want to continue offering both technologies; we will not shelve one because we believe there is room for both solutions.

IM: Could this combination then enable you to offer a more customised solution for customers?

SK: That is where the benefit (from the combined Metso Outotec) for the industry really kicks in; our customers are not just getting standard solutions; some tailoring is involved. They will be able to get more specific and solution-oriented, performance-balanced pieces of equipment.

IM: Would you like to add anything else?

SK: I need to say that I am quite excited about the opportunities for the new company, Metso Outotec. There are benefits for both us and the wider industry.

Personally, I am humbled to be elected to run such a large organisation of industry experts and high-quality equipment. It is exciting times ahead.

Rio, BHP and UWA establish tailings management learning platform

BHP and Rio Tinto have agreed to jointly fund a new initiative at the University of Western Australia that aims to improve global tailings management.

Over five years, the companies will invest A$4 million (($2.7 million) A$2 million each) in training, research, education and practice to support tailings and waste management facilities as part of the Future Tails program.

The initiative includes leading-edge training programs to build talent and capability; publications that summarise state-of-the-art tailings analysis, design, operation and management; and new research collaborations with industry to drive further innovation, according to UWA.

“Future Tails will provide education, training, and professional development to senior executives, senior technical personnel, junior engineers and operational staff in Australia and internationally,” the university explained.

Program Director, Professor Andy Fourie, from UWA’s School of Engineering, said there was a clear imperative to improve tailings management.

“Future Tails represents a step change in education, training and accreditation,” Professor Fourie said. “Moreover, it will drive cutting-edge research and innovation that will feed into future training.”

Program participants will be awarded micro-credentials from UWA and there will be opportunities to follow a postgraduate pathway, which will include a Masters in Tailings Management.

The Global Tailings Standard being developed by the Global Tailings Review will underscore industry management of tailings and waste, UWA said. Just last week, the partners of the Global Tailings Review said it expected to publish the standard in the coming weeks.

Matt Currie, Vice President of BHP’s Tailings Taskforce, said there was an increasing demand for tailings expertise and for qualified people and methods to train these new professionals.

“The program will provide essential training and development to people at all levels of their career and help reinforce the different career paths within the tailings discipline,” Currie said.

Rio Tinto’s Head of Group Technical Mining, Santi Pal, said it was clear the industry needed to improve operational management and engineering practices.

“We need to enhance this capability right across the industry,” Pal said. “Future Tails will develop and retrain talent needed to safely and sustainably run mining operations of the future. Over time, it will help support improved global tailings management standards, knowledge-sharing and the transfer of best practice.”

Metso to help Gold Fields with dry tailings processing at Salares Norte

Metso says Salares Norte, a Chile greenfield project owned by Gold Fields, has ordered three of its Vertical Plate Pressure Filters with all the ancillary equipment for dry tailings processing.

The order has been booked in Metso’s June quarter orders received, with the filters expected to be commissioned in October 2022.

Francois Swanepoel, Technical Manager at Salares Norte, said Gold Fields’ vision is to be the global leader in sustainable gold mining.

“The Salares Norte greenfield project is located 4,500 m above sea level in the Andean Mountains, where water is scarce and needs to be used wisely,” he said.

“To minimise the use of water and improve the physical and chemical stability of our tailings, we have decided to adopt filtered tailings for the project. Salares Norte will be a benchmark plant for dry tailings processing.”

Earlier this month, Outotec announced it would provide one 4 MW SAG mill and one 4 MW ball mill as well as five thickeners and one clarifier to be used in different process phases at the project.

Metso said Salares Norte was an exciting project for the company to work on as it considers dry tailings as the “most socially responsible and economically viable solution for tailings management”.

Patricio Mujica Dominguez, Senior Manager, Mining Equipment at Metso, said: “Besides the front-running tailings management solution, Salares Norte has challenged its partners to come up with other innovative solutions. The location of the plant at a height of almost 5 km above the sea level comes with its own unique challenges.

“For example, the design and transportation of the equipment, as well as commissioning, needs to be done with special care. To save manpower at such a high altitude, Metso will semi-assemble the filters in its service centres and deliver them in six specially designed easy-to-assemble modules to the site.”

A 2019 feasibility study on Salares Norte envisages an open-pit mining operation with an initial mine life of 11.5 years, producing 450,000 oz/y of gold-equivalent for the first seven years.

Los Andes Copper addressing Vizcachitas project energy and water needs in PFS

Los Andes Copper has ideas on adding to the number of large open-pit mines in Chile’s copper industry with the development of its Vizcachitas project, but it is eyeing up a different route to many of them that includes the use of energy-efficient HPGR technology and dry-stacked tailings.

In an update on its pending prefeasibility study (PFS), the company said it was re-evaluating the conceptual plan it laid out in its June 2019 preliminary economic assessment, which envisaged a base case 110,000 t/d operation using a SAG mill grinding circuit and thickened tailings dam.

The PFS is currently underway and areas of work being advanced include processing, the tailings facility, infrastructure, geology, the mine plan, environmental and social and community engagement, it said.

While delaying some of the metallurgical test work and field work, the current COVID-19 situation had not impacted the progress of the main engineering study, according to Los Andes. “All employees and subcontractors are working from home where possible and only a small group of individuals are working to prepare samples in the company’s Santiago core storage area,” it said.

The full PFS is not expected until the March quarter of 2021, but the company did outline some engineering leaps it has made since the PEA publication.

It said test work had shown that a HPGR circuit is feasible for the project and could provide “enhanced project economics with lower energy consumption and increased operating flexibility”.

The PEA outlined a SAG and ball mill crushing circuit with a target grind size of P80 (240 microns), but the more recent test work had shown room for an alternative with a three-stage crushing circuit using secondary crushers in open circuit and HPGR as a tertiary crusher in closed circuit. This circuit would target a grind size of P80 between 240-300 microns, the company said.

Such a change would avoid the use of a coarse ore stockpile, reduce energy consumption, reduce maintenance, and reduce the project footprint, it said.

HPGRs have previously been used at Chile mining operations, including the Compañía Minera del Pacífico-owned Mina Los Colorados iron ore mine and KGHM’s majority-owned Sierra Gorda operation.

Los Andes clarified: “HPGR technology has been identified as the most attractive grinding alternative given the data obtained from the preliminary test work conducted to date.”

The next big advance was made on the tailings side, with the company saying test work had shown that the project is amenable to filtering and dry-stacked tailings.

“This change would significantly reduce the project’s water consumption, footprint and environmental impact,” it said. It would also, one would expect, provide a much smoother environmental permitting route for Vizcachitas considering the negative sentiment surrounding thickened tailings dams in the industry.

There are knock-on benefits to this move too, with the reduced footprint required for dry-stacked tailings meaning all project infrastructure could fit into one operating complex in the Rocin Valley of Chile, around 150 km northeast of Santiago. The PEA previously outlined the use of infrastructure in both the Rocin Valley and the Chalaco Valley.

The preliminary filtration circuit Los Andes is working with shows the coarse fraction (87% of total tailings) could be filtered in belt filters, with the fine fraction (13%) filtered in pressure filters.

Recent studies on other dry-stack tailings project have tended to use either belt filters or pressure filters, but Los Andes said the combination of the two added flexibility to the tailings filtration operation at Vizcachitas and reduced operational risks due to variability of the finer fraction in tailings.

This would see the company require 12 belt filters and three filter presses for the 110,000 t/d copper-molybdenum operation.

According to the company, dry-stacked tailings would:

  • Reduce water consumption by around 50%;
  • Reduce the project’s footprint;
  • Be better suited for areas of high seismic activity;
  • Be transported by trucks or conveyors;
  • Eliminate the need for a traditional dam wall; and
  • Reduce the environmental risk by avoiding contact with ground water.

Weir Minerals continues to go with the Multiflo in barge applications

Even with 40 years of custom barge solution expertise under its belt, Weir Minerals says it is continuing to innovate with new designs for applications in oil sands, tailings management and tropical and cold climates.

Developed over the decades, the Weir Minerals range of Multiflo® barges provides a solution for numerous applications, according to the company.

Water reclamation for oil sands market

Reclaim water barges are an integral part of tailings management solutions in oil sands applications, where tailings contain high percentages of water that can be recycled back through the process plant.

Upon identifying the need for reliable systems which were easy to manage and maintain, Weir Minerals developed its mega-barge exclusively for the oil sands market. This all in one package includes pumps, valves, hoses, and piping.

“This is where our turnkey value proposition really took off,” Kris Kielar, Product Manager for engineered-to-order dewatering products at Weir Minerals Canada, explains. “Our largest barge system includes a fully integrated electrical control houses that powers 9,000 hp (6,711 kW) worth of pumps, overhead cranes, remote monitoring and control, and the longest floated walkway we’ve ever provided, with ‘warm-up’ stations every 150 m for one kilometre.”

Mega-barges are the ideal solution for unique applications, such as the scale of water reclaim needed at some of the world’s largest oil sands operations, according to Weir Minerals.

“A typical oil sands operation requires nine barrels of water per barrel of bitumen produced,” continues Kielar, “so the more water that can be reclaimed, the better. The larger the operation, the bigger the water saving potential.”

In addition to the mega-barges for the oil sands market, Weir Minerals also developed modular barge packages as a fully customisable solution for ease of shipment, and a reduction in both capital costs and onsite installation costs. The introduction of both static and mobile, land-based, booster stations and pumphouses further expands the Multiflo barge solution capability while maintaining a single point of contact for customers, the company says.

Tailings management

The need for custom barge solutions for tailings management has increased in recent years. Where previously dewatering pumps in tailings applications were “set-and-forget”, the increased focus on tailings dam safety has shined a new spotlight on barge solutions that can provide heavy-duty, reliable pumping, Weir Minerals said.

Not only must sites revisit current arrangements to consider how their tailings will be handled in the future, they also need to empty the old dams decommissioned by environmental and mining authorities, the company said.

Ricardo Menezes, Barge Systems Specialist at Weir Minerals Brazil, said: “We are equipped to provide the entire solution. From initial consultation and design, to manufacturing, commission, and training and supervision of site operators. We work hard to bring our customers the best possible solution for their site, and we do it all under one roof.”

These all-in-one Multiflo packages eliminate the headache of integrating civil construction, electrical control rooms, control systems, pipes, cables, and mechanical and electrical works, according to the company. Weir Minerals engineer these dewatering barges in-house and employ naval engineering consultants to create tailored solutions for its customers.

Menezes continues: “Sites are being asked to transport tailings on a larger scale than before. An off-the-shelf solution might not work with their existing site infrastructure and that is where our fluid transport expertise comes in.”

Reliability in any situation

Applications in tropical environments, which experience heavy and sometimes unexpected rainfall, often require barge-mounted dewatering pumps to handle the rapidly rising water levels.

Multiflo land-based barges are built to float, protecting the pump unit from being flooded as often happens with a traditional skid pump unit, Weir Minerals says.

These land-based barges are fitted with integrated skid runners that allow them to be towed around mine sites and launched or retrieved with the use of dozers or excavators. The integrated skid runners also provide the added benefit of using the barge as a skid pump operating at the pond edge with easy land access for operators and servicing, the company says.

Marnus Koorts, Product Manager for dewatering pumps at Weir Minerals South Africa, says the company gets very specific requests for these land-based barges.

“We recently completed a project for a customer experiencing regular high wind speeds and tropical storms,” he said. “We needed to account for wave action and wind loading to ensure our solution would minimise risk of structural damage during these storms.”

Other considerations such as water quality, where pH can range from very low through to high, and water content, such as high percentages of suspended solids and floating debris, are also key to maintaining dewatering equipment on site, according to the company.

“Multiflo barges maximise reliability through innovative protection systems chosen specifically for the environment that the barge will operate in,” Weir Minerals says.

For one customer in South Africa, the Weir Minerals team needed to account for more than just water, according to Koorts.

“One of the design requirements for this particular installation was for the handrails and other structures to be engineered to prevent crocodiles from gaining access to the deck space.”

Dewatering in cold climates

In the last year, Weir Minerals barge specialists from Canada have been working with teams in Russia and Finland, to establish a European centre of expertise specifically for dewatering barges in cold-climate applications. Key environmental factors such as wind, snow and seismic loading can affect the buoyancy and stability of the barges, which they looked to address.

“We’re building on the work of the North and South American teams,” Artem Filippov, Dewatering Product Manager at Weir Minerals Russia, said. “Working together and using insights gained from their years of experience have allowed us to create unique barge dewatering systems for our European customers.”

Weir Minerals’ cold-climate expertise comes from experience in floating barge systems at temperatures below -45°C, de-icing systems and winter barge access systems. In addition, Multiflo barge systems are fully marine naval certified under all weather conditions and are marine architect certified, the company says.

Phibion brings AMC tailings management approach to Brazil

Phibion has stepped up efforts to bring its accelerated mechanical consolidation (AMC) technology to Brazil, having recently opened an office in Belo Horizonte, Minas Gerais.

The Phibion Brasil Tecnologia e Inovação em Mineração Ltda office complements the company’s recent expansion into the Latin America market, it said.

Phibion explained the rationale for the move: “Recent catastrophic failures in associated tailings dams have highlighted the critical need for innovative and cost-effective technologies that can recover residual processing water from the tailings coupled with improvements in tailings density and strength.

“Remaining with conventional technology or trying to adopt cost-prohibitive technologies is not an option. Collectively, the mining industry, the regulators and the people of Brazil demand a new approach.”

Phibion thinks its AMC technology can help. AMC is a systematic and low energy tailings management approach that can reduce tailings volumes and deliver enhanced water recovery with the associated benefits of increased tailings density and strength, according to the company.

Phibion’s Global Business Development Manager, Marco Miranda, guides Phibion’s operation in Latin America and is now based out of the Belo Horizonte office.

Back in October, Phibion announced it was opening an office in Santiago, Chile, to service the rapidly growing mining and tailings management opportunities in Latin America.

Vale evaluating wet tailings processing alternatives at Brucutu iron ore mine

Vale says it is evaluating short-term alternatives to the wet processing of tailings at its Brucutu iron ore mine, in Brazil, as it looks to step up processing activities at the Minas Gerais operation.

The Brucutu plant, which used to dispose of tailings in the Norte/Laranjeiras dam – that has been at “emergency level 1” since December 2, 2019 – is continuing to operate at around 40% of its capacity through wet processing and tailings filtration, Vale noted.

Yet, the miner said it was evaluating “short-term alternatives” for tailings disposal, such as the optimised use of the Sul dam. These options are being tested by geotechnical and operational teams and may increase Brucutu plant’s processing capacity to 80%, Vale noted.

It warned that, if such alternatives for tailings disposal or the reclassification of the emergency level for Norte/Laranjeiras dam are not achieved until the end of the June quarter, there will “likely be an impact on the 2020 annual iron ore fines production volume”.

Vale took the decision to temporarily suspend the disposal of tailings at the Laranjeiras dam, part of the Brucutu iron ore mine, while assessing the dam’s geotechnical characteristics, back in December. During the shutdown, the dam will have the Level 1 emergency protocol adopted, Vale said. At that point, Vale put the suspension period at one-to-two months.

At the same time, the company reiterated its plans to continue to invest in dry stacking technologies to reduce its exposure to wet tailings dams.

Karara Mining to stack tailings high to keep costs, water use and footprint low

Bis, FLSmidth and Karara Mining have developed a “unique mobile stacking conveyor” solution that has cut water use, costs and the environmental footprint at the iron ore miner’s operation in Western Australia.

If Karara’s iron ore mine had chosen a wet tailings storage facility, the tailings pond would have been roughly 8 sq.km based on its 30-year mine life, according to FLSmidth.

The operation is also in the Mid-West region of Western Australia, an area with scarce water reserves, so losing so much water to wet tailings would have been costly to both the environment and Karara’s bottom line.

With these factors in mind, Karara looked at implementing a dry-stacked/filtered tailings system to allow for significant water recovery and reuse. As well as reducing costs, dry stack technology would reduce the tailings footprint to around 4 sq.km, according to FLSmidth.

Bis worked with Karara and FLSmidth to develop a solution to build, own, operate and maintain a “unique mobile stacking conveyor”, FLSmidth said. This fixed infrastructure solution was developed by the three companies to integrate a walking conveyor and stacking technology normally used in large-scale copper mining operations.

Aside from the significant reduction of the physical footprint compared with the wet tailings alternative, Karara was looking for cost efficiencies in other areas, FLSmidth said. “For instance, the planning of a wet tailings storage facility needs to factor in an ongoing maintenance strategy. This comes with a perpetual cost that can only be guessed at while the decades pass,” the company said. “With dry-stack tailings, the total cost of ownership over the mine’s lifetime is easier to estimate and Karara were confident the dry stack solution would be cost competitive.”

Water usage was another key consideration for Karara. With environmental and cost factors in mind, Karara wanted to look at ways to have greater control over water assets on site. The ability to reuse and recycle water in the mining process would lead to substantial cost efficiencies by minimising the amount of makeup water needed for the mining operation, FLSmidth said.

The technology implemented into Karara’s tailings storage facility was also an important factor as Karara wanted the flexibility to continually update the equipment with the view of running it more efficiently as new technology became available. It engaged Bis to operate the facility machinery based on its deep industry experience with materials handling and bulk logistics, FLSmidth said.

FLSmidth, meanwhile, was identified by Karara as being able to meet the project’s requirements and mine-specific needs.

The mining OEM said: “A primary demand was the ability to supply a cost-effective dry stacking technology ideal for dry climate mining operations that reduced water requirements. With FLSmidth’s advanced stacking capability (machinery working off stacked pile) and ability to stack tailings at 15% moisture content, this meant tangible water savings for Karara.

“At Karara, the dry tailings will be stacked in four lifts to the maximum height approved by the Western Australia Government. The solution proposed by FLSmidth also created a smaller tailings storage footprint, which also meant improved site rehabilitation potential.”

Karara worked closely with Bis and FLSmidth to get the project off the ground and make Karara the first mine in Australia to take full advantage of this dry-stack technology, FLSmidth said.

The tailings storage facility is fast approaching the completion of Lift 1 and, together with Karara, Bis and FLSmidth are already in the planning stage to lift the equipment to the second level.