Tag Archives: water management

Weir Minerals’ Terraflowing offers up tailings storage and reprocessing options

More details of Weir Minerals novel dewatering process, TerraFlowingTM, have emerged as the company steps up marketing of its tailings management offering.

This week, on May 27, Nils Steward, General Manager Operations and Development at Weir Minerals, will describe the test work and results achieved in the development of TerraFlowing in a webinar and, ahead of that, the company has provided some important details about the technology.

“This process has been developed to address both the value proposition of tailings inherent in the tailings, and tailings storage,” the company said.

Weir Minerals is able to look at tailings reprocessing as well as storage with TerraFlowing thanks to the incorporation of a two-stage cyclone dewatering process followed by centrifugation of the final stage of cycloning overflow, it said.

In this process, three dewatered tailings streams are produced: a primary cyclone underflow, a secondary cyclone underflow and a centrifuge pulp. These three streams can be combined or used in different configurations, according to Weir Minerals.

This three-stage system offers the flexibility to make provision for variations in mineralogy and particle size distribution (PSD) as well as the opportunity to recover ‘tailings as a resource’, it said.

This ability to deal with feed variations in PSD and mineralogy, and deliver variations in PSDs, tailings solids concentrations and recoveries is owing to the ability to vary the cyclone and centrifuge configurations and operation, Weir Minerals said.

“This flexibility further allows for optimisation of power utilisation,” Weir Minerals said. “In many instances, water is an annual issue; during the rainfall season water recovery is less important than dry seasons. During the rainy season, the need to operate the process at maximum water recovery, associated with maximum power consumption, is less necessary and power can be conserved.”

Two main TerraFlowing process outcomes have been identified by the company corresponding to:

  • A maximum solids recovery at maximum solids concentration of the two cyclone and centrifuge streams; and
  • A recovery of a tailings stream for tailings storage facility (TSF) embankment construction with the remaining cyclone and centrifuge streams being combined for deposition within the TSF.

Water recovery can be up to 85% with a 78% wet solids concentration final tailings product from combining the three streams in the maximum solids concentration case, the company says. Transport of this final stackable tailings product will be by positive displacement pumps, conveyors or trucks, the company noted.

For the case where the primary cyclone underflow has been shown to deliver a PSD suitable for TSF embankment construction, through geotechnical investigation, the remaining secondary cyclone underflow and centrifuge pulp is suitable for beaching deposition within the TSF, it said. The water recovery in this process is up to 75%, while transport of these tailings products can be through centrifugal pumps.

Weir Minerals says: “TerraFlowing is an opportunity to not only store a thickened product but also recover the value in the tailings through the construction of TSF embankments or the manufacture of structural concrete products, as well as shotcrete for reinforcement and support.”

To find out more about the webinar click here.

Weir Minerals targets customer ‘pain points’ with integrated solutions teams

Weir Minerals says its integrated solutions teams are combining experience from comminution to tailings, from chemistry to hydraulics, to deliver reliable solutions that solve its customers’ most frustrating pain points.

Since brothers James and George Weir founded what would become the Weir Group with their 1871 invention on the Weir boiler feed pump, engineering expertise, the company says, has been the driving force of its success.

“For almost 150 years, Weir has built its business on the principle that if something’s worth doing, it’s worth doing right and to do something right on a mine, you need the right team,” it said.

This is where the company’s integrated solutions teams come in, which combine technical expertise, local access and global knowledge to optimise mining companies’ entire process, according to the company.

John McNulty, Vice President of Global Engineering and Technology for Weir Minerals, says the industry needs integrated solutions now more than ever.

“With this approach, we continually listen to our customer’s pain points and identify ways in which we can improve their process,” he said. “Integrated solutions also aligns closely with the Weir Group’s sustainability strategy.

“We often talk to our customers about the challenges they face in terms of energy consumption, water usage and waste, and brainstorm ways in which we can help reduce their environmental impact. In this current climate, this approach is absolutely critical.”

When confronted with a problem that requires more than a single piece of equipment, Weir Minerals draws on its integrated solutions teams, made up of process engineers, design engineers, product experts, materials scientists, supply chain and logistics experts, as well as local sales teams who know the customer’s site.

These multi-disciplinary teams ensure a problem is considered from all perspectives, identifying potential issues and opportunities to optimise the circuit with upstream and downstream benefits, according to Weir Minerals.

With almost 10,000 employees operating in more than 50 countries, Weir Minerals can build teams with experience working in every kind of mine and quarry, in environments ranging from Canada’s frozen oil sands region and Indonesia’s rain-prone coal mines to remote deserts in Chile, Mongolia and Australia.

“As well as optimising equipment to provide maximum efficiency and wear life in any given situation, the integrated solutions team’s expertise allows them to tailor solutions that can be flown onto site when the roads freeze in the winter, prevent crocodiles climbing onto floating equipment, and utilise waste products like tailings as a resource,” the company says.

Seda Kahraman, a Regional Process Engineering Manager for Weir Minerals, says the company believes nothing is ‘impossible’, with engineers continually looking for better ways of doing things.

“Our team is made up of specialists each possessing different process systems’ expertise including, but not limited to: troubleshooting, designing tools and process simulation programs,” he said. “We combine this wealth of knowledge to deliver innovative solutions that address our customers’ varied needs.”

The key to Weir Minerals’ integrated solutions approach is the entire team of experts collaborating to identify all root causes of a customer’s challenge, considering all the contributing factors – which is where Weir Minerals’ interdisciplinary expertise is so important, it says.

The team perform process audits during site visits to identify bottlenecks and then, using flowsheets, mass balances, 3D layouts, and feasibility studies, advise on the most appropriate solution for the customer to not just resolve the problem they came to Weir Minerals with, but to optimise their process to save energy, reduce water waste or increase capacity, and ultimately save the customer money.

Talbot provides total water management solution for South Africa coal producer

Talbot recently came to the rescue of a South Africa coal producer looking to remove gypsum from its waste stream, thereby freeing up capacity at a downstream dam.

While Talbot has more than three decades of experience in delivering industrial water management solutions across the African continent, what is not generally realised is the fact the company’s expertise extends beyond the ambit of water itself, the South Africa sustainable water and wastewater specialist says.

“Dealing with sludges and waste streams, typically with high suspended loads, is often required to provide a total water management solution and is viewed as being both a complex and expensive process,” Talbot said, explaining this needn’t be the case.

Talbot Consulting Services General Manager, Claire Lipsett, says the leading Highveld coal producer in question called on the company to provide a solution for the removal of gypsum generated as a by-product of its coal mine water purification process.

Lipsett explains the waste stream flowing out of the treatment process into a downstream holding dam contained a high content of gypsum, to the extent it significantly reduced the facility’s finite storage capacity.

Following an on-site examination of the processes involved, Talbot proposed a simple and well-known technology that would provide an effective solution and could be proven on site during live operations through pilot testing.

In this case, a hydraulic filter press was selected to dewater the solids, dry and press them into briquette form for transportation to end-use customers. The filtrate – minus the extracted solids – was directed to the evaporation dam before returning to site processes via a blend line, Talbot said.

The effectiveness of the solution was proven during a two-week trial in March, which achieved impressive results, according to Lipsett. “We reduced the waste solids from around 2,900 mg/l to just 84 mg/l,” she said. “We also demonstrated that the technology would extract gypsum at a rate of 100 kg/h on a full-scale site operation.”

The trial, Lipsett says, showed that effective solids removal could be achieved in a single-step process, without the use of flocculants or coagulants. It also offered the client an easy-to-operate, appropriate solution to achieve total water management for the site.

Pilot trials conducted by Talbot, such as this, generate several benefits that enable clients to not only fully understand the short-term implications of investing in a new technology but how they will positively impact on the future operation of a business, according to Lipsett.

“Before making any form of commitment, the client has the opportunity to engage with the technology and equipment in terms of look and feel, its effectiveness and ease of operation, all the while receiving technical and commercial guidance from a supplier that is a leader in its class and is committed to providing long-term support, not just a one-off sale,” she said.

Financial projections from Talbot of conceptual models prepared during the piloting process include not only the original capital cost of the equipment but anticipated expenditure on items like membrane replacement, operational and maintenance costs.

The company said: “This provides potential users with a comprehensive set of economic life-cycle projections, thus enabling them to make informed decisions on the short-, medium- and long-term benefits and implications with no hidden extras.”

Lipsett cites the results obtained in a similar process employed by a South Africa platinum producer where the recovery of precious metals from a wastewater stream was achieved using the same technology and significantly exceeded initial design expectations. Pilot trials had a substantial impact on the business case and ultimately enabled the client to invest in the solution, according to the company.

“While this may be an extreme case, there are many instances in which the materials recovered have significant intrinsic value so that solids recovery projects not only pay for themselves but deliver sustainable economic value into the future,” the company said.

AGQ Labs to monitor and control water for Chile miners

AGQ Labs says it has been awarded three-year water control and monitoring plan contracts with MLCC Caserones and Codelco, in Chile.

Dedicated to providing laboratory analysis, advanced analysis and specialised chemical consultancy services, AGQ will service the two contracts from its new branch in Copiapó, northern Chile.

MLCC (SCM Minera Lumina Copper Chile) is owned by Pan Pacific Copper Co and Mitsui & Co SCM. It owns Caserones (pictured), a deposit in the Atacama Region of Chile, which is 162 km from Copiapó.

Codelco, meanwhile, is currently the biggest copper producer in the world by production, owning a number of mines in northern Chile.

AGC said the inauguration of its new Copiapó branch, which will provide operational coverage to other clients in the area, sees AGQ Labs Chile take a new step, “consolidating itself as a leading supplier to the Chilean mining industry”.

De.mem to put the BOOT in at Metro Mining’s Bauxite Hills mine

Water and wastewater treatment company, De.mem, says it has received new orders worth a minimum A$470,000 ($317,202) of revenue from Metro Mining for work at its Bauxite Hills mine in Queensland, Australia.

The orders include the delivery of wastewater treatment equipment, plus a contract award to supply equipment in combination with the provision of operations & maintenance services under a build, own, operate, transfer (BOOT) agreement.

Bauxite Hills, which produced 3.5 Mt (wet) of bauxite in 2019, is currently carrying out detailed engineering and design work related to a stage two expansion at the mine, which could see annual operating capacity reach 6 Mt (wet) by 2021.

De.mem CEO, Andreas Kroell, said: “We are pleased to provide our customers with a complete water treatment solutions offering, which includes the flexibility of either purchasing or leasing equipment from De.mem. Our build, own, operate/BOOT solutions are a key part of our services business, whereby we are engaged by leading players from mining and other industries under long-term agreements for the provision of water treatment equipment and ongoing operations and maintenance services.”

This is not the only Queensland bauxite mine De.mem is currently working on. Back in February 2019, the company secured a 12-month A$780,000 operations and maintenance contract to manage potable water and sewage treatment plants at Rio Tinto’s Amrun bauxite mine in the state.

Outotec looks to strike the right water balance with Pretium platform

Outotec has launched a new real-time water monitoring tool to enable miners to simulate and evaluate proposed water-treatment investments and process changes, and keep tabs on water use across their operations.

As the company says, water is a scarce and valuable resource, and mining operations are under increasing pressure to optimise their water usage in order to improve environmental and economic performance.

Outotec Pretium Water Advisor enables real-time monitoring of the water balance across an entire site, allowing operators to create short-term forecasts for water volume and quality, it said.

The platform predicts changes in water balance and quality based on changing production and environmental conditions. This enables simulation and evaluation of proposed water-treatment investments and process changes.

“The solution combines intelligent water measurement stations and instrumentation with Outotec’s predictive water balance computing to eliminate the need to rely on time-consuming manual water-balance and key performance indicator (KPI) calculations,” Outotec said.

Plant managers and engineers can view water KPIs as both graphical views and historical trends via a web-based interface and also access scenario management tools for performing simulations and evaluating the impacts of new water treatment investments, process changes, or the impact of expansion plans on the site’s water resources, the company said.

“Water Advisor monitoring stations provide accurate and reliable real-time data on both environmental and process waters, and are designed to perform reliably in harsh environments even under constant exposure to rain, humidity, dust, frost, and sun,” the company said. “Stations can be easily connected to the Outotec technical platform for data collection, processing, visualisation, and device management.”

Outotec Pretium Water Advisor has been commercialised with the help of funding from the European Institute of Innovation and Technology, a body of the European Union, under Horizon 2020, the EU Framework Programme for Research and Innovation.

‘World-first’ public database of mine tailings dams launched

Environmental organisation GRID-Arendal, with support from the UN Environment Program (UNEP), says it has launched the world’s first publicly accessible global database of mine tailings storage facilities.

The database, the Global Tailings Portal, was built by Norway-based GRID-Arendal as part of the Investor Mining and Tailings Safety Initiative, led by the Church of England Pensions Board and the Swedish National Pension Funds’ Council on Ethics, with support from the UNEP. The initiative is backed by funds with more than US$13 trillion under management, according to GRID-Arendal.

Professor Elaine Baker from the School of Geosciences is Director of the GRID-Arendal office at the University of Sydney. She said: “This portal could save lives. Tailing dams are getting bigger and bigger. Mining companies have found most of the highest-grade ores and are now mining lower-grade ones, which create more waste. With this information, the entire industry can work towards reducing dam failures in the future.”

The release of the Global Tailings Portal coincides with the one-year anniversary of the tailings dam collapse in Brumadinho, Brazil (pictured above – CREDIT:IDF/Flickr), which reportedly killed 270 people. After that event, a group of institutional investors led by the Church of England Pensions Board asked 726 of the world’s largest mining companies to disclose details about their tailings dams. Many of the companies complied, and the information they released has been incorporated into the database, GRID-Arendal said.

The database will allow users to view detailed information on more than 1,900 tailings dams, categorised by location, company, dam type, height, volume and risk, among other factors.

Kristina Thygesen, GRID-Arendal’s Program Leader for Geological Resources and a member of the team that worked on the portal, said: “Most of this information has never before been publicly available.”

When GRID-Arendal began in-depth research on mine tailings dams in 2016, very little data was accessible. In a 2017 report on tailings dams, co-published by GRID and the UN Environment Program, one of the key recommendations was to establish an accessible public-interest database of tailings storage facilities.

“This database brings a new level of transparency to the mining industry, which will benefit regulators, institutional investors, scientific researchers, local communities, the media and the industry itself,” Thygesen said.

Xylem continues sustainable water technologies investment with new R&D hub

Xylem, a leading global water technology company, has launched a new multi-disciplinary centre for water, wastewater and energy technologies at the company’s regional headquarters in Singapore.

The expanded headquarters brings the company’s regional R&D capability into a new Xylem Technology Hub Singapore (XTHS), alongside its regional leadership and personnel, the company said.

It explained: “The XTHS represents Xylem’s continued investment in sustainable water technologies, and research at the new centre will focus on developing breakthrough technologies in water distribution and water and wastewater treatment.”

Xylem is well known in the mining industry for its own and other brand series of mine dewatering and slurry pumps and accessories.

One of the first projects Xylem is pursuing at the centre is a collaboration with A*STAR’s Institute of High Performance Computing (IHPC). Xylem will combine its leading expertise in water technologies with IHPC’s expertise in computer modelling and simulations. Together, they will evaluate fluid-structure interaction in pipe flow to develop a new computational fluid dynamics model tailored for Xylem’s applications such as SmartBall and PipeDiver, it said. The model will then be applied to the design and testing of other advanced products and solutions to be deployed in treatment plants and water distribution networks.

Patrick Decker, President and CEO of Xylem, said: “This new multi-disciplinary centre will create ample opportunities to innovate and collaborate with our customers, as we work with them to tackle the region’s greatest water challenges, including water scarcity, affordability and infrastructure resilience.

“Bringing research and development capability into our regional headquarters in Singapore puts all of Xylem’s market-leading technology capability in one location, focused on the region’s water technology and infrastructure solutions.”

In addition to the research and development hub, Xylem’s new office will feature a customer experience centre and training centre, bringing together all of Xylem’s sales, customer support and technical capabilities for Southeast Asia, it said.

Work at the centre will also be supported by Xylem’s ongoing partnership with PUB, Singapore’s National Water Agency, to address challenges brought about by climate change and increasing water demand. Xylem continues to work with PUB on the development and implementation of technologies in common areas of interest, such as high-precision leak detection and condition assessment technologies, and using data analytics to pinpoint water loss.

Global Tailings Review opens public consultation period

The ICMM-backed Global Tailings Review has launched a public consultation on its draft Global Tailings Standard in order to “develop a robust, fit-for-purpose international standard for the safer management of tailings”.

The public consultation, which ends on December 31, will take place in two parts.

First: online via a survey which has been translated into seven languages. Second: in-country consultations across a range of mining jurisdictions in the northern and southern hemispheres.

The Global Tailings Review was co-convened by the United Nations Environment Programme, International Council on Mining and Metals (ICMM) and Principles for Responsible Investment following the tailings dam collapse at Brumadinho, Brazil on January 25, 2019, to establish an international standard on tailings facilities management. The final Global Tailings Standard will need to be endorsed by all three parties.

The draft standard addresses six key topics:

  • Knowledge base – requires mine operators to develop knowledge about the social, economic and environmental context of a proposed or existing tailings facility;
  • Affected communities – focuses on the people living and working nearby. It requires human rights due diligence and meaningful engagement of project-affected people;
  • Design, construction, operation and monitoring of tailings facilities – aims to review design, construction, operation and monitoring of tailings facilities;
  • Management and governance – focuses on ongoing management and governance of tailings facilities. It defines a number of key roles, essential systems and critical processes;
  • Emergency response and long-term recovery – covers emergency preparedness and response in the event of a disaster, the re-establishment of ecosystems, and the long-term recovery of affected communities; and
  • Public disclosure and access to information – requires public access to information about tailings facilities in order for all stakeholders to be informed of the risks and impacts, management and mitigation plans, and performance monitoring.

“The review is committed to transparency and once the final standard is published, the Global Tailings Review will provide a consultation report that reflects feedback, key themes, topics and sentiments from different stakeholder groups, as well as how that feedback was processed and addressed in the final version of the standard,” the ICMM said.

It is expected that the final standard and accompanying recommendations report, which will outline broader proposals to support the uptake and implementation of the standard, will be published in 2020.

Outotec consolidates filtration expertise with new Larox PF-DS filter press

Outotec says its new Larox® PF-DS tower press filter combines two proven technologies in one unit to meet the challenging process requirements of the chemical process industry.

With filtration applications getting more demanding due to challenging materials, increased cake washing needs, strong acid processes, and fine grinding, there is an increasing need for technologies that can handle these challenges in a reliable and more automated manner, Outotec says.

The new Larox PF-DS is a tower press filter where the plate pack is composed of polypropylene membrane filter plates stacked on top of each other. The cake forms between the closed filter plates on the top and bottom side of the filtration chamber, hence it being called a double-side filter.

The mechanical operation and frame of the Larox PF-DS are shared with the Outotec Larox PF pressure filter while the unique filtration process is powered by the double-side plate pack from the Outotec Larox DS filter (earlier known as Hoesch® DS).

The individual filter chamber has a double-side filtration area of 4.7 m2 and an operating pressure of up to 16 bar. The plates are stacked vertically to give a total filtration area of 38–94 m2 depending on the unit size, according to Outotec.

One endless filter cloth runs through the whole filter and one side of the filter cloth is used for filtration. A wide range of different cloth types is available to meet the application needs, the company said. This filter cloth ensures efficient discharge of all cake from each individual chamber at every cycle, eliminating the need for manual intervention.

With the PF-DS now sharing the mechanical design with the PF family, local Outotec service teams are available for technical support and maintenance needs. Likewise, the availability and compatibility of the spare parts is significantly improved compared with earlier technology.

Outotec said: “PF-DS Filters are fully automatic, operating either with a standalone panel or through a distributed control system. Automation extends beyond basic filter sequencing to full process control, ensuring consistent results under varying process conditions.”

The filtration process is a batch operation which includes filtration, membrane pressing and air drying stages, with several options for cake washing added to the process depending on customer needs.

When the process cycle is ended, filter cakes will be discharged from the one side of the filter. Due to the cloth being on both sides of the chamber together with the cloth scrapers, cake discharge is fully automatic without an operator present.

After each cycle, the moving filter cloth passes through water sprays to remove any embedded solids. This maintains cloth permeability, consistent filter performance and extends cloth life, according to Outotec.

The single cloth system makes cloth change simple and quick, typically taking as little as 30 minutes. Furthermore, cloth inspection can be carried out without the need for equipment shutdown.