Tag Archives: mineral processing

Metso lines up LatAm tailings tests after setting up full-scale VPX filter in Brazil

Environmental, Mineral processing, Mining services, Water management, , , , , , ,

Metso says it has started full-scale testing of its VPX™ filter for tailings dewatering in Brazil, with eight tailings tests lined up with companies that process iron ore, copper and gold.

In 2019, Metso launched Tailings Management Solutions (TMS), its response to the global challenge of managing mining tailings efficiently. The company sees the dewatering of waste as the future of mining, allowing the removal of water and its reuse in the plant, itself, or as part of restoration projects. Its VPX filter is part of this TMS platform.

With an operating pressure of up to 25 bar, the VPX can deal with difficult-to-dewater tailings and enable up to 90% water recovery, according to the company.

Metso says a full-scale VPX filter is now in place at its facilities in Sorocaba, Brazil, where the first tests from samples sent by several mining companies from Brazil and Latin America started in March.

“This is not a laboratory test, but filtration in industrial-scale conditions using VPX technology, which has the capacity to process high volumes of ores,” Rodrigo Gouveia, Metso’s Vice President, Tailings Management Systems, said. “Tailings dewatering is technically and economically a viable option for today and the future. Dry stacking is widely acknowledged to be the safest, most sustainable option for tailings storage. We see that there is a strong demand for short- and medium-term technical solutions.”

Fausto Rezende, Metso’s Mining Equipment Sales Director in charge of TMS in Brazil, said there is another potential application in the adoption of tailings management: legacy dams. “We can develop projects for the dredging and concentration of the tailings and, in many cases, it is possible that this operation is more economically viable than virgin ore,” he said.

Metso already has expertise in dewatering solutions and, depending on each mining application and customer needs, carries out engineering to determine the specifications for the most suitable dewatering technology. It can pick from lamella thickeners, hydrocyclones and filters to tailings stackers, through pumping solutions and conveyor belts.

SMC Test comminution benchmark hits new milestone

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

This month, the Australia-invented SMC Test®, used by leading mining companies over the globe to improve concentrator performance, optimise throughput, and decrease energy use, reached its 50,000th test. This makes it, the company says, the most widely used comminution test in the world for AG & SAG mills, HPGRs and crushers.

The SMC Test database spans over 1,900 orebodies, 100 countries and 47 different commodities ranging from copper, gold, and iron to diamonds and rare earths. This makes it the largest database of its kind in the world, according to SMC Testing, giving unparalleled insight into the energy required to fully extract valuable minerals from ore.

A laboratory comminution test that provides a range of information on the breakage characteristics of rock samples for use in the mining/minerals processing industry, the SMC Test uses either crushed rock pieces that are very closely sized (‘crush and select’ method), or particles cut to similar size from drill core using a diamond saw (‘cut core’ method). The latter approach is used when a limited drill core sample is available, with almost any drill core size suitable, even core that has been quartered (slivered).

The chosen rock particles are broken using a closely controlled range of impact energies on a JK Tech Drop Weight Tester. The high degree of control imposed on both the size of particles and the energies used to break them means the test is largely free of the repeatability problems that plague tumbling mill rock characterisation tests, SMC Testing says. The results from the SMC Test are used to determine the drop-weight index – a measure of the strength of the rock as well as the comminution indices Mia, Mih, and Mic. In conjunction with the Bond ball mill work index, they can be used to accurately predict the overall specific energy requirements of circuits containing AG and SAG mills, ball mills, rod mills, crushers, and high pressure grinding rolls (HPGRs).

The SMC Test also generates the JK rock breakage parameters A, b, and ta as well as the JK crusher model’s t10-Ecs matrix, all of which are generated as part of the standard report output from the test. These values can be used to simulate crushing and grinding circuits using JKTech’s simulator – JKSimMet, according to SMC Testing.

The SMC Test’s broad-ranging uses include comminution plant design, circuit performance optimisation, throughput forecasting, geo-metallurgical modelling, as well as cutting energy costs and reducing CO2 emissions.

“The precision and accuracy of the SMC Test have been the main driving forces behind its success globally,” Dr Steve Morrell, SMC Testing CEO and inventor of the SMC Test, said. “These attributes of the test are hallmarks of reliability and quality that mining companies base important forecasting decisions and financial models upon.

“It has been proven through benchmarking against an unprecedented 120 processing plants around the world, covering just about every type of comminution circuit in operation, including the largest to the smallest equipment available on the market, and treating some of the softest to the hardest ores that have been discovered to date.”

Used by 18 out of 20 of the largest mining companies in the world, the SMC Test helped Barrick Gold achieve a 20% net energy improvement and a reduction in CO2 emissions by 43,000 t, a cost saving of $5 million/y in energy costs, SMC Testing says. The comminution circuit throughput also increased annual gold production by 60,000 oz.

The approach taken to benchmark and improve Barrick’s global operations was later developed into an international guideline by the Global Mining Guidelines Group, called ‘The Morrell Method’. Morrell, meanwhile, in 2018, was inducted into International Mining Technology’s Hall of Fame.

Further increased efficiencies and cost savings include Batu Hijau in Indonesia, where a throughput decline was reversed and annual revenue increased by an estimated $150 million, while optimisation initiatives at one of Polyus Gold’s sites led to an annual increase in revenue of over $30 million with the assistance of the SMC Test. Compañía Minera Doña Inés de Collahuasi, the Chile copper asset co-owned by Anglo American and Glencore, meanwhile, has developed a 99.85% accurate throughput forecast model using the SMC Test.

“Many people assume that such large revenue benefits must mean that the SMC Test is expensive to conduct,” Morrell stated. “However, for what often works out as less than 1 cent per tonne of ore, there is a significant upside when resultant savings or revenue increases can be measured in tens-of- millions-of-dollars.”

SMC Tests can be done on as little as 5 kg of sample and ordered through a global network of approved laboratories licensed to conduct the test.

Multotec continues to service miners during COVID-19 outbreak

Comminution of minerals, Equipment maintenance, Mineral processing, Mining equipment, Mining services, , , , ,

Multotec has reaffirmed its support for customers during the COVID-19 outbreak, saying it will continue to provide assistance, especially to operations declared as essential services, throughout this tumultuous period.

As a global company serving six continents, the mineral processing original equipment manufacturer has operations in Canada, Chile, Australia, Europe, China, Ghana, Zambia, Botswana, Mozambique and South Africa.

Multotec CEO, Thomas Holtz, said: “We certainly find ourselves in challenging times and the global COVID-19 pandemic is giving us the opportunity of modifying the way we do business across the world.”

With South Africa currently in lockdown, Multotec is producing only ‘essential services’ products there, but expects to return to full production at the end of the lockdown on April 17, 2020, Holtz said.

“Our manufacturing facilities in China are fully operational, while our facilities in Canada, Chile and Australia are in various stages of operational capacity,” he says. “We have committed to working on weekends and over public holidays over the next months to ensure any order backlogs are caught up and there is the least possible disruption.”

Holtz highlighted that where some countries’ mining and power generation operations have been declared by their governments as essential services, Multotec is providing full product and service support from its local bases in these locations.

“The safety of our staff and customers is an absolute priority and every precaution is being taken to ensure the continued health of all our stakeholders,” he says. “At the same time, please be assured that – as far as possible and using various means – we continue to provide full technical and sales support to all our customers, wherever they may be.”

Multotec has taken the worldwide travel restrictions as an opportunity to run online training workshops in multiple languages with many customers in remote locations, it says. There are also informative training videos available on the company’s YouTube channel.

Outotec to deliver sustainable plant improvements at First Majestic Silver assets

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

Outotec has been awarded a contract by First Majestic Silver for the delivery of minerals processing technology for its mill optimisation projects at the San Dimas silver-gold mine and Santa Elena silver-gold mine, in Mexico.

The circa-€15 million ($16.3 million) order has been booked in Outotec’s 2020 March quarter order intake.

Outotec’s scope covers the design and delivery of an AG mill, counter current decantation thickener and a tailings filter for San Dimas, and thickeners and a tailings filter for Santa Elena. The deliveries are expected to take place in 2020 and 2021, it said.

Outotec previously delivered HIGmill® high-intensity grinding mills to First Majestic, with one of these going to the Santa Elena operation (pictured), where it has significantly improved the recovery of silver and gold.

Paul Sohlberg, Head of Outotec’s Minerals Processing business, said: “The energy efficient AG mill and environmentally sound thickeners and tailings filters will enable First Majestic to improve plant operations in a sustainable way.”

Back in January, First Majestic President & CEO, Keith Neumeyer, said the company’s 2020 focus remained on “adopting new innovation projects to modernise our processing plants to achieve higher recoveries, improve efficiencies and reduce operating costs”.

He added: “We have witnessed significant benefits from high-intensity grinding at our Santa Elena operation in 2019 and we plan to install the same technology at San Dimas in 2020.”

The company, at that point, said it expected to increase production at San Dimas by restarting mining operations at the past-producing Tayoltita mine by the end of the March quarter, expecting to ramp up production to 300 t/d by the end of 2020. The Tayoltita mine was the original mining area at San Dimas and known to contain higher silver grades.

It said a new 3,000 t/d HIGmill circuit and AG grinding mill would be installed in the second half of 2020 to further improve recoveries and reduce operating costs.

At Santa Elena, meanwhile, it said it planned to install an AG/SAG grinding mill by the end of the year, with a dual-circuit flowsheet implemented to separate the ultra-fine and coarse particles prior to leaching to further improve metallurgical recoveries and reduce energy costs.

JKMRC researchers tackle SAG mill fill productivity challenge with new ‘soft sensor’

Comminution of minerals, Equipment maintenance, IoT, Mineral processing, Mining maintenance, Power supply for mines, Sustainable mining, , , , , , , ,

Researchers from the Sustainable Minerals Institute’s Julius Kruttschnitt Mineral Research Centre (JKMRC) say they are developing a soft sensor to overcome previously-accepted performance challenges facing SAG mills.

SAG mills are a key asset for mineral processing operations as one of the critical stages of extracting mineral out of ore, and their continued stable operation is central to productivity, the JKMRC says.

However, the performance of a SAG mill changes rapidly in response to conditions such as feed size and hardness, as well as longer-term variability due to liner wear – something no instrumentation can directly observe, according to the research centre.

The new Mill Filling Prediction (MFP) tool is a soft sensor (a mathematical model that act as a sensor) to provide information about the mill’s contents and enable it to be controlled closer to its maximum capacity, it says. The MFP tool is developed by Dr Marko Hilden (pictured with Mohsen Yahyaei here), a Senior Researcher at JKMRC, who transformed and updated models that have been developed by various researchers at JKMRC and developed new models to suit the new application.

Associate Professor, Mohsen Yahyaei, who is JKMRC’s Advanced Process Prediction and Control (APPCo) Group Leader, said the MFP tool includes mathematical models that predict the wear condition of the mill, the level of mill filling, the filling of the steel grinding media and particle trajectory.

“The models capture data from commonly installed sensors around SAG mills, which allows the model to run in real time, giving the operator instant feedback on the critical conditions that affect mill performance,” he said.

“The MFPT is already being implemented at a number of industrial sites, and they are starting to see multiple benefits in the control of the grinding circuit.”

In the mining sector, most energy is used during mineral processing, with comminution – which includes grinding – accounting for 70% of total energy usage in some sub-sectors, according to the JKMRC.

Associate Professor Yahyaei said precisely predicting mill filling can increase operators’ confidence in running the mill at a higher average filling and power draw, thereby increasing overall equipment effectiveness and throughput.

“The operator can be alerted when undesirable conditions such as slurry pooling are imminent, reducing the risk of the mill being overloaded,” he said.

“Estimation and display of steel ball level reduces the need to perform regular manual measurements which require stopping and sometimes entering the mill, and, therefore, reduces the impact on production and personnel health and safety.

“And warnings, when shell impacts are likely, can help the operators select operating conditions that avoid excessive liner wear and grinding media consumption.”

JKMRC’s APPCo Group aims to transform unit process modelling and simulation by moving from steady-state models to techniques that make greater use of data generated on-site and sensor technologies in combination with advanced process control, computational analytics and modelling techniques, according to the JKMRC.

Weba’s custom-designed chutes find favour in Africa

Bulk handling, Equipment maintenance, Mineral processing, Mining equipment, Mining maintenance, Mining services, , , , , , , ,

Weba Chute Systems’ Wade Vandenberg says mines across Africa are recognising the value of the company’s custom-designed chutes in controlling material flow, extending wear life and reducing maintenance downtime.

The South Africa-based company’s transfer point solutions have made their way into mines across Africa, from platinum to diamond operations, to gold, coal and copper mines.

In addition to mining hotspots including Ghana, Mali, the Democratic Republic of the Congo, Zambia, Zimbabwe and Botswana, Weba Chute Systems have been installed in countries like Tanzania, Mauritania and Eritrea, it says. Authorised Weba Chute Systems agents are deployed to support customers in key countries, while technical experts from the company’s head office in Germiston, Gauteng, South Africa, are on call to assist.

Vandenberg, Weba Chute Systems’ Technical Advisor, Africa, said: “Not only do these operations gain the benefits of controlled material flow in their operations, but they experience, first-hand, how our engineering design extends wear life and reduces maintenance downtime.”

He highlighted that better dust control – a key part of health and safety policies in the mining sector – is another important benefit Weba chutes bring to an operation.

“Our state-of-the-art digital engineering design facilities and expertise makes use of the latest technologies to simulate the specific material flow conditions in each customer’s application,” Vandenberg said. “This allows us to apply our philosophy that no two chute designs are identical, and to scientifically accommodate exact flow characteristics into our design.”

Discrete element modelling allows close control over the flow of material through the chute. This minimises turbulence, reducing the levels of dust created in the working area. It also cuts spillage levels, which, in turn, means a saving of valuable material and less time spent on cleaning activities.

Izak Potgieter, Systems Manager at Weba Chute Systems, said: “We work towards the ISO dust management standards, supporting our customers in managing health and safety in this critical area of transfer points. Our testing measures dust down to 0.03 micron particles, to make sure that our designs meet stringent health-related targets.”

Flow control also creates more material-on-material movement to reduce wear on chute liners, according to Weba. This ensures longer liner life when compared with that of conventional chutes. Custom design and use of simulation technology allow for the wear life to be carefully predicted, based on operating conditions, the company says.

Vandenberg said: “Our technical expertise and solutions-oriented approach mean that customers can always rely on us. When we commission one of our chutes, it is part of an ongoing productivity journey with our customer, no matter where they are located.”

Metso invests in Arizona repair facility after stellar 2019 results

Equipment maintenance, Mineral processing, Mining consumables, Mining equipment, Mining maintenance, Mining services, , , , , , ,

Metso has made further investments in its Mesa repair facility in Arizona, USA, in order to, it says, optimise safety and broaden service capabilities.

The facility offers repairs and field services while supporting Metso’s Life Cycle Services contracts. It has seen steady growth since the opening in 2015, with 2019 setting a record for safety performance, revenue and profitability, according to the company.

One of the many upgrades to the facility includes the installation of “a state-of-the-art stress relief oven”. This investment was made to offer a more complete service to customers on large rebuilds, Metso said. “This will improve quality control as well as accelerate the turnaround times for our clients,” the company explained.

In addition to the stress relief oven, Mesa has also invested in other equipment to support the repair of mining screens, Wet Low Intensity Magnetic Separator (LIMS) drums, and babbitted bearings for mills.

A screen test stand has been manufactured and will be operational by the end of March, the company said. This will allow each screen rebuilt at Mesa to be test-run before being sent back out into the field, which will reduce the potential for issues during installation and start-up, according to the company.

Equipment needed to repair LIMS drums was also put in place last year and has seen a steady inflow of repairs coming from mines in the Iron Range of Minnesota, the company said.

Metso said: “In the future, the facility aims to further grow its portfolio of value-added services, to improve productivity and reduce operational costs for its clients in both the mining and aggregates sectors.”

TOMRA’s XRT ore sorting aids recoveries, costs at South Africa chrome mine

Comminution of minerals, Mineral processing, Mining equipment, Steel and iron ore, Sustainable mining, Water management, , , , , , ,

One of TOMRA’s X-ray Transmission (XRT) sensor-based ore sorters is helping improve recoveries and lower costs at a South Africa chrome operation.

As South Africa chrome mining operations have increased production in the face of rising demand from stainless steel buyers, the cost of using traditional methods for separating low-grade chromite material, such as dense media separation (DMS), cyclones and spirals, has increased. XRT ore sorting, an established technology in physical separation that has proved extremely effective in mining operations for a variety of minerals, including chrome, is another pre-concentration route they are looking into.

“Its benefits are significant: less complexity in the process, considerably lower costs, higher productivity and profitability – and the added advantage of a lower environmental impact,” TOMRA, a supplier of XRT solutions, said.

The X-ray sensor accurately establishes the density of each particle in the feed, and high-speed pneumatic ejectors separate ore with high chromite content from barren or low-grade ore at throughputs between 60-200 t/h. “The resulting output is a high-grade product that is ready to sell, with no need for additional comminution,” the company said. “It is a dry process that requires no water or reagents, and is frugal in its energy consumption, resulting in a fraction of the capital expenditure and running costs of traditional methods, as well as a smaller footprint.”

Engineering and project management company P2E Consulting has first-hand experience of the advantages of TOMRA’s XRT technology in sorting chrome ore at Eastern Chrome mines, in South Africa. It was looking for a solution to improve the efficiency of the sorting plant and turned to TOMRA.

“We have installed TOMRA sorters on diamond and copper plants in the past and we believe their technology is ahead of their competitors,” Craig Meadway, Business Development Executive of P2E Consulting, said.

P2E Consulting commissioned a TOMRA COM XRT 2.0 sorter to replace an existing drum DMS plant.

“The mine used the DMS plant to produce saleable small lumpy product from the mine’s LG6 Chromite run of mine and dumps at a minimum grade of 38%, but it was very inefficient,” Meadway explains. “The TOMRA XRT sorter has resolved this issue. It is used to upgrade under value material with a head grade of 20-28%, to produce a saleable product at a minimum grade of 38% Cr2O3. It does this efficiently and at a low cost of production.”

The TOMRA COM XRT 2.0 sorter has exceeded Meadway’s expectations, with grades being achieved in excess of 40% Cr2O3 and mass recoveries of 25-30% from scalped waste resulting in chrome-in-tails as low as 12%.

“No other technology has given us such a high recovery rate. Not only that, with TOMRA’s XRT there was no water usage at all, and we didn’t need to spend on expensive reagents, so that we are producing small lumpy product for approximately 50% of the cost compared to a DMS plant,” he said.

The environmental benefits of TOMRA’s XRT solution were also an important factor in P2E Consulting’s choice of technology. “We are looking to introduce greener technologies into the mining industry. The fact that no water or chemicals are used is a major advantage,” Meadway said. “Also, South Africa has major power limitations, and the lower energy consumption when compared to DMS is a huge driving force.”

The ease of operation of TOMRA’s XRT sorters proved to be a further advantage: “It is very easy to use: once the sorter and feed system control philosophy is set up correctly, the plant runs with very little input from the operators,” Meadway said.

TOMRA’s collaborative approach and all-round support was also an important factor in P2E Consulting’s decision to turn to them for this project, according to Meadway.

“We knew from our experience in previous projects that the support from TOMRA is very good, and with the installation of this machine in a relatively new application, it was excellent,” he said. “The local team has bent over backwards to help us make this happen.”

Multotec renews power commitment in South Africa

Bulk handling, Comminution of minerals, Environmental, Mineral processing, Mining equipment, Mining services, Power supply for mines, Sustainable mining, , , , , , ,

Mineral processing original equipment manufacturer Multotec says it has installed renewable power at one of its facilities in Spartan near Johannesburg, South Africa.

The investment saw 684 photovoltaic solar panels being installed in November 2019, creating a 223 kW generating system. It serves Multotec’s most energy-intensive works – its injection moulding facility – providing almost 20% of the daily electricity demand, the company says.

According to Multotec’s Group Manufacturing Executive, Werner Stessl, the impact of the system is both economic and environmental.

“Multotec is committed to environmental sustainability and we value the fact that this installation is likely to save about 30,000 kg of carbon dioxide emissions each month,” Stessl said. “This is the equivalent of planting about 100 trees a month.”

He says the organisation has been carefully monitoring its rising electricity costs and sought a responsible solution that would leverage the latest renewable energy technology. In collaboration with solar power experts Energy Capital, a thorough investigation of its energy consumption and available opportunities was conducted.

“After months of planning and research, it was established that we could run a battery-less system which would valuably augment our current municipal supply,” Stessl said. “After some structural engineering to prepare our designated roof areas, the panels were efficiently placed and linked up by mid-November last year.”

To date, the system has more than met Multotec’s expectations, which were contractually guaranteed by the service provider, it said. The detailed upfront investigation showed that the installation could be repaid by energy savings within about four-and-a-half years. System performance – right down to the electricity generated by each PV solar panel – can be monitored daily on an online dashboard, he says.

The local municipality has also begun to benefit from Multotec’s initiative, as there is usually ‘overflow’ power generated at weekends the moulding facility does not need. This excess electricity is now channelled back into the main grid by Multotec, at no cost to the municipality.

Weir Minerals Africa putting newly designed vibrating screens to the test

Comminution of minerals, IoT, Mineral processing, Mining equipment, Mining services, , , , , , ,

Weir Minerals Africa, having over the last 40 years proven the credentials of its Enduron® range of vibrating screens, is now locally designing and manufacturing new-generation linear motion vibrating screens.

One of these new, modern screen designs is part of a recent Weir Minerals Africa complete comminution plant contract for a South Africa mining project. The scope included two crushing stations, a screening station and all the related feed chutes, bins and conveyors.

According to Christian Stehle, Head of Engineering at Weir Minerals Africa, the company’s design capability provides the flexibility to produce vibrating screens to suit each customer’s plant layout. At the same time, the designs will optimise cost, efficiency and performance. South Africa also hosts Weir Minerals’ global screening and separation technology group.

“This expertise ensures that our robust Enduron vibrating screens provide exceptional classification and dewatering screening performance,” Stehle said. The screens are deployed in a wide range of minerals processing applications.

He noted that vibrating equipment is generally more challenging to design than static equipment due to the high frequency cyclic loading to which the machines are subjected.

“The final design must address key criteria like screening efficiency, throughput and loading, while still operating within the acceptable fatigue life limits of the materials of construction,” he said.

Stehle highlighted that the use of finite element analysis (FEA) tools allow engineers to optimise screen life by obtaining the stress and deflection levels in the equipment and applying the appropriate structural design and utilisation of materials in the areas experiencing high stresses.

“Traditionally, screen designs used to be heavier in an effort to extend the life of the equipment,” he said. “Using FEA tools during the design stage allows us to retain structural integrity while actually reducing the overall weight of the machine.”

While there are areas of high stress on the equipment that need more strength, technology tools indicate where lower stresses occur. In these areas, less steel can be used to make the structure lighter, according to Weir Minerals Africa. Leveraging this technology, the weight of some new-generation screens has been cut by up to 15%, the company said.

Stehle noted that Weir’s Synertrex™ IoT platform can also be applied to monitor and improve the performance of the company’s vibrating screens. Synertrex technology is an industrial internet of things system that allows operators to monitor every aspect of their equipment’s operation, to prevent problems and increase throughput.