Tag Archives: chrome

Three-machine train Metso mobile crusher ups productivity at chrome mining project

A newly acquired Metso Lokotrack® LT200HPS™ is winning the day for Zizwe Opencast Mining at one of its strategic chrome mining projects in Steelpoort, Limpopo, according to the leading South African mining contractor.

With productivity high on the agenda in a highly abrasive chrome-processing application, a three-machine train of Metso mobiles – comprising a Lokotrack LT120™ jaw crusher, a Nordtrack® S2.11 scalping screen and a Lokotrack LT200HPS™ cone crusher – is making light work of the 200 t/h production target.

Joe de Beer, Crushing and Screening Plant Manager at Zizwe Opencast Mining, has been impressed in particular by the new Lokotrack LT200HPS cone crusher, equipped with a hanging screen. By featuring a detachable screen and return conveyor on one tracked chassis, he says, the LT200HPS is basically ‘two machines in one’, thus eliminating double-handling on site.

“The fact that the LT200HPS does the job for two machines was central to our purchasing decision,” De Beer says. “It features a detachable screen and return conveyor which guides screened oversize material back to the cone crusher. It is essentially a cone crusher, a screen and a conveyor on one tracked chassis.”

Yeshen Achary, Sales Engineer at Pilot Crushtec, said: “Traditionally, we have always brought the LT200HP in a standard configuration. Because cone crushers by their nature are not 100% efficient, the added benefit of having a screen post the crushing chamber is that it allows for recirculation of any oversize material back to the cone crusher.”

This, explains Achary, eliminates the need for another machine to work in closed circuit with the cone crusher. Having a single machine doing the job of two machines offers significant cost benefits for the customer.

Achary says: “Apart from the obvious capital cost benefit, having the cone and screen on a single chassis means that the machine is powered by a single engine, making one less machine to maintain. Having a closed loop on a single chassis also makes it easy to transport the machine between sites.”

Francois Marais, Sales and Marketing Director at Pilot Crushtec, explains that the LT200HP now comes in three different configurations. Apart from the standard cone crusher configuration, it is now available with a pre-screen called the HPX™, which is placed just before the crushing chamber or alternatively with an overhanging screen called the HPS, located post the crushing chamber.

He said: “In traditional operations, you would need two machines – a cone crusher and a screen – to do the same job done by this single machine. In addition, you would probably have to deploy a minimum of two to three conveyor belts to recirculate oversize material from the screen back to the cone crusher.”

Boston Metal looks to disrupt and decarbonise steel and iron ore industries

Boston Metal is looking to decarbonise the steel-making sector at the same time as helping iron ore producers with their Scope 3 emissions dilemma.

The concept of ‘green steel’ has been widely discussed over the last few years, with LKAB, SSAB and Vattenfall’s HYBRIT project being the most cited case study, thanks to both its advanced stage of development – it has already produced fossil-free steel on a trial basis – and its revolutionary way of introducing hydrogen in place of coke as the iron ore reduction method in the steel-making process.

SSAB and LKAB are leveraging HYBRIT to completely transform their production processes: SSAB is building new hydrogen-based steel making facilities able to match its current base of 8.8 Mt/y of steel by 2030 and LKAB is moving from iron ore pellet production to direct reduced iron (DRI) in line with this.

Tadeu Carneiro, Chairman & CEO of Boston Metal

The ambitions of such a project are impressive, but can such a green steel-making process be applied to the circa-1,900 Mt of steel currently being produced for the world market?

The answer is no, according to Tadeu Carneiro, Chairman & CEO of Boston Metal.

He expands on this: “There are four ways of reducing iron oxides into a metal for steel-making. One is through the use of carbon; another way is through using another metal as a reductant, which is currently not feasible; the third one is with hydrogen, which is possible – as HYBRIT has shown – but is limited to premium iron ores; and the last is through our solution.”

The solution in question is – like HYBRIT – a green option, but – unlike HYBRIT – is applicable to all iron ores, regardless of grade, according to Carneiro.

Boston Metal’s process, which it calls Molten Oxide Electrolysis (MOE), works by adding iron ore to an electrolytic cell and passing electricity through said cell. The electricity both breaks the bonds of the iron oxides present, as well as heats up the whole batch within the cell, creating molten iron that sinks to the bottom of the cell ready for collection (tapping).

During the bond breaking and heating process, MOE produces oxygen as a by-product, with the resultant oxides forming the electolyte and remaining in said electrolyte (floating above the liquid iron).

“Because it is molten, the iron gets separated from the electrolyte and sits in the bottom of the cell,” Carneiro said. “As the molten iron is heavier than the electrolyte, the impurities float to the top and can be tapped separately.”

So, not only do companies using MOE get a molten iron product, they also get a slag by-product that can be used in various applications in the construction industry – all without using coking coal or coke.

“In traditional blast furnace-based steel making, you have to pelletise or sinter the iron ore, you need to process coking coal into coke and you then have to mix the two in the blast furnace and blow air to get pig iron,” Carneiro explained. “This pig iron contains around 4% carbon, which needs to be burnt off through, typically, a process in the basic oxygen furnace to get molten iron.”

Boston Metal’s MOE process gets to this same point using just iron ore and electricity, according to Carneiro.

“All of this is replaced by a battery of cells that, when assembled in significant numbers, can compete with blast furnaces in terms of molten iron capacity,” he said.

Carneiro expanded on what he meant by ‘significant numbers’, offering up an example of 300 MOE modules assembled in two lines of 150 able to produce 1 Mt of steel.

And all of this is in an incremental capital expenditure range within the millions of dollars, instead of the billions of dollars often required to build a traditional steel-making plant.

This puts a green process in the reach of not only steel-makers but iron ore producers, according to Carneiro.

“If you have green electricity at an iron ore mine, you can bring the cells there, melt the iron and ship a metallic product to steel-makers,” Carneiro said.

This pure iron product can be remelted elsewhere and processed into flat and long steel products for the automotive and construction industries.

“This represents a higher value-added product for iron ore miners, enabling them to ship a product that is 40% lighter in terms of weight,” Carneiro explained.

Finding a ‘green’ end-user that brings down a miners’ Scope 3 emissions while holding a molten iron ore product is a lot easier than finding one when shipping iron fines, concentrate or sinter: hence the reason why iron ore miners’ Scope 3 emission goals appear a lot less ambitious than the Scope 1 and 2 targets within their control.

It is no wonder BHP and Vale have been early backers of Boston Metal.

It sounds too good to be true, and there is a reason for that.

From speaking to Carneiro, the company could start producing molten iron through the chosen method today – not at a scale the steel-industry would yet consider commercial, but at a pilot scale at least.

For the commercial process to be considered green, the company would need renewable electricity to do this; and lots of it.

Carneiro doesn’t shy away from this, explaining that MOE will require 4 MWh of electricity per tonne of steel to work at such a scale. This is the equivalent of up to 500 MW for a 1 Mt/y molten iron plant.

The incumbent process Carneiro and his US-based team are looking to take market share from requires 5.5-6 MWh of energy per tonne of steel, while the electric arc furnace (EAF) method of making steel – which uses predominantly scrap metal – has a much smaller electricity requirement.

“If you had 2 billion tonnes of scrap to be melted, the EAF route is the best way to make steel, hands down,” Carneiro admits. “The problem is you don’t have such scrap availability and, in order to increase supply, you would need lots more steel coming from iron ore.”

For reference, the HYBRIT process is expected to require 600 MW of hydrogen electrolyser capacity to 2025 to get LKAB to the 1.3 Mt/y sponge iron (DRI) mark.

Yet, scrap steel is not the only thing in short supply currently. Green electricity is far from abundant, with only the likes of Quebec (hydro power capacity) and some Nordic countries having a plentiful supply – a fact Carneiro acknowledges.

“If you don’t believe that green electricity will be available, abundant, reliable and cheap in the future, you can forget about the MOE process,” he said. “But then you also have to forget about a lot of other processes that are set to use green electricity and the massive amounts of investment the green energy space is seeing on an annual basis.

“Society has decided to go electric and to go electric in a green way, so it is only reasonable to expect that, in the future, electricity will be all of this.”

Carneiro is planning for such a transition, with his company in the process of commissioning a full-size industrial MOE cell at its Woburn, Massachusetts headquarters. This could be ready as early as next month.

It follows a trial of a pilot cell at Brazil-based ferroniobium producer CBMM’s production plant in Araxá, Brazil, where the technology was able to use the same process to turn niobium ore into high-value ferroniobium-based products.

“We were able to prove out the process with CBMM on a smaller scale, which has given us the confidence to make a much bigger cell.”

The company plans to use this bigger cell and, through a subsidiary in Brazil, take advantage of other opportunities to extract value from mining waste using the MOE technology. This could see Boston Metal assemble a battery of MOE cells to manufacture some 5,000-10,000 t of high value-added metals.

While this is deemed ‘pilot scale’ for steel producers, it is sizeable for those producing high value-added products such as niobium, vanadium, tantalum, chrome and others, Carneiro said. And the project will only aide the company’s steel-making ambitions.

“By developing the cell for these high value-added metals, we are finding lots of the answers for the steel-sized cells as well,” he said.

Such groundwork today is preparing the company for a time when steel-makers and iron ore miners have assessed the green electricity landscape and are ready to invest in such technology.

“All the leading steel-making companies have made pledges to be carbon neutral by the 2050s,” Carneiro said. “This means they need to phase out carbon reduction by the mid- to late-2030s. By this point in time, we will be ready to offer our solution on a commercial scale, allowing them to take advantage of the abundance of iron ores – low and high grade – around the world.”

Multotec supplies 38 slurry pumps to Kazakh chrome project

Mineral process equipment specialist Multotec’s global reach has recently been highlighted with the supply of slurry pumps to a chrome project in Kazakhstan.

According to Gerhard Hendriksz, General Manager, responsible for slurry pumps at Multotec, an order of 38 slurry pumps was delivered in mid-December 2021 through a collaboration of Multotec’s international business team and the company’s distributor in Kazakhstan.

“The pumps were produced according to the specifications provided by Multotec’s distributor, ensuring the units will deliver the required duty for the end customer,” Hendriksz said. “This includes being designed to withstand highly abrasive operating conditions.”

Certain chrome deposits in Kazakhstan boast some of the world’s highest concentrations of chrome oxide (Cr₂O₃) – up to 62% content – making the slurry particularly abrasive. The pump range Multotec delivered includes models from the HD25 to the MD300, in metal- and rubber-lined configurations to suit their respective duties.

A turnaround time of just 10 weeks was achieved, with Multotec leveraging its local supply chain that included foundry work, machining and other suppliers, as well as collaboration with Multotec’s technical partner, 7D, based in Perth, Australia.

Andre Burger, Production Manager, responsible for pumps at Multotec, emphasised that a close working relationship with the end user and Multotec’s Russian-speaking business team ensured smooth preparation and delivery.

“Our distributor has in-depth knowledge of the customer’s applications and has the engineering expertise to ensure optimal product specification and performance,” Burger said. “Multotec will support the products with aftersales and support services, including availability of spare parts.”

Despite the trade disruptions related to the COVID-19 pandemic, Multotec has continued to perform strongly on the export front. Last year, it earned a place in the Exporter of the Year Awards – presented by the South African Capital Equipment Export Council.

Multotec supplies a complete range of pumps for medium- and heavy-duty slurry applications, including cyclone feed, spirals feed, mill discharge, tailings disposal, filter feed, effluent discharge and spillage. The range caters for flow rates from around 15 cu.m/h up to 2,000 cu.m/h.

Total Eren, Chariot and Tharisa to build solar PV plant at PGM mine

Total Eren, a renewable energy independent power producer, and Chariot, an Africa-focused transitional energy company, have signed a Memorandum of Understanding (MoU) with Tharisa plc to develop, finance, construct, own, operate and maintain a solar photovoltaic project for the supply of electricity to the Tharisa PGM mine, in the North West province, South Africa.

The solar PV project is initially anticipated to be 40 MW peak with demand expected to increase over the life of the Tharisa Mine. This MoU is the first step towards implementation of the project and signing of a long-term Power Purchase Agreement for the supply of electricity on a take-or-pay basis, the companies said.

Fabienne Demol, Executive Vice-President & Global Head of Business Development of Total Eren, said: “We are very pleased to be entering into this MoU with Tharisa. Through our partnership with Chariot, we are keen to assist mining companies in Africa to reduce their carbon intensity and energy costs, via implementing renewable power solutions into their operations. We are eager to bring our global expertise in solar generation to Tharisa mine and we look forward to delivering further renewable projects for our mining customers in Africa and worldwide.”

Benoit Garrivier, Chariot Transitional Power CEO, added: “This is a great outcome for Chariot’s Transitional Power division and demonstrates the financial and sustainable benefits that our offering can bring to mining companies operating in Africa. The Tharisa team are very forward looking and understand that the addition of a solar PV project at their mine in South Africa will bring significant benefits to the business. Together with Total Eren, we are excited to start working on the financing and development of the project and we will update the market further on this and other opportunities that we are progressing in due course.”

Tebogo Matsimela, Head of ESG at Tharisa, said: “Tharisa plays a significant part in the global energy transition movement, and we are committed to producing these key metals in a sustainable manner. The solar power solution provided by Total Eren is but one of several steps we are taking to ensure our flagship Tharisa Mine, which has a life of mine of over 50 years, has a reduced carbon footprint.

“Our goal is to reduce our carbon emissions by 30% by 2030 and ultimately become net carbon neutral by 2050.”

Tharisa Minerals produces PGM concentrate and metallurgical- and specialty-grade chrome concentrates from a shallow open-pit mine near Rustenburg, North West province. The Genesis and Voyager plants at the operation have a combined nameplate capacity of 4.8 Mt/y of run of mine.

BME’s achieves another record-breaking blast with AXXIS Titanium electronic detonators

Another record-breaking blast has been notched up by Omnia Group company BME using its latest generation AXXIS Titanium™ electronic detonation system.

The blast of 5,209 detonators was conducted recently at a chrome mine in South Africa’s North West province, according to Tinus Brits, BME’s Global Product Manager – AXXIS. Brits highlighted how the enhanced features of AXXIS Titanium allows mines to respond quickly and easily to raised production demands.

“While a record blast is always an achievement to be celebrated, this was a standard production blast requiring nothing different or extra from the mine,” he said. “The ease-of-use of AXXIS Titanium, the speed at which blasts can be prepared, and its rapid testing features make this possible.”

The dual-voltage basis of the new system means that detonators can be tested while they are logged in, with the logging and testing conducted as a single function. As a result, this record blast could be primed, charged, tied-up, logged, tested and programmed in just two days.

“With AXXIS Titanium, the logger does everything for you,” Brits said. Multiple loggers were used on the blast, with each operator logging a portion of the blast to speed up the process; the log files were then seamlessly combined.

By consuming less energy, AXXIS Titanium allows up to 1,000 detonators to be initiated by each blasting box – reducing the amount of equipment that is needed on site.

“This helps improve the reliability of blasts, as there are fewer items of equipment to communicate with each other,” Brits said. “These high levels of reliability ensure a quality blast with no misfires, even in single-prime blasts – where there is just one detonator per hole – as was the case in this record blast.”

He also emphasised the intuitive fault-finding capacity of the AXXIS Titanium system, which identifies those detonators which have not been logged onto the harness wire. The operator is informed precisely where the relevant detonator is to be found, so it can be quickly logged.

“It also solves the problem of ‘intruders’ – those detonators that were accidentally missed during the logging process,” Brits said. “Again, the operator can speedily fix this issue wherever it occurs, ensuring that there are no misfires in the blast.”

The design of the AXXIS Titanium connector is another important factor, allowing blasters to log and test detonators without the need to open the connector. The gel in the connector that ensures a good seal, therefore, is not disturbed during testing and logging.

“It only gets opened up once you connect it to the surface wire, which is why the sealing of our connectors is so good – eradicating resistance or leakage on the block,” Brits said.

Tharisa kicks off Vulcan ultra-fine chrome recovery and beneficiation plant commissioning

Tharisa, the platinum group metals (PGMs) and chrome co-producer, has announced that cold commissioning of its Vulcan ultra-fine chrome recovery and beneficiation plant has commenced.

The timetable to completion of the new $55 million plant remains firmly on track with initial saleable production due before year end, it says.

Once fully commissioned, the plant is expected to see Tharisa Mine, in South Africa, materially increase its chrome recoveries from circa-62% to circa-82% resulting in increased chrome production of some 20% at low incremental unit operating costs.

The plant, which will process live tailings produced by the independent Voyager (pictured) and Genesis plants, will ensure further beneficiation of the company’s chrome production at the Tharisa Mine, while reducing unit output of carbon emissions, aligned with Tharisa’s recently announced decarbonisation plan, the company says.

The Vulcan plant has a nameplate capacity of 340,000 t/mth of tailings and involves “proprietary ground-breaking use of existing technologies in fine chrome recovery”, the company says. The board initially signed off its construction in 2019, appointing Wood as the engineering, procurement and construction management contractor in the process, with hot commissioning targeted for the December quarter of 2020. This timeline was impacted by COVID-19.

Some final elements of the construction process remain to be completed, yet Tharisa’s engineering team has commenced cold commissioning, with comprehensive testing of the entire circuit, to be completed prior to chrome tailings material entering the plant. Of the total capital expenditure, over 90% was procured locally in South Africa, with up to 1,000 contractors locally sourced and over 100 new permanent jobs created.

Vulcan is, Tharisa says, the first large-scale plant to produce chrome concentrates from chrome ultra-fines. The concept of Vulcan was developed by Arxo Metals Proprietary Limited, a wholly owned subsidiary of the company and housing Tharisa’s in-house R&D team, to extract the ultra-fine chrome from tailings.

With Tharisa Mine near Rustenburg having a 14-year open-pit life remaining, and a further 40 years underground, Vulcan will ensure maximum value extraction and beneficiation of the chrome ore, Tharisa says. The Tharisa Mine has 860 Mt in mineral resource containing 172 Mt in contained Cr2O3 and 42.8 Moz platinum group metals.

Internally funded by Tharisa, Vulcan recommenced construction in October 2020 after the lifting of restrictions by the South African government during the height of the first wave of the COVID-19 pandemic.

Phoevos Pouroulis, CEO of Tharisa, says: “Commissioning of the Vulcan plant perfectly exemplifies two Tharisa philosophies: challenging convention through innovation and delivering on our promise of maximising value through beneficiation of every cube mined.

“Vulcan provides the company with the ability to further beneficiate our product whilst staying on track to meet our decarbonisation targets, thanks to the dedicated work from Arxo Metals, that has not only delivered the Vulcan process but has also delivered further beneficiation opportunities, including metal alloys and PGM products using non-conventional methodologies.

“Vulcan is an important part of our sustainable growth strategy and ensures that Tharisa continues to drive sustainable returns for all of our stakeholders, while simultaneously pushing us even lower on the cost curve.”

Kazchrome achieves chrome tailings flotation breakthrough

Engineers at the Donskoy Ore Mining and Processing Plant of JSC TNC Kazchrome, in Kazakhstan, have successfully completed trials of a first-of-its-kind industrial flotation technology to increase the enrichment of chrome oxide-bearing tailings, Eurasian Resources Group reports.

Kazchrome, the world’s largest high-carbon ferrochrome producer by chrome content with a total resource base of over 200 Mt of chrome ore, is owned by ERG.

The novel technology is part of the group’s R&D efforts to maximise chromite concentrate output and reduce the site’s environmental footprint, the company reports, with the process yielding the recovery of over 55% of chrome oxide and conforming to the applicable requirements for concentrate used in ferrochrome smelting.

As a result of these trials, the flotation technology will be used to construct a new facility to process over 10 Mt of chrome oxide-bearing tailings with a planned annual capacity of 1.7 Mt for 450,000 t/y of chrome concentrate, ERG says.

Benedikt Sobotka, CEO of Eurasian Resources Group, said: “This pioneering technology is a major milestone on our path towards ensuring sustainable and low-cost chromite concentrate supply for our operations in Kazakhstan, and is part of the group’s broader strategy to reinforce our leading position in the global ferrochrome market.”

Sergey Opanasenko, Chairman of the Management Board of ERG R&D Centre, added: “We are very pleased with the results of the flotation trials, particularly considering the complex mineralogy and physical characteristics of our ores. Building on this success, we look forward to working on incorporating this technology into the design of our new tailings processing facility.”

Sedibelo Platinum to expand PPM operations and leverage Kell Technology

Sedibelo Platinum Mines has announced plans to expand its Pilanesberg Platinum Mines (PPM) operation on South Africa’s Bushveld Complex, as well as construct a 110,000 t/y beneficiation plant at PPM employing Kell Technology.

The company plans to mine the three contiguous deposits of Sedibelo Central, Magazynskraal and Kruidfontein – known as the Triple Crown properties – as part of the expansion. These three come with an estimated resource base in excess of 60 Moz of 4PGE.

The predominantly shallow deposits will enable safe and sustainable mining activities for potentially more than 60 years, according to the company. The approved expansion will be funded through Sedibelo’s existing cash resources and future cash flow, with first ounces from Triple Crown expected to be extracted in 2023.

The Triple Crown expansion will be mined simultaneously with ore from the existing open-pit UG2 and Merensky operation, using two separate decline shaft systems, the company said.

The existing PPM concentrator plant has the capacity to be used to process the Triple Crown ore as well as ore from the open pits. With minimal reconfiguration, the Triple Crown UG2 and Merensky ore will be blended and processed through the existing Merensky plant, thereby reducing capital expenditure as well as lowering operating cost significantly, it said.

Speaking of the 110,000 t beneficiation plant, Sedibelo said Kell Technology reduces energy consumption by some 82% with the associated significant reduction in carbon emissions, also improving recoveries and lowering operating costs.

“Benefitting from being robust in operation, Kell is unconstrained by concentrate grade, is insensitive to chrome levels as well as being resistant to other impurities,” it explained. “Hence, using Kell will improve the economic return of the Triple Crown expansion and is an integral part of Sedibelo’s future development.”

As applied to treatment of PGM concentrates, the Kell Process comprises four main unit operations (pressure oxidation, atmospheric leach, heat treatment and chlorination), all of which are conventional and in commercial use in the minerals and metals industry.

Sedibelo shares an interest in Kell South Africa with the Industrial Development Corp and Founder Keith Liddell, through Lifezone.

Arne H Frandsen, Chairman of Sedibelo, said: “Today is a significant day in Sedibelo’s history. We are opening our next door 60 Moz Triple Crown deposit, thereby securing the future of Sedibelo for many decades to come. The construction of our Kell plant will allow us to produce metal and lower our cost profile further. Equally important, it will reduce our carbon footprint and water usage significantly.

“We trust our environmentally friendly platinum group metals will become an important part of future electrification and the ‘green revolution’ used in fuel-cells around the world.”

Keith Liddell, Founder of Kell and CEO of Lifezone, said: “I developed Kell Technology as a cost-efficient alternative to the conventional smelting of PGMs. We are excited to now proceed with the construction of the Kell plant at PPM. The benefit for Sedibelo and the industry will be significant; delivering beneficiation, energy and cost advantages as well as a reduction in CO2 and SO2 emissions.”

TOMRA connects ore sorters to the cloud with TOMRA Insight

After a successful launch in its recycling division, TOMRA is rolling out its cloud-based data platform, TOMRA Insight, to mining customers.

TOMRA Insight enables sorting machine users to improve operational efficiencies through a subscription-based service that turns these machines into connected devices for the generation of valuable process data.

Following a successful launch last year by TOMRA Sorting Recycling, TOMRA is now also being made available to customers of TOMRA Mining and TOMRA Food. For all three industries, the platform is enhanced by new features and functionalities that make TOMRA Insight even more valuable than when it was launched to recyclers in March 2019.

The data from TOMRA Insight is gathered in near real time, stored securely in the cloud, and can be accessed from anywhere and across plants via a web portal available for desktop and mobile devices, according to the company.

Felix Flemming, Vice President and Head of Digital at TOMRA Sorting, said: “By capturing and using valuable data, TOMRA Insight is transforming sorting from an operational process into a strategic management tool. This tool is constantly becoming more powerful as we continuously develop it in response to customers’ needs and priorities. New functionalities and features are released every three weeks – a routine during which TOMRA works closely with customers in pursuit of shared objectives.”

Data captured by TOMRA Insight provides valuable performance metrics that help businesses optimise machine performance.

Operating costs are reduced by simplifying spare part ordering and offering flexible access to data and documentation, according to the company. Downtime is reduced by monitoring machine health and performance in near real time, identifying gaps in production and analysing potential root causes. This allows management to move to predictive and condition-based maintenance, preventing unscheduled machine shutdowns.

Throughput, meanwhile, is maximised by evaluating variations and optimising sorting equipment, accordingly. Sorting to target quality is enhanced by having accurate material composition data to enable decisions to be based on more detailed information.

For the mining and mineral processing industries, TOMRA Insight’s ability to collect detailed data from TOMRA’s sorting machines means that previously hidden information can lead to improvements in efficiencies and profitability.

Data captured by TOMRA Insight is analysed on behalf of customers by TOMRA Mining engineers, and key findings shared in confidential reports supplied to customers on a monthly basis. This arrangement has the advantage of combining objective statistical analysis with the interpretive skills of a service team familiar with the customer’s unique challenges, TOMRA says.

“TOMRA Insight’s data-gathering helps mineral processors in near real time and in retrospect,” the company said. “Machine operators are empowered to take prompt action in response to changes in material composition on the line and managers are empowered to make operational and business decisions based on more complete information.”

Comparisons between multiple sites or lines can now be made more accurately and difficult-to-reach processing operations can be remotely monitored from more convenient locations, the company said. This functionality is especially useful in the face of widespread travel restrictions related to COVID-19.

One early, pre-launch user of TOMRA Insight is the Black chrome mine in South Africa (pictured above), one of two mining projects that form the basis of the Sail Group’s plans for long-term sustainable chrome production. Since TOMRA Insight was connected to sorting machines here at the start of 2020, the data platform has convincingly proven its effectiveness, TOMRA said. Among the gains made so far are improvements in process monitoring and streamlining, more efficient line-feeding and machine running times, and reduced downtime.

Albert du Preez, Senior Vice President and Head of TOMRA Mining, said: “By accessing information, TOMRA Insight is unlocking new opportunities. Mineral processors can now move from making decisions based on experience and local observations to decisions based on experience and hard facts. This means TOMRA Insight can help reduce waste rock and downstream processing costs, enabling processors to earn more dollars per tonne.”

To build on these benefits, TOMRA Mining is working closely with customers to continuously develop TOMRA Insight. The future will bring the addition of more features and functionalities, which customers will automatically receive as part of their Service Level Agreement.

Multotec solution scrubs up well at Ekapa Minerals diamond plant

A revolutionary new concept in fines scrubbing is proving to be a game changer for Ekapa Minerals at its Combined Treatment Plant (CTP) in Kimberley, South Africa.

The innovation, developed by Multotec Wear Linings, is processing both virgin underground kimberlite as well as tailings for retreatment at the CTP. The solution is effectively a pulping chute that scrubs and washes the re-crushed product after it has passed through the high pressure grinding rolls (HPGR) inter-particle tertiary crushing circuit.

The important advantage here, according to Multotec Wear Linings Projects Sales Manager, John Britton, is that it performs the scrubbing action faster and more efficiently than a traditional rotary scrubber would, and at much lower cost.

Multotec commissioned two of these pulping chutes at Ekapa Minerals in late 2019, where they have been operating consistently and in line with expectations. With the use of patented wave generators, the pulping chute uses the gravitational energy from the slurry flow to create a constant turbulent mixing action that releases the mud, clay and slime sticking to the kimberlite particles.

According to Ekapa Minerals CEO, Jahn Hohne, the pulping chutes are a welcome contribution to the company’s cost saving efforts, and a clear demonstration of Multotec’s expertise in developing value-adding solutions in the mining sector.

“The dual chute pulping plant is ideally suited to de-conglomerating the HPGR cake product and is exceeding expectations in efficiency and effectiveness at over 600 t/h, which is a major relief on the existing overloaded pair of CTP scrubbers,” he said. “The net result is a meaningful increase of up to 20% throughput capacity of the entire processing plant which substantially improves the economy of scale of CTP, feeding directly to the bottom line.”

Britton highlighted the efficiency of the system, which is able to aggressively scrub the material in just three to four seconds as it passes through the chute. This represents just a fraction of the usual retention time in a rotary scrubber, which is three to four minutes, according to the company. He also emphasises the drastic reduction in running cost which the pulping chute achieves.

“From our experience of plant layouts and flow diagrams, it is clear that fines scrubbers are significant contributors to a plant’s capital, operating and maintenance costs,” Britton said. “Scrubbers are equipped with large drives with gears and gearboxes to rotate the drum. They are high consumers of power and require mechanical component maintenance which means higher operating costs.”

Substantial structures and supports are also needed for the scrubber and its drive mechanisms. In designing the pulping chute, Multotec sought a simplified solution, Britton says. In addition to improving scrubbing efficiency, the objective included reducing the cost of replacing scrubber liners and the downtime that this demanded. The cost of replacing the steel shell of a scrubber – which is constantly subject to stress, wear and fatigue – was another cost to be considered.

“The pulping chute, by contrast, is a stationery and much simplified innovation, focused on the scrubbing of fines less than 32 mm in size,” the company said. “Slurry deflectors located at the top end of the scrubbing chute direct at least part of the slurry away from the scrubbing chute floor. This curls into an arched form which flows backwards into the approaching flow of slurry, creating the turbulent scrubbing effect.”

Britton said: “We custom-design the chutes to suit the application and can increase chute capacity to up to 800 t/h. This is achieved with no moving parts, bearings, hydraulic packs or girth gears; the only power required is to supply material and water to the receiving chute. These actions are also required to feed the scrubber, then gravity takes over and provides the required energy.”

Maintenance is also streamlined by designing the chute in segments. Should one segment be wearing more than others, it can be quickly removed and replaced – putting the chute back into operation while the original segment is refurbished as a spare.

Britton says the pulping chute has drawn interest from other diamond producers in southern Africa, Australia and Canada. It can also be applied in commodity sectors such as coal, platinum, chrome, iron ore and mineral sands.