Tag Archives: dense media separation

Multotec expands Brazilian presence with new manufacturing facility

Comminution of minerals, Equipment maintenance, Mining consumables, Mining equipment, Mining services, Steel and iron ore, , , , , , , ,

Multotec has recently expanded its operation in Brazil with the opening of a manufacturing facility that, it says, enables the company to bring its manufacturing capabilities closer to its customers in the country, increasing its speed to market and enabling it to better serve the local mining sector.

Located in the city of Contagem, in the south-eastern state of Minas Gerais, the manufacturing facility is within close proximity of a multitude of iron ore mines that require an extensive range of mineral processing equipment for their plants.

Multotec Brazil Country Manager, Anthony Artin, explains that with Brazil being the world’s second-largest iron ore producer, Multotec had identified the country as a potential area of growth many years ago.

Artin says that, initially, Multotec Chile was overseeing the full South American region, with the company deciding to open a sales office in Brazil in 2019, giving focused service to Multotec’s customers here.

“The dynamics of Brazil are very unique as it is the fifth biggest country in the world, with the sixth largest population,” Artin says. “It has strict and complex import regulations.”

The feedback from clients emphasised the importance of localised sales and manufacturing in Brazil, according to Artin. Commercial and legislative requirements prompted a shift in Multotec’s approach, transitioning from a sales office to establishing a manufacturing facility in the country.

He said: “Our clients highlighted the significance of Brazil for Brazilians, emphasising the need for local manufacturing facilities to cater to the Brazilian market.”

The new facility focuses strongly on screening media, using compression moulding for the production of rubber screen panels and also hand-casting polyurethane (PU) panels. However, customers are increasingly requesting other products too, such as samplers and spirals that are used in mineral processing and separation.

“There are currently two bays in the manufacturing facility,” Artin says. “One is used for stockholding, assemblies and shipping, while the other is used for fabrication. Fabrication is done in two areas, with presses used for compression moulding of rubber and hand-casting moulding PU tables, alongside a PU preparation section and ovens.”

Artin notes that the facility has the capacity to produce 15-20 t/mth of elastomers and employs trained people in manufacturing and in stores, shipping and receiving. Plans are in place to increase the factory’s manufacturing capability in terms of injection moulding and more compression moulding, he said, adding that more machines will be incorporated into the operations – resulting in more people being employed in the future.

In addition, the premises also contain an office currently staffed by commercial, sales and administrative people. Having the office and manufacturing facility in one location is an added advantage, according to Artin. “It is beneficial having the people who sell the products located in the same space production,” he says. “They can thus understand the intricacies of the product and the processes that are involved in the manufacturing of the equipment.

“The ultimate goal is to have a fully localised branch. We want to have an all-Brazilian team, working for Multotec Brazil. Local partners and suppliers are key to us as we rely on local raw materials to deliver completely locally manufactured products.”

While the company’s focus has been on establishing the manufacturing facility, Artin says it has already applied for an extension of its environmental licence to ramp up its monthly production as it takes advantage of Brazil’s current lithium boom, which presents considerable opportunities in dense medium circuits.

Multotec Brazil will receive support from Multotec’s global industry knowledge and expertise, leading to enhanced operational efficiencies and providing customers with comprehensive solutions over and above a quality product offering, the company says. Furthermore, Brazil will collaborate closely with Chile on the Multotec range of customised samplers. With input from Chile and local manufacturing in Brazil, this collaboration will create a seamless workflow that maximises efficiency, ensuring the delivery of high-quality samplers tailored to the specific requirements of customers, it concluded.

Tungsten West set to bring Hemerdon tungsten-tin mine back into production

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Tungsten West, the mining company focused on recommencing production at the Hemerdon tungsten and tin mine in Devon, England, has announced its intention to proceed with an initial public offering on London’s AIM market.

The company has conditionally raised £39 million ($53 million) before expenses, with plans to debut on the bourse on October 21 with a market capitalisation of approximately £106.2 million.

The net proceeds of the offer, together with the $49 million project financing from a fund managed by Orion Resource Partners, will be used to, among other things, execute the planned capital expenditure and corporate commitments of £44.6 million for improvement works at the Hemerdon Mine, bringing it back into commercial production.

Hemerdon is, Tungsten West says, the third largest tungsten resource globally, as well as being a previously producing mine that was operational from 2015-2018. Tungsten West purchased the Hemerdon Mine in 2019, and has since completed a bankable feasibility study that demonstrated an extensive reserve of approximately 63.3 Mt at 0.18% W and 0.03% Sn, as well as 37.4 Mt of saleable aggregate material. The company estimates that the life of mine is currently 18.5 years with the opportunity to extend this through future investment.

The mine already has the majority of its infrastructure in place, with previous owner Wolf Minerals Ltd having invested over £170 million into the development of the mine and its processing facilities, which include an open-pit mine, mineral processing facility and mine waste facility, the company says. With a substantial amount of existing infrastructure, the development costs associated with re-starting the mine are estimated to be £44.6 million. This existing infrastructure also means that the rebuild is only expected to take 12 months, with parts of the restart project already underway.

Having acquired the mine out of a receivership process, Tungsten West completed a significant amount of work to enable it to understand and address the issues historically experienced by Wolf Minerals, including a 6,113 m geological exploration drilling program and several technical studies. The company has identified the past issues experienced by Wolf Minerals that required rectifying.

“One of the main issues was a poor mineral process route design, with several items of equipment, particularly in the front end of the plant, causing plant downtime and hindering the recovery of the tungsten and tin minerals,” Tungsten West says. “Tungsten West has therefore designated a material proportion of its rebuild costs to modifying and updating the front-end of the processing plant. This will include replacing the existing crushing circuit with new duty and standby primary jaw crushers and secondary cone crushers.”

In addition, the introduction of X-ray Transmission ore sorting, which the company previously carried out tests on with TOMRA Mining in Germany, substantially reduces processing costs by rejecting around 70% of the ore fed to the sorters, it says.

Further upgrades to the plant commenced by the previous operator will be completed, including the dense media separation feed stockpile where 24 hours of surge capacity will be installed, decoupling the front-end of the plant from the concentrator circuit.

“Through these actions, the company expects plant operating time to improve from circa-53% under previous operatorship to the industry standard of circa-81% under Tungsten West,” Tungsten West says.

Tungsten West has identified further opportunities for by-product cash flow through the production and sale of aggregates. A new aggregate plant will be fed with ore sorter rejects and with the waste streams from the processing plant. The business plan is to sell to local aggregate consumers, such as GRS, providing them with a stable, long-term and sustainable source of these materials.

The company says it has implemented a number of initiatives to ensure a minimal impact on the surrounding environment and local community. These include optimising the plants low frequency noise to ensure minimal environmental impact and a fully cash funded £13.2 million restoration bond.

Max Denning, CEO of Tungsten West, says: “With the proposed £39 million raise announced today, and the £36 million funding package from Orion, we will be fully funded for the development of Hemerdon back into production. We look forward to welcoming new investors into this compelling business and working with all our stakeholders to ensure that the newly reinvigorated Hemerdon mine is a beacon of mining excellence in the UK.”

Kumba plans Sishen UHDMS iron ore project kick off

Comminution of minerals, Environmental, Mine operation news, Mineral processing, Mining equipment, Mining finance, Mining services, Steel and iron ore, Water management, , , , , ,

Kumba Iron Ore, energised by a record annual EBITDA of R45.8 billion ($3.12 billion) for its 2020 financial year, has made plans to extend the life of its Sishen iron ore mine in South Africa out to 2039.

The R3.6 billion ultra-high dense media separation (UHDMS) project was approved by the Kumba board late last week. It is expected to enhance the operation’s product quality and extend the life-of-mine by four years to 2039.

Kumba’s total iron ore production for 2020 came in at 37 Mt, down from 42.4 Mt in 2019 as both COVID-19-related events and weather-related headwinds impacted output. The company said reduced equipment reliability and availability also played a part to a lesser extent.

In line with this, total tonnes mined decreased by 14% to 256.3 Mt (2019: 297.9 Mt) and total waste stripping by 16% to 204.8 Mt (2019: 244.3 Mt) in 2020.

Owner fleet efficiency (OEE) reduced to 63% of benchmark for the year, compared with 68% for 2019.

“A number of interventions have been implemented to mitigate these impacts,” the company said. “We have enhanced our high rainfall readiness and associated recovery plans to manage through such weather impacts going forward.

“Our focus on improving equipment uptime through the implementation of defect elimination and work management programs, as well as artisan and supervisor skills development programs, is also delivering results and we are seeing improvements in equipment reliability across the fleet.”

The company is continuing to focus on improving operational efficiency through its P101 productivity improvements and various efficiency programs at both Sishen and Kolomela through the implementation of technology such as guided spotting, adaptive controls, truck speed digital twin and real-time condition-based monitoring.

Kumba’s total shovel fleet OEEs came in at 55% during 2020, but the company has a plan to hit the 80% mark in 2022. At Sishen, Kumba has six rope shovels consisting of Komatsu P&H 4100XPCs and Komatsu P&H 2800XPCs, while, at Kolomela, it has two Liebherr R996 hydraulic shovels.

Its total truck fleet OEEs came in at 82% in 2020, with a 100% target for 2022. At Sishen, Kumba has 100 Komatsu 860E and 960E trucks, while Kolomela has 36 Komatsu 730E trucks.

Meanwhile, at the UHDMS project, Kumba expects to break ground in the second half of 2021. This is ahead of commissioning in the second half of 2023.

Kumba, majority-owned by Anglo American, says the project will lower the strip ratio at the operation, extend the life-of-mine, as well as reduce its carbon footprint due to the reduction of waste material at the end of the operation’s life.

The total capital cost of the project of R3.6 billion is expected to be paid back with an after-tax internal rate of return of circa-30% and an EBITDA margin of around 40%.

Kumba already has a dense media separation plant that processes low-grade, non-DSO ore and separates it to higher grade iron ore at Kolomela (pictured).

TOMRA makes recovery promise to diamond miners

Automation, Bulk handling, Diamond mining, IoT, Mineral processing, Mining equipment, Mining services, Mining software, Sustainable mining, , , , , , , , , , , , , , , , , , , , ,

TOMRA is offering diamond mining customers a guaranteed diamond recovery of greater than 98% with the use of its sensor-based ore sorting technology.

The company is making this guarantee alongside a promise of 100% detection in the specified range, irrespective of luminescence profile or coating.

As the company says, maximising diamond recovery while optimising costs is the top priority for every diamond producer.

“With TOMRA’s holistic approach and cutting-edge technologies, both can be achieved to deliver outstanding results,” it said, adding that its X-ray Transmission (XRT) diamond recovery technology has helped recover some of the largest and rarest gemstones in history.

TOMRA says it approaches every project as a partnership with the customer to deliver a complete solution that meets their operational and business requirements.

This begins with a detailed analysis of the customer’s requirements and operational needs.

TOMRA – Operations Hub Johannesburg

Working collaboratively, it assists in developing a tailor-made flowsheet redesign that combines its XRT technology with its Near Infrared (NIR) and Laser solutions as needed. This collaborative approach continues throughout the project, with testing at its Test Center in Germany and, on-site, as required, through to installation and beyond.

More recently, this approach has been enhanced with the development of a remote testing option.

“The complete solution can also include the web-based TOMRA Insight platform that turns all the sorters into connected devices for monitoring and tracking the system’s performance,” the company said.

Once the system is fully operational, TOMRA offers its Service Level Agreement to ensure its solution continues to deliver the desired results.

“The tailored agreement can include on-site presence as required, seven days a week product support, application engineer visits, tiered urgency support, targeted site response, training, as well as spare and wear parts coverage to ensure maximum uptime and protect the customer’s investment,” the company said.

Advanced technologies adding value

TOMRA’s XRT technology recognises and separates material based on its specific atomic density. It uses a cutting-edge X-ray camera with DUOLINE® sensor technology to measure spectral absorption information.

TOMRA’s proprietary high-speed X-ray processing unit uses the data to produce a detailed “density image” of the material. The result is a high level of purity in sorting materials, irrespective of size, the degree of moisture or surface pollution present, TOMRA says. This makes TOMRA’s XRT high-capacity sorters effective in the recovery of free, liberated diamonds at high feed rates up to 300 t/h.

TOMRA’s NIR sorters recognise and separate kimberlite and waste rock based on their chemical composition. This technology is useful in upgrading lower grade run of mine and stockpiles, producing a kimberlite concentrate for further processing, the company says.

Marie-Claude Hallé had first-hand experience of how TOMRA’s solutions can add value to diamond mining operations when she held the role as Marketing Operations Manager for diamond exploration and producing company, Stornoway Diamonds.

“You have to really envision that TOMRA has actually changed the game in terms rough diamond recovered around the world and allowed producers to access large exceptional quality goods that perhaps in the past would be crushed to pieces,” Hallé said.

Customised solutions for kimberlite, lamproite and alluvial applications

With its customised approach, TOMRA says it can deliver on its promise of guaranteed results both in hard-rock kimberlite/lamproite and alluvial deposits – each of which presents their specific challenges.

In kimberlite, the challenge is to recover “needle in a haystack” diamonds, which requires controlled crushing of kimberlite ore to avoid damaging or breaking the diamonds, the company says.

“High waste dilution impacts the crushing energy needed and further increases diamond breakage risk,” TOMRA says. “Utilising TOMRA NIR technologies, we can remove non-diamond bearing material, not only improving the crushing profile of the ore, but also increasing the value of each tonne of ore processed. TOMRA NIR waste sorting technology can make diluted marginal kimberlite deposits economic.”

Additionally, complex, energy- and water-intensive kimberlite liberation processes, and the cost of transportation for crushing and processing, are challenges facing modern diamond miners today.

“TOMRA’s XRT and NIR technologies, which offer extremely high concentration factors, allow the production of hand sortable, ultra-high grade concentrates in as little as two stages compared to up to seven in traditional methods,” the company claims.

The challenge of economically mining low-grade alluvial deposits is due to their typically lower grade and the sporadic nature of the deposits.

The high recovery performance of TOMRA’s XRT technology enables single-stage or double-stage diamond recovery, offering a drastically lower operating cost and capital investment so that mining marginal deposits becomes economically viable, according to TOMRA.

“Another advantage of TOMRA’s XRT solution is that it can operate as a dry process, which dramatically reduces its environmental impact and operational complexity,” it says. “Besides, it opens the door to new opportunities, making it possible to mine deposits in arid areas where water access is minimal.”

TOMRA XRT machines have proved effective in alluvial operations, the company says.

One such case is that of the Lulo mine in Angola, operated by Lucapa Diamonds, where TOMRA XRT technology is used to process material between 18 and 55 mm in size and allows the recovery of diamonds of up to 1,100 ct – and where it has recovered Angola’s second-biggest diamond on record, a 227 ct stone in 2017.

Stephen Wetherall, Lucapa Diamonds Managing Director at the time of the recovery, said: “The recovery of the 227 ct diamond using the new XRT circuit justifies our investment in TOMRA’s large diamond recovery technology, which has more than paid for itself with the recovery of this one stone alone.”

Optimised flowsheet

TOMRA is in the unique position of being able to offer diamond operations a full XRT recovery flow sheet to 2 mm that delivers concentration factors up to 1 million with a much-reduced number of concentration stages, it says.

Geoffrey Madderson, Diamond Segment Manager for TOMRA Sorting Mining, explains: “TOMRA XRT technology replaces multiple stages of diamond concentration by virtue of its ability to concentrate diamonds to a hand sortable product after only a single step. This concentration factor allows for the removal of multiple recovery steps, drastically reducing both the capital investment and operational costs to recover diamonds.”

Geoffrey Madderson, Diamond Segment Manager for TOMRA Sorting Mining

TOMRA’s XRT technology can replace traditional methods such as dense media separation (DMS), wet magnetic separation and XRL final recovery with single-stage solutions for +8 mm and double-pass for -8 mm +4 mm particles, it claims.

“TOMRA’s solution eliminates up to seven concentration stages, dramatically reducing the complexity of the supporting plant and infrastructure,” the company says. “This results in significantly lower power and water consumption, which not only reduces costs, but also the environmental impact of the recovery process.”

An additional benefit of TOMRA’s solution is that it is a fully automated process, so there is no manual handling during pre-concentration and recovery, which has positive implications on security and eliminates human error, resulting in greater accuracy, the company says.

Recoveries

TOMRA’s sorters process these volumes with great efficiency, finding more diamonds than other, traditional separation methods – including coated and low- or non-luminescent diamonds, the company says.

The performance of its XRT sorters is independent of the “heavies” content in the feed, and is ideal for processing high-yielding ores unsuitable for DMS. The result is an exceptionally high recovery rate, it claims.

“TOMRA guarantees >98% recovery: that is how confident we are in our technology,” Madderson states.

With TOMRA’s sorting solutions, diamond producers can install large diamond recovery systems with a small capital investment and operate with a fraction of operating expenditures per tonne compared with traditional recovery methods such as DMS and XRL, it claims. In addition, the economic recovery of ultra low-frequency exceptional diamonds of +32 mm is now possible.

“TOMRA’s ability to deliver not only a technology that can detect such large diamonds, but also an economical process solution for the recovery of ultra-rare, exceptional diamonds is what sets it apart from its competitors,” Madderson said.

“This is the reason that, to date, TOMRA XRT has become synonymous with the recovery of extraordinary diamonds from all around the world.”

Weir’s Cavex hydrocyclones boost yields, production at Yoctolux Collieries operation

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Yoctolux Collieries in Mpumalanga, South Africa, has achieved improved yields and production throughput with the installation of a Cavex® 500CVXT20 DM hydrocyclone from Weir Minerals Africa, the OEM says.

Part of the Tala Group, the open-pit coal mine was looking to improve the performance of its dense media separation (DMS) circuit in its Wash Plant 1. The existing 610 mm cyclone, installed during the mine’s initial design phase, had an operational life of only six months between refurbishments.

Members of the Weir Minerals Middelburg branch and hydrocyclone product team conducted a site audit, revealing the incumbent cyclone was operating inefficiently. A “wash-ability” analysis showed that an improved yield could be achieved using the Cavex hydrocyclone technology on the DMS circuit, Weir said, with the customer specifying that the product would have to offer improved separation efficiency, increase wear life and match the existing cyclone footprint.

Following a proposal that included dense media (DM) hydrocyclone simulations, a Cavex 500CVXT20 DM hydrocyclone was installed in August 2017. Manufactured from mild steel, it is lined with 25 mm slip-casted radius ceramic tiles manufactured with 92% alumina content.

To date, the hydrocyclone has achieved higher separation efficiency through an average 15% yield increase, according to Weir. It has achieved an overall average of 75% yield for both of the mine’s coal types – grains and peas. This compares favourably with the 65% achieved previously by the competitor’s cyclone, Weir said.

There has been a 49% throughput increase in production tonnage, from 78 t/h to 116 t/h as a result of the reduced turbulence in the hydrocyclone’s design. The mine has also seen significant wear life improvement, with the Cavex DM hydrocyclone requiring only a spigot replacement after nine months, according to the equipment manufacturer.

So satisfied was the management at Yoctolux Collieries that they placed an order for an additional Cavex 500CVXT20 DM hydrocyclone in May 2018. This replaced the competitor’s cyclone on Wash Plant 2, with the replacement based on the improved metallurgical and operational benefits obtained by the Cavex hydrocyclones.