Tag Archives: Platinum

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.

Weba custom-engineered chutes cut the dust at platinum mines

Weba Chute Systems says it has been able to demonstrate to platinum mining customers how its custom-engineered chutes significantly reduce dust at transfer points.

Using the latest dust measuring technology, the company has carried out tests at mines in South Africa and Zimbabwe to compare the impact of Weba designs on material flow and dust levels, Izak Potgieter, Systems Manager at Weba Chute Systems, said.

At the site in Zimbabwe, considerable dust levels were created at bunker discharge chutes. Material of up to 500 mm in size was moving through at a rate of 600 t/h.

“The material flow was the biggest factor generating dust in the conventional chute, as material was not flowing as evenly as it should,” Potgieter says. “This created a lot of energy for the dust particles to expand into the surrounding atmosphere.”

The installation of the Weba chute – with its engineered design for optimal flow control – reduced the dust levels by about 40%, according to the company.

“By controlling the velocity of material, the design not only cuts dust creation but also reduces impact and wear for increased productivity and less maintenance downtime,” Weba said.

At the South Africa operation, the tests were conducted at a transfer point in the milling plant where an average tonnage of 190 t/h was being moved. Despite the use of water sprays, the existing chute was still creating considerable dust. The installation of the Weba chute was able to reduce dust levels by 15%, according to the company.

“Dust levels have shown to have a serious impact on human health, especially smaller particle sizes of 0.3 micron,” Potgieter says. “Health effects of dust relate mainly to particle size and dust may contain microscopic solids or liquid droplets that are small enough to get into the lungs and cause serious health problems.”

Spores and contaminants associated with dust and aerosol can also adversely impact human health, causing a range of issues from respiratory infections to toxic exposure, according to Weba.

Ivanhoe advances Platreef development studies after Moolmans completes sinking

Ivanhoe Mines has announced another milestone at the Platreef platinum group metals project in South Africa, with construction complete at the 996-m level station of Shaft 1.

The achievement, completed well ahead of the contractual schedule, according to Ivanhoe, positions the company to equip Platreef’s initial production shaft, if it chooses to proceed with phased development of the mine on the Northern Limb of South Africa’s Bushveld Complex.

Sinking was carried out by contractor Moolmans, with the project remaining ‘Fall-of-Ground’ incident free since shaft sinking operations began in July 2016, the company said. On top of this, in June 2020, Moolmans and the Platreef team achieved South Africa shaft sinking industry leader status in terms of safety performance, according to Ivanhoe, which owns 64% of the project through Ivanplats.

Ivanhoe’s Co-Chairmen, Robert Friedland and Yufeng “Miles” Sun, said: “Given the flurry of recent transactions in precious metals markets, we are actively exploring a number of options that can help us unlock Platreef’s extraordinary value for the benefit of all Ivanhoe stakeholders.

“After all, Platreef is among this planet’s largest precious metals deposits.”

Platreef now has a completed shaft within a few hundred metres of the initial high-grade mining zone, according to Friedland and Sun.

“We have a mining licence, we have water and we have a team of highly-skilled employees,” they said. “The deposit has enormous quantities of palladium, platinum, rhodium, nickel and copper; and it has more ounces of gold than many leading gold mines.”

They concluded: “Given the current precious metals environment, I am confident that the pending studies will showcase the exceptional economics that one would expect from such a thick, high-grade and flat-lying deposit.”

Ivanhoe is updating the Platreef project’s 2017 definitive feasibility study (DFS) to account for development schedule advancement since 2017 when the DFS was completed, as well as updated costs and refreshed metal prices and foreign exchange assumptions.

The DFS for Platreef covered the first phase of production at an initial mining rate of 4 Mt/y, estimating Platreef’s initial average annual production rate would be 476,000 oz of platinum, palladium, rhodium and gold, plus 21 MIb (9,525 t) of nickel and 13 MIb (5,897 t) of copper.

Concurrently, Ivanhoe is finalising a preliminary economic assessment for the phased development production plan for Platreef. The plan targets significantly lower initial capital to accelerate first production by using Shaft 1 as the mine’s initial production shaft, followed by expansions to the production rate as outlined in the 2017 DFS, Ivanhoe said.

“The re-evaluation is being done in parallel with the ongoing mine development work to access the thick, high-grade, flat-lying Flatreef deposit that was discovered in 2010 and outlined in the Platreef 2017 feasibility study,” it said.

The new auxiliary winder for the 7.25 m diameter Shaft 1, which is scheduled to be delivered to Platreef later this year, will be used to assist in equipping the shaft; and thereafter for logistics, shaft examination and auxiliary functions. The auxiliary winder will provide a second means of ingress and egress from the shaft after removal of the stage winder.

Shaft 1 is around 350 m away from a high-grade area of the Flatreef orebody, planned for bulk-scale, mechanised mining.

thyssenkrupp navigates South Africa lockdown to replace platinum mine HPGR roll

As the COVID-19 pandemic tightens its grip, thyssenkrupp Industrial Solutions says it is assisting customers in maintaining operational efficiencies through sustainable service delivery and innovative technologies.

“The global economic crisis, as a consequence of the COVID-19 pandemic, has put the drive for efficiency into top gear,” Philipp Nellessen, CEO of thyssenkrupp Industrial Solutions Sub Sahara Africa, said. “Fundamental to this drive is cutting-edge technology. Through our ongoing investment in people and R&D and our over 200 years of expertise, we are able to develop advanced technologies to assist mining and other industries in achieving maximum operational efficiencies.”

Although the South Africa mining industry was not operational during national lockdown Level 5, critical repairs were still permitted. As an essential service provider, thyssenkrupp has been delivering maintenance and repair as well as rebuild work to local mines.

The company assisted a platinum mine in Limpopo Province with a roll change on one of thyssenkrupp’s flagship products, a high pressure grinding roll (HPGR).

Nico Erasmus, thyssenkrupp Industrial Solutions Sub Sahara Africa Head of Service Operations, explained: “The scope of work required a rebuild on the HPGR set as well as the installation of the hardware on the mine site, making this our largest project in the national lockdown period.

“We are very pleased that even in a complete lockdown situation, we were able to complete the project in a healthy and safe manner, in excellent co-operation with our customer.”

The customer had “excellent controls” in place and thyssenkrupp complemented the risk mitigation with its own additional preventative protocols, he added.

Procedures included pre-selection of a team that falls inside the recommended age and health categories, pre-screening at both thyssenkrupp and customer sites, limiting the amount of people on shifts and in spaces, adhering to stringent hygiene measures (hand sanitising, wearing face masks, social distancing, cleaning of surfaces, tools and equipment), and implementing special transport and accommodation measures.

According to Erasmus, despite several challenges, the team adapted quickly to all the controls while still being responsive enough to get the work done safely and within the scheduled timelines.

“The transport of super loads (two trucks with 120 t loads each) was a real challenge, but our logistics team rose to the occasion and got the loads on site in no time and ready for installation,” Erasmus said.

To remain operational and continue seamless service delivery to customers, thyssenkrupp has implemented all necessary policies in line with South Africa Government COVID-19 regulations.

These include possession of all essential services permits and strict entry control protocols for employees, visitors and suppliers at all premises. Employees are required to attend mandatory training sessions conducted by the OSH department, wear all necessary personal protective equipment, sanitise regularly and maintain social distancing.

A dedicated COVID-19 committee has been set up to assess changing regulations and risks associated with office and site working environments, the company said.

“With the majority of employees working from home, we have faced our fair share of challenges but the process was very well organised with IT managing it all incredibly well ensuring that everybody was equipped in time,” Erasmus said. “We only had one day of downtime at our essential service workshop site.”

Wrapping up, an optimistic Nellessen says he is in no doubt that South Africa/Sub-Sahara Africa will recover.

“The people here are incredibly brave and innovative and companies will find their way out of the crisis,” he said.

“Despite tough times ahead for some industries, the mining sector continues to show growth and here I foresee a restart and a good recovery, depending on mining commodities probably taking anything between three to 12 months to reach previous and required pricing levels.”

Concor Opencast Mining provides ‘seamless transition’ at Anglo’s Mogalakwena PGM mine

Contractor Concor Opencast Mining says it is helping Anglo American Platinum’s Mogalakwena open-pit platinum group metals (PGM) mine team, in South Africa, boost annual production.

This growth can be attributed to various optimisation efforts on site at the largest open-pit PGM mine in the world, as well as the steady performance of its Zwartfontein pit, which Concor Opencast Mining is in charge of, the contractor said.

The majority of Mogalakwena’s production originates from the Central, North and South pits, supplemented further by the nearby Zwartfontein pit. Together these deposits should deliver on Anglo American Platinum’s record-breaking production target of 1.22 Moz of PGMs for 2019, Concor said.

While the three main production pits are operated by the mine’s personnel, it relies on a contractor for the smaller Zwartfontein pit, which requires an earthmoving fleet suited to its smaller size and production targets. Despite its size, it is an important contributor to Mogalakwena’s annual performance, Concor said.

A year and nine months ago, the pit underwent a significant transition that saw Concor secure the load and haul contract from Anglo’s previous operator.

“Because the mine required a smooth changeover with minimal disruption to production, we took over most of the previous contractor’s fleet, as well as its entire workforce,” Concor Opencast Mining’s Zwartfontein contracts manager, Donald Sisiya, said.

Having completed work at Mogalakwena’s tailings storage facility in the past, Concor Opencast Mining brought to the project not only an existing relationship with the mine but its solid reputation for mining open-pit, hard-rock PGM operations in South Africa, the company said.

Sisaya continued: “Combined with our cost competitive offer, the mine placed its faith in our ability to deliver a seamless transition and then to further optimise production without disrupting day-to-day running during the changeover period.”

Concor Opencast Mining’s agreement at Zwartfontein comprises a three-year load and haul contract, as of December 1, 2017. Over this period, it must move 32.4 Mt of material and, more specifically, 12 Mt of ore and 20 Mt of waste material.

With an effective change management structure in place, Concor Opencast Mining has improved the pit’s production performance, having revised the shift structure for all plus-100 of its employees, the company said.

It has also invested significant capital into upgrading most of the old earthmoving equipment on site which had not been properly maintained, according to Concor.

“We have over recent months added three 130 ton (118 t) excavators to the pit, over and above introducing 10 new 100 t (91 t) trucks as well,” Sisiya states.

Moving forward, Concor Opencast Mining has production targets to meet by the end of the year and Sisiya is confident of achieving these: “Taking over an existing contract while ensuring minimal impact to the employees and the production targets is a success story for the company which highlights our strong capabilities in the open-cast mining space.”

Master Drilling lays groundwork for record breaking hole

Master Drilling is set to break a drilling world record having recently commenced collaring for a 1,420 m pilot hole at a South Africa platinum mine.

The 4.6 m diameter hole is being sunk as part of an expansion project at the mine. It will help lead to the development of a rock hoisting shaft equipped with steelwork, according to Master Drilling.

Master Drilling said it was using its RD8 raisebore rig for the project. This rig, which has been operational since 2015 and used at various mine sites across South Africa, is capable of drilling 8.5 m in diameter and over 1,500 m deep, the company added.

The current construction schedule at the mine indicates the holing of the pilot during the first week of May 2020, some eight months from the collaring date.

The previous longest pilot drilled to date was 1,180 m, according to the company.

SPH Kundalila crushing it at Pilanesberg platinum mine

Raubex Group subsidiary SPH Kundalila has recently seen its contract expand at the Pilanesberg platinum mine on South Africa’s Bushveld Complex.

The two already have a nine-year relationship to fall back on, with SPH Kundalila’s primary contract at Pilanesberg entailing managing the mine’s primary crushing requirements. This includes crushing all run of mine (ROM) material from the mine before it is transported to the concentrator.

Pilanesberg, which has many outsourced contractors, recently celebrated 10 years of production excellence at the mine.

The nine-year relationship between Pilanesberg and SPH Kundalila can be attributed to the trust and partnership the company has built with the mine but also its high level technical skills set, according to the contractor.

SPH Kundalila Production Manager, Walter Eriksen, said: “With our 260 people on site, 75% from the local Bakgatla tribe, we operate four 63 t mobile crushing machines on the outskirts of the pit which have a combined design capacity of 380,000 t/mth.

“Our crushers have been replaced over the years as the mine’s production requirements have grown. Throughout this process we have maintained our machines’ high availability thanks to an in-depth knowledge and understanding of the mine’s production requirements.

“To ensure our performance further, we have established on-site technical support infrastructure including a workshop and plus-40 workshop crew. This facility enables us to conduct preventative maintenance equipment routines as well as full services and minor repairs which results in minimal downtime.”

The mine has expanded SPH Kundalila’s work on site of late, which now includes materials handling services delivered from its fleet of wheel loaders, dump trucks and tippers. In June 2018, the company’s workload expanded even further to include loading and hauling waste material from the pit.

SPH Kundalila Pit Manager, Danie de Jager, said: “Since June of last year we have successfully been moving waste material from the northern side of the pit. We have also steadily grown our volumes which started at 145,000 t/mth to around 500,000 t/mth. Through this service we are giving the mine quick and easy access to the reef.”

SPH Kundalila’s earthmoving fleet comprises two excavators, two bulldozers and eight 45 t dump trucks carefully selected to allow accurate waste-only removal.

SPH Kundalila Site Manager, Pieter Boonzaier, said: “Our service delivery, technical capability and ongoing dedication to helping Pilanesberg platinum mine meet its 150,000 oz per annum of PGM production requirements is a proud achievement for SPH Kundalila and we hope to continue working with the mine as its explores new and exciting chapters of its life.”

Anglo Platinum and Platinum Group Metals look downstream with Lion Battery Technologies JV

Anglo American Platinum and Platinum Group Metals Ltd have launched a new venture, Lion Battery Technologies Inc, to, they say, accelerate the development of next-generation battery technology using platinum and palladium.

This is all geared towards creating additional demand for platinum and palladium in the battery technology space.

The new Lion venture has entered into an agreement with Florida International University to further advance a research program that uses platinum and palladium to unlock the potential of lithium air and lithium sulphur battery chemistries to increase their discharge capacities and cyclability, the companies said. As part of this, Lion will have exclusive rights to all intellectual property developed and will lead all commercialisation efforts. “Lion is also currently reviewing several additional and complementary opportunities focused on developing next-generation battery technology using platinum and palladium.”

Thanks to considerably higher energy density, lithium oxygen and lithium sulphur batteries can perform better, by orders of magnitude, than the best-in-class lithium-ion batteries currently on the market or under development, according to the two companies. “This new generation of lightweight, powerful batteries has the potential to grow to scale on the back of the attractiveness of battery electric vehicles and the use of lithium batteries in other applications beyond mobility.”

Benny Oeyen, Executive Head of Market Development at Anglo American Platinum, said: “This exciting early-stage technology aligns with our broader strategy to bring new technologies to market that will help us secure future demand for the platinum group metals we mine and pave the way to a more sustainable energy future. Our commitment to market development is underscored by our relationship with AP Ventures, of which we are a cornerstone investor and who is a potential investor in this technology as it matures.”

Michael Jones, CEO of Platinum Group Metals Ltd, commented: “Developing new applications for platinum group metals is key to ensuring long-term sustainable demand, demand which will be important to the future success of our large-scale Waterberg palladium and platinum mining project, in South Africa.”

Weir’s Warman AHF slurry pumps cut through the froth in South Africa

Weir Minerals’ Warman® AHF pumps have been put to the test at two mines in South Africa’s Limpopo Province, the company said.

The pumps were tasked with pumping frothy, high density and viscous slurries at the platinum and phosphate mines.

Weir said: “Handling froth in some process circuits can be very challenging, as froth will air-bind a conventional slurry pump. In froth applications, the Warman AHF inducer impeller solves this problem, producing far less surging. The inducer impeller and oversized inlet enhance the movement of the froth, high density or viscous slurries into the impeller, facilitating effective transportation.

“In addition, its higher efficiencies mean a smaller pump will deliver the required results.”

At the platinum operation, a Warman AHF 2 pump was commissioned in early 2016. It has met the specified flow rate of 40 m3/h with no pump-related stoppages, repairs or replacements, according to Weir.

A 12-month trial period showed the unit saved the mine over R200,000 ($14,153) when compared with the cost of the competitor pump installed previously. Based on this, the mine replaced another eight competitor products with Warman AHF pumps, Weir said. It has approved the Warman AHF 3 pumps as standard for all frothy applications at the plant’s first flotation section, and Warman AHF 2 pumps for the second flotation section, the company added.

The Warman AHF pumps – with Hi Seal® expeller (dry gland) design – were also tested in a viscous slurry application at the phosphate mine in Limpopo for six months. According to Weir, they demonstrated they could continuously pump the high-density viscous underflow slurry at relative densities above 1.9. “As a result, the customer purchased the pump and began upgrading all the remaining concentrate thickener underflow pumps to the Warman AHF pump technology,” Weir said.

This reduced the plant’s operational costs significantly, decreased dewatering and concentrate moisture extraction operations, improved filtration efficiency and increased concentrate throughput to the dryers, according to Weir. The Warman AHF pump also extended the underflow pumping boundaries and the overall reliability of the thickener underflow pumping system.

“Other field and laboratory tests have proven that the Warman AHF pump has largely overcome the problem of high-density viscous underflow slurries, with negligible effects on head at slurry yield stresses up to 200 Pa,” the company said.

Jacques Pretorius, Weir Minerals Africa’s Pump Product Development Specialist, said the approach to solving any thickener underflow pumping problem must be based on a thorough understanding of the entire application, the mineralogy and rheological behaviour of the slurry.

“Successful thickener underflow pumping projects are only achievable through involving a team of thickener engineers, pumping engineers and rheological consultants,” he said. “Weir Minerals’ pump trial campaigns confirm the successful operability of the Warman AHF pumps in viscous slurry applications.”

FLSmidth takes nextSTEP in flotation technology at South Africa platinum mine

FLSmidth’s innovative nextSTEP™ rotor and stator flotation technology has proven itself at a large platinum mine in South Africa, the mineral processing company says.

According to Ricus van Reenen, Regional Product Line Manager – Separation at FLSmidth, the nextSTEP rotor and stator combination has been at work for over a year at the mine, achieving positive results.

“The customer has achieved significantly lower power consumption on the full-scale retrofits we installed early in 2018,” van Reenen says. “The more efficient design allows the same or higher slurry circulation at reduced rotor speed, leading to lower power draw.”

The retrofits have been applied to both primary and secondary flotation applications, where energy savings of over 10% have been achieved, according to FLSmidth.

Years of research and development have been invested in the nextSTEP technology, which was originally launched in 2015, the company says. Among the key design elements are the addition of slots to the stator, adjustments in the rotor profile and a parallel distance between the rotor and stator.

“Energy dissipation is now more uniform than in traditional forced-air designs,” van Reenen says. “This means a more even wear pattern across the rotor and stator, and therefore longer intervals between maintenance.”

In the South Africa installations, the wear on the rotors and stators has been minimal after more than a year’s operation, the company says. In one flotation cell, the equipment has been operational for 15 months. The thickness of the rotor has reduced from 65 mm to only 60 mm, and the stator from 75 mm to 70 mm. After 13 months of operation in the second installation, the wear is even less, with the rotor’s thickness having reduced from 65 mm to 63 mm and the stator going from 75 mm to 73 mm.

van Reenen highlighted that there have been other benefits experienced by South Africa users of the new technology. Among these has been 16-18% less blower air usage, with more concentrated bubble formation.

“Better turbulence energy dissipation around the rotor and stator region, with its related finer bubble size distribution, creates more surface area for bubble-particle attachment,” van Reenen says. “This has delivered more froth and a higher mass pull on our local units.”

The success of the nextSTEP technology has led to further retrofits being planned in South Africa, in line with FLSmidth’s drive to promote mines’ productivity and performance. Van Reenen says the intensive R&D process continues apace and is not just in the rotor and stator design but also includes areas such as smart control systems and continued digitalisation of process solutions.