Tag Archives: Screening

Haver & Boecker Niagara’s Pulse Vibration Analysis to premiere at MINExpo 2021

Haver & Boecker Niagara is to showcase its Pulse Vibration Analysis (VA) software at the upcoming MINExpo 2021 event in Las Vegas, USA.

Providing mining and aggregate operations insight into their equipment’s performance, Pulse VA is specifically designed to examine the health of a vibrating screen to ensure optimum screening performance and equipment reliability, according to the company. It detects irregularities that could translate into diminished performance, decreased efficiency, increased operating costs and imminent breakdown.

Pulse VA will be front and centre of the Haver & Boecker Niagara booth at MINExpo 2021, taking place on September 13-15.

Karen Thompson, President of Haver & Boecker Niagara’s North American and Australian operations, said: “We understand screening equipment is a significant portion of an operation’s budget, which is why we developed Pulse VA. Pulse VA offers operations the tools to optimise screening efficiency on a daily basis. This helps increase their operation’s profitability by minimising downtime as well as maintenance costs.”

Pulse VA is designed to be easy to operate, with components specifically chosen and engineered for the harsh environment where screening takes place. The system uses an industrial-grade tablet computer that connects wirelessly with eight tri-axial sensors, which attach to key places on the equipment and send up to 24 channels of data to the tablet. The table then displays a real-time view of the machine’s orbit, acceleration, deviations and more, Haver & Boecker Niagara said.

Beyond the real-time view on the screen, all information from the sensors is electronically stored in the database for an historical overview of the machine, with the information downloadable online in two report formats. The Orbit Report provides a visual of orbit and wave form, as well as data about acceleration, stroke, speed and phase angle. Fast Fourier transformation, or FFT, plots are processed by the software for values for three channels of data for each measuring point. The Tuning Report extrapolates deviations between measurement points while providing recommendations on balance, acceleration, stroke and speed. It provides feed and discharge analysis as well as diagonal measurements.

Haver & Boecker Niagara says it also offers its signature Pulse Vibration Analysis Service program to help customers achieve production targets, minimise unscheduled downtime and demonstrate sustainable improvements through online asset management, it said. The service program includes a complete vibrating screen inspection by a Haver & Boecker Niagara certified service technician, along with a Pulse Diagnostic Report.

Pulse VA technology, the company says, serves as a critical part of PROcheck, Haver & Boecker Niagara’s service process dedicated to keeping customers’ operations running at peak performance. PROcheck applies Haver & Boecker Niagara’s expertise in diagnostics, processing equipment, engineered screen media, original parts, rebuilds and upgrades, services, plants and process engineering to inspect customers’ screening processes in order to recommend best practices for processing proficiency.

Cedric Minería selects CDE EvoWash wet processing tech for Buin sand, gravel ops

Chilean mining and aggregates company, Cedric Minería, has announced a major overhaul of its aggregates business following a significant investment in advanced wet processing technology from CDE, the Belfast-based company says.

The family business, which expanded into aggregates production in 2003, has revealed plans for a new wet processing solution at its Buin operation.

Established in 1981, Cedric Minería specialised in the production of calcium carbonate and sulphur products before diversifying its interests and launching its silica operation, Mina Nancy, near the city of Calama in Antofagasta Region.

It soon secured listing as a strategic supplier of silica to state-owned copper mining company Codelco for its copper smelting plant in Chuquicamata, northern Chile.

Following the success of its silica business, Cedric Minería soon after commissioned its first aggregates processing plant in Buin which supplies the local market with a range of washed sand and gravel products for pre-cast concrete, asphalt, pipe bedding and more.

This summer, CDE will commission the EvoWash™ sand wash plant and an AquaCycle™ water management system at the company’s Buin site, replacing their existing washing screws.

Using CDE cyclone technology, the new plant will enable Cedric Minería to produce two grades of high quality, in-spec fine sands: 0-5 mm and 0-8 mm.

A compact, modular sand washing system, CDE’s EvoWash screens and separates the smaller sand and gravel fractions through an integrated high-frequency dewatering screen, sump and hydrocyclones which provide control of silt cut points and eliminates the loss of quality fines with significant commercial value.

An alternative to water extraction and the costly process of pumping water to the plant, CDE’s AquaCycle significantly reduces costly water consumption by ensuring up to 90% of process water is recycled for immediate recirculation, the company says. It helps to accelerate return on investment by maximising production efficiency, minimising the loss of valuable fines and reducing water and energy costs. A single, compact and user-friendly unit, it can be applied to high and low tonnages across many market sectors.

Cedric Minería owner, Cedric Fernández, says the investment in CDE technology is a significant step forward for the company.

“We’re making a huge technological leap forward with this new plant. Cedric Minería branched into the aggregates business almost two decades ago and throughout that time we have operated a traditional system,” Fernández said. “The existing plant has served us well, but we need a modern solution that is future-ready. Our latest investment in CDE wet processing technology represents the beginning of a new chapter for our company.”

Fernández says the COVID-19 pandemic had a significant impact on the construction industry but anticipates strong future demand for sand and aggregates to support the country’s public works investments.

CDE Business Development Executive, Gustavo Brasil, says older technology is very much under the spotlight for materials processors as they work to remedy inefficiencies.

“Recognising the limitations of the existing setup, the team at Cedric Minería are setting out on an ambitious transformation project to replace a traditional processing plant with a much more advanced and efficient technological solution,” he said.

The CDE solution engineered for Cedric Minería will revolutionise its current process, he added.

“CDE’s Evowash solution will enable Cedric Minería to produce superior fine sands with less moisture content while the AquaCycle water management system will deliver massive efficiency gains by recycling process water and driving down operational costs,” he said.

Pilot Crushtec and Metso Outotec extend partnership

After five years representing global leader Metso Outotec in southern Africa, South Africa-based Pilot Crushtec has renewed its distributorship for another half decade.

Pilot Crushtec, despite periods of challenging economic conditions in recent years, has earned global accolades within the Metso Outotec distributor network, with Francois Marais, Director Sales and Marketing at Pilot Crushtec, saying the company has already won annual awards for Best Aftersales Distributor and for Best Sales Growth.

“We value this partnership with one of the world’s leading brands and have demonstrated through our solid performance the positive synergies that we leverage,” Marais says. “The years from 2017 through to 2019, in particular, saw exceptional growth year-on-year for both our Metso Outotec offering and our business as a whole.”

He highlights that the two companies’ offerings in the crushing and screening market complement each other very well, and they share a commitment to high quality products, service and support.

“For customers, the renewal of our distributorship confirms their faith in our products and strengthens their security of investment going forward,” he says. “It assures the market once again that their capital investments are being well supported through our extensive parts holdings and service excellence.”

The new agreement covers additional products and territories within the region, facilitating a wider offering in terms of new equipment and aftermarket aspects. According to Adam Benn, Director Capital Sales, North EMEA, Russia & CIS and Southern Africa at Metso Outotec, there was no hesitation in renewing the distribution agreement with Pilot Crushtec.

“Having just celebrated its 30th anniversary in business, Pilot Crushtec has built a strong reputation,” Benn says. “This applies not only to their supply of equipment and associated services, but their experienced team’s hands-on knowledge and can-do attitude to opportunities and challenges.”

He emphasised Pilot Crushtec’s investment in time and resources training their teams and their customer base – an effective strategy for keeping skills current and for listening to customers’ development needs. With technical facilities that, it says, rank among the industry’s best, the company manufactures plant locally while also offering a one-stop repair and refurbishment solution.

“Having a distribution network that is close to its customers is a fundamental part of Metso Outotec’s group strategy,” he says. “In addition to being well located, our distributors need to keep a good inventory of equipment and parts, which is something that Pilot Crushtec prioritises as a vital cornerstone of their business strategy.”

Metso Outotec boosts end-user service offering in central, southern Sweden

Metso Outotec has signed a distribution contract with Mining and Construction Equipment Sweden AB and Värnamo Krosskonsult AB that will see the two Sweden-based firms distribute Metso Outotec’s mobile and stationary crushing and screening equipment, as well as crusher wear parts, to mining and aggregate customers in southern and central Sweden. The pair will also provide service support such as start-ups and repairs in the regions.

Roar Vasbø, who is heading Metso Outotec’s sales and service in the Nordics region, said: “We’re very pleased to enter this cooperation. For the customers, it means better and faster local service. For us, it means that we can improve customer experience and reach out to more potential customers in the region, especially contractors.”

Fredrik Wennberg, Managing Director of Mining and Construction Equipment Sweden, said: “Our aim is to serve the markets as one-stop-shop. We offer service, parts, equipment and know-how close to the customer.”

He added: “Flexibility is very important to our customers, especially for the contractors. We offer rental possibilities and stock units so that the customers are able to get their equipment quickly.”

Kristofer Almén, Managing Director of Värnamo Krosskonsult, concluded: “This is a great opportunity for us to be able offer Metso Outotec aggregate equipment to greenfield projects or to brownfield stationary plant projects. It will strengthen our competitiveness and help us serve the market better.”

The main location is Värnamo with equipment and parts stock, and a service workshop. Sales offices are in Stockholm, Värnamo and Ystad. The staff includes around 20 personnel in service, sales, and construction engineering.

MLG Oz bolsters NSR Jundee work, adds Norton Gold Fields and Mincor to contract mix

MLG Oz says it continues to experience historically high levels of tendering opportunities for its suite of mining services, with three new integrated site services and haulage contracts recently added to its remit across its Western Australia operations.

MLG, which listed on the ASX earlier this year, says it offers a range of value added services from bulk haulage, crushing and screening, aggregate and sand supplies through to export logistics.

At Northern Star’s Jundee gold operation in Western Australia, the company has been awarded preferred contractor status for an expansion of its services, providing integrated site support and haulage capacity at the mine. Subject to negotiation and execution, this new three-year contract is expected to commence around August and deliver some A$12 million/y ($9.2 million/y) in revenue.

The scope of works will consist of integrated site support to the company’s mill feed operations from both its Jundee central underground mines and its regional satellite operations, MLG said. It will see the ASX-listed contractor conduct all crusher feed, bulk haulage and site civil works for the operations under its integrated operating platform.

MLG has added two new clients to its roster, too – Norton Gold Fields and Mincor Resources.

Norton Gold Fields has chosen MLG as its successful tenderer to provide integrated site support services and haulage for its Paddington gold operation over a three-year period expected to commence in September. Revenue from this opportunity is estimated to be around A$14 million/y, with formal contract documentation anticipated to be finalised in the coming weeks.

And, in line with MLG’s desire to broaden its service offering across different commodities and, in particular, the battery metals space, it has executed a contract with Mincor Resources for the provision of the logistics services associated with its Kambalda nickel operation. The contract is expected to deliver approximately A$3 million/y in revenue over four years and is expected to commence in the March quarter of 2022.

Reviewing these contract awards, MLG Founder, Managing Director and majority shareholder, Murray Leahy, said: “We are very pleased to be given the opportunity to continue to support and grow with Northern Star which has been a long-standing customer of MLG.

“We are delighted that the Norton Gold Fields Board has selected MLG to support the Paddington processing facility. The mill is 35 km northwest of Kalgoorlie and aligns very strongly with our existing Kalgoorlie network.

“Our new contract at the Kambalda operations is an important first step for MLG in developing a longer-term relationship with Mincor in support of its goal of being a key supplier of nickel to the emerging battery metals market.”

In addition to announcing these contract awards, MLG also provided a market update on its crushing and screening activities.

It said: “MLG’s crushing and screening operations, which account for 20% of MLG’s forecast financial year 2021 revenue of A$241.6 million, have experienced a reduction in available material to process from several clients across the last quarter of financial year 2021, due to production constraints at various client operations. We anticipate this will negatively impact the crushing and screening revenue in the first half of financial year 2022. Despite this, and given the company’s current pipeline, including as evidenced above, the board expects the overall impact of this to be mitigated in the second half of financial year 2022.”

eHPCC: the future of grinding in mining?

A lot has been made of the potential of high pressure grinding rolls (HPGRs) to facilitate the dry milling process many in the industry believe will help miners achieve their sustainability goals over the next few decades, but there is another novel technology ready to go that could, according to the inventor and an independent consultant, provide an even more effective alternative.

Eccentric High Pressure Centrifugal Comminution (eHPCC™) technology was conceived in 2013 and, according to inventor Linden Roper, has the potential to eliminate the inefficiencies and complexity of conventional crushing and/or tumbling mill circuits.

It complements any upstream feed source, Roper says, whether it be run of mine (ROM), primary crushed rock, or other conventional comminution streams such as tumbling mill oversize. It may also benefit downstream process requirements through selective mineral liberation, which is feasible as the ore is comminuted upon itself (autogenously) in the high pressure zone via synchronous rotating components. Significant product stream enrichment/depletion has been observed and reported, too.

As IM goes to press on its annual comminution and crushing feature for the April 2021 issue – and Dr Mike Daniel, an independent consultant engaged by Roper to review and critique the technology’s development, prepares a paper for MEI Conferences’ Comminution ’21 event – now was the right time to find out more.

IM: Considering the Comminution ’21 abstract draws parallels with HPGRs, can you clarify the similarities and differences between eHPCC and HPGR technology?

MD & LR: These are the similarities:

  • Both offer confined-bed high-pressure compression comminution, which results in micro fractures at grain boundaries;
  • Both have evidence of preferential liberation and separation of mineral grains from gangue grains at grain boundaries; and
  • Both have an autogenous protective layer formed on the compression roll surfaces between sintered tungsten carbide studs.

These are the differences:

  • eHPCC facilitates multiple cycles of comminution, fluidisation and classification within its grinding chamber, retaining oversize particles until the target product size is attained. The HPGR is a single pass technology dependent on separate materials handling and classification/screening equipment to recycle oversize particles for further comminution (in the event subsequent stages of comminution are not used);
  • Micro factures around grain boundaries and compacted flake product that are created within HPGRs need to be de-agglomerated with downstream processing either within materials handling or wet screening. In some instances, compacted flake may be processed in a downstream ball mill, whereas, in eHPCC, preferential mineral liberation is perfected by subsequent continuous cycles within the grinding chamber until mineral liberation is achieved within a bi-modal target size (minerals and gangue). The bi-modal effect differs from ore type to ore type and the natural size of the minerals of interest;
  • The preferential liberation of mineral grains from gangue grains generally occurs at significantly different grain sizes, respectively, due to the inherent difference in progeny hardness. eHPCC retains the larger, harder grains, hence ensuring thorough stripping/cleaning of other grain surfaces by shear and attrition forces;
  • eHPCC tolerates rounded tramp metal within its grinding chamber, however does not tolerate high quantities of sharp, fragmented tramp metal that create a non-compressible, non-free-flowing bridge between roll surfaces, which risks the damage of liner surfaces;
  • The coarse fraction ‘edge effect’ common in HPGR geometry is not an issue with eHPCC. In fact, the top zone of the eHPCC grinding chamber is presumed to be an additional portion of the primary classification zone within the grinding chamber. The oversize particles from the internal classification process are retained for subsequent comminution;
  • The maximum size of feed particle (f100) entering the eHPCC is not limited to roll geometry as is the case with HPGRs (typically 50-70 mm). eHPCC f100 is limited to feed spout diameter (for free flow) and dependent of machine size ie eHPCC-2, -5, -8 and -13 are anticipated to have f100 60 mm, 150 mm, 240 mm and 390 mm, respectively. The gap between rolling surfaces is greater than the respective f100; and
  • eHPCC technology shows scientifically significant product stream enrichment.

IM: What operating and capital cost benefits do you envisage when compared with typical HPGR installations?

MD & LR: Both operating and capital cost benefits of the eHPCC relative to HPGR technology are due to the eHPCC not requiring the pre-crushing and downstream classification equipment required by HPGRs.

The eHPCC operating cost benefits are associated with eliminating maintenance consumables, downtime, reliability issues and energy consumption associated with the equivalent HPGR downstream equipment listed above.

The eHPCC capital cost benefits are associated with eliminating the real estate (footprint) and all engineering procurement and construction management costs associated with the equivalent HPGR upstream/downstream equipment listed above. eHPCC flowsheets are likely to be installed as multiple ‘one-stop’ units that maintain high circuit availability due to ongoing cyclic preventative maintenance.

IM: Where has the design for the eHPCC technology come from?

LR: It was invented in early 2013 by me. I then pioneered proof-of-concept, prototyping, design and development, culminating in operational trials in a Kazakhstan gold mine in 2020. A commercial-grade detailed design-for-manufacture has since been undertaken by a senior team of heavy industry mechanical machine designers and engineers.

IM: In your conference abstract, I note that the eHPCC technology has been tested at both laboratory and semi-industrial scale with working prototypes. Can you clarify what throughputs and material characteristics you are talking about here?

LR: The first iteration of the technology, eHPCC-1, was tested at the laboratory scale from 2013-2015. This proof-of-concept machine successfully received and processed magnetite concentrate, copper-nickel sulphide ore, alkaline granite, marble and a wolfram clay ore dried in ambient conditions. The typical throughput was between 200-400 kg/h depending on the feed size, particle-size-reduction-ratios (dependent of grain size) and target product size. The feed size was limited to a maximum of 25 mm to ensure free flow of feed spout.

Alkaline granite: eHPCC-2 coarse product (left) and fine product (right)

MD & LR: From 2016-2020, we moved onto the semi-industrial scale testing with the eHPCC-2 (two times scaled up from eHPCC-1). This was designed for research and development (R&D) and tested on magnetite concentrate, alkaline granite, and hard underground quartz/gold ore. The throughput capabilities depended on the geo-metallurgical and geo-mechanical properties of feed material, such as particle size, strength, progeny (grain) size and particle size-reduction-ratios (subject to confined bed high pressure compression). Larger-scale machines are yet to be tested against traditional ‘Bond Theory’ norms.

The eHPCC, irrespective of the outcomes, should be evaluated on its ability to effectively liberate minerals of interest in a way that no other comminution device can do. The maximum feed size, f100, at the gold mine trials was limited to 50 mm to ensure free flow through the feed spout. R&D culminated in pilot-scale operational trials at the Akbakai gold mine (Kazakhstan), owned by JSC AK Altynalmas, in 2020, where SAG mill rejects of hard underground quartz/gold ore were processed. The mutual intent and purpose of the tests was to observe and define wear characteristics of the eHPCC grinding chamber liners (roll surfaces). These operational trials involved 80% of the feed size being less than 17 mm and a variety of targeted product sizes whereby 80% was less than 1 mm, 2 mm, 2.85 mm and 4.8 mm. The throughput ranged from 1-5 t/h based on the size.

IM: What throughputs and material characteristics will be set for the full-scale solution?

LR: There will be a select number of standard eHPCC sizes. Relative to the original eHPCC-1, the following scale-up factors are envisaged: -2, -3, -5, -8, and -13. These are geometrical linear scale-up factors; the actual volumetric capacity is a cube of this factor, with adjustments for centripetal acceleration. Currently -13 times seems to be the maximum feasible size of the present detailed design philosophy, but there are no foreseeable limitations in terms of feed materials with exception to moist clay. Clay was successfully processed after drying the feed in ambient temperatures during testing. Further testing of moist clays blended with other materials that can absorb the moisture as they comminute would be desirable.

IM: Other HPGRs can also be equipped with air classification technology to create dry comminution circuits. What is the difference between the type of attrition and air classification option you are offering with the eHPCC?

MD & LR: Two modes of comminution occur in the particle bed of eHPCC repetitively and simultaneously. First, confined bed pressure compression breakage occurs at a macro level that promotes shear/compression forces greater than the mineral grain boundaries. Second, Mohr-Coulomb Failure Criteria (shear/attrition) that completes the separation of micro fractures on subsequent cycles takes place.

The nip angle between the rotating components of eHPCC technology never exceed 5°. During the decompression and fluidisation portion of the cycle, the softer species – which are now much smaller – are swept out of the fluidised particle bed against centrifugal and gravitational forces by process air. The larger species, influenced by centripetal acceleration, concentrate at the outer diametric and lower limits of the conical rotating grinding chamber, continuing to work on each other during each subsequent compression phase.

HPGRs are limited to one single-pass comminution event, requiring downstream external classification and subsequent recycling/reprocessing of their oversize and/or flake product.

IM: How will it improve the mineral liberation and separation efficiency compared with other grinding solutions that combine both?

MD: eHPCC technology could compete with the Vertical Roller Mill and Horomill, however, eHPCC is likely to be more compact with high intensity breakage events contained within the all-inclusive system of breakage, classification and removal of products.

IM: When was it most recently tested and over what timeframe?

LR: The eHPCC-2 pilot plant was mobilised, setup and commissioned in March 2020, but its operation was suspended until June 2020 due to COVID-19 quarantine restrictions and a need to cater to abnormal amounts of ball fragments in the feed, the latter of which pushed the treatment of tramp metal to the extreme. The machine operated for the months of June and July using liners constructed of plasma transferred arc welded (PTAW) tungsten carbide (TC) overlay. During this period, a total of 795 t was processed at various targeted product sizes, with, overall, an average throughput of 3 t/h (nominally 265 operating hours) processed.

Side view of pilot system including feed hopper and weigh-scale feeder (right), feed conveyor (middle foreground), control and auxiliaries (middle background), eHPCC-2 (left foreground), dust bag-house (left background) and product conveyor and stockpile (not shown left background)
Front-end loader filling feed hopper with SAG mill rejects f80 18 mm

The PTAW-TC overlay was deemed unsustainable as it was consumed rapidly and demanded continuous rebuilding due to the high pressure intensive abrasive wear on the convex cone. The pilot plant operation was mostly suspended during the month of August while an alternative tungsten carbide studded liner, analogous to HPGR studded rolls, was manufactured for simulating a trial of this studded liner philosophy. The studded liner philosophy was operated in the eHPCC-2 in Kazakhstan for sufficiently long enough to ascertain the creation of the autogenous protective wear layer of rock between the studs, with the simulation trial deemed a success. The design philosophy shall be adapted on the commercial-grade eHPCC.

eHPCC-2 TungStud™ as-new (left) high-pressure-air-cleaned (middle) and brushed (right)

The pilot plant was demobilised from the Akbakai site laydown area on September 10, 2020, to release the area for construction of a non-related plant expansion. The operational experiences of the pilot plant at Akbakai provided valuable knowledge and experience pertaining to mechanical inertia dynamics and design for eliminating fatigue within eHPCC components.

IM: Aside from the test work on trommel oversize at the Kazakhstan gold mine, where else have you tested the technology?

LR: eHPCC has no other operational experiences so far. Investment and collaboration from the industry to progress the commercialisation of eHPCC is invited. The commercial-grade eHPCC-2.2 is designed and ready for manufacture.

IM: Is the technology more suited to projects where multiple streams can be produced (fines, coarse piles, etc)?

LR: eHPCC is configurable to meet the demands and liberality of a diverse spectrum of feed materials and the potential downstream extractive processes are complementary to eHPCC product streams. Therefore, it would be incorrect to categorise it as more suitable in any one niche; it is configurable, on a case-by-case basis, to meet the liberality of the specific progeny of the feed.

IM: What energy use benefits do you anticipate by creating a one-step comminution and classification process over the more conventional two-step process?

MD & LR: The energy saving benefits include:

  • Elimination of tumbling mill grinding media consumption;
  • Elimination of the liberal wastage of randomly directed attrition and/or impact events that indiscriminately reduce the size of any/all particles (gangue or precious mineral) with the conventional tumbling mill; and
  • Elimination of energy consumption of the materials handling systems between the various stages of comminution and classification, be it dry belt conveying, vibrating screens, classifiers, cyclone feed pumps, cyclones and their respective recirculating loads that can be upward of 300% of fresh feed.

IM: Do you anticipate more interest in this solution from certain regions? For instance, is it likely to appeal more to those locations that are suffering from water shortages (Australia, South America)?

MD & LR: We suspect the initial commercialisation growth market to be from base metals producers seeking to expand or retire existing aged/tired comminution classification capacity, followed by industry acknowledgement of the technology’s potential to shift the financial indicators of other potential undeveloped projects into more positive territory. This latter development could see the technology integrated into new projects.

In general, the technology will appeal to those companies looking for more efficient dry comminution processes. This is because it offers a pathway to rejection of gangue at larger particle sizes, early stream enrichment/depletion and minimal overgrinding that creates unnecessary silt, which, in turn, hinders or disrupts the integrity of downstream metallurgical extraction kinetics, and/or materials handling rheology, and/or tailings storage and management.

LR: There are a number of rhetorical questions the industry needs to be asking: why do we participate in the manufacture and consumption of grinding media considering the holistic end-to-end energy and mass balance of this (it’s crazy; really why?)? Why do we grind wet? What are the barriers preventing transition from philosophising over energy efficiency, sustainability etc and actually executing change? Who is up for a renaissance of bravely pioneering disruptive comminution and classification technology in the spirit of our pioneering forefathers?

The more these questions are asked, the more likely the industry will find the solutions it needs to achieve its future goals.

Dr Mike Daniel’s talk on eHPCC technology will be one of the presentations at the upcoming Comminution ’21 conference on April 19-22, 2021. For more information on the event, head to https://mei.eventsair.com/comminution-21/ International Mining is a media sponsor of the event

Kwatani breathes new life into scalping screens with rubber, polyurethane wear panels

As mines move towards using one large scalping screen between primary and secondary crushers – rather than a modular approach using multiple smaller screens – Kwatani says it has found ways to triple the panel life in these single mission-critical units.

According to Kenny Mayhew-Ridgers, Chief Operating Officer of Kwatani, any downtime in this single-line stream would require the mine to store several hours of production. While some mines schedule regular weekly production halts during which an exciter or worn screen panels can be replaced, many operations are not so lenient, he said.

“The message from these mines is clear: the longer the scalper can run between maintenance interventions, the better,” Mayhew-Ridgers said. “Our research and development efforts, together with extensive testing in the field, have allowed us to extend the life of screen panels from eight weeks to over six months.”

While smaller screens use wire mesh screening media, Kwatani has evolved larger screens that use rubber or polyurethane screen panels. Although these panels present less open area, they deliver important advantages.

“Key to the success of our design is our integrated approach – which matches the panel design with that of the scalping screen itself,” Mayhew-Ridgers said. “This allows us to achieve a balance between screening area, aperture layout and screen panel life – a result based on a sound understanding of screen dynamics.”

Whereas wire mesh undergoes rapid wear from abrasive materials, the rubber or polyurethane panels are more wear resistant and deliver longer life, according to the company. The latter require gentler declines for effective stratification, but a key factor is the stiffness of the screen bed.

“The stiffness of the supporting structure must go hand-in-hand with the screen panel design to achieve our required results,” Mayhew-Ridgers said.

Polyurethane panels, while strong and lightweight, have screening apertures that tend to be too stiff for heavy-duty scalping applications. This leads to blinding. Rubber overcomes this problem, however, and also delivers improved wear life.

Kwatani has also developed a panel replacement system – with a fastening mechanism on the underframe – that improves safety and saves time, it says.

Multotec expands presence, product line in Asia with new China facility

Bucking global economic trends, mineral processing equipment specialist Multotec says it has opened a new, larger manufacturing facility in China to meet growing demand.

The 3,200 sq.m factory, based in the port city of Tianjin about 100 km southeast of Beijing, is more than double the size of the previous premises, according to Ken Tuckey, Director of Multotec Screening Systems (Tianjin) Ltd. The facility focuses on producing the company’s polyurethane screen panels, including specialised panels for fines dewatering and classification.

“The expanded facility was necessary to increase production capacity, as sales have grown rapidly since Multotec became directly involved in this business in 2017,” Tuckey says. “The investment in China is also an important part of Multotec’s global strategy to get manufacturing operations closer to end-customers wherever possible.”

Multotec had taken over the business from Tema Screening Systems in 2017, which had started up in 2006 and focused mainly on the aggregate and quarry sectors. Multotec’s sales have expanded, mainly into China’s mining industry, but the factory’s increased capacity is also allowing it to produce for other parts of the world.

Running the operation on the ground since 2018 is General Manager, He Pu, a local expert with 20 years’ experience in mineral processing.

“The new factory has taken careful planning over the past year, and had to obtain a range of strict government approvals,” he says. “Even though the COVID-19 pandemic did present some challenges to our schedule, we were still able to move into the new plant in May this year.”

Multotec Screening Systems (Tianjin) Ltd General Manager, He Pu

He Pu highlighted the importance of innovation as a key ingredient for any company looking to break into the Chinese market. This has been vital to the early success of Multotec, which has a range of product advances operating in Africa and other markets. Recent improvements in China’s manufacturing sector has also underpinned the success of the local business, according to He Pu.

“The focus in the mining sector in China has shifted towards increased efficiencies and improved quality,” He Pu says. “Multotec is now well positioned to take advantage of this, especially with the innovative screen panel technology that it can offer the market. This is underpinned by our quality manufacturing processes as well as our excellent local supply chain.”

Multotec’s Chinese company is ISO-accredited with in-house quality control expertise, he says. The number of local staff members has increased and includes a strong sales team with good links to the mining sector. The company also has distributors and agents across China, bringing services and products closer to the mines.

With the new polyurethane moulding machines, the upgraded plant is running double shifts to optimise production levels. The latest technology equipment – combined with Multotec’s experience and ongoing training in factory – ensures a consistently world-class quality of polyurethane panels, it says. Accelerated in-house manufacture is also speeding up the delivery times to local customers.

“The opening of this plant marks the beginning of a new era for Multotec,” He Pu says. “We have ascended to a new level, not only by enlarging the area of the workshop but by adding new equipment.”

Multotec Manufacturing tools up Spartan facility on screening demand

Continued growth in demand for Multotec Manufacturing’s screen panels has led the company to expand and upgrade the dedicated toolroom at its manufacturing facilities in Spartan, Gauteng, in South Africa.

According to Ian Chapman, Engineering Manager at Multotec Manufacturing, these technology investments have accelerated the tool manufacturing process and delivered better tool finishes. This translates into enhanced product quality, greater speed to market and more cost effectiveness for the end customer.

The tools required are mainly for rubber and polyurethane injection moulding, rubber compression moulding and cast polyurethane products. The wide variety of tooling produced includes ‘mother moulds’ and components such as frame bars, cores and inserts, Multotec says.

“By 2015, our success in growing markets had placed considerable demand on our toolroom,” Chapman said. “This led to the replacement of two CNC milling machines and adding two new wire electric discharge machines (EDM) in recent years.”

The new milling machines use specialised Heidenhain controllers, which strengthen Multotec’s jobbing capability for customised tooling, it says. Based on the specification from the sales team, drawings are created for the company’s tool and dye makers. They, in turn, convert these drawings using computer-aided manufacturing software to create the tool path for the CNC machine.

“Our experts’ familiarity with the Heidenhain language speeds up our work and avoids human error,” he noted.

Wire EDM machines are another key resource in the toolroom, using electrical erosion technology to cut relatively long tool pieces accurately and finely.

“Unlike a milling machine – where there is contact between a tool and a work piece – on the EDM, there is no engagement with the wire and hence no forces to accommodate and few residual stresses,” Chapman said. “This allows us to cut pre-hardened steel without distorting its shape, creating very fine tolerances in our finished tooling.”

To augment the existing two EDMs, a third was acquired in 2018, with even larger wire spools than the previous models.

This allows longer production runs of up to 90 hours, improving cutting strategies and productivity, Multotec says. So successful was this investment that a fourth wire EDM was purchased and installed in 2019.

Venture Minerals takes the dry screening route at Riley iron ore project

Venture Minerals Ltd has decided to start operations at the Riley iron ore project, in Tasmania, Australia, using dry screening as a way of realising early cash flow.

The company’s Board of Directors has delivered a positive final investment decision (FID) for the mine prompting preparations for mining and dry screening operations to commence immediately, the company said. This could see mining occur in the next week.

“The dry screening operations of the Riley mine is part of the ramp-up phase of the project with the full production rate to occur upon successful commissioning of the wet processing plant (which is subject to financing),” Venture Minerals said.

It is another key milestone on the company’s push towards its first shipment of Riley ore.

The company recently signed a Port Access Agreement with TasPorts and signed the Road Access Agreement with Hydro Tasmania, securing the pathway for Riley output from mine gate to shipping.

The Riley mining team has commenced preparations for low cost mining and dry screening activities given the zero strip ratio (iron ore at surface) characteristics of the Riley DSO deposit, it said. “The contracting of a dry screening plant for processing the top layer of the Riley deposit affords the company the opportunity to accelerate production and capture the current iron ore prices before the wet screening plant has been built and commissioned, and also reduce the capital cost requirements,” it added.

Venture is now finalising discussions on financing options including a debt facility to fund capital to complete construction of the wet screening plant at Riley. It is also focused on concluding the road haulage tender process as well as achieving more efficient ore handling logistics, including finalising negotiations on gaining access to other on-wharf storage.

The current Riley mine economics are well above the August 2019 feasibility numbers, which were based on a $90/t 62% Fe price, according to Venture. This is due primarily to higher iron ore prices (>$120/t 62% Fe price) and lower fuel prices, and further supported by a strong iron ore market outlook, it said.

At the $90/tonne 62% Fe price, the August 2019 feasibility study returned a post-tax cash surplus of A$31 million ($22 million) over the two-year production life of the mine.