Tag Archives: MULTOTEC GROUP

MULTOTEC BRINGS VALUE OF SPIRALS TO MORE MINERALS

Experience in the field and in its test laboratory has allowed Multotec Process Equipment to prove the economic impact of applying spiral concentration technology to high value minerals used in cellular phones and electric cars.

“A number of customers mining minerals such as copper, lithium, tin and tantalite are already benefiting from using spirals to upgrade the value of their concentrate, either replacing their conventional processing technique or augmenting it,” says Graeme Smith, application engineer at Multotec Process Equipment.

Smith highlights the likely growth in the demand for these kinds of minerals, in line with the mass production of various electronic devices and the imminent prospects for electric car manufacture. Lithium is important to battery production, tantalite is used in resistors and capacitors, and copper and tin are key contributors to electroconductivity.

He says that spirals are proving their worth in helping producers become more efficient, potentially raising output levels while holding down the cost involved in downstream processing. This upgrading of the value of mined material also contributes to lower transportation costs and higher revenues earned.

Recent successes have been enjoyed by copper mines in the Democratic Republic of Congo, Zambia and Zimbabwe, where Multotec’s spirals are upgrading product from 1-3% run-of-mine to 20%-plus copper concentrate.

“These mines can achieve an upgraded product which can be sold as copper concentrate,” he says. “Spirals can also be applied as a bulk reduction strategy to achieve a higher-grade material for more efficient leaching.”

Working with tin producers in countries including Morocco, the DRC and Spain, Multotec spirals have been able to raise initial head grades of 1-3% to levels of over 50% tin in concentrate. Treating tantalite from a tailings operation in the DRC, spiral technology has performed massive bulk reduction and upgrading, while shaking tables clean the final product.

“This allows existing downstream processes to become more productive, and to ramp up production by maximising recoveries and reducing rand per tonne costs,” he says.

In test work in its extensive Spartan manufacturing and research facility near Johannesburg, Multotec has also succeeded in separating elements of lithium using spiral technology, aiming for 80% concentration of the element petalite.

Smith emphasises the value of the company’s experience in modular plants, allowing spiral applications to be conveniently containerised for transport to and commissioning at remote sites.

“Our mobile plants – capable of treating 20 tonnes per hour – can be moved in two standard containers – one of 12 metres in length and the other of 6 metres,” he says.

Engineered for use in the most aggressive duties, Warman® Mill Circuit pumps easily manage large size particles in highly abrasive slurries. These pumps are designed for the most severe slurry applications such as ball and SAG mill cyclone feed as well as water-flush crushing in mineral processing plants. Weir Minerals Africa is showcasing its flagship mill circuit pump – the Warman® MCR®450 at Electra Mining Africa 2018. Marnus Koorts, Product Manager – slurry pumps at Weir Minerals Africa, says “customers will be able to see this massive pump with its 1.5 metre diameter. Like all pumps in the Warman® MCR® range, this 13 ton slurry handling machine is designed to increase productivity and decrease downtime, compared to older generation and other pumps in the industry”. Koorts says that the Warman® Mill Circuit pumps are based on 80 years of fundamental and applied research, backed by wear performance field trials. “Mill circuit applications are among the toughest in a minerals processing plant, and the Warman® MCR® pumps incorporate the latest in hypereutectic alloy and elastomer technology,” he says. “This significantly extends the wear life of the pump in highly abrasive and corrosive slurries, reducing operational costs.” The high resilience rubber wear liner enables the handling of coarse particles and ball scats with ease, while its lightweight design relative to other pumps in its category facilitates safer handling. It is also a lower cost than traditional heavy metal liners. Importantly, different material combinations are available to ensure that the customer gets a fit-for-application pump capable of providing reliable performance cost effectively, tailored to their site conditions. The Warman® MCR® pump has a large diameter, low speed, high efficiency impeller. Koorts explains that this can be manufactured from a range of abrasion resistant alloys allowing the most appropriate material to be selected for the customer application. This will increase wear life and reduce operating costs when compared to other pumps in its category. Reduced recirculation is achieved by the deep expelling vanes on the front of the high chrome alloy impellers. Expelling vane tip turbulence is minimised by the patented shroud feature that traps tip vortices and prevents localised scouring on the throatbush face. This, again, extends wear life and reduces maintenance. The split outer casing on the Warman® MCR® pump provides structural integrity and high operating pressure capability, ease of maintenance and safety. This feature also allows internal liners to be fully worn before replacement. Warman® throatbushes feature pre-swirl vanes which offer optimum reliability and wear life. There is a patent pending on this innovative throatbush design which was developed to improve impeller eye wear life and reduce the wear caused by recirculation at the impeller-throatbush interface. This has been accomplished by a series of guide vanes in the pump inlet which induce a rotational velocity in the slurry. An adjustable stuffing box allows for the centering of the stuffing box and lantern restrictor to the shaft sleeve. This increases packing life and decreases gland seal water consumption. Another new design feature is the single-point gland adjustment which facilitates safe packing adjustment outside of the stuffing box guard while the pump is operating. “Our Warman® Mill Circuit pumps are engineered to offer the most cost effective solution across a range of applications, and with installations on many leading mine sites across the globe it is proven to be the mill circuit pump of choice for the hard rock mining industry,” Koorts concludes.

Process control slurry samplers from Multotec Process Equipment are installed at the Gamsberg Zinc project near Aggeneys in the Northern Cape, and will allow reliable real-time process results to be generated by the metallurgical plant.

The Gamsberg Zinc project is currently being constructed by ELB Engineering Services, and Multotec Process Equipment’s process engineer Modisaotsile Nyokong says the equipment supplied includes gravity (shark fin type) and pressurised (pressure pipe) samplers. Significantly, each sampler is custom-designed to suit the flow requirements of each analyser.

The samplers will provide a continuous sample to the online particle size analyser (PSI) and X-ray fluorescence (XRF) analysers. PSI analysers require 100 litres per minute, while XRF analysers require 100 to 300 litres per minute.

According to Nyokong, the unique single-stage vezin sampler and double-stage ‘Two In One’ metallurgical accounting samplers will collect representative final composite sample sizes of less than 20 litres per shift from streams ranging from 80 NB to 700 NB inlet-correct.

Nyokong emphasises the importance of metallurgical accounting in ensuring that AMIRA standards and best practice are being applied in the plant’s sampling applications. “The metallurgical plant needs to ensure that samples collected from metallurgical accounting samplers are representative of the whole shift operation and are used for accurate metal accounting balances,” he says.

The benefit of the total sampling solution supplied by Multotec is to have both a process control sampler and a metallurgical accounting sampler in the same stream. Process control samplers are specimen takers, providing samples that are used for real time process control purposes.

The ‘Two in One’ metallurgical accounting sampler comprises two separate sample units in one, with a primary and a secondary sampler unit assembled into a compact unit allowing for a net plug and play solution. The design allows easy access, as the primary cutter can be inspected through a bolted hatch on the top and side of the housing. The secondary cutters can also be inspected with ease, through an inspection cover on the top of the secondary housing.

An advantage is that the sampler cutter of the primary unit cuts the full stream of the slurry at constant speed with sufficient volume to collect the sample, minimising sampling extraction and delimitation errors. The sampled slurry then reports to the secondary vezin sampler where the four cutters cut the full stream of the primary sample.

MULTOTEC IS FIRST UP FOR SABS LOCAL CONTENT VERIFICATION

Leading South African mineral processing equipment manufacturer Multotec has taken the pioneering step of having its local content verified by the South African Bureau of Standards (SABS), in line with the requirements of the draft Broad-Based Socio-Economic Empowerment Charter for the Mining and Mineral Industry, 2018.

At the end of the verification assessment in July, Multotec Group chief operating officer Jannie de Jonge commended the work of the technical teams from the SABS and Multotec, who had pursued the creation of this “prototype” process as a starting point for promoting local content in mining goods. Whereas mines’ procurement requirements have in the past been linked mainly to the B-BBEE ownership of suppliers, the new draft Mining Charter proposes a more direct measurement of local manufacture embodied in the products themselves.

“Following the publication of the National Development Plan, the Department of Trade and Industry (DTI) and the Department of Mineral Resources (DMR) have put more emphasis on the promotion of the South African manufacturing industry,” says De Jonge. These proposals were incorporated by the Department of Mineral Resources in the 2018draft of the Mining Charter.

The amendments propose that 70% of all goods procured by mines are required to be “South African manufactured goods”, which are in turn defined as “goods with a minimum 60% of the value added during the assembly or manufacturing of the product is created in the Republic.” It is also proposed that this plan is phased in over five years, giving suppliers time to align themselves and become compliant if they wish to continue supplying mines.

The Multotec Group decided to become more pro-active in this process after a DTI-SABS presentation early this year to the South African Mineral Process Equipment Council (SAMPEC) – part of the South African Capital Equipment Export Council (SACEEC) – where the benefits of the local content requirement were outlined.

“South Africa’s manufacturing sector has shrunk considerably in recent years, and this localisation drive was part of efforts to support and grow local manufacturing and job creation,” de Jonge says. “The department was also able to outline generally how it thought the process would unfold.”

The Multotec Group decided that action would be better than words, so showed its support for the spirit of these local manufacturing requirements by investing in having its products verified. While there were reasonable standards in place against which such verification could be initiated, there were aspects of the requirements and processes that were still not clearly defined.

“Both Multotec and the SABS agreed that we needed to create a prototype of how this verification process could work, and this would need practical engagement,” he says. “We committed to go through the process to see what was involved and what we could learn and provide useful feedback to the SABS and the DTI. The learnings gained from the process and the experience gained by all involved are priceless.”

The Multotec Group has invested millions of Rands over the four decades since its establishment in 1978 in state-of-the-art manufacturing plant and equipment and is actively engaged in training initiatives to ensure that the skills are developed and maintained to put these investments to best use.

“We certainly appreciate seeing this recognition from government for our own progress to date,” he says. “Despite the uncertainty of the outcome, and the rules and definitions still being under review and open for comments, we are committed to the process and supporting the initiative by the DTI and DMR to prioritise local content.”

However, de Jonge emphasises that this process will need to be embraced with a significant responsibility and accountability to the industry by local mining suppliers.

“The key focus among all stakeholders – including local manufacturers – must be the sustainability and success of our mining sector, so we need to ensure that we can supply world class products at competitive prices to the mining industry,” he says.

The concerns expressed by the Minerals Council South Africa – previously the Chamber of Mines – that some of the elements of the Draft Charter do not promote competitiveness, must be taken seriously.

“The mining industry is under severe cost pressure and is not in a position to absorb higher prices from suppliers,” says de Jonge. “Local manufacturers are therefore obliged to continue becoming more competitive themselves, and to improve productivity as a strategic priority going forward. We must all understand and accept that for mining in South Africa to be competitive, it must have an efficient and competitive supply chain.”

He also firmly believes that the promotion of local manufacture can gain momentum and can itself attract substantial foreign direct investment to enable its expansion and improvement.

3D PRINTING BOOSTS MULTOTEC’S PRODUCT INNOVATION

Three-dimensional printing – otherwise known as ‘additive manufacturing’ – gives minerals processing equipment solutions leader Multotec a new string to its bow, enabling rapid and effective technology innovation for optimal customer benefit.

While computer-aided design (CAD) software has, for many years, allowed manufacturers to test new or improved products by simulating their behaviour on-screen, there comes a point at which it is quicker and easier to build a prototype of the product to elicit user feedback on the design and its functionality.

Multotec invested in 3D printing technology to improve its efficiency in creating and testing these prototypes, thereby improving the speed to market of its newly developed products.
There are already several examples of how successfully the group has done this, both here in South Africa and for its customers abroad.

In one case, a Multotec Canada customer had a specific requirement for its unique spiral application and wanted the concentrate splitter to cut the flow in a specific location. To do this, a spiral flow diverter was designed that would attach to the spiral’s working surface in front of the product box.
A prototype unit was 3D-printed in-house, and trial-tested and refined in South Africa.

To minimise the lead time, a digital model of the prototype was sent to Multotec Canada, who was able to have the item 3D-printed in Canada within 48 hours – showing how rapid prototyping could create a customer-specific solution in just a short timeframe, almost anywhere in the world.

Similar success was achieved in developing a quick-release spigot holder and coupling for a cyclone, following feedback received from customers. The customers had noted that the process of changing out the spigots was taking a considerable amount of time and effort, as all the bolts to the spigot holder had to be removed to replace the spigot.

The solution pursued allowed the spigot holder to be screwed apart rather than unbolted; the prototype was 3D-printed in-house by Multotec and presented to the cyclones division – giving experts the ability to see and feel the product before any investment in tooling was made.

The screw spigot holder and coupling are now being injection-moulded, which has further reduced the component’s mass, as well as the cost and time it takes to manufacture.

In another example, a Multotec customer requested a solution to completely block material flow from the sliding splitters to the concentrate gully of their spirals.
After a solution was designed, 3D-printed and successfully tested, a silicon rubber mould could be produced from the 3D-printed component. This mould was then used for casting polyurethane and producing a final product which met the customer’s needs, speeding up the time to market and cost of production.

Multotec’s 3D printing capabilities have also allowed the company to study the concentrate flow in a spiral, by using a 3D-printed spiral off-take prototype that fits to the profile and slope of the spiral. Research is underway to ascertain what the different grades are that exist within the concentrate section of the flow, so that equipment and processes can be continually optimised for customers – thereby enhancing plant efficiency and the overall cost per ton.

MORE VALUE FROM MULTOTEC THROUGH LOCAL INNOVATION

Leveraging digital technologies in its range of mineral processing equipment will again allow Multotec to display new product developments at Electra Mining Africa that optimise recoveries and reduce cost of ownership for mineral processing plants.

“Technologies such as smart panels and 360˚ virtual reality video can make a valuable contribution to pioneer greater efficiencies, by helping predict and schedule equipment maintenance,” says Multotec group CEO Thomas Holtz. “This assists planning at plant level and means less unexpected downtime as a result of equipment failure; every step we can take on this innovation journey gets us closer to a more sustainable mining sector.”

Inspired by the philosophy ‘think global and act local’, Multotec can draw from its experience around the world to feed into its ongoing research and development programme that continuously improves its wide range of offerings from screen media and wear solutions, to solid-liquid separation and mill linings.

“Retaining the technological edge is one important way that South Africa can sustain and grow its local manufacturing capability,” says Holtz. “As a Level 4 B-BBEE company with a 26% black shareholding, we are fully supportive of the emphasis that the Mining Charter places on local content, and especially about the plans for formal verification of local content.”

According to the Manufacturing Circle – in which Multotec is an active member – the country’s percentage of local manufacture as a percentage of GDP has dropped from 24% in 1994 to just 12% today, with the difference going to imported products.

“If we want to drive a local manufacturing agenda and create jobs in the manufacturing sector, we must have an effective way of verifying local content in manufacturing activity,” says Holtz.

He says the company is already participating in the engagement process with the South African Bureau of Standards about how such a verification system could be designed and implemented, as an auditing authority, such as the SABS, would be required to make the system work.

“Equipped with the right framework and incentives, the mining sector could improve its already substantial contribution to stimulating local manufacture and technology development,” he says.

With 45 years of specialised experience in its field, Multotec also provides skills development through its in-house training facility, constantly raising the expertise in its extensive network of branches around South Africa and the rest of Africa.
Its innovation even goes beyond product development, to evolving new service models – such as its ‘cents per tonne’ model in which customers pay a monthly invoice based on process tonnages to maintain their process equipment.

Multotec can be found in Hall 6A22 and outside OSP20.