Tag Archives: water management

Integrated Pump Rental up for southern Africa pit dewatering challenge

Environmental, Mining equipment, Mining maintenance, Mining services, Water management, , , , , , ,

As open-pit mines continue to get deeper with the maturing of operations, pit dewatering is becoming more vital, with ground water not only posing an operational challenge but also a potential safety hazard if not attended to appropriately.

In this scenario, it is not a case of one pump fits all dewatering application requirements and it is advisable to deal with a reputable pump supplier to ensure the most appropriate solution is selected, according to Integrated Pump Rental.

Lee Vine, Managing Director of the company, said each application requires a site-specific solution.

“There are numerous options available in terms of the actual pump and ancillary equipment, as well as the choice between rental and outright purchase,” he says. “The differentiator that our team offers is the ability to assess a given application and provide a pit dewatering solution with the correctly sized pump.”

There are several factors that can have an impact on the pump selection, and this includes available power sources; the volume of water to be pumped; and the condition of the dirty water, including size and type of particles in the water.

“What adds complexity to pit dewatering applications is that, in many cases, the need to dewater a pit can be urgent and customers are forced into making an incorrect pump selection or tying themselves into a contract that does not work in the longer term,” Vine says.

While the decision to hire or purchase is an important commercial one, so is the actual selection of the pump itself, he said.

“If the pump is not sized correctly for the dewatering application at hand, it will not perform as required. This, in turn, leads to further operational challenges including production losses and sometimes even the need to change the pump resulting in further costs.”

One of the most important factors to consider is the available energy source. If there is no access to power, options such as diesel-driven or pumps fitted with hydraulic power packs must be explored.

When selecting the pump, it is also important to understand the specifics of the water ingress conditions and whether this is a long-term issue or simply a short-term challenge. This scenario will dictate the pump size, its rated output and what ancillary equipment is required.

As an example, Vine points to a recent dewatering application on a mine in Lesotho where a constant flow of water into the mine’s pit area demanded that water be urgently and reliably pumped out.

Over time the pit depth had increased, and the groundwater level had been exacerbated by the winter snowfall in the highlands of the country. As a result, the total dynamic head for the duties of the installed dewatering pump installation changes and the mine required an urgent solution.

Initially a Sykes XH150 diesel driven pump was deployed, pumping at 120 l/s at 150 m head. Subsequent to this, a second Sykes pump was dispatched to site to ensure the level of water remained at an acceptable level.

With the two Sykes pumps on site, the mine was assured of enough pumping capacity, should the groundwater level increase.

The call from this mine came in and, within 24 hours, the first Sykes pump was installed on site, according to Vine.

“This is very significant, when one considers that the mine is situation some 500 km from the company’s front door and across the border into a neighbouring country.”

Integrated Pump Rental not only rents out Sykes diesel driven pump sets, the company is also responsible for the sale of these dewatering pumps across southern Africa. The robust units are designed for reliable performance, under even the harshest operating conditions, according to the company.

FLSmidth reflects on KREBS slurry pump dominance in Africa

Equipment maintenance, Mineral processing, Mining equipment, Mining services, Water management, , , , , , ,

KREBS® slurry pumps have become leaders in mill discharge applications in Africa, with the latest Ultimate Mill Discharge (UMD) pump leading the way in these heavy-duty applications, according to FLSmidth.

Andre Hall, FLSmidth Regional Product Line Manager — Pumps, Cyclones and Valves, said: “West African gold mines and the copper operations of Zambia and Democratic Republic of Congo are among the areas where these robust pumps dominate.

“Their popularity,” he says, “is based on their long wear life and high efficiency.”

Ghana is a particular success story for UMD pumps, according to Hall, with nearly all gold mines there using the equipment manufacturer’s pumps to discharge slurry from their mills, he added.

“The KREBS UMD is popular at these mines largely because it lowers the total cost of ownership due to the millMax™ proprietary design that eliminates inefficient recirculation and grinding of slurry within the pump,” FLSmidth said.

“Prior to the millMAX wear ring design, slurry pumps experienced two major problems: mechanical grinding of solids between the suction liner and impeller, and flow recirculating back to the impeller eye on the suction side. Both of these problems decrease pump life and increase power consumption.”

The wear ring stops recirculation by closing the suction-side gap, while still allowing for a large clearance between the impeller and the suction liner, according to FLSmidth. This eliminates the grinding of solids. Adjusting the wear ring while the pump is running, meanwhile, restores performance and provides longer wear life and higher continuous efficiency, in all, lowering the total cost of ownership.

Hall says: “The UMD’s casing symmetry also means less inventory for customers. Mines that have pumps rotating in both left-hand and right-hand orientations must stock different casings, liners and impellers, adding to the operational costs.”

The advantage of the UMD is that it uses the same casing, suction liner, wear ring and back liner, which reduces overall net working capital.

The KREBS gravelMAX™ pumps continue to do well in the Mpumalanga coal sector of South Africa, according to FLSmith, where 14 of these pumps recently replaced competitor units on a single site.

Commonly applied in a cyclone feed application within the dense medium separation (DMS) circuit, the pump’s wider passage allows pumping of larger solids.

“We are also active in iron ore in South Africa with pumps in the DMS circuit,” Hall says. “A Lesotho diamond mine also operates KREBS pumps, which have demonstrated a four-fold increase in wear life compared to a competitor’s previous units.”

In sump pumps, FLSmidth has the vMAX™ range, which features a recessed impeller design allowing the pumps to run dry.

The company explains:“When the sump has been emptied of slurry, the recessed impeller allows the slurry to return safely down the discharge pipe without contacting the impeller, ensuring that it does not vibrate when dry.”

Another recent innovation in the KREBS slurryMAX range of pumps is being introduced to the Africa market after an enthusiastic response in the US and Australia, FLSmidth said. With multiple liner and impeller material options, the slurryMAX split-case pump can handle the majority of applications for any plant across multiple industries.

Vesconite water flingers seal the deal for mining pump manufacturer

Equipment maintenance, Mining consumables, Water management, ,

Vesconite Bearings has come to the rescue of a southern Africa pump manufacturer looking to improve the performance of horizontal centrifugal pumps operating in mines across the continent.

The company has now received its order for Vesconite low-swell hard-wearing water-flinger polymer bearings for four of its pump sizes.

Vesconite Bearings said the manufacturer found its horizontal centrifugal pumps, as a result of high pressure, had a problem of water escaping from the gland packing – the material that should form a watertight seal around the shaft.

This resulted in dirty water being sprayed on to the non-drive-end bearing assembly and, in turn, seizure, failure, and a high maintenance and down-time cost to replace the bearing assembly.

“The manufacturer designed a water flinger (deflector) solution that would attach to the release collar on the shaft,”  Vesconite Bearings Technical Sales Consultant, Phillip de Villiers, said.

“This would mean that excess water from the gland packing would be deflected with the rotation of the shaft.”

However, the initial solution employed a phenolic laminated material, which was found to absorb water and delaminate.

To eliminate these problems, the company called on de Villiers, who suggested Vesconite as an alternative material that would not swell or delaminate and had the added advantage of being suitable in dirty environments because of its excellent wear-resistant properties.

“Samples were produced and tested and, proving successful, the manufacturer ordered water flingers of various designs for its different pump sizes,” de Villiers said. “The whole process from sample production to first order took three months.”

The pump manufacturer intends to use Vesconite water flingers in all of its pumps, which are used in a variety of applications, according to Vesconite Bearings.

It is active in a multitude of African countries, including South Africa, Zimbabwe and the DRC, in which some of the first Vesconite water flingers will be installed in a dewatering pump in a mine, Vesconite Bearings says.

Kalium Lakes draws a liner under Beyondie sulphate of potash ponds

Energy minerals, Environmental, Mineral project development, Mining consumables, Mining project news, Mining services, Water management, , , , , , , ,

Jaylon Environmental Systems is to supply and install the evaporation pond liner at Kalium Lakes’ Beyondie sulphate of potash project (BSOPP), in Western Australia, as part of a contract agreed between the two parties.

The contract includes the supply, management of delivery and installation of 1 mm HDPE liner covering a total evaporation area of approximately 400 ha for the Stage 1 BSOPP 90,000 t/y sulphate of potash (SOP) facility.

The BSOPP project aims to commence production at 82,000 t/y of SOP in 2020, before ramping up to 164,000 t/y of SOP for domestic and international sale. An initial mine life of between 30-50 years is anticipated for a project designed to be a low cost, long life and high margin producer, Kalium Lakes said.

Earlier this month, Kalium Lakes secured gas supply and transport for Beyondie SOP project following deals with APA Group and Shell Energy Australia.

In 2017, Jaylon successfully completed the supply and installation of the liner for the BSOPP’s 10 ha pilot scale ponds, according to Kalium Lakes. “Jaylon has now submitted the most competitive and compliant offer for the full project works, resulting in this A$15 million ($10.3 million) major contract award,” the company said.

The scope under this contract has already commenced, with an initial order of A$1 million worth of liner placed in May 2019 as part of early works and first deliveries to site already completed. The balance of the contract scope will commence following a final investment decision (FID) by Kalium Lakes, due shortly.

Kalium Lakes Chief Development Officer, Rudolph van Niekerk, said: “The use of Jaylon during the pilot scale trials continued to validate Kalium Lakes’ de-risking strategy, where we work collaboratively to develop bespoke, low cost and fit for purpose solutions for the BSOPP.

“The use of an evaporation pond liner has been a much-debated topic. For Kalium Lakes, the cost of the supply and installation of the liner represents less than 7% of the project’s total capital cost but results in an increased SOP process recovery of more than 15%.

“Our lined pond design provides a pond system constructed on trafficable, off lake surfaces, allowing for harvesting by heavy machinery months, if not years, ahead of the alternatives.

“With lined ponds there is virtually no leakage of the high value concentrated brines, delivering excellent recovery rates, a smaller pond area, less brine pumping, low operating costs and an extended mine life. It simply is a ‘no brainer’,” he said.

Weir Minerals’s Essack on end-to-end tailings and pipeline solutions

Bulk handling, Comminution of minerals, Environmental, Mineral processing, Mining equipment, Mining services, Sustainable mining, Water management, , , , , , ,

As mining companies’ tailings facilities continue to be scrutinised by regulators and non-governmental organisations, Weir Minerals Africa Process Manager, Hoosen Essack, has talked up the need for tailored tailings solutions for the future.

Combined with the stringent accountability that mine operators have to local communities, tailings management is now a significant consideration, with processing requirements and technology changing rapidly. Traditionally involved in the pumping of tailings, at Weir Minerals we have extended our expertise into this area to encompass the entire tailings process. From dewatering to transport, disposal, and the conversion of tailings into a resource, we can provide customers with an end-to-end tailings and pipeline solution.

This holistic, solutions-based approach to tailings management strengthens our relationship with customers and adds value to their operation beyond pumping. In light of water conservation, operational sustainability and safe deposition of tailings, it’s important that we invest in this area to help solve crucial issues within the mining sector.

Our extension into the tailings processing field means we are now involved in the production of the material, as opposed to simply transporting it. Through extensive consultation, site visits and audits, our team ascertains the customer’s objectives and recommends a complete, optimal solution to meet their needs, which can include dewatering equipment, piping, pumps, valves and instrumentation.

This seamless approach is a departure from the traditional industry practice of sourcing components from multiple suppliers, which are challenging to integrate. Our extensive research and development capabilities means we can provide a wide spectrum of tailings management options not limited by a particular type of technology or equipment.

This involves assessing the variations in capital and operating expenditure along with the overall and long-term benefits of each, providing a truly customised solution. Prior to implementation, rigorous testing and trials are conducted to assess viability and performance ahead of final selection, detailed design and engineering, delivery and commissioning. Another key benefit to customers is the ability to transform tailings into products, which can safely be used by the mine, such as road construction material. This involves dewatering of tailings, in which we have extensive expertise.

Dewatering involves removing liquid from waste slurry so that the remaining solids can be deposited in a tailings storage facility or returned to the site from which it was mined as backfill. There are several dewatering methods to render waste slurry to differing degrees of dryness, ready for transport from the plant to the deposition site. Any liquid recovered through dewatering is returned for reuse in the process.

We can provide a variety of processing systems inclusive of equipment and infrastructure to achieve the final tailings product that is required by the customer, from thickening to create a paste, or applying a filter to produce a product which can be dry deposited. As tailings management evolves, the industry is moving towards the latter for increased safety and stability, and in the process maximising water recovery.

As mine operators become more vigilant in managing their tailings, new processing technology is continually developed, including at the Weir Technical Centre in Australia. Innovative, uniquely tailored solutions incorporating high performance equipment and a global service footprint means we are leading the industry in making tailings more sustainable. Ideally, this will lead to a future where tailings related hazards are a thing of the past.

Metso commits to a filtered tailings future

Bulk handling, Comminution of minerals, Environmental, Mineral processing, Mining equipment, Mining industry recognition, Mining services, Sustainable mining, Water management, , , , , , , , , , , , ,

Metso might have just launched a new tailings management concept, but the management of tailings and dewatering solutions are nothing new for the mineral processing company.

Helsinki-headquartered Metso developed its first VPA filter for mining in the 1980s – the maiden unit being delivered to the Greens Creek mine in Alaska (now owned by Hecla Mining) – and has since dispatched hundreds of units to mines across the globe.

In addition, Metso has a long history of designing and manufacturing tube presses and other complementary dewatering solutions; its current membrane-type filter press offers pressures up to 100 bar for particularly difficult dewatering applications, such as china clay, while its inclined plate settler (IPS) and dewatering spirals offer separation and thickening options for miners.

The VPX™ filter is the launch product that comes with this new tailings management concept, but there is much more to this focus than a lone invention.

As Niclas Hällevall, VP, Process Equipment for Metso, told IM: “It is no longer a matter of just finding the most technically-suitable equipment or solutions to do the job. It is about how to transform mining into a sustainable and long-term development.”

Metso is intent on “challenging the conventional” in this regard. This includes looking at its own approach to designing mineral processing equipment – ensuring all products use, recycle and recover water in a responsible manner – as well as the industry’s way of thinking. Instead of pursuing short-term fixes, such as implementing tailings monitoring solutions using sensors, the company thinks miners should prepare for a future where wet tailings dams are eradicated from mine sites. Dry stacking – or filtering – tailings is the end goal Metso is pursuing.

This unconventional mindset is also apparent in the design of Metso’s VPX filter. Instead of equipping the machine for high throughputs alone, Metso has built the filter to manage varied input materials and to offer pressures up to 25 bars (and perhaps even higher pressures).

Metso has eliminated the use of hydraulics on this new filter, instead using electromechanical screws to achieve the high-pressure closing that turns wet material into dried cakes with as low as 7% moisture content in some applications. This electromechanical switch could cut operating costs due to a reduction in maintenance requirements, according to the company. The modular design, meanwhile, allows the filter to be scaled to any size, plus fit it into a container for easy logistics.

An advanced control system (ACS) using self-learning functions provide customers with a solution to monitor the operation of the filter, while there are plans to equip the machine with artificial intelligence functionality to monitor the conditions of the input material and select the optimal dewatering route.

Also, the filter press offers a variable and very fast opening and closing time thanks to the robust rack and pinion system, thus providing the high-capacity dewatering large mines require.

Metso is ready with its “future-ready” solution – a pilot VPX filter is currently in Sala, Sweden, about to be taken on a roadshow. This unit has already been tested on a mine tailings application in Sweden, IM understands, with the company expecting many more trials over the next year.

As Lars Gustavsson, Business Manager, Beneficiation Solutions, explained, the company’s filter press trial plan includes taking small size samples in its laboratory before graduating to the full-scale pilot unit, which is equipped with the same ACS and sensors commercial units will have. “This gives customers all they need to build the business case,” he said.

The Metso tailings management concept goes further: Hällevall says the use of the Metso IPS and Metso MHC™ hydrocyclone, in circuit with a VPX filter, results in less use of chemicals and energy in the dewatering process, on top of water recoveries of up to 90% in some applications. This is achieved by controlling the feed and optimising the filtration process. “We simply separate the stream into fine and coarse streams by using Metso MHC hydrocyclones,” Hällevall says, explaining that the overflow – the fines stream – is directed to the Metso IPS thickener, with the coarse stream going direct to the filter.

With two separate streams, the company can decide the optimum way to filter and dewater the material, with the IPC, in particular, offering the most “superior setting of fines using minimum amounts of flocculants and energy”, Hällevall says.

This new concept has allowed Metso to become one of only a few mining OEMs talking up the use of pressure filters – and accompanying separation and thickening infrastructure – to reprocess legacy tailings dams. The ability to “turn waste into value” could enable mining companies to not only clean up these dams, decrease their footprint and improve their sustainability credentials with local and other stakeholders, it could also allow them to generate additional revenue from the recovery of valuable minerals and metals.

This could potentially provide the positive investment case miners need to start making wet tailings dams a thing of the past.

Just 5% of all fresh tailings generated in 2018 were dewatered in some way, according to Metso’s data. With its own “future-ready” solution now in place, the company is doing its bit for industry to ensure this figure continues to rise.

Anglo American’s FutureSmart Mining on its way to tangible technology results

Automation, Base metals, Bulk handling, Coal technology, Comminution of minerals, Environmental, Explosives and blasting, IoT, Mineral processing, Mineral project development, Mining equipment, Mining industry recognition, Mining people, Mining policy, Mining safety, Mining services, Mining software, Mining techniques, Steel and iron ore, Sustainable mining, Water management, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

“It’s clear that the pressures on us are unsustainable, whether it is around our carbon footprint, water footprint, or physical footprint, and we are always looking for different ways to push us in this future direction where our footprint will be very different.”

Tony O’Neill, Anglo American Technical Director, knows the company he works for is up against it when it comes to retaining its reputation as one of the world’s leading sustainable mining companies.

It’s clear from the company’s 2018 sustainability report – which saw it achieve a best-ever performance in terms of injuries, a cut in energy use and an increase in greenhouse gas emission savings – that Anglo is going down multiple paths to reach its goals. O’Neill, who joined the company almost six years ago, believes Anglo’s FutureSmart Mining™ programme will play a major role in confronting and overcoming many of the issues it (and the industry) is facing.

“If you look at FutureSmart Mining, at its absolute essence, it is about footprint; how do you change the footprint of mining? How do you have a mine that draws no fresh water? Mines without tailings dams? Mines that look very different?” he told IM.

“It’s getting people to believe there is a different way for mining in an industry that has, to this point, been quite traditional. It is not going to happen overnight, but I think we have a genuine vision that is, in my view, quite feasible.”

IM spoke with O’Neill and Donovan Waller, Group Head of Technology Development, this week to get to the bottom of how technology is making Anglo ever more sustainable.

IM: Could you explain how the Anglo operating model facilitates and fosters innovation within the context of FutureSmart Mining?

TO: The Anglo American operating model is the chassis that underpins everything, giving us certainty in the delivery of our work. When you have got that stability – and the lack of variability – in your business outputs, it is much easier to overlay new technologies and processes. When you then see a difference in operating or financial results, you can confirm it is down to what you have implemented, rather than the underlying processes.

I look at it a little bit like a three-legged stool: you have the operating model on one leg, the P101 benchmark-setting on another, and technology and data analytics on the third leg. They all co-exist in this system and work off each other. Without one, the stool falls over.

The operating model has given us a drumbeat of delivery, and we get the licence to innovate because of this drumbeat.

IM: Do you think FutureSmart Mining is starting to be understood and valued by investors?

TO: They’re awake to it now. I think it is still in the early stages of the story, but they can see what we are doing and the ambition behind it. Ultimately, it will result in a different investment profile, or more investors because of it, but I am not sure that it’s translated in full up to now. The recognition has been more around the general results of the company.

With all these technologies coming through – much of them driven by higher levels of data and the ability to interrogate that data – the vision we imagined way out into the future, I think, is a lot more tangible than when we started out four years ago.

IM: Out of all the tailings dam elimination work you are carrying out (around passive resistivity, fibre-optics, micro-seismic monitoring, coarse particle recovery, polymers, and dry stacking), which innovation will have an impact on Anglo’s operations in the next three-to-five years?

TO: All of them. We started out with our tailings programme in 2013; in fact, our group technical standards were re-issued at the beginning of 2014 and they are now one of the main guidelines the ICMM (International Council on Mining and Metals) uses.

Tailings dams have always been at the back end of the mining process and, in a way, the science behind them has never been part of the mainstream operation. Our view, internally for many years, is tailings dams are one of the industry’s greatest risks.

“Our view, internally for many years, is tailings dams are one of the industry’s greatest risks,” Tony O’Neill says

Ultimately our aim is to eliminate tailings dams. Period. Coarse particle flotation – getting that coarser particle size that drains much more freely – is core to that and you can see a development pathway there. For example, with some of these new flotation techniques, we now only need 1% exposure of the mineral for it to be effective. In the past, it was much higher.

When we upgraded the capability of our tailings organisation, it became clear we needed to get a lot more data off these tailings dams. About three years ago, we started putting fibre-optic sensors into the dams. We have since developed, through our exploration arm, passive resistivity seismic monitoring, which basically tells you where your water sits in the dams. And, we’re putting into Quellaveco micro-seismic measuring techniques, which will be more granular again. You can see the day coming really quickly where tailings dams are a real-time data source for mining companies.

We’re also, with our joint venture partner Debswana, building the first polymer plant in Botswana, which could have an impact on dry tailing disposal.

The thing we need to crack – both ourselves and the industry – is how to dry stack at scale. At the moment, that is still a work-in-progress, but it is doable in the long term.

IM: How is the bulk sorter you have operating at El Soldado, which is equipped with a neutron sensor, working? How has it made a difference to recoveries and grades at the operation?

TO: With the bulk sorter, we’re taking packages of tonnes rather than individual rocks to enable us to get both speed and volume. At El Soldado, we are sorting in four tonne packages. You can adapt the sorting profile by the characteristics of the orebody. We’re generally looking to sort tonnages that are less than you would put in a haul truck body or bucket.

If you step right back, in the past, most processing plants wanted to blend to get an average feed. We are going the other way. We want to use the heterogeneity of the orebody to its advantage; the less mixing we can get ahead of these sorting processes, the better it is for recoveries.

Being able to remove an orebody above the cut-off grade alongside waste tonnages and upgrade the latter has led to an effective lift in head grade. It has been enabled by new sensing technology with a particular type of neutron sensor.

What we have seen in early results has surprised us on the upside. We thought we would see a 5% uplift in head grade, but in fact we have seen about 20% – to qualify that, it’s in its early stages.

O’Neill says the bulk sorting trial at El Soldado has seen about a 20% uplift in head grade in its early stages

If you take this to its logical conclusion, you can see the day coming where you would cut the rock – no drilling and blasting – immediately sort the rock behind the machine cutting it and distribute said rock efficiently into its value in use; you don’t have stockpiles, you have plants sensing the material right through and adapting in real time to the change in mineralogy. I think there is another 3-4% increase in recovery in that whole process when we get it right.

Our sweet spot when we created FutureSmart Mining was always the orebody and processing plants, more so than automation (although that is part of the potential mix). That was different to a lot of the other players in the industry. This focus could lead to the development of different types of plants; ones that are flexible, more modular and you can plug and play.

IM: Do you see these type of neutron sensors being applied elsewhere across a mine site?

TO: Yes, through processing plants and conveyors. In fact, we’re preparing for this on conveyors right now.

What we have found with all this new technology is that, when we implement it, quite often another opportunity arrives. They end up playing off each other, and that is the context for the bulk sorting and coarse particle flotation.

IM: How have Anglo’s Open Forums played into these developments?

TO: We have held eight Open Forums on sustainability, processing, mining, exploration (two), future of work, energy and maintenance.

Out of those eight, I think we have got around 10,000 ideas from them. These forums have been specifically designed where only about a third of participants are from the mining industry, with the other two thirds coming from the best and brightest analogous industries we can tap into – automobile, oil & gas, food, construction, even Formula 1 racing and NASA.

The reality is that out of those 10,000 ideas, the success rate is about 1:1,000, but the one that makes it is quite often a game changer.

IM: Going back to the bulk sorters, am I right in thinking you plan to put these into Mogalakwena and Barro Alto too?

TO: The aim is to have them across our business. At El Soldado, the copper angle is very important. The technology – the sensing and using the data – is probably a touch more advanced in copper, but we are building one currently in our PGMs business at Mogalakwena and a bit behind that, but ready to be built, is one in nickel, yes.

In terms of our programme, you will see them spread across our business in the next, hopefully, 18 months.

IM: Where does your approach to advanced process control (APC) fit into the FutureSmart Mining platform?

TO: We want to have APC in some form across all our business by the end of this year. We have probably come from a little behind some of the other players in the industry, but we’re pushing it quite aggressively to give us the platform for data analytics. The upside we have seen just by putting the process control in so far has surprised me a bit – in a good way; power reductions, throughput, having this different level of control. All of it has been pleasing.

We spent about 12 months looking at the whole data analytics space to see how we were going to implement our solution. If you look around at the sector, everyone wants to be involved and profit share. If you add it all up, you could end up with not a lot of profitable pieces at the end. We have strategically chosen the pieces we think are important to us and our profit pool and have been happy to be a little looser on some of the non-core areas.

The other key plank to the APC is that we own the data. The reality is, in the new world, data is like a new orebody and we’re not willing to let go of that.

IM: Your Smart Energy project involving a haul truck powered on hydrogen has certainly caught the attention of the market: how did you come up with this innovation?

TO: Initially, we couldn’t make renewables work from an investment criteria perspective – it was always close, but never quite there. Donovan’s team then took an approach where they said, ‘forget the normal investment criteria. All we want to do is, make the business case wash its face.’ In doing so, it enabled them to oversize a renewable or photovoltaic energy source – the power plant – using that extra power to produce hydrogen and putting that hydrogen to use in the haulage fleet. Re-engineering the haulage fleet gave us the business outcomes we were looking for.

DW: These business cases bring you to temporary barriers. When you hit that temporary barrier, people normally stop, but what we said was, ‘OK, just assume it is not there and go forward.’ That brought the whole business case back again by looking at it differently again.

Anglo’s Smart Energy project is aiming to power a 300-t class truck with hydrogen fuel

IM: Where is this project likely to be situated within the group?

TO: We’re still not 100% fixed as the initial work will be done here (the UK). You are talking about quite specialist skills working with hydrogen.

When the system has gone past its initial testing, it will go to a site, probably in South Africa, but we are not 100% locked into that at this point.

IM: On the 12-month timeline you have given, when would you have to be on site?

TO: The infrastructure will be pre-built here in the UK. We’re effectively testing it here. In a way, the physical truck is the easy bit.

It’s going to be using a 300-t class truck. The guys have already done quite a bit of the detailed measuring and the design elements are well under way.

We’ve also taken the approach to use pre-approved technology, which Donovan can talk about.

DW: This minimises the risk on the first go and allows us to, later, tailor it. For example, if you don’t have a right sized fuel cell currently available off-the-shelf, you just use multiple standard-size fuel cells for now. Then, when you get into the final version you could tailor them into something more specific.

IM: On mechanised cutting, you recently mentioned the building of a “production-sized machine” for at least one of your mines in South Africa. Is this a variant of the Epiroc machine – the Rapid Mine Development System – you have been using at Twickenham?

TO: It’s the next generation of machines. It’s fair to say that, in the last 12 months, the technology has come to the point where we are confident it is viable.

What we’re looking for is a fundamental breakthrough where, for example, we can take the development rates up three or four times from what you would usually expect. That is what we’re chasing. It would involve some sort of pre-conditioning of the rock ahead of the cutting, but the cutting, itself, works.

For us, mechanised cutting is a real solution to some of the safety issues we have had on our plate. Regardless of whether it goes into South Africa or another underground mine, we see it as a key part of our future underground design and operation.

IM: What type of rock pre-conditioning is this likely to be?

TO: I think around the world, people are looking at electricity, microwave, laser, a whole suite of things. None of them have yet quite landed, but they all have potential.

IM: Where does haul truck automation fit into the pipeline for Anglo American?

TO: All the equipment we buy, going forward, will be autonomous-capable, which means we can run it in either format (manned or unmanned). You are then left with a number of decisions – have you got the design to retrofit automation? Is there a safety issue to be considered? Is there a weather issue to contend with? There are a whole series of gates that we’ll take it (automation projects) through.

It’s good to go back to P101 here. Where P100 is getting all of our key processes to world-class benchmarks, P101 is about establishing a new benchmark. By definition, if you get your operations to that point, the gap between that manned performance and autonomous performance is not that great.

Autonomy is part of our future armoury, but when and where and how, we’ll have to wait and see. For example, we are currently looking at the option of autonomous haulage trucks at one of our open-cut mines in Queensland.

When you look at our portfolio of operations, it’s often a more complex environment than when you are just working in the wide open Pilbara.

BHP establishes task force to handle tailings dams

Environmental, Mining industry recognition, Mining maintenance, Sustainable mining, Water management, , , ,

BHP says it is establishing a dedicated Tailings Task Force to drive enhanced focus on internal dam management plus support the development of international best practice.

The announcement came during an environmental, social and governance briefing where the company also revealed it is “progressing the investigation of new technologies to further mitigate current dam risks and eliminate future risk”.

BHP has interests in 67 operated tailings facilities across all its sites. Of these, 13 operated facilities are active, (12 in Australia, one in Chile), 29 are operated upstream facilities (five of which are active). In addition, its non-operated joint ventures have nine facilities, five of which are upstream, of which all are inactive.

Back in 2016, the company carried out a Dam Risk Review, which identified no immediate concerns regarding dam integrity. This was undertaken to assess the management of tailings facilities following the failure of the Fundão dam at Samarco (a joint venture with Vale).

BHP has since undertaken Dam Safety Reviews which provide assurance statements on dam integrity, the company said.

The company said on the appointment of the task force: “Prior to Brumadinho we already had a significant focus on looking at how we could deliver a step change reduction in tailingsrisk. Brumadinho however has further strengthened our resolve.”

The new Tailings Task Force will be accountable for further enhancing the company’s focus on tailings including the continued improvement and assurance for BHP’s operated tailings storage facilities, the company said. It will also progress its technology efforts and ongoing participation in the setting of new international tailings management standards.

On the latter, BHP said it continued to work with the International Council on Mining and Metals its peers to “drive a step change in tailings management across the sector”.

Outotec looks for consistent and efficient dewatering with new paste thickener

Environmental, Industrial minerals, Mineral processing, Mining equipment, Mining services, Sustainable mining, Water management, , , , , , , , , , , , ,

Outotec has introduced the 2nd Generation Paste Thickener to, it says, maximise underflow density regardless of challenging mineralogy and tailings feed-rate variation.

The thickener enables consistent and efficient dewatering performance – even with changing process conditions, according to the company.

“Through consistent performance and high underflow density, the 2nd Generation Outotec Paste Thickener maximises beaching angle in the tailings storage facility to provide safer operations and maximised lifespan,” Outotec said.

The new paste thickener provides ease of operation and reliability for applications requiring a high degree of dewatering, such as minerals tailings, mine backfill, and pre-leach and counter current decantation circuits, according to the company. “The technology is customised to address each operation’s unique drivers, which can include environmental concerns, water recovery, regulatory requirements, tailings management, or limitations on available land space,” the company said.

Outotec has a history of developing paste thickeners, as well as the design and delivery of large-scale paste thickening projects. “This has given us a deep understanding of the key aspects of high-density thickeners, including effective flocculation, dewatering, raking, prevention of rotating mud beds, process control, and the discharge of thickened solids,” it said.

“One such case was the deployment of Outotec paste thickener technology – including a full-scale paste tailings plant and Outotec ACT Thickener Optimizer system – at Yara’s Siilinjärvi apatite mine in Finland (pictured),” Simon Courtenay, Product Manager for the Outotec 2nd Generation Paste Thickener, said. “The plant generates around 10 Mt of tailings a year and, thanks to the Outotec ACT Thickener Optimizer, the paste thickeners can consistently run with a high and stable underflow solids content of 66-68%, regardless of challenging mineralogy and tailings feed-rate variation. This results in average beach slope angles of 3.5° (6.1%) in the tailings disposal area, helping to extend its lifespan. The system has also enabled a 10-20% reduction in flocculant costs.”

The new 2nd Generation Paste Thickener builds on this proven performance with a range of innovative new features, according to the company. For example, vertical load monitoring with the Smart Rake Lift system means the Outotec Paste Thickener is one of the only systems in the world that can detect early formation of rotating beds, enabling counteractions to be taken early, Outotec said.

The system also monitors and actively adjusts the individual hydraulic cylinders to maintain alignment of the rake mechanism. Incorporating vertical load sensing with plant process data in the Outotec ACT Thickener Optimizer control system means the solids inventory within the tank can be maintained to ensure a consistent underflow density, stable process, and improved overall thickener performance, according to the company.

In addition to mechanical improvements, process control has been further developed to stabilise and optimise the performance of the paste thickener, Outotec said.

The company said: “Outotec’s ACT Thickener Optimizer utilises a multivariable controller to manage process changes and the associated delays in the response time of the thickener that can be challenging for traditional control systems. It can also be configured to manage the effects of variable feed types to ensure optimum performance despite changing inputs to the process. Short installation and configuration time of the system is coupled with on-going services to ensure a practical yet flexible long term control solution.

“Our application-specific design of the thickener begins with the use of methods such as discrete element modelling to understand solid particle movement within the thickener, computational fluid dynamics for feed system design and finite element analysis for structural steel design. Our paste thickening solutions are also designed with ease of maintenance in mind, with a skid-mounted hydraulic power unit for centralised connection of hydraulic hosing from the rake lift cylinders and drive unit.”

Other key design features include:

  • Low profile rakes with tie-cable load sharing that minimise rake drive torque requirements;
  • Rake blades supported by thixoposts to move the rake arm away from the highest density thickened solids;
  • High sidewall and steep tank floor slope for more efficient dewatering of flocculated solids and compaction of the bed, as well as better transport of the solids inward toward the tank discharge point;
  • High installed drive torque to move the rake blades through beds of thickened solids with high yield stress and viscosity, and;
  • Feed systems with break tanks when required for different thickener feed situations, including our patented Vane Feedwell, and break tanks inside the thickener perimeter to save on site layout space.

“Beyond technology and equipment, Outotec provides complete solutions for thickening needs,” the company said. “Proven design features and process guarantees, combined with lifecycle service support, help ensure operational reliability. We can also support customers with ongoing operation and maintenance services after plant commissioning.”

ANDRITZ pumps draining flooded mining tunnels in South Africa

Environmental, Mining equipment, Mining services, Precious metals, Water management, , , , , , , ,

Just as IM’s water management feature goes live, ANDRITZ has released details of a project it has been working on to de-water old mines in Johannesburg, South Africa.

South Africa has been dealing with an acid water problem in recent years. Underneath the old gold mining city of Johannesburg is a lake containing heavily contaminated water, which spreads horizontally and vertically into the abandoned pits of the former gold mines, according to ANDRITZ.

The water line has reached a critically high level, as determined by the specialists from the ANDRITZ subsidiary, ANDRITZ Ritz, in Schwaebisch Gmuend, Germany, which was given the first order to drain the mine water back in 2010.

The execution of the project was delayed by four years, however, and it was only in Spring 2014 that two powerful ANDRITZ submersible motor pumps were installed in the middle of Johannesburg city centre, in the so-called ‘Central Basin’. Each pump is capable of bringing 1,500 m³/h (1.5 million litres per hour) of water to the surface, according to ANDRITZ; with 60 million litres of water per day pump, it is a never-ending task, ANDRITZ said.

“In Johannesburg, however, acid mine water is an ongoing problem. Rainwater seeps into the tunnels and reacts chemically with residual minerals like pyrite, producing corrosive sulphuric acids. In the worst case scenario, this can result in a pH value of 2, which is enough to cause lasting damage to humans and the environment.

“Because of this corrosive acid, the Johannesburg pumps had to be completely redesigned. The design is based on ANDRITZ’s proven HDM (Heavy Duty Mining) technology, which uses the concept of a double-suction pump. The thrusts produced are offset by the counter-rotating arrangement of the impellers and the pumps run without axial thrust, giving a properly maintained pump a service life of 10 to 15 years.”

The pumps for the Johannesburg project are a tailor-made, customised design built for this special individual application, according to ANDRITZ. Part of the new system is an encapsulation of the submersible motors (see top photo), which enables the creation of an internal pressure higher than the external pressure. This prevents the intrusion of the corrosive water and the components inside the motor being attacked and possibly destroyed. “At the same time, the water being drained is used to cool the motor by means of a heat exchanger,” ANDRITZ said.

ANDRITZ engineers spent weeks developing the sophisticated technology needed to encapsulate the motor so it could withstand the higher internal pressure. The first two pumps have been running since June 2014. These 21-t pumps, each 15 m long with a 1-m diameter, were installed side by side in March, 5 m apart, but could only be started after completion of the water treatment plant.

Freely suspended on 430-m-long duplex steel pipes, they transport the acid mine water to the surface and onwards into an adjacent treatment plant (pictured). Here, through the addition of lime, the pH value is raised, the acid is neutralised and the heavy metals dissolved in the water are absorbed and precipitated as hydroxides, ANDRITZ said.

The South African authorities are planning a total of three pumping stations, which will each be developed at the mines’ disused extraction shafts. In addition to the Central Basin in Johannesburg’s city centre, invitations to tender for the ‘Eastern Basin’ and the ‘Western Basin’ are currently in progress, according to ANDRITZ.

“The long-term goal is to force the water level in the flooded mines back from its current level of approximately 200 m to a depth of 1,000 m, and to keep it there, to then be able to begin mining gold and gold ore in the drained upper layers of the mines once again,” the company said.