Tag Archives: HRC

Metso Outotec ticks the TCO box with latest HRC HPGR design

The design and operating principle of Metso Outotec’s HRC high pressure grinding roll has been well proven since going commercial in 2014.

The elimination of the edge effect with a flange design brings with it high throughput, while the anti-skew assembly means customers find faster machine restarts and no downtime from skewing events.

These benefits have been proven at Freeport McMoRan’s Morenci mine, in Arizona, USA, with the company’s largest unit – a HRC 3000 – having now processed more than 120 Mt of ore at that operation. This HRC 3000 is still going strong.

Yet, there was room for improvement, hence the reason Metso Outotec has just released the HRC™e HPGR.

Christoph Hoetzel, Head of Grinding business line at Metso Outotec, explained the rationale for such an update.

“To enable this flange technology, it was very important to have a simple, mechanical solution that works under any circumstances,” he told IM. “Our solution with the HRC was the arch frame, which was a mechanical fix to keep the rolls parallel at all times.

“This, however, came with a compromise. You had to have access to both sides of the machine and, in general, the units were relatively heavy and tall.”

These attributes meant that, if the customer investigated the total installed cost of the HRC – especially if they were weighing the purchase of more than one unit – the cost sometimes outweighed the benefits.

“This was a case of where the economics did not match the sustainability and efficiency of the unit,” Hoetzel said.

Metso Outotec has listened to customer feedback with the HRCe.

“The enabling factor for the flange technology is a mechanical solution for eliminating skewing on the machine,” Hoetzel said. “We have now achieved this with a much simpler, compact design. This is really where the step change has come from.”

Now, when you look at the specifications of the HRCe, which comes with a large feed size acceptance of 60-120 mm and typical capacities of 1,810-6,930 t/h, the footprint is almost the same as other HPGRs on the market, according to Hoetzel.

“Yet, the unit benefits from the proven and reliable flange design of the original HRC,” he said. “You could, potentially, even use a smaller unit for the same application.”

By reducing the size and associated installation cost that comes with the HRC technology, Metso Outotec is suddenly levelling the HPGR playing field. The advantages the company spelt out back in 2014 when the HRC technology was originally publicised now come with no cost drawbacks.

With more miners looking for not only energy-efficient grinding solutions in their flowsheets, but processing options that reduce their water intake, HPGRs are increasingly being used in tertiary or quaternary crush applications, or in lieu of traditional SAG mills.

In this regard, an updated HPGR is coming to the market at just the right time.

Metso Outotec, cognisant of this trend, has also sought to offer the benefits of its HPGR technology to the wider market.

The mechanical skew control HPGR (High Pressure Grinding Roll) retrofit kit takes the key components responsible for minimising skew from the HRC and makes the technology more accessible without the major investment or need to acquire a new machine, according to the company. The technology can also be incorporated into non-Metso Outotec machines.

These latest product updates are in keeping with Metso Outotec’s defined purpose of “enabling sustainable modern life”, fitting the mineral processing reality that miners face today.

Hoetzel reinforced this message: “Customers should not have to choose between sustainability and lowest total cost of ownership with their machines. At Metso Outotec, we truly want to be the partner for positive change, which means we really need to combine both.

“With the HRCe, we think we have achieved that.”

Metso Outotec to bring HRC benefits to other OEM’s HPGRs

Metso Outotec says it is launching the mechanical skew control HPGR (High Pressure Grinding Roll) retrofit kit for improved throughput and energy efficiency on the heels of its new HRC™e HPGR release.

The HRC HPGR was launched back in 2014 pioneering the use of flanges and non-skewing design and, now, those same benefits can be had on existing, non-Metso Outotec machines, the company says.

The new HPGR retrofit kit takes the key components responsible for minimising skew from the HRC and makes the technology more accessible without the major investment or need to acquire a new machine, according to the company.

“We are very excited to introduce the new flanged roll with mechanical skew control HPGR retrofit kit, which allows customers to maximise the performance of their existing equipment without the capital expenditure investment of purchasing expansion machines,” Jack Meegan, Product Director, SVS, Stirred Mills and HPGR at Metso Outotec, says. “This is truly a value option for an extended customer reach.”

Key benefits of Metso Outotec HPGR retrofit kit include the ability to increase throughput by up to plus-20%; improved energy efficiency with the flanges ensuring even breakage rates across the whole width of the roll; reduced circulating loads as less material bypasses the rolls and more ore continues to the next stage of the process; and reduced wear costs with the flanges allowing harder studs for longer tire life.

Los Andes Copper engineers a Vizcachitas alternative

It is a combination of improved technology, reduced fine grind requirements and maintenance benefits that led to Los Andes Copper replacing the SAG and ball mill crushing circuit proposed in its Vizcachitas copper-molybdenum project preliminary economic assessment (PEA), with a three-stage crushing circuit that uses high pressure grinding roll (HPGR) technology in the tertiary crushing stage, according to Executive Chairman, Fernando Porcile.

In the middle of a prefeasibility study on the Vizcachitas project, Los Andes recently issued an update on the study progress.

A delay of PFS publication to the March quarter of 2021 due to the onset of COVID-19 impacting some of the metallurgical test work and field work at the project might have been the key takeaway for investors, but those in the mining technology game will be focusing on the revised process flowsheet being put forward at the Chile project.

One of the big changes was seen at the front end on the comminution side.

In the close to year since issuing the June 2019 PEA, and with the arrival of Porcile and his team, the company’s understanding of its orebody characteristics and the technology available to it as a new greenfield project owner has grown.

Porcile said the ore at Vizcachitas is very suitable to this energy efficient HPGR technology, with metallurgical test work showing an HPGR circuit can reduce the sensitivity to changes in hardness, providing a product that is more consistent in size. This will help reduce major process fluctuations downstream – where there have also been some changes.

The P80 target grind size of 240 microns hasn’t changed much – moving up to a P80 of 240-300 microns – but the SAG and ball mill circuit has been replaced with a three stage crushing circuit using secondary crushers in open circuit and HPGR as a tertiary crusher in closed circuit.

On the preliminary comminution process flowsheet, this includes the use of a Metso Superior™ MKIII primary gyratory crusher, feeding three Nordberg® MP2500™ cone crushers, which move into 40,000 t crushed ore bins. This material is then conveyed to two Metso HRC™ 2600 HPGRs.

Los Andes says the configuration of secondary cone crushers in an open circuit avoids the use of a coarse ore stockpile and recirculation conveyor belts – reducing dust emission sources – while the closed reverse grinding circuit allows less production of fines, which is helpful for the follow-on thickening and filtration stages.

On top of this, the secondary crushing and grinding plant in this setup is close to the primary crusher, which also reduces coarse ore conveying costs.

Porcile said HPGR technology has moved on a long way in the last decade and now represents a more reliable proposition than using the SAG and ball mill circuit previously proposed.

“There is much less risk associated with using HPGRs in a new operation,” he told IM. “Large SAG mills not only take up lots of space within the plant, they can also come with teething problems during start up.”

He added: “HPGRs used to come with lots of wear problems, meaning you had to replace the rollers often. The maintenance on them is that much better now; the rollers do not wear out as quickly and, when they do, you can easily replace them.”

On top of the obvious benefits in energy consumption that come with using HPGR technology, there are positives that can be felt further down the process flowsheet.

“We are very confident that HPGR is the best alternative for our project due to the nature and quality of our ore,” Porcile said. “We produce very little fines, which has an impact on the way we deal with tailings.”

The combination of a lack of fines and low presence of clays (mainly kaolinite) has helped filtration performance in test work, indicating that a dry-stacked tailings solution may be viable at Vizcachitas, Porcile said.

This could provide an up to 50% reduction in water consumption compared with the PEA at Vizcachitas. It could also see some 82% of water recovered throughout the process, in addition to a significant reduction in infrastructure requirements.

“We go from having infrastructure in two valleys in the PEA to one in the PFS,” Porcile said on the latter point.

One may think creating a dry-stacking operation at a 110,000 t/d throughput mine would prove costly and difficult, but the lack of fines and low presence of clays already mentioned means the process is a lot simpler to other dry-stacking projects currently on the table across the globe, according to Los Andes.

Test work to date has indicated that coarse material from the plant (plus-400 microns) could produce a cake with 14%-18% moisture through the use of belt conveyors. This material currently makes up 87% of the envisaged tonnage.

Only 13% of tonnage classed as fines (less than 400 microns) would have to go through pressure filters to produce a 16-19% moisture cake, according to the company.

Porcile says these belt filters work just as well as pressure filters on the coarse material from Vizcachitas but are that much more cost effective.

“Belt filters come with high filtration rates, are low cost (in terms of capex) and are reliable,” Porcile said. “In the study, we envisage saving pressure filters only for the very top level of material.”

While it is too early to talk about the impact these changes will have on the capital expenditure and net present value numbers to be included in the PFS, expect the $1.87 billion and $1.8 billion (after tax and with an 8% discount), respectively, to change.

Metso looks to grind down GHG emissions with energy-efficient technology

Having recently won the approval of the Science Based Targets initiative (SBTi) for its greenhouse gas (GHG) targets, Metso’s Climate Program now has the recognition it deserves.

The GHG goals are applicable to all relevant emission sources: production, procurement, inbound and outbound transportation as well as the use of Metso’s products.

Following on from this environmental win, IM put some questions to Metso’s Director of Sustainable Business Development, Kaisa Jungman, to find out what impact these climate change aims might have on the mining equipment manufacturers’ product offering and how the company is already leading from the front with its environmental sustainability initiatives.

It’s worth acknowledging, first, that these GHG goals are all-encompassing.

As a scope 1 and 2 GHG target, Metso has committed to a 25% reduction in carbon emissions in production by 2030, while 30% of its suppliers – in terms of spend – are required to set science-based emission targets by 2024. Metso also aims for a 20% reduction in transportation emissions by 2025 (scope 3 GHG emissions target) by streamlining transportation routes and optimising warehouse locations.

Through extensive research and development work, Metso says it has been able to significantly reduce the energy consumption in customer processes. To continue this development, the company is aiming for a 10% reduction in GHG emissions in the most “energy-intensive customer processes” using Metso products by 2025.

The company is also demanding energy-efficiency targets in its Metso R&D projects, and offsetting flight emissions by 100% by 2021.

The target to lower GHG emissions by 10% in the most “energy-intensive customer processes” stood out in these targets, and it was hardly surprising to find out grinding falls into this category.

“Grinding is the most energy-intensive stage of minerals processing,” Jungman said. “Overall, it is estimated that comminution counts for 3-5% of the energy consumption in the world and grinding is part of this.”

In the company’s climate program it has included three of its products – the HRC™ high pressure grinding roll, Vertimill® and stirred SMD (stirred media detritor) – to help achieve this 10% cut in GHGs.

“We have estimated, based on our installed base, in 2018, that approximately 1,073,648 t of CO2 emissions were saved through these energy efficient grinding technologies,” she said, explaining that these savings were calculated by comparing its three solutions with conventional technology.

At this stage, it is only the HRC, Vertimill and SMD included in this calculation – due to their substantial energy and emission reduction credentials and the company’s ability to quantify accurately the estimated savings – but Jungman said Metso plans to widen the scope of the technologies to be included.

“In addition to our climate program, we are also looking into other environmental benefits the customers are gaining through our solutions,” she said.

“To improve energy and emissions efficiency in the future, our target is that all our R&D projects will set energy-efficiency targets by 2021.”

She concluded on these technologies: “I would say that this climate program is an important first step and we will continue developing even more comprehensive sustainability targets for our technologies.”

When it comes to displaying evidence of where the company is reducing scope 1 (generated from fuels used in production) and 2 (generated from purchased energy) emissions, Jungman could point to several examples.

“We have installed solar panels in some of our locations already and are looking now for opportunities to install more in several locations in the coming years,” she said.

In some of the company’s facilities, a percentage of the electricity it purchases is already from renewable sources, and Metso is investigating the possibilities of expanding this, Jungman added.

“In addition to electricity consumption, we are also searching for renewable alternatives for the other forms of our energy consumption, including, for example, replacing natural gas consumption with renewable alternatives.”

The company has also, in recent years, invested in many energy efficiency and renewable energy projects, according to Jungman.

“As an example, in our foundry in China, we have invested in a new type of melting furnace to gain better energy efficiency.

“In another production location, we have installed technology to recover process heat from the exhaust air to be used as heating energy. We have also invested in the process automation and insulation of the furnaces to gain better energy efficiency.”

She concluded: “Reducing greenhouse gas emissions is something we take seriously, and to which Metso is fully committed. We want all our stakeholders to be involved in the work to reach these important targets and to aim even higher.”