Tag Archives: SAG mill

Outotec mineral process equipment destined for Okvau gold project

Outotec says it has been awarded a contract from Renaissance Minerals, a subsidiary of Emerald Resources, for the delivery of process equipment to the greenfield Okvau gold project, in Cambodia.

The order value, booked into Outotec’s 2020 March quarter order intake, is around €13 million ($14.2 million).

Outotec’s scope includes the delivery of an Outotec HIGmill® high intensity grinding mill, a semi-autogenous (SAG) mill, TankCell® flotation cells, an OKTOP® Conditioner, thickeners and spare parts.

The Okvau gold project is in the Mondulkiri province of eastern Cambodia. The 2 Mt/y operation will be the first large-scale mining project in the country, according to Outotec, with project commissioning expected in the June quarter of 2021.

Last year, ASX-listed mining contractor, MACA, entered into a memorandum of understanding with a subsidiary of Emerald Resources to supply equipment and contract mining services at the project.

Paul Sohlberg, Head of Outotec’s Minerals Processing business, said: “We are pleased to be part of Cambodia’s first significant gold processing project with Emerald’s highly credentialed gold project development team.

“Outotec’s leading technologies such as energy efficient ultrafine grinding, proven flotation technology for low grade sulphide ore and superior thickening technology, enable our customer to do profitable business sustainably. This order will strengthen Outotec’s position as a supplier of advanced minerals processing technologies in Southeast Asia.”

FLSmidth to help modernise crushing, grinding circuit at Zijin’s Serbia copper op

Zijin Mining Group has chosen an FLSmidth gyratory crusher, SAG mill and ball mill for the Majdanpek mine, part of the Chinese mining company’s majority owned Zijin Bor copper mine, in Serbia.

The delivery of the equipment to Majdanpek, 180 km from Belgrade, is expected to occur between 12 and 18 months from now, with the project estimated to reach completion by the end of 2020. The order has a combined value of around DKK200 million ($30 million), according to FLSmidth, and has been recognised in the order intake for the September quarter.

The order of the new FLSmidth crushing and grinding circuit for the front end of the concentrator comes as Zijin looks to modernise Majdanpek, which will be the largest of its three Serbian copper concentrators, FLSmidth said.

Acquired as part of the majority acquisition of Bor in late 2018, the Majdanpek mine uses open-pit mining and flotation to produce copper concentrates, with a designed mining and processing scale of 10 Mt/y, according to Zijin. The operation is currently at a scale of 6 Mt/y, it said.

In the next six years, the company says it plans to invest more than $1 billion in the upgrading, expansion, or construction of the four mines and smelter at Bor. After the completion of the first phase of the project, it is estimated output will go to 82,000 t/y of copper in concentrates, with the smelter producing 80,000 t/y of copper cathode. After the completion of phase two, this could go to 120,000 t/y of concentrate and 150,000 t/y of cathode.

Manfred Schaffer, President of Mining and Group Executive Vice President at FLSmidth, said: “This extensive order underlines the strong value proposition of FLSmidth to our customers in the copper industry. Our market leading crushers and mills will provide significant improvements for Zijin Mining in terms of productivity and processing efficiency.”

Flotation and grinding circuit classification rise to the top in CEEC awards

The Coalition for Energy Efficient Comminution (CEEC) has announced the recipients of its 2019 CEEC Medals, which are granted annually to authors of outstanding papers presenting “innovative approaches to enhancing energy efficiency in comminution and mineral processing”.

Dr Zeljka Pokrajcic, CEEC Medal Evaluation Committee Chair, announced that the CEEC Medal for Technical Research was awarded to Laureate Professor, Graeme Jameson AO, and Dr Cagri Emer from the Centre for Multiphase Processes, University of Newcastle, New South Wales, Australia, for their publication, ‘Coarse chalcopyrite recovery in a universal froth flotation machine.

The CEEC Medal for Operations was awarded to Kyle Bartholomew, Rob McIvor and Omar Arafat from Metcom Technologies, Grand Rapids, Minnesota, USA, for their publication, ‘A guide to maximising ball mill circuit classification system efficiency (CSE), for operators and equipment designers.’

Dr Pokrajcic said: “The Evaluation Committee closely considered a number of high quality nominations from leading global industry experts before shortlisting two research papers and three operations papers.”

Jameson and Emer’s (pictured) CEEC Medal winning paper was published in Minerals Engineering (134, 118-133) in January and documents a flotation device, the NovaCell. The NovaCell features a fluidised bed for coarse particle collection and a high shear aeration zone for ultra-fines separation, CEEC said. The researchers’ case study showed the device resulted in a 40% reduction in comminution energy and a 12% reduction in overall site operating cost.

Dr Pokrajcic said the entry was a clear standout in the Technical Research category, presenting high quality research that was well supported by strong technical information and cost analysis.

“The paper presents a new dual-zone flotation device for both coarse and fine particle separation. It reinforces important developments that are supporting industry’s move to coarse particle flotation at scale,” Dr Pokrajcic said.

“This work shows leadership in flotation approaches that can significantly improve comminution efficiency and productivity. It also provides a compelling case for the reduction of operating and capital costs by removing coarse size waste in the comminution circuit.”

The winning Operations Medal paper by Bartholomew, McIvor and Arafat was presented at the 14th AusIMM Mill Operators’ Conference, in Brisbane, in August 2018.

Dr Pokrajcic said the paper provided a “useful methodology for measuring and improving classification efficiency in a grinding circuit”, highlighting the importance of classification in comminution circuits to improve efficiency and productivity.

The paper’s case study measured an almost 25% increase in the generation of new -25 micron material following an increase in ball mill re-circulating load and optimising cyclone performance, according to CEEC.

“The three authors from Metcom Technologies are highly regarded contributors to the field of comminution efficiency, last year publishing (along with Jim Finch) a paper on ball mill classification system optimisation that was Highly Commended by the CEEC Medal judges,” CEEC said.

Dr Pokrajcic said: “This year’s exceptional CEEC Medal winning paper by Bartholomew, McIvor and Arafat provides a succinct, clear, systematic approach to practical operational improvements that not only helps inform operations of the efficiencies that can be achieved, but also demonstrates the economic case for change.”

The 2019 CEEC Medal Evaluation Committee also selected three papers for High Commendation. The recipient in the Technical Research category was Hamid Manouchehri for his paper, ‘How Far the Crushing Performance Can be Pushed? Cone Crusher vs Vertical Shaft Impactor (VSI)’. This paper was presented at Comminution ‘18, in Cape Town, South Africa.

CEEC said: “Manouchehri’s paper presented an adept comparison of the conventional cone crusher and the VSI in a fine crushing duty, and third and fourth stage crushing duty.”

The judges added: “His trials conducted at pilot scale and at laboratory showed the VSI produced more fines, and in some cases product of higher porosity, reducing downstream power consumption.”

In the Operations category, Malcolm Powell, Sarma Kanchibotla, Vladimir Jokovic, Marko Hilden, Benjamin Bonfils, Anand Musunuri, Pamela Moyo, Sam Yu, Jace Young, Paul Yaroshak, Emrah Yalcin and Barun Gorain were awarded High Commendation for their paper, ‘Advanced mine to mill application at the Barrick Cortez Mine.’ This paper was presented at the 14th AusIMM Mill Operators’ Conference.

The CEEC Medal Evaluation judges commented that this was an “outstanding paper” building on the commonly applied mine-to-mill optimisation where grade deportment and dilution, as well as blast movement during high intensity blasting, is considered and evaluated.

Also winning a High Commendation in this category was Berge Simonian for a paper titled, ‘Mount Milligan Mine Performance Update.’ Presented in January at the 51st Annual Canadian Mineral Processors Operators Conference in Alberta, Canada, CEEC said the paper detailed the optimisation and debottlenecking of a relatively new mineral processing circuit.

“Efficiency gains achieved through modification to secondary crushing screening, SAG mill lifter design and ball mill charge optimisation enabled the circuit to operate at throughput beyond design,” the judges said.

CEEC CEO, Alison Keogh, praised the CEEC Medal recipients and Highly Commended authors, saying their outstanding contributions help inspire and foster industry uptake of eco-efficient comminution and processing.

Keogh said: “The CEEC Board thanks the successful authors and each of the nominees for their important research efforts and case studies. These publications, shared widely via CEEC’s global network, provide tangible value by helping operators, researchers and METS companies take steps to operate more efficiently while reducing their energy usage, footprint and costs.”

To view the abstracts and to find out more about the CEEC Medal visit www.ceecthefuture.org/ceec-medal

Miners able to pick ‘n’ mix with latest FLSmidth mill lining components

FLSmidth says it has launched redesigned mill lining components engineered to suit the specific functions and differing operating environments of the mining industry with its.

The new PulpMax™ mill liners are designed to increase the throughput of semi-autogenous (SAG) mills and substantially boost the wear life of liners, the company said.

FLSmidth said: “Delivering on a promise to provide increased productivity to the mining industry, the composite design incorporated in FLSmidth’s new PulpMax mill liners ensure that users enjoy reduced downtime and maintenance, increased throughput and improved worker safety.”

With lighter weight mill liners, installation is faster and safer as each liner is easier to manipulate, according to the company. There are also fewer parts, and, hence, fewer movements are required to perform a reline, resulting in a significant decrease in scheduled downtime.

The composite nature of the liner reduces its weight by almost 50%, according to FLSmidth, which allows the plant to increase its ball charge level without increasing the total weight of the mill.

This higher ball charge further contributes to the higher throughput.

“The lighter weight of these liners has an important impact on size, design and installation time,” the company said. “Each liner can now be larger – subject to the size of the mill opening – and the mill can be lined with fewer of them, reducing the downtime required to conduct replacement.

A lighter liner means fewer bolts to hold it in place, a factor further reducing installation time, according to the company. This shorter downtime also means less time for contractors inside the mills, leading to a faster and safer liner changeout.

Another important benefit of the composite material used in many of FLSmidth’s redesigned liners is it is not necessary to torch the liners, as is sometimes required when removing old steel liners, the company said. “This torching process in the mill is best avoided, as it can cause costly damage to the mill shell,” FLSmidth explained.

Finally, there has also been the development of composite material shell liners bolted from the outside of the mill, once again, speeding up installation and reducing risk.

Jack Meegan, Product Line Manager for Comminution at FLSmidth, said: “As mines increasingly recognise the positive financial impact derived from just a few more percentage points in throughput improvement, many are looking beyond conventional steel cast liners for mills. FLSmidth’s innovations, based on combinations of steel, rubber and ceramic components, allow the liners to be thinner, resulting in a larger volume inside the mill, making higher charge levels possible.”

He continued: “Responding to the continuous assessment of customer needs, FLSmidth has launched a mill liner solution based on extensive data on mill operations, shutdowns, wear profiles and other factors. These have been used to develop a high-end technical and financial solution.”

Following installation, an ongoing measurement of actual wear, tonnage processed and estimated wear life is conducted so further recommendations can be made to improve performance, Meegan explained.

FLSmidth’s SAGwise makes an impact on mill consumables

Just over a year since launching its SAGwise™ total process control solution for semi-autogenous (SAG) mills, FLSmidth is putting some savings statistics behind the sensory and process optimisation system.

SAGwise is designed to optimise the use of the three main consumables in SAG milling: power, media and liners.

Winston Mokoena, Key Account Manager at FLSmidth, said the solution reduces critical impacts inside the mill by up to 45%. This adds life to wear liners and grinding balls, helping to prolong liner life between maintenance and giving mills more uptime, he added.

“SAGwise can improve mill production by 6% and substantially reduce process variability,” Mokoena said. “This ensures that the mill provides a constant and optimal feed to the next stage of the process, effectively facilitating better performance of downstream operations.”

Among the challenges mill optimisation tries to address is too little material in the mill, or too much. Too little leads to critical impacts between the grinding media and the mill liners, damaging both elements without producing value. If the mill is overfilled with mined material, on the other hand, this results in grinding inefficiencies.

“The SAGwise system uses four or eight unidirectional or bidirectional audio sensors located in close proximity to the mill, which detect the analogue sounds and convert them into digital signals for analysis by a processing unit,” FLSmidth said. “This unit uses the sound patterns and other process variables to determine the necessary adjustment to the mill’s feed, speed and pulp density.”

So direct are the improvements that can be achieved by this solution that customers can pay back their investment in less than six months, depending on the commodity value and the specific mill environment, according to FLSmidth.

“The parameters that are monitored by SAGwise include the mill’s power consumption, load impacts, mill load and pulp density,” Mokoena said. “The system then responds to these parameters by controlling the mill speed, the feed rate and the water to achieve the ‘sweet spot’ where the mill runs at optimum efficiency.”

Norilsk Nickel chooses Metso Megaliner for Talnakh concentrator

Norilsk Nickel has recently switched out the chrome and molybdenum alloy lining of a SAG mill at its Talnakh concentrator in Russia as the company looked to increase the life of these all-important wear parts.

Sever Minerals and Norilsknikelremont (a subsidiary of Norilsk) were contracted to complete the mill relining project, using liners supplied by Metso’s global team, which also used the OEM’s Megaliner™ concept.

The new lining is more durable, weighs less and ended up being safer to install than previous the previous lining, according to Norilsk.

A Norilsk spokesperson told IM that the mill lining was replaced with two elements, the Metso Poly-Met; a rubber-steel combination installed on the front-facing part of the mill; and the Metso Megaliner, which has large shell or head liners used to protect the drum.

The spokesperson added: “The cladding manufacturers guarantee that the mill can work for 5,600 hours uninterrupted (that is about eight months non-stop). The previous version required the SAG mill to be stopped for replacement every six months.”

By developing the technology, adopting better project management and using the specialised equipment, Norilsk said it was able to reduce the time taken to replace the mill lining by three days.

The Megaliner is, according to Metso, a new, innovative mill liner concept, dramatically improving worker safety and maximising mill availability. Each shell or head liner covers a large area, has few attachment components and an attachment system which gives a safer working environment for the installation crew, it said.

The weight of the mill lining also came down with the switch from pure metal to a metal-rubber compound, Norilsk said.

“The new mill liner weighs close to 130 t, which is 120 t less than the old mill liner. The average weight of one mill liner element is 1.8 t (elements have different configurations and respective mass),” the spokesperson said.

This reduced weight came with other benefits.

“Due to the lower weight of the capstan, the new mill liner is more wear resistant and better technologically-equipped to cope with an increased number of planned tasks,” the spokesperson explained.

Amplats goes down innovation path for further operational gains

In Anglo American Platinum’s 2018 results, the company revealed how its latest technology and innovation efforts were coming along.

Amplats, in 2018, recorded earnings before interest, taxes, depreciation and amortisation (EBITDA) of ZAR14.5 billion ($1.03 billion), compared with ZAR11.99 billion a year earlier, as total platinum group metal production rose 4% to 5.19 Moz.

In the company’s strategic overview of the business – under a section titled: “Extracting the full potential from our operations through our people and innovation” – the company talked up several processes it was pursuing to “drive improvement in operational performance from current levels”. This was through “greater stabilisation and process optimisation, towards best in class in the industry, known as P100”.

Amplats said: “The next step is to operate our assets and equipment at levels beyond what is currently thought to be possible in the industry, known as P101.”

Examples of areas of P101 improvement include increasing the rope shovel performance at its massive Mogalakwena PGM mine (pictured) in South Africa, from 26 Mt/y to over 45 Mt/y, increasing throughput at the concentrators by over 10%, boosting operating time of concentrators to over 94%, increasing recoveries of concentrators to over 83% and increasing the operating factor at processing facilities (defined as availability multiplied by utilisation).

“Beyond P101, a number of step-change technologies are being developed and deployed, including coarse particle flotation, which can reduce energy intensity by over 30%; advanced fragmentation and shock-break technology at concentrators, which has the potential to also reduce energy intensity by 30%; and fine recovery of chrome and PGMs, in conjunction with bulk sorting, which can lead to a 10% increase in feed grade and recoveries,” Amplats said.

Shock-break technology at concentrators has the potential to eliminate the use of SAG mills, according to Amplats. The company is piloting this technology after successful tests of Mogalakwena pebbles indicated a more than 50% saving in power consumption.

Pilot plant trials, “leveraging Element 6 wear resistant tools”, started in April 2018, according to Amplats.

To “unlock” this additional value through P101 and a number of FutureSmart Mining™ technologies and digitalisation, additional investment in a number of fast payback, value enhancing projects is required, Amplats said. “This is expected to deliver EBITDA margin uplift of 5-8% on a mine-to-market basis, within a three- five-year-time horizon, before the benefit of any expansion projects using 2018 prices and exchange rates”.

Capital guidance, including for these fast-payback and P101 investment projects will be in the region of ZAR1.5–1.8 billion in 2019, and around ZAR2 billion for each of 2020 and 2021.

Independence Group’s nickel output SAGs on mill liner issue

A SAG mill liner issue at Independence Group’s Nova nickel operation in the Fraser Range of Western Australia has seen the miner miss its annual production guidance for the financial year.

The problem, which saw a reduction in processing plant availability in the second half of June, resulted in an 800 tonne shortfall in nickel output, Independence said. The company produced 22,258t in the 12 months to the end of June, compared with its 23,000-27,000t guidance.

Independence said it is rectifying the situation: “The SAG mill liners are currently being replaced in a planned processing plant shutdown and are not expected to affect availability or productivity going forward.”

Even with this setback, the company produced 7,344t of nickel metal in the June quarter, up 23% from the March quarter. Independence noted that, as planned, tonnes mined, and milled, ore grades and metallurgical recoveries continued to improve.

Nova has a nameplate 1.5 million tonne per annum ore capacity with a primary crushing, two-stage grinding and differential flotation circuit. It has both a 2.4MW SAG mill and 2.4MW ball mill.

The mine, which produced its first concentrate in October 2016, is expected to average more than 26,000t of nickel, 11,000t of copper and 1,000t of cobalt annually.