COMMINUTION
Introducing the Ro-Star Mill
Speaking of fine and ultra-fine grinding , Maelgwyn Mineral Services ( MMS ) has launched the Ro-Star™ grinding mill , at the same time announcing a joint venture for the manufacture and supply of the mill with ERSEL Heavy Machinery Inc of Turkey .
ERSEL is ranked as one of the top 10 grinding mill manufacturers in the world , while MMS has a long history of involvement with the design and installation of various manufacturers ’ proprietary ultra-fine grinding mills going back over 20 years , as part of its Leachox™ patented gold recovery process . There is currently some 4 Moz / y of gold produced by the Leachox process worldwide .
MMS explained : “ With such experience in ultra-fine grinding , MMS engineers believed they could design an improved mill and have been working on the design of the Ro-Star mill for over 10 years , with pilot and test equipment being placed in selected research facilities . However , a review of the design concept in 2020 , driven by the industry ’ s desire to reduce energy consumption and wear in ultra-fine grinding led the inventor , Dr Rainer Imhof , to come up with the unique and novel design of grinding chamber that is now part of the Ro-Star mill .”
The Ro-Star Mill ( schematic of the 500 kW mill illustrated here ) uses a suspended , bottom-fed , high-intensity wet grinding system with a rotor / stator disc mechanism on the shaft and shell of the mill , ensuring consistent bead contact and improved energy transfer . The Ro-Star mill operates at low disc tip speeds of around 3-5 m / s . This ability to operate at such low speeds is due to the unique design of the grinding chamber , MMS says . The shaft holding the rotor disc is encased within a proprietary designed sleeve , moving the grinding area away from the shaft and outwards towards the shell .
Unlike most vertical stirred mills , which tend to be tall and narrow , the Ro-Star design is now much lower and wider . In tall , narrow mills , most of
The Ro-Star Mill uses a suspended , bottom-fed , high-intensity wet grinding system with a rotor / stator disc mechanism on the shaft and shell of the mill , ensuring consistent bead contact and improved energy transfer
the grinding occurs at the disc tips . There is an area next to and near the shaft where no grinding is taking place , but the grinding media is consuming energy . This is negated in the Ro-Star mill due to the sleeve moving all the grinding media away from the shaft , ensuring more energy goes into the liberation of the material to be ground .
“ The lower and wider design of the mill significantly reduces wear rates and improves access to the mill ' s interior parts for maintenance ,” MMS said . “ The Ro-Star mill shell is hinged in two parts , making access for maintenance easier .”
Test work with prototype pilot units conducted at various locations has demonstrated that the Ro-Star achieves low energy consumption levels , according to the company . Comparative studies have also confirmed that the Ro-Star consumes 10-15 % less energy than an existing type of fine grinding mill , while delivering consistent P80 particle sizes below 20 μm .
“ In an era where energy efficiency and fine particle liberation are critical to modern mining operations , the Ro-Star Mill is an ultra-fine grinding solution designed to optimise mineral recovery while reducing operating costs ,” MMS said .
With extensive research MMS has established the design of a 10-litre volume Ro-Star mill as the preferred size of unit for laboratory-scale testing . A number of these units will be placed in key laboratories worldwide with the ability to perform signature grinding plots of client material .
ERSEL is currently manufacturing the first industrial sized Ro-Star mill with a 500 kW installed motor for an ultra-fine grinding duty . The mill will be commissioned in the September quarter of 2025 .
loop circular economy model . This is due to the pilot – already operational – in the El Teniente Division , where Magotteaux will remove between 50 t and 75 t of disused worn grinding balls and metal waste ( scrap ) monthly , revaluing it as raw material to manufacture new balls .
The New Ecomax cast balls manufactured by Magotteaux – whose manufacturing generates a 53 % lower carbon footprint , compared with the input previously used at El Teniente – not only match the operational performance of traditional forged balls , but are also cost competitive , with the added value of circularity and sustainable development , according to the companies .
Mauricio Acuña , Vice President of Supply at Codelco , said : “ At Codelco we are leading the way towards a more sustainable future . This agreement positions us as a reference in the implementation of large-scale supply contracts , with a firm focus on sustainability . This is the first contract for grinding balls that incorporates a 100 % supply model from recovered material .”
During 2025 , the Andina Division will gradually incorporate this circular supply model , leveraging the El Teniente case study . If successful , the system could be expanded to other operations .
Enrique Vargas , General Manager of Magotteaux Andino , said the company has been working in recent years with Codelco , universities and certified laboratories to develop a 100 % Chilean product that meets the demanding quality and performance standards of clients in the national market .
“ This circular economy model with Codelco is a global example , generating a positive social impact in the communities where we operate and inspiring the entire industry to move towards sustainability , demonstrating that responsible innovation is the path to truly sustainable development ,” he explained .
Executive President of Codelco , Rubén Alvarado , said : “ At Codelco we want to be a reference in the implementation of large-scale supply contracts with a sustainable focus . We have to work collaboratively to achieve our objectives and make our purpose of being a pillar of sustainable development for Chile and the world a reality .”
Reducing bolting-related downtime
Bradken says it has partnered with Copper State Bolt & Nut to deliver its latest technology solution to support customers , the BoltSense Load Monitoring Fastener Plus ( LMF +) system .
LMF + is designed to ensure critical hardware is not only properly installed , but also enhances operational reliability while in service . It can be used across ball , AG , SAG and rod mills ( liners , flange and rotational ).
A wireless , accurate and automatic tension monitoring fastener system , the LMF + is easy to use and will allow users to continually observe and record the true tension of fasteners , both during installation and while the assembly is in operation . Automated alerts will notify operators if tension deviates from desired values , according to the company .
Operators can set pre-defined tolerances for
26 International Mining | MARCH 2025