COMMINUTION
maintenance shutdown for relining , but replacing the sealing system still takes time .
ABB hosts GMD User Meetings , where feedback from previous se essions indicated a desire for an improved sealing system , which would be faster and more convenient to replace . Responding to this , ABB completely redesigned the GMD sealing system . The new modular version has 50 % fewer parts , and its patented concept significantly reduces replacement time , according to van de Vijfeijken . “ It was first presented at the last ABB GMD User Meeting , where customers were able to perform the replacement on a specially prepared full-size stator segment for training purposes ,” he added .
In April last year , the new sealing system was installed as a pilot project on one of the two large 22.5 MW GMDs at Boliden ’ s Aitik mine site in Sweden , on its 38 ft ( 11.6 m ) diameter AG mills . Simon Eriksson , Section Manager responsible for electric power and GMD systems at Boliden ’ s Aitik concentrator , said : “ The dust seal replacement should not only be faster but also have a positive impact on safety as the stator covers don ’ t need to be removed using heavy lifting equipment , which takes up floor space and often disrupts other work disciplines such as relining . The pilot installation went smoothly , and all parts fit perfectly , despite the short time frame for planning , design and manufacturing . Aitik expects the overall mill availability
, which is already very high at over 96 %, to increase further with the new dust sealing system .”
The final results and lessons learned from this pilot project will be evaluated in the coming months , and the sealing system is scheduled to be launched in the middle of this year .
Rotor pole temperature monitoring The GMD motor has approximately 56 to 72 rotor poles mounted on the mill shell . Once again , customers approached ABB and requested reliable temperature monitoring of each individual GMD rotor pole . ABB developed a concept to continuously monitor temperature by means of a contactless infrared temperature sensor , strategically located for best accessibility , minimal cabling requirements and suitable distance to the rotating rotor poles . In addition , ABB is exploring a more holistic approach that correlates individual rotor pole winding temperature measurements with other GMD operating parameters , signals and measurements available through the GMD Connect condition monitoring platform . van de Vijfeijken explained : “ The goal is to identify any anomalies in trends and patterns that could be an early sign that perhaps something abnormal is happening before they develop any further and potentially cause an unscheduled mill shutdown .”
A pilot was installed on a customer ’ s GMD for a 26 ft diameter ball mill during a scheduled mill shutdown at the beginning of this year . Everythin g went according to plan ; the system appears to be working properly in the harsh environment and the first measurement results are being received , van de Vijfeijken says .
The GMD rotor pole temperature monitoring system is expected to be launched in the middle of this year and will be integrated into ABB ’ s GMD Connect condition monitoring platform .
Measuring up to size
TAKRAF is another company with a growing reputation in the comminution space , having been named in contract awards related to several major development projects over the past 18 months .
When speaking to IM earlier this year , CEO Thomas Jabs reflected on these wins , saying the ability to supply a full line from primary crushing right through to the export terminal and shiploader had proved to be a key differentiator for clients .
“ Simandou , for example , includes primary and secondary in-pit crushing and conveying ( IPCC ) systems and stacking reclaiming at the train load out area plus the wagon loading systems ,” he said .
While TAKRAF can supply equipment from other OEMs for contracts , it can also call on its own X-TREME class sizers and HPGRs . Both of these will be delivered to Simandou , in Guinea , as part of the agreement to design , fabricate and deliver an advanced and integrated IPCC and material handling system for the mine .
On sizers specifically , Jabs said : “ We have pushed the envelope with our sizers quite a lot – I would say that what is possible to crush with
our designs , especially our TAKRAF X-TREME Class Sizers , is much higher than many expected .
“ Part of this has been driven by our deep understanding of wear behavi iour , including being able to supply our WolfRAM armour solution , which is a very robust tungsten carbide overlay , for handling harder materials . This tooth hardening approach , combined with optimised tooth configurations and high torque drivetrains , I would say , are standout features for our sizer offering in mining , not to mention some of the clever maintenance solutions we have also developed . And I think that these factors have been a major factor in our success in the Alberta oil sands , for example .”
Closed-loop circularity
Speaking of CO 2 emission savings , Codelco and Magotteaux Andino SA recently signed an agreement to implement a circular economy model in the supply of grinding balls .
The contract , which is valid for five years and started at the beginning of 2024 , includes a pilot that allows Magotteaux to manufacture new grinding ball input with metal waste and worn balls from the El Teniente Division , which translates into a significant carbon footprint reduction . Specifically
, there will be almost 40,000 t / y of CO 2 saved , Codelco says .
The project marks a milestone for Codelco in terms of reducing its Scope 3 emissions . Recently
, the company committed to reducing its emissions intensity associated with strategic operational inputs by 25 % by 2030 , and this initiative with Magotteaux represents progress towards meeting said goal , applying the circular economy in its business vision
, it says . Likewise , it is the first major contract in the corporation ’ s supply area thatt adopts a closed-
Codelco and Magotteaux Andino SA recently signed an agreement to implement a circular economy model in the supply of grinding balls
24 International Mining | MARCH 2025