COMMINUTION & CRUSHING
predictive maintenance culture and making use of the available state-of-the-art digital solutions is key to achieving this .”
Alongside this , ABB will also be at the event discussing the challenges associated with operating large grinding mill drives in renewable energy-dominated grids : a topic it believes will represent more of an ongoing challenge as more mines move towards zero carbon emission operations .
ABB recently reached a major milestone of 160 gearless mill drive units sold
1985 . On the latter , it has supplied HPGR drive systems to high profile mines across the globe , like Southern Peru Copper ’ s Toquepala mine .
Like other companies and experts consulted for this article , ABB sees the relevant use of these technologies depending on the application at hand .
Wilson Monteiro , Business Line Manager , GMD , ABB , explained : “ HPGR and vertical mills ( such as Vertimills and stirred mills ) have shown promise in some applications , especially for certain types of ores . However , when we compare the efficiency between the drive powertrain of GMDs , RMDs ( ring-geared mill drives ), HPGRs and Vertimills , the GMD is always more efficient due to its intrinsic construction characteristic .” GMDs do not have an intermediate power transmission system , enabling an efficiency gain on HPGRs / vertical mills of around 2-4 % depending on the model , according to Monteiro .
A wider awareness of this fact has led to ABB ’ s GMD sales surging over recent decades .
“ It took us 32 years to reach a production of 40 GMDs , then we doubled the quantity in eight years , and then it took another 15 years to double it again , reaching , today , around 160 units sold ,” Monteiro said .
With ore grades continuing to fall , Monteiro envisages the need for even larger GMDs than the 28 MW ones the company has supplied the sector to date . These GMDs will , he says , prove to be even more efficient in operation than using two or more HPGR / vertical mill units .
This efficiency is key when it comes to mining companies achieving their climate change goals , as Monteiro explained .
“ The use of more efficient solutions will play a key role in future decision-making processes ,” he said . “ Any gain in efficiency , no matter how small , will have a huge impact on reducing carbon emissions . As mentioned before , the gearless
motor technology offers the highest availability , highest energy efficiency and the highest achievable power .
“ We estimate that our GMD installed base is avoiding between 106,000-195,000 t / y of CO 2 emissions when compared with other grinding technologies . That is equivalent of taking 49,000- 89,000 cars off the road every year .”
To achieve these emission reductions , companies need to not only purchase the equipment but more readily move from conditionbased maintenance practices to predictive processes , according to Monteiro .
At the upcoming SAG 2023 conference in Vancouver , Canada , Monteiro and his colleagues will be presenting the latest features of its digital platform , ABB Ability™ Predictive Maintenance for Grinding , which aims to extend the lifetime of grinding assets through better use of resources and to support non-stop operation and avoid unforeseen downtime .
“ We do believe that the mining industry still has some room for improvement in terms of more efficient operations ,” Monteiro said . “ Having a
Ten Derrick SuperStacks closing the grinding circuit at AM / NS India
Derrick dealing with the fine print
This ongoing upstream evolution has a big impact on those further down the process flowsheet , as Baojie Zhang , Director of Application Engineering at Derrick Corporation , explained .
“ Comminution and classification are advancing in different directions for different minerals ,” he told IM .
“ For example , many iron ore operators are grinding finer to achieve better liberation and higher-grade concentrate , driven by green steel transitions . Fine screens down to 38 microns are sometimes required to produce high grade (> 67 % Fe , DRI-grade ) concentrate .”
Derrick , a supplier of screening equipment , is engaged with this transition , as evidenced by a recent case study with ArcelorMittal Nippon Steel India ( AM / NS India ).
ArcelorMittal Nippon Steel India manages a 253-km-long continuous iron ore slurry pipeline , one of Asia ’ s longest , connecting the Dabuna beneficiation plant to the Paradeep pellet plant .
As part of a plan to increase the Dabuna beneficiation plant capacity from 8 Mt / y to 12 Mt / y , the steel maker sought to address one of the bottlenecks in its process : the hydrocyclonebased classification system . This system was deemed inefficient in producing the desired product , producing excess ultrafine and coarse particles .
“ The ultrafines negatively affect the final iron ore pellet quality and limit the grinding capacity , while the coarse particles may cause excessive
International Mining | SEPTEMBER 2023