INTERVIEW
11,000 t / h as well as the e-house with MV and LV power distribution plus a cooling system for the motors and e-house . The automation of the conveyor system will use our process control system Simatic PCS-7 .
Q Technically , why are gearless drives having such a big impact in the market for the world ’ s largest mining conveyors ? Is the technology now being considered as a first option ? A It has been well proven that for these large capacity and high torque drive conveyors , the gearless drive enables efficiency to be increased by 3 %, but beyond this it cuts down the necessary maintenance work and associated costs , as wearing parts such as couplings , motor bearings and gearboxes are no longer required . Plus , it reduces energy consumption and CO 2 emissions . And you are right – on our reference list with the exception of Oyu Tolgoi which was only really possible with gearless drives – all the others have involved trade off studies between conventional and gearless with gearless coming out on top . The references plus the seamless performance of these installations , with no serious issues to date at any of the installed projects – means mining companies with large projects having a major overland conveyor element are now looking to gearless first whereas before it was seen as a relatively new and untested solution . To quote one of our South American customers : “ Whenever it is possible I would like to replace every geared system to gearless .” The only issue today is that gearless still involves a higher initial investment so in some cases it may not be suited to a short life mining project eg less than ten years .
Q Is real time analysis going to play a major role in material conveying going forward ? A It is increasingly something major miners are asking for , with the greater focus on areas like in the pit ore sorting and ore characterisation in the mine up to the stockpile stage before it gets to the plant . We signed an agreement back in 2018 with MineSense to combine their BeltSense on-conveyor analysis solution with the Siemens Simine MAQ single material and quality management system to enable customers to significantly increase efficiency via a single view of quality across the whole conveying process . A stockpile installation at a copper mine in British Columbia will represent the first time we will have worked together on a full project .
Q Moving on to grinding mills – what would you highlight there as the key factors in Siemens gearless success plus are there any milestones you would single out ? A We installed the first mill Simine GMD in 1980 and are now approaching 100 installations for ore grinding mills . Even though the global COVID-19 pandemic led to delays or postponement of larger projects worldwide , we were still able to win several major contracts during 2020 / 2021 in Southeast Asia and Central America . And within that total number is included a number of industry firsts . I would highlight the world ‘ s first gearless drive for a SAG mill in 1988 at Chuquicamata and the first 40 ft mill GMD at Cadia in 1998 and the first GMDs at an altitude above 4,000 m at Antamina in 2011 . In 2016 we also set a record at one project with six of the highest powered 40 ft GMDs ever built on AG mills at the CITIC Pacific magnetite iron ore project in Australia . Also notable is the rugged outdoor version of Simine GMD which has been successfully in operation since 1998 . The outdoor version design takes into account tough environmental conditions as well as the absorption of solar radiation . In more recent years , the advancements in asset health analytics ( AHA )/ condition monitoring and further digitalisation of elements like our SINAMICS closed-loop drive control system and PCS7 process control system have taken these mill GMD installations to another level again . After successfully starting up nine Simine GMDs in 2020 , we will commission a further eight Simine GMDs through 2021 for multiple expansion projects and a greenfield mine in Indonesia , Chile and Peru , all of which can avail of these latest digitalisation advancements . Today , these systems are integral to the grinding circuits of our customers to avoid any kind of unplanned shutdowns by incorporating AHA based on anomaly detection , mathematical models and AI algorithms . And as mentioned there is now a lot of market activity – Antofagasta alone is expanding Los Pelambres and building a new Centinela concentrator as an example . We are also seeing a lot of project activity in Russia on the back of the successful 2020 start-up of six Simine GMDs for a copper
Siemens has now installed almost 100 grinding mill gearless drives worldwide
mine in Chelyabinsk , which are currently the largest in operation in Russia . On technical aspects of why our GMDs have succeeded in the milling market – there are many reasons but two to highlight would be round-the-clock reliability and availability based on mature technology like
our rugged ring motors and fuseless cycloconverters , and of course our process of continuous improvement like enhanced control for better overall operation including reducing reactive power draw during start-up , inching and creeping .
Q Are there any downsides to GMDs in mill circuits ? A Not in terms of performance . Again , higher initial CAPEX cost can be an issue for some projects , plus the installation time is longer . In both GMDs for conveyors and for mills , they tend to be best suited to larger and longer life mining projects , partly due to the ROI relating to less maintenance OPEX and fewer stoppages plus increasingly the fact they are much more energy efficient . It is helped by the fact that many mines are switching to all or at least a majority of renewable energy use . These are high speed , high torque applications without a complex gearbox attached . Ring-gear , pinions , motor bearings , couplings and gearboxes using several stages are needed for conventional drives at these projects , all with losses in efficiency due to mechanical resistance .
Q Moving on to mobile equipment , how would you summarise your market presence there ? A Siemens Commercial Vehicles through the
Siemens Mining Mobility division provides electric drive solutions for numerous mining
applications , ranging from 3.5 t underground utility vehicles to 450 t class haul trucks as well as shovels and draglines . It includes various
116 International Mining | SEPTEMBER 2021