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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 CO2 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
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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
