Copper and gold mine Oyu Tolgoi recently marked the beginning of its C2S underground conveyor belt commissioning in Mongolia with the posting on February 24 of an informational video on the project to coincide with the first belt pull. Delgerdalai Lkhamsuren, Senior Manager Construction at MCS Property LLC, which has been carrying out underground facilities development for Oyu Tolgoi since 2016 commented: “Today is a big day for us. MCSP started working on the construction of the conveyor to surface (C2S) project in 2022. It is a big project that involves a lot of people. It is a huge conveyor system that is 6.7 km in length from a depth of 1,300 m, capable of transporting 95,000 t/d of material.”
He adds: “Behind me you can see that the belt is being prepared for a pull up and flaked at the surface facility. Then the belt is pulled down the decline conveyor for about 2.2 km. The decline is at an 18 degree incline angle which can be compared to pulling from the regular inclination of a mountain. Just 1 m of belt weighs about 112 kg, the belt at its overall length weighs about 320 t. This is a high risk task that is performed by many people based on engineering calculations, with pre-determined methodology and risk assessments. After all the risk mitigation controls are in place, the task is being performed…right now we are pulling the first ever belt and in total we will go through 6.7 km of belt ups. It should be noted that the task if being performed in cold weather, therefore the preparation works from an ambient temperature point of view are extra challenging. However, our team has made all possible preparations for this moment.”
The C2S system is a key component of the Oyu Tolgoi underground Material Handling System (MHS) and will be the main means of transporting ore from underground as well as providing direct access to the mine from the surface. The first phase, often called MHS1 entails production shaft 2 which has a production capacity of 25,000 t/d through the hoisting system. With the second phase, often referred to as MHS2, the conveyor to surface (C2S) system will take the mine to approximately 95,000 t/d of ore. The C2S system comprises three identical 2,202 m long, 1.6 m wide steel cord conveyors that will operate at 6 m/s.
Andrew Weir, Worley Commissioning Manager talked specifically about MHS2 and C2S project: “So the belt up of CVB2022 represents 14 months of planning and execution. That equates to 2,291 FICs or 176 CVC packs. Overall that equates to 23% of total completion for MHS2.” He said it has taken the collaboration of a number of companies to get to this this point – these include MCSP, Worley, FLS, Bubenzer, Siemens, Ampcontrol, ABB, Belle Banne, Tavan Ord, Energy International, Sempertrans, Syntron Material Handling and of course OT. He adds: “It’s been a fantastic effort to date – we still have a long way to go to get overall completion for MHS2, but this represents a significant milestone in our journey towards first ore for MHS2.”
These companies have supplied a range of technologies, services and products. Worley’s involvement with the Oyu Tolgoi Underground Project began in April 2015, when it provided mine restart support services. In June 2016, it was then appointed to provide EPCM services for Oyu Tolgoi’s materials-handling systems and associated surface and underground infrastructure.
To detail some of the other companies involved, the main conveyor contract was originally awarded to thyssenkrupp in 2017, whose mining business was then sold to FLSmidth in 2022. The main components were four high-lift conveyors, each equipped with 1.6 m wide steel cord belts and dual 5,500 kW gearless drives from Siemens, and one of these Siemens drives can be seen in the latest video. Siemens has also supplied a range of other electrical equipment such as transformers and switchgear as well as E-houses.
Siemens spun off its large drives business, including those for mining, in 2023 to new company Innomotics and its ASEAN & Taiwan CEO based in Singapore, Christian Dirscherl said recently of the project: “Innomotics is playing a key role in the implementation of our gearless conveyor drives in a cutting-edge underground material handling system at Oyu Tolgoi. This system will efficiently transport 95,000 tons of copper ore daily to the surface. Proud to be part of this innovative project.”
Ampcontrol has supplied a full range of electrical equipment to power the mine including jumbo, pump and fan starters, substations and distribution control boards. It has also provided a range of electronic monitoring equipment including iMAC conveyor control equipment. ABB has supplied motor solutions plus electrical installation services. US company Syntron Material Handling and Australia’s Belle Banne Conveyor Products have supplied the key conveyor components including rollers/idlers, belt cleaners and pulleys. Dellner Bubenzer is a major conveyor braking systems supplier. Tavan Ord supplies fire safety systems and is a distributor for Tyco and Energy International is a specialised energy consultancy.
Sempertrans has also made a significant contribution to the project, supplying nearly 21 km of conveyor belts. This includes approximately 15 km of its advanced ST6300 Transevo belts, which it says are known for their low rolling resistance and exceptional durability. Sempertrans told IM that its commitment to quality extends beyond product delivery, adding that its dedicated supervisors were on-site to ensure the precise splicing of most of the belts, ensuring optimal performance and reliability.
Looking at the big picture, Oyu Tolgoi has also recently released its latest performance scorecard highlighting key performance metrics for the fourth quarter of 2023 and provided an update on underground mine production. Oyu Tolgoi continues the ramp-up of the underground mine safely ahead of plan with a total of 86 drawbells opened from Panel 0 as of 30 December 2023, including 14 drawbells during the fourth quarter. The operation is expected to ramp up to deliver an average mined copper production of ~500,000 t/y (100% basis) between 2028 and 2036. Construction of the conveyor to surface works continued to plan and was approaching 88% completion as at the end of December. Commissioning remains on track for the second half of 2024. Construction works for the concentrator conversion remains on schedule. Commissioning is expected to be progressively completed from the fourth quarter of 2024 through to the second quarter of 2025.