Modernizing for higher reliability and throughput
The Chilean mining company Compañía Minera Doña Inés de Collahuasi SCM is one of the biggest copper ore operations worldwide – with a mining district in an Andean area that causes not just special challenges because of its remote location, but also because of its high altitude.
How to increased reliability and throughput for ore mills
The Collahuasi area has a long history of commercial mining activity that dates back to 1880 with 50 years of mining of high-grade copper and silver veins. The mining company Compañía Minera Doña Inés de Collahuasi SCM started its commercial operations in 1999 and became one of the world’s biggest copper ore operations since. As the reliability and throughput of their mills is crucial to the company’s success, Compañía Minera Doña Inés de Collahuasi SCM was looking for a solution to modernize four copper ore mills at their site in the North of Chile, around 180 kilometers southeast of the port of Iquique.
The decision was made in favour of Siemens, resulting in an order for modernizing the drive system of the four ore mills – two 8 MW semi-autogenous (SAG) mills and two 9.7 MW ball mills.
This project had quite a few challenges
Take off – giants conquer the air
The order Siemens was in charge of sounds gigantic: four complete state-of-the-art dual-pinion drive systems for the mill, six 4,000 kW and six 4,850 kW synchronous motors, FLENDER couplings ZAPEX with torque limiting, SINAMICS SL150 converters with thyristor columns, and a transformer. That raised the question, how to get everything on site in time?
How to get giants off the ground
The first four gigantic motors were urgently required in advance for production line two. But transporting the heavy machines – each weighing 42 tons – to the high-altitude site in northern Chile normally takes a great deal of time. And considering the tight project schedule of less than nine months, time was scarce goods. Therefore the team decided to use the express air freight delivery instead of the sea transport and got the four gigantic motors, once completed, from Dynamowerk Berlin, Germany, by truck as a wide load to Leipzig/Halle Airport.
But what kind of plane could handle the precious overweight XXL cargo? The answer was delivered by another giant: the world’s largest cargo aircraft, the type Antonov 225, with a wingspan of 88 meter, 32 wheels, aa tare weight of 285 tons, and a payload of 160 tons. And thanks to its 84-meter-long length, the flying colossus had no problem at all to take on the motors despite their enormous external dimensions. Using the Antonov 225, the four motors arrived at the airport near Iquique, Chile, in record time, while the remaining motors followed by ship.
Come along on the journey
Safe landing – and the arrival of other components
Back on the ground, the drives continued their journey by special transport up the Chilean mountains to the mine and arrived on time for the installation phase which was also conducted by the Siemens team. The remaining components like the E-Houses followed to Chile by ship.
How to get the systems up and running
The Siemens team wasn’t just in charge of delivering the dual-pinion drives, but also responsible for upgrading all software and hardware systems and for the installation. To minimize the costly standstill of the mills, the team had just 13 days to install the new drives and systems.
To speed up the replacement, saving adjustment time and effort, the Siemens engineers had to design the new systems to fit the existing foundations of the old motors. They also replaced the entire mill automation system with modern technology to minimize any time-sensitive risks that could occur by just adapting the hardware and software. The electrical and thermal dimensioning of the components were made with the mine’s location at an altitude of over 4,200 meters in mind. Using new pre-assembled E-Houses (Electrical Houses) for installing the automation systems and direct converters were an enormously time-saving measure.
The E-Houses were fully developed, produced and pre-tested in the Siemens plant in Santiago, Chile, making the process of connecting and commissioning on site much easier. This way, it was possible for the Siemens team to keep the deadline and install the system within the extremely short standstill period of just 13 days – and for everything to be online within nine months.
Six months later …
The four motors already proved their value within the first six months: with increased reliability and mill throughput, leading to a significantly higher availability of Chilean copper in the market – and higher profits for Collahuasi.
