Mining equipment is never permanent. Once an area has been mined of its resources, the equipment must be demobilised and moved to a new location so that operations can continue.
Typically, this plant will stay in location for around 10 years before the inevitable move must happen. When it does, planning an efficient method of disassembly with the least number of cuttings is essential to ensure productivity stays as high as possible.
Codelco is Chile’s state-owned copper mining company and has mines near the city of Calama.
There were 16 components, including the ‘big six’: the largest items that made up the crusher system – which extracts materials from mines and breaks them down into smaller pieces.
Codelco had never carried out an operation of this size before. It approached Mammoet for guidance on the best heavy lifting and heavy transport equipment, as well as engineering solutions to achieve its goal.
Engineers at Mammoet proposed a series of different extraction methods to allow the key components to relocate as whole units – reducing cost and resulting in the project finishing earlier than expected.
Planning the route, methodology and the heavy lifting and transport equipment to carry out the operation was the first step, with engineers at Mammoet supporting throughout every stage.
“We worked with Codelco for a year and a half on the planning,” explained Mammoet sales manager Vanessa Labana. “We created all the route plans and drawings and supported them to answer all the questions and considerations they had to face on site. For example, the correct slope, turn ratios, and width of the road to facilitate the fastest transport route”.
One of the biggest challenges was sourcing and mobilising all the equipment and personnel for a project of this scale from Mammoet’s branches. By pooling its global resources, Mammoet was able to meet this challenge.
To bolster the equipment that was already available in Chile, Self-Propelled Modular Transporters (SPMTs) came from Malaysia, skidding systems from the US, and additional equipment was sourced from Colombia.
There were six key components to relocate, and the method for removal and transporting was different for each. Most were lifted using climbing jacks and then relocated with SPMTs fitted with support beams.
For the drive system, this same approach was used, but with the addition of a skidding system. This was used to slide the component twelve meters, before it could be jacked down into its final position.
The two heaviest items to perform heavy transport and heavy lifting for were the silo (1,100t) and crusher itself (1,300t), with the latter being the most complex of the six cargo movements.
“This was a big challenge”, said Labana. “We created a support beam that was especially adapted for this cargo. We had to make some alterations to our original beams by applying lead reinforcements on top, at the four lifting points, to prevent deformation.”
The crusher was extracted from its housing using skid tracks and skid shoes before being lifted into the air high enough for SPMTs to move underneath. Lashing was used to add additional support and hold everything in position during the 4.5km journey.
An area close to the demobilisation location was created to allow the crusher to be rotated 180 degrees so it would be in the correct position for installation.
Once it arrived at the installation site, the earlier process was repeated in reverse, with SPMT trailers lowering the cargo onto skid tracks to slide it back into its new position.
The gallery unit was also a challenge due to the ground soil not being completely level, with a 1% slope. As a result, two hydraulic jacks were used to perform heavy lifting on its back end at three different intervals to keep everything level as it was skidded forward.
The operation was completed in just over a month, taking less time than was expected - due to crusher parts being removed as complete units. This allowed the mine to get back up and running quickly.
Mammoet successfully managed the team, equipment and engineering steps to deliver the project safely and efficiently, mobilising everything to site on time and avoiding costly delays and penalties.
A team of 70 people, and a total of 160 axle lines of SPMT, eight skid shoes (500t), eight jacking systems (400t), as well as support beams, rails, and lashing, were used across the project.
“If this project had been done this in a conventional way, Codelco would have needed to cut and disassemble the equipment, and this would have taken a lot of time”, Labana noted.
“This is the first time Codelco has done something like this. With us, they have a partner for future projects due to trust in our experience, equipment and background.”