Sometimes finding a better way to approach a project is more about finding ways that are good … better … and then best!

The Las Bambas copper mine is located in mountainous terrain near Cusco, Peru, 4,300 m above sea level and more than 700 km from the Pacific Ocean shipping terminal at the Port of Matarani. When base metals miner MMG purchased Las Bambas from Xtrata in 2014, plans were already in place to transport copper concentrate slurry by pipeline from the crushing and floatation plant at the mine to Antapacay and then to the Port of Matarani by rail. Planning and engineering had been completed, and most of the pipe, pumps and other assets had already been purchased and transported to site.

But with the Global Financial Crisis still weighing heavily on the markets, MMG was under considerable pressure to get product to market.

“They said, ‘We don’t have time to complete the permitting process to get the pipeline in place,’” recalls Joel Shirriff, VP and Global Practice Lead, Terminals & Transportation. “We need to get cash flow happening.”

MMG proposed moving the concentrate the entire 700 km distance to port by a large fleet of open trucks – a conventional solution that could be put into motion almost immediately. Good idea.

Good doesn’t mean good enough.

Ausenco engineers looked at the problem and came up with a better idea. Our Better Way was to develop a unique containerized bulk handling (CBH), multi-modal system that had a number of advantages over open trucks.

Custom containers were designed, including a bespoke container loader and lid handling facility at the mine site. The containers integrated with customized tractor and trailer units, as well as maintaining compatibility with the rotary spreader, to simplify and streamline the loading process. Containers would be loaded at the mine and trucked 420 km to a trans-load facility where they were moved onto trains for the remaining 310 km trip to the port. There they would be discharged into the conventional bulk system for storage and loading onto ships.

The advantages of this multi-modal approach were far-reaching. On the business side, sealed containers had a nearly 8% capacity improvement over open-top bulk trailers. The mutli-modal design allowed for an easy transfer to rail, which eliminated significant driving distance and the number of trucks required, especially through congested roads around the city of Arequipa. That meant bringing more product to market, quicker and more cost-effectively.

On the environmental side, sealed containers reduced the potential for heavy metal concentrate leaking into nearby communities and ecosystems, and less environmental contamination in case of accidents.

“If a [conventional] truck goes off the road,” Shirriff explains, “basically most of that cargo goes onto the ground, creating significant environmental concerns.” These specialized containers are designed to avoid this problem. “The individual bulk containers we use are essentially sealed and have been tested to not break open. Even if a truck goes off the road and rolls over, the copper concentrate is not exposed to the environment. The product does not see the light of day until it gets to the terminal.”

Covering almost half the distance using existing rail lines also meant reducing truck traffic through a number of communities, lowering the potential for accidents and reducing the total fleet size. We anticipated that significant truck traffic would be problematic for the remaining communities along the route, as well as a potential danger. The use of rail transport for 310 km of the 730 km route would avoid potential conflict with several important settlements.

A better Better Way.

Those predictions proved to be true. While the significant use of rail had kept the trucking fleet out of a number of congested cities and towns on the lower section of the transit, several communities along the remaining truck route began to push back against the additional traffic, and the potential dangers the truck fleet introduced. Local protests have led to roadblocks and other temporary closures, and that pushed MMG to look for alternatives to the existing plan.

“They were looking at alternative routes – bypass roads, additional bridges that would allow them to run the trucks on a different route – even changing the connection point to the rail section so that the truck routes were shorter,” says Shirriff.

With all of the required pumps and piping already acquired and in storage, however, the original slurry pipeline once again appeared to be the solution of choice. Having recently helped MMG add a third ball mill to their crushing operation, our teams had a strong relationship that could position us well for the pipeline re-activation feasibility study.

“Because we had the inside knowledge from the previous work, our pipeline teams are better suited to do this,” Shirriff explains. “That's what we always want to have happen with our clients.”

Ausenco has assessed the situation and is studying alternative scenarios in how to implement the original pipeline system given several challenges. This would provide a long-term sustainable option and eliminate the truck traffic entirely heeding the requests of the local communities – neighbourhoods that are home to a large proportion of the mine’s workforce.

Continuing to support our clients throughout the life of a project – helping them deal with issues as they evolve – is part of what defines our commitment to building strong relationships.

“We don't just build a project and move onto the next one,” Shirriff says. “We continue to work with our clients, engaging with them to ensure satisfaction, and continuing to find a better way to make their systems more efficient and appropriate for the societal needs at the time.”

For more information on the multi-modal transport system, contact Joel Shirriff and for information on the pipeline system, contact Roberto Easdale.