Cerro Lindo is an underground copper mine with an average daily production of 20,000 tons. The mine is located in central Peru, 175 kilometers southeast of the capital city of Lima, and operated by Nexa Resources.
A decade of continuous work
The relationship between Metso and Nexa Resources has deep roots. Cerro Lindo has been using three Metso grinding mills and two Lokotrack mobile crushing plants for a decade. They continue to turn to Metso whenever they are facing a challenge.
Cerro Lindo is renowned for its eagerness to implement new innovations into its processes. For example, it was the first mine in Peru to use Osmosis treated sea water instead of fresh water in their process. So it was no surprise that they wanted to try Poly-Met™ mill lining, a significant industry innovation.
Bringing important savings to the mine’s economy
In 2013, Cerro Lindo was looking to increase the wear life of the mill linings in its primary 14’x23.5’ ball mill. A longer interval between lining change-outs would increase availability, help to avoid unnecessary operational costs and, in turn, result in more production hours.
Cerro Lindo turned to Metso and decided on a trial of the Poly-Met lining in the shell of their primary ball mill in November 2014. The Poly-Met concept combines the most desirable properties of rubber and metallic alloys. This concept allows for the use of more resistant alloys than those used in conventional metallic lining, as the rubber substantially dampens the impact force.
As the benefits of Poly-Met started to show, Cerro Lindo awarded Metso with an order for the whole set. The first test installation was completed in July 2015 and the second full installation was completed in March 2016. The new lining design lead to 50% increased lifter bar wear life and as much as 200% longer life of the shell plates, resulting in decreased downtime. The lifter bars are now changed every 12 months and the shell plates every 24 months, compared to the 8 months change-out cycle of the previous metallic lining.
“We reached our goals”
“The important thing to point out is that we reached our goal, thanks to the product support and service given by Metso at every stage. They helped us out during the installation, the plant’s shutdowns, and so much more. We worked as a team and that’s difficult to find in the market,” says Gustavo de la Torre, Mineral Processing Manager of Cerro Lindo.
“I encourage other mining operations to try Poly-Met linings, they worked for us and I’m sure that they will work for others. These linings can definitely bring huge benefits to every mining operation,” he adds.
Metso’s unique solution helped the customer not only to accomplish their main goal of extended liner life, but also to reduce the mill’s weight. It was demonstrated that rubber has positive effects on the grinding process.
Metso’s deep industry knowledge has helped to create a Poly-Met solution that works just as well as the previous metallic lining, but reduces downtime, increases production, and reduces operational costs, among many other benefits.