Chilean State-owned miner Codelco’s underground copper mine, El Teniente, in Cachapoal, has become the first mine worldwide to use diversified engineering group Metso’s innovative grinding technology.
Metso says that the technology is the “next level” of Poly-Met discharge grates for semi- autogenous grinding (SAG) mills. The group states that the grinding innovation and close cooperation in 2015 between Metso’s experts and Codelco’s operations and maintenance specialists at El Teniente saw the mine achieve its all-time record for commercial production with substantially lower operating costs.
“At El Teniente, we are constantly innovating to improve our processes and maximise results. In this specific case, we incorporated Metso’s solution into our processes and we have already seen substantial improvements in operations and maintenance,” says El Teniente GM Mauricio Larraín.
El Teniente has been in operation since 1907 and is the biggest underground cooper mine worldwide. The copper mine has a production volume of up to 140 000 t/d.
To show appreciation for the good collaboration over the years, Metso minerals services president Perttu Louhiluoto recently visited the site and personally presented a recognition award to Larraín.
Metso recounts that, in 2010, El Teniente’s problems with grate piece breakage in their SAG mill resulted in low mill availability and operational instability. However, the miner worked in close cooperation with Metso to solve the problem. As a result, the “next level” of Poly-Met discharge grates were deployed in a SAG mill for the first time.
Louhiluoto states that this “innovative” technology improves the copper production process by increasing the throughput and pebble production while also decreasing wear rates.
“The results have been impressive, as, in 2015, El Teniente achieved record commercial production of over 71 000 t of fine copper at one of the industry’s lowest-cost levels,” he points out.
Larraín adds that an increase in slot size and operational stability has increased throughput by 7%, with pebble production having increased by 24% during the first 50 days of operation, while the wear rate decreased from 0.26 mm/d to 0.11 mm/d.
Mill availability increased, owing to the elimi- nation of pinning and breakage. Larraín highlights that El Teniente also achieved historical results in safety in 2015 with an accumulated frequency rate of 1.
Meanwhile, Louhiluoto explains that the Poly-Met discharge grates are made of metal and rubber, which means less weight and greater elasticity.
“The composite material was identified as the best solution for this type of application after a series of trials with El Teniente between 2012 and 2014,” he remarks.
Metso is planning a global launch of Poly-Met grates in the latter part of 2016.