:: New Nordberg Crusher Increases Production for Copper Mine in Peru

The Condestable mine is one of the few copper mines in Peru located at sea level, just south of the capital Lima. It has been in operation since 1964 and has estimated reserves for another five years of production.

The company runs an underground mine from which the ore is processed through a Metso Minerals supplied crushing line to grinding, flotation and concentrators. The concentrate is crystallized, sold to Colmira and transported by truck to Lima. For every 20 t of processed ore, the yield is 1 t of concentrate.

The crushing line at Condestable consists of four steps, each using Nordberg crushers. A Nordberg C110 jaw crusher was installed earlier this year as the primary crusher. Previously, an Allis Chalmers 30 x 55 inch had been used since the mine opened around forty years ago. The new Nordberg C110 not only ensures a higher production but the mine was also able to reduce the discharge fraction from 6 to 4 inches.

"We knew the C110 was operating at other mines, such as Atacocha so we asked their engineers and were convinced that this was the best solution for our requirements," says Marco Delgado, Plant Manager at Condestable, "We still use the Allis Chalmers once a week during our weekly maintenance on the Nordberg C110."

For its secondary crushers, Condestable has invested in a Nordberg HP400 crusher, discharging a 30 mm fraction. For maximum wear protection, Trellex Poly-Cer plates are used in the discharge chute of the crusher.

"The specific weight of the ore at Condestable is 2.9 t/m3 in the bench and the ore is very hard with a work index of 19. This means that the linings in the crusher have to be changed every six weeks," says Fernando Samanez, Product Manager, Metso Minerals, Peru.

The tertiary crushing is carried out with a Symons 5 ½ SH cone crusher, and the fourth step uses two Nordberg HP400’s; one installed in November 2002 and a second in February 2003. This step gives a 6 mm final product size, which is fed to the grinding mills.

The mine has several ball mills, three large primary mills and three smaller mills. Metso Minerals has supplied two of the biggest - Allis Chalmers 9x12 and 12x14.

Rubber is becoming more frequently used for lifters and wear protection throughout the mills at Condestable. The 12x14 ball mill has Metso Minerals Skega Poly-Met lifters and despite a production increase over recent years, the lifetime for the lifters is equal or better than previous alternatives.