The Slag Treatment Plant (PTE) of the El Teniente Division defines the initiative that reduced the ball mill revolutions per minute from 12.5 to 9.5 and achieved energy and economic savings equivalent to US$1 million annually as a “change in the operational standard.”

“At the PTE, 40% of the costs are energy costs. And of these, 60% corresponds to the ball mill. So we set ourselves the goal of lowering the mill's revolutions per minute, without affecting the metallurgical variables,” explains Cristian Miranda, head of the unit.

Ignacio Arriagada, maintenance engineer, adds that “in order to achieve this reduction in energy costs, the operators were consulted and the current speed of the mills was reached. We tested how to reduce the speed without having a decrease in production results.”

Thus, after a series of tests, the standard operating speed of the ball mill, which was 12.5 revolutions per minute, was gradually reduced to 9.5 and even 8.5 revolutions per minute at times.

According to the expert operator, Cristóbal Pérez, “it is good to make these adjustments, because we have already passed the start-up of the plant (which began operations in 2019) and we are in the process of optimizing to get the most out of each piece of equipment.”

Paula Calvo, superintendent of the Slag Treatment Plant, highlights that “the reduction in energy consumption has been a collaborative effort by both the operations and maintenance teams, which is in line with seeking new opportunities to make our business more competitive. The initiative had a very good impact on the energy and economic savings of the plant, without affecting our product, which makes us feel proud.”