Solito Solution™  #35

Sag Mill


Far too frequent lube oil filter changes were eating into the mill’s productivity due to far too frequent oil and filter changes. Eleven unscheduled changes each year were causing complete shut downs.


$247,500 of lost production was returned to operations. An immediate reduction of $187,000 was achieved in annual maintenance costs.

We Found: The lubricating oil filtration system on the Sag Mill appeared to be operating correctly. A review of sequential oil analysis determined that the rate of particle build up was faster than it should have been, indicating ingression of external contamination.

We Fixed: The filtration system was upgraded using standard parts and FilterMag magnetic fluid filtration to increase efficiency and contaminant holding capacity. Fresh oil was filtered as it was transferred into system reservoirs. Beginning lubricant cleanliness levels were improved by 75%. High efficiency, high capacity desiccant breathers were added to the equipment to reduce contaminant ingression. Overall lubrication oil particle counts were reduced by an average of 97%, resulting in less equipment wear, higher reliability, and longer life.

How We Facilitated Changes: Maintenance technicians were trained in the use of filter carts for oil changes. Maintenance procedures were implemented for breathers and magnetic filtration. Overall awareness of proper lubrication procedures was emphasized throughout the time Solito was on the project.

The numbers: Each filter change required approximately 45 minutes of downtime. Eleven filter changes per year were eliminated. Production was valued at $30,000 per hour.

Returned production to mine:

.75 hours X $30,000 = $22,500 lost production per filter change.

11 filter changes X $22,500 = $247,500 production returned to operations.

Annual maintenance savings:

Unscheduled oil and filter consumption was eliminated.

$17,000/oil & filter change X 11 changes/year = $187,000 maintenance savings per year.