Mill Performance KPIs: Which to Monitor or Disregard

Mill performance is integral to the success of mining operations. This makes the identification of KPIs that reveal mill performance more pronounced. As the mill performance KPIs are numerous, separating the relevant from the irrelevant can be tedious. This article identifies the most relevant KPIs and the KPIs that are problematic and require the most discretion (Entomo, 2023).

KPIs to Monitor

Throughput

This KPI denotes the quantity of samples that are milled in a particular time frame and is representative of the operational capability of the mill (InetSoft, n.d.).

Recovery Rate

This KPI is indicative of the efficiency of processing the ore. The higher the recovery rate, the higher the efficiency of the processing and the optimal utilization of resources (Unison Mining, 2024).

Energy Consumption per Ton

This KPI is indicative of the operating costs of the mill. A mill that processes ore with a lower consumption of energy is optimal (InetSoft, n.d.).

Overall Equipment Effectiveness (OEE)

This KPI is representative of the efficiency of the operations of the mill and the effectiveness of the operations of the mill (Entomo, 2023).

Mean Time Between Failures (MTBF)

This KPI denotes the reliability and stability of the mill. A higher MTBF leads to a more reliable and stable mill (InetSoft, n.d.).

Mean Time to Repair (MTTR)

A mill with a low MTTR will be disrupted less and will thus have a higher productivity and efficiency (Entomo, 2023).

Analyzing these KPIs allows a comprehensive examination of mills focusing on aspects of productivity, process, and the reliability of equipment.

KPIs That Require Caution

Utilization Rate

It only measures how much time equipment is running. This metric cannot determine if production is being done effectively or if it is done efficiently (Entomo, 2023).

Maintenance Cost per Hour

This can be a deceptive metric. If maintenance costs are becoming lower, this could show that maintenance is becoming neglectful and costs could be incurred due to failures of the equipment (InetSoft, n.d.).

Labor Hours per Ton

This can show how much equipment is being run due to the amount of automation, but it will not show how efficient the processes or operations are (Unison Mining, 2024).

Downtime Percentage

This metric will fail to show how equipment is run if unplanned downtime is not separated from planned maintenance (Entomo, 2023).

These KPIs can be valuable, but the limitations should always be considered along with the direct performance of metrics.

KPIs Versus Operational Goals

KPIs should be adjusted to meet the specific goals of the operations. If reliability of equipment is the goal, OEE, MTBF, and MTTR become so much more important (InetSoft, n.d.; Unison Mining, 2024).

These goals can be achieved by incorporating new technology. Using advanced analytics with real-time technology can further enhance KPIs to better aid with operational goals and lead to ongoing improvements. (Entomo, 2023).

Conclusion

To evaluate mill performance efficiently, KPIs must be chosen to match operational goals, and KPIs must deliver insights that are not trivial. Mining operations focusing on throughput, recovery rate, energy, and reliability can achieve positive changes to their business performance by increasing productivity and reducing the costs and the risks associated with achieving higher profits. When interpreting secondary metrics, performance context must always be included as secondary metrics may be misleading.

People Also Ask (FAQs)

Which mill performance KPIs are most important?

The throughput and recovery rate may be the only KPIs that are important.

Why is mining mill OEE important?

OEE gives a total view of mining mill operations.

How does energy consumption affect mill performance?

Less energy used per ton reduces overall costs and improves the effect of the operation.

What does MTBF in a mill operation mean?

MTBF is the measurement of reliability.

Can downtime be used as the only performance indicator?

No, as the real meaning of downtime is only apparent when maintenance and reliability are also taken into account.