Case Study




Paste Plant operation at a Gold Mine.


Xenco was asked to investigate the cause of unreliability of a paste plant at a Western Australian gold mine.

  • Achieving production rate
  • Paste plant availability
  • Declined condition of plant equipment
  • Minimal preventive maintenance plans
  • Access to critical insurance spares
  • Low priority of the paste plant
  • Low interest, knowledge and ownership of the paste plant

Xenco commenced with a standard diagnostic activity involving remote data analysis followed by a site visit. This resulted in an improvement plan that was executed to improve the reliability and operation of the paste plant. Key actions included:

Diagnostic activity

  • Remote analysis of maintenance and production data, and interviews followed by a site visit to gain insight into the nature of the problems
  • Facilitated two “Lean” process workshops to highlight opportunities.
  • Identified key areas of Paste distribution system delays.
  • Identified critical, insurance and consumable spare parts and created ANSI’s and BOMs.

Improvement plan

  • Provided training for supervisors, tradespeople and planners to improve ownership.
  • Planned and executed a series of shutdowns to eliminate the causes of chronic performance issues.
  • Develop approximately 70 detailed high-quality maintenance work instructions.
  • Revised the equipment structure in Pronto.
  • Restored the physical condition of the plant and eliminate persistent failure modes.

The Diagnostic Activity
The analysis revealed that although downtime on the filter was significant, there was more downtime associated with the wider paste plant and underground paste fill activities, resulting in approximately 70 new high-quality maintenance work instructions that delivered overall operational improvement.

Process mapping workshops of the underground paste placement activities were run to identify opportunities to streamline underground paste fill activities and reduce delays.

Improvement Plan
Providing training to stakeholders led to an enhancement in their knowledge and comprehension of the plants’ operations. As a result, production levels increased, and this positive shift in performance led to a sense of greater ownership.

Reduced Maintenance Costs
The implementation of the high-quality maintenance work instructions enabled the team to pinpoint and eliminate the root cause of chronic performance issues that affected the entire paste plant, including the paste filter. This improvement resulted in substantial cost savings across maintenance and repair activities.

Increased Reliability and Production Rate
The production increased to record daily tonnages since implementation. The plant previously struggled to achieve 105 m3 per hour and is now running at up to 200 m3 per hour (against a design of 120 m3) due to the improved processes and maintenance work.

The root causes of damage to the filter cloth were identified and eliminated prolonging the cloth life from 21 days at its worst, to 238 days (most recent) while also producing a record cubic meter production of paste.


“I thought I’d share some good news, … which is the highest 24hrs of production ever at this site.”
– Management