Reduction of Plant´s Energy Cost and Kw/Ton

Decreasing power intermittencies leveraging supervisory daily routines

  • Short Interval Control
  • Operational SOP´s improvement
  • KPI´s development
Driver Goal
  • To efficiently manage energy consumption of the Processing Plant.
  • To install an Energy Cost Management System to impact Milling Circuit and Flotation area as two of the main energy costs areas.
  • Monthly Energy Cost ($) per tonne milled decreased in 37% for the milling circuit, and 41.2% for flotation area.
  • With these percentages total savings projection were estimated in $211.5k / yr which represents a 14% of the 2015 yearly expenditure for the two mentioned areas.
  • Monthly Energy Consumption per tonne processed presented a reduction of 7.9% for the milling circuit, and 11.4% for flotation area (kg/ton).
Energy costs increased in 38% from December 2015 to March 2016, trending up. Plant was being managed by lowering mills tonnage as a result of low levels of ore entering to crushing circuit. Lowering tonnage of the two mills and switching mills as for different capacity needs, led in to an erratic and intermittent on and off of the equipment impacting costs. The plant was using the same amount of energy to mill less tonnes, not to mention the impact in recovery due to the lack of efficiency in TPOH.
Solution Approach
Making a call for powering off and on of a mill is normally a management call not a supervisor call. In these terms, the management consulting team worked with the client, redesigning the plant way of response for low tonnage scenarios. In this improvement, the plant would not have to adapt to the amount of ore as an input of the system, but would lead the plant into an efficient way of processing what is available.
Actions Taken
Management Team was trained to use simple MOS tools to be able to measure their weekly energy performance and improve decision making.

The system changed in to a very different scheme with the following features:
  • Introduced an improved Mill shutdown schedule.
  • This new schedule complied with the 93% of milling circuit required availability.
  • Removed all power intermittencies, decreasing power peaks due to rebooting.
  • Assured long runs by accumulation of ore due to this new shutdowns scheduling system.
  • Increased milled tonnage per hour to the optimal technical limit.
VÉA Management Consulting
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