Plant Efficiency Assessment Technique

Below is a summary of the Coal Preparation Plant Efficiency Assessment Technique adopted by Elsa Consulting Group.


To provide reliable estimates of existing plant performance that can be used in a variety of business and technical ways, including:

  • Quantify and determine value of any loss of saleable material in plant rejects
  • Determine whether or not plant, circuit or individual equipment items meet vendor performance guarantee(s)
  • Audit the performance of custom toll processing operations
  • Audit the performance of contractor-operated plant operations
  • Identify and quantify potential plant circuit improvements


The technique is applicable to all coal (metallurgical and thermal) and mineral processing plants with and without by-pass options.

Basis of technique:

Determine a pseudo steady-state mass balance for all process flow streams relating to a process equipment item, circuit or entire plant.  Typically this will involve:

  • Maximised use of on-line and routine measurements.
  • Determination of critical parameters, for example:
    • rejects ash
    • moisture
    • sizings
    • proportion of product material in rejects
    • Cut points and Eps for multiple circuits
    • Flotation response curves.

The pseudo steady-state mass balance would then be used to, for example:

  • Reconcile actual performance against expected performance or design performance from bore core or other data sources
  • Identify significant gaps and design gap closure strategies
  • Investigate other potential improvement options including:
    • Consideration of alternative feed and/or product blending options
    • Substitution of particular equipment items with newer and/or alternative technologies.

Typical inclusions in a comprehensive coal preparation plant performance assessment are:

  • Feed blending system
  • Bore core data
  • Coarse coal circuit
  • Small coal circuit
  • Fine coal circuit
  • Magnetite circuit
  • Reagent systems
  • Control systems
  • Routine measurements
  • Moisture control systems.