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

Purpose:

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

Application:

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.