The Industrial Comminution Efficiency Sub-Committee aims to provide tools for practitioners to measure the energy efficiency of comminution circuits using standardized metrics and methodologies. The guidelines developed by this group aim to define the recommended methods for quantifying grinding circuit efficiency using grinding power analysis, following the approaches developed by Bond (1961) and Morrell (2009). The group is a community of interest that includes operators, suppliers, and subject-matter experts interested in improving comminution efficiency in their operations.

To join the sub-committee, click here.


Comminution is incredibly energy-intensive, and improving efficiency not only saves mining operations money but also reduces their ecological footprint. This sub-committee aims to assist the industry by defining methods and best practices for the industry.

Published Guidelines to Review:

Proposed Projects:

  • Fine Grinding Ore Characterization Basis
    The goal of this project is to develop an open-source laboratory test and specific energy basis that mine owners and design engineers can use to both generate first-pass “generic stirred mill” equipment sizes.
  • Standard Bond Ball Charge and Bond Test Reference Materials
    These two projects will be carried out concurrently and will provide a source of the standard Bond Ball Mill Test ball charge to the industry and generate reference materials that can be used by the industry to check individual lab results compared to a standard.
  • Starkey SAGDesign Guideline for Comminution Testing and Grinding Mill Design
    This project will clearly outline the Starkey SAGDesign test and design methodology and make it widely available for public use, while the patent on the Starkey SAGDesign mill and test method protects Starkey’s ability to earn a living and allowing full public access to the design methods used.
  • A Grinding Simulation Program (Millpower2000) using Bond Work Indices
  • Grinding Circuit Efficiency


  • Define standard methods for quantifying grinding circuit efficiency using grinding power analysis
  • Coordinate a global network of multi-disciplinary and multi-sector professionals with knowledge on comminution efficiency to share lessons learned, best practices and drive valuable conversations
  • Enable a centre of knowledge, training and sharing on the topic of comminution efficiency



GMG Guideline Morrell2016 Aug | Morrell method for determining comminution circuit specific energy and assessing energy utilization efficiency of existing circuits

The guideline reviews the data required for the analysis, including hardness characterization data generated from the SMC Test®, the Bond Ball Mill Test Work Index and the Morrell equations and their application. Click here to read.

GMG Guideline Surveying and Sampling2016 Apr | Methods to survey and sample grinding circuits for determining energy efficiency

This guideline details methods to survey and sample grinding circuits to generate sufficient information of suitable quality to support reliable efficiency analysis by these and comparable methods. It deals specifically with surveying and sampling Autogenous Grinding (AG), Semi-Autogenous Grinding (SAG), rod, and ball mill circuits operating within the normal range of application. Click here to read.

GMG Guideline Bond Efficiency2016 Feb | Determining the Bond Efficiency of industrial grinding circuits

The Bond method allows for quantification and comparison of relative energy efficiencies of most industrial communication circuits. It is an essential tool for managing the important business (cost) of grinding. Click here to read.