Methods to Survey and Sample Grinding Circuits for Determining Energy Efficiency

Published: 2016-08-28
Working Group: Mineral Processing Working Group
Status: Review Pending


This guideline covers surveying and sampling Autogenous Grinding (AG), Semi-Autogenous Grinding (SAG), rod, and ball mill circuits within the normal range of application. The intended application of this analysis is to treat a complete grinding circuit as a singular process block, irrespective of the number of grinding stages or internal classification steps. This approach allows a quick, relatively low-cost assessment of overall grinding circuit efficiency and can identify if more detailed analysis or circuit optimization work is required. Following circuit changes, the same methods can be used to compare the impact on circuit efficiency of varying operating conditions. This approach removes the need to survey internal circuit streams and mass balance around classification stages, greatly reducing labour requirements, survey turnaround time, and costs associated with sampling, sample analysis, and circuit modelling. While the intent of this guideline is not to define a full grinding circuit survey procedure, the techniques described observe industry best practice and can provide a firm starting point to analyze mineral comminution circuits at any required level of detail.


DETERMINATION OF CHARGE LEVEL IN A MILL by Measuring Free Height Above the Charge
Coarse (+75 mm) Belt Sample Size Analysis


Success story? Input on how to improve this guideline? Let us know.

To share your experience using the guideline, please fill out this case study form. 

For more general feedback, please fill out the form below:



    Bond, F.C. (1961, August). Crushing and grinding calculations. Reprinted from British Chemical Engineering, Parts I and II, with additions and revisions, April, 19962. Allis-Chalmers Publication No. 07R9235D.

    Doll, A.G. (2021). Mill motor power definitions. Revised August 26, 2021. 

    Predicting The Overall Specific Energy Requirement Of Crushing, High Pressure Grinding Roll And Tumbling Mill Circuits: Relevant publications from Dr. Steve Morrell in the field of comminution