A comparative analysis of grinding circuit design methodologies

Over the past decade the growth and development of mining projects have increased dramatically, as have the requirements to design and develop grinding circuits, mainly in the field of SAG and ball mill circuits. There are several design methodologies available in the market or through the use of commercial software or expert consultants. This article presents a comparative analysis of three methods for grinding circuit design widely used in the market today, Millpower 2000, JKSimMet and Aminpro, applied to a new mining sector of a current Anglo American mine. The parameters were obtained from 100 drill core composites, each representing 30 metres of drill core, in a sector that represents the first five years of production for a new concentrator. An important feature of this material is its high hardness for SAG grinding (average SPI of 140 minutes), and this perhaps provides an additional advantage to this study as it represents an extreme condition. The analysis compares the resulting equipment sizes for each of the three methodologies, considering a proposed tonnage of 90 ktpd at 180 micron P80.