Materials Chemistry and Pl?ysics, 25 ( 1990) 3 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK I 35 21 C~~~I~UTION ENERGETICS PART III : BOND'S LAW AND BREAKAGE ENERGY S. Tarasiewicz and P. Radziszewski Departement de genie mecanique, Universite Laval, Ste. FOY. @Gbec, GIK 7~4 Canada Received June 7, 1989; accepted September 12, 1989 ABSTRACT Based on a so-called comminution energetics approach, a developed breakage energy function is modified to include an experimentally determinable comminution law. In re-evaluating the classical eomminution law, such as Bond's, as an inte- gral element in a quasi-fundamental breakage energy function, we combine in a natural way any energy lost in grinding as well as, the specific energy rate of change into the determination of material size evolution. The comminution law thus completes the comminution energetics approach as both a fundamental law of comminution and a practical tool to optimizing real and/or conceptual grinding systems. INTRODUCTION The grinding process, characterized by an effort spent on a material to change it into another smaller material size distribution, has existed for centuries. Serious study on the comminution process was initiated with the Rittinger law of grinding (1867), followed by Kick (1885) and later by Bond (1952) [1,21. All of these laws relate the total energy consumed in grinding to particle size reduction. Despite a certain success in sizing ballmills for given contexts, the comminution laws fall short in determining an answer to the question : "How can a comminu- tion process be optimized ?" Further, with the advent of the batch grinding equation, these comminution laws have been relegated to a consequence of the batch grinding equation and unapplicable to cases of non-standard feed data !21. In this work, we will attempt to determine if such comminution laws, fore- runners to the comminution energetics approach, are applicable in the modifica- tion of the wholly theoretical breakage energy function into a quasi-fundamental 0X4-0584/90/$3.50 OEIsevierSequoia/Printed in The Netherlands