An Experimental Study of Fragmentation by High Velocity Impacts on a Target

Publication Reference: 
ARR-27-03
Author Last Name: 
Dodds
Authors: 
J Dodds P Guigon M-N Pons and A Thomas
Report Type: 
ARR - Annual Report
Research Area: 
Size Reduction
Publication Year: 
1995
Country: 
France

This report presents the work on cornmunition under the IFPRI grant since 1993, A literature review has already been produced together with a detailed presentation of the experimental methods used (see report AR 27.02). Complementary references can be obtained from the literature review on communition research at the university of Karlsruhe (report SAR 012-06).

The objective of this research is to advance understanding of the fundamentals of fragmentation behaviour and develop experimental techniques to predict communition behaviour from a universal test. An experimental rig has been built to reproduce single particle impacts on a target and study the influence of the material properties on breakdown in ultra-fme grinding. Another experimental rig has also been constructed to study the impact of two jets of particles, as in an air-jet mill. Further experiments concern grinding experiments in laboratory scale equipment in particular wet grinding with a stirred bead mill and dry grinding with an air jet mill. The develoment of methods for characterizing debris from fragmentation forms a link between these two experimental studies.

Part A of this report presents the results of the experiments performed with the single jet apparatus. Seven kinds of particles have been used showing different behaviour depending on the type material and the processing involved in its manufacture.

Part B gives the results of the study with the opposed jet rig, Three diffent powders have been used so far.

Part C presents the methods being developped for morphological analysis.

Part D describes a method developed for analysing fine grinding kinetics for determining breakage and selection functions.