Abstract
Rock blasting is the first phase of comminution, completed by mechanical means downstream in the crushing and milling phases. Nevertheless, mineral processers and blasters seldom work together. The total energy of mechanical comminution depends on feeding grain size and on the internal resistance of the material to grinding. Blasting heavily influences both of these aspects: i) it induces visible fracturing: this is the particle size distribution visible to the naked eye, that is measurable by means of image analysis or sieving; ii) it induces invisible fracturing: this is the system of micro-fractures, invisible to the naked eye, that are detectable only by microscopic analysis but show their direct effect by reducing the grinding energy ("softens" the material). A proper management of blasting can greatly benefit the comminution circuit. In this article, the author analyzes data from literature and from field experiments and discusses the benefits that rock blasting can produce for the comminution process.
keywords:
blasting; comminution; grinding; WI