Energy-Efficient Concept for Fine Size Reduction of Rocks and Ores

摘要

In the mineral processing industry, conventional tumbling mills crush/grind about a billion tons of rock/ore annually in the U.S. These mills are extremely inefficient, with 97% to over 99% of the energy being wasted in the form of heat and other losses. In response to this situation, a radically different processing concept was investigated. The approach involves hydraulically creating and propagating microcracks along grain boundaries, microcavities, and pores of the material, whereby the applied energy can do the work necessary to effect fracture with a minimum of waste. The concept has a potentially high operating efficiency level for comminuting copper ores, requiring only 11.4% of the energy consumed by a conventional ball mill. Practical considerations limit the effectiveness of the process on ores with extremely low or extremely high permeabilities and porosities (e.g iron and gold ores, coal). In such cases, only a small portion of the charge is reduced in a given cycle.