Experimental research on energy-size distribution model of coal particle bed comminution

Abstract

In order to accurately predict the particle size distribution (PSD) of coal particle bed comminution under different applied pressures, the tests of two kinds of coal with four size fractions under five different applied pressures were carried out by TAW-3000 hydraulic servo testing machine. The Gaudin-Schumann(G-S) distribution is extended by the fractal theory and the JK size-dependent breakage model is discussed. Two mathematical models for predicting PSD of crushing products in coal particle bed comminution are proposed. Results show that the relationship between the mass-specific energy and applied pressure is linear. Because of the protective effect of fine particles, the change of particle size modulus d0 in G-S distribution is not significant, while the distribution parameter α decreases logarithmically with the increase of mass-specific energy. With the decrease of size fraction, the crushability of coal particle bed decreases, and a master curve can be used to fit the comminution characteristics of coal particle bed with different size fractions. The extended G-S distribution model and the JK size-dependent breakage model have better fit the results of coal particle bed comminution. This research provides a useful reference for the mathematical modelling of coal particle bed comminution.

Study on coal pulverization characteristics and gas desorption mechanism based on impact crushing experiment

“…According to fractal rationale and particle extent allocation information, Zhang et al [ 22 ] constructed the fractal model of particle extent of compacted and crushed coal. Zhou et al [ 23 ] studied the crushing experiments of coal samples with two particle extents under five external pressures by using a hydraulic servo testing machine, and proposed models for predicting the particle extent allocation of coal particle crushing products. Zhang et al [ 24 ] found that the double phase fluid of gas will break great particles into granulum while it is ejected from the outburst port at high velocity, and the crushing outcome rises with the increase of methane pressure.…”