Effect of Particle Sizes on the Physical and Mechanical Properties of Briquettes

Longlong Pang,Yuzhong Yang,Fei Wang,Liyun Wu,Han Meng

doi:10.3390/en12193618

Longlong Pang, Yuzhong Yang + Show 3 more

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https://doi.org/10.3390/en12193618

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Journal: Energies	Publication Date: Sep 23, 2019
Citations: 16	License type: CC BY 4.0

Affiliation: Henan Polytechnic University

Abstract

The particle size of coal particles is an important factor affecting the physical and mechanical properties of coal. In this study, uniaxial and triaxial compression tests were conducted to investigate the effects of coal particle size on the physical and mechanical properties of briquettes and their impact mechanism using a rock mechanics test-150B servo system (RMT-150B). The results showed that the uniaxial compression strength, elastic modulus and deformation modulus of briquettes increase when particle size is decreased. The deformation characteristics of the briquettes directly prepared by raw tectonic coal were similar to those of coal specimens with a particle size of 0.18–0.25 mm. The cohesion and strength of coal specimens increased when particle size was decreased, and the plastic deformation capacity decreased when particle size was decreased, showing a strong correlation. The f briquette directly prepared by the raw tectonic coal had a strength between that of coal specimens with a particle size of 2–6 mm and those with a particle size of 0.18–0.25 mm. The mechanical properties of briquettes mainly depend on the meshing force between the coal particles. The smaller the particles, the greater the mechanical meshing force. The “floating particles”, generated in the voids between coal particles during the preparation process, are a significant factor affecting the plasticity characteristics. The research results may be used as a basic reference in the study of the mechanical properties of tectonic coal, gas migration and coal and gas outburst mechanisms.

Highlights

A coal and gas outburst is a serious power disaster in coal mining, and can cause a large number of casualties and property losses
Where ρ is the density of the briquette specimen; m is the quality of the briquette specimen measured by the precision electronic scale in kg; and V is the volume of the briquette specimen in m3
This study aimed to investigate the influence of coal particle size on the physical and mechanical properties of briquettes

Summary

Introduction

A coal and gas outburst is a serious power disaster in coal mining, and can cause a large number of casualties and property losses. Coal seams that are prone to outburst are subject to historical tectonic movement, resulting in the development of tectonic coal [9,10,11]. This type of coal is composed of coal particles of different sizes, its structure is loosened and broken and its macroscopic strength is extremely low, making coal and gas outbursts more likely to occur [12,13,14,15]

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