TY - JOUR
T1 - A feasibility study on confinement effect on blasting performance in narrow vein mining through numerical modelling
AU - An, Long
AU - Suorineni, Fidelis T.
AU - Xu, Shuai
AU - Li, Yuan Hui
AU - Wang, Zhe Chao
N1 - Funding Information:
This work was financially supported by the National Natural Science Foundation of China ( 51604060 ), and the Fundamental Research Funds for the Central Universities ( N160104001, N160107001 ), the China Postdoctoral Science Foundation ( 2016M601324 ).
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Due to the limited free face in narrow-vein stoping, blasting is usually subjected to excessive confinement effect that often result in difficulties in ore loss and dilution. The aim of this study is to analyze the blasting confinement mechanism in narrow-vein mining, and to quantitatively define the confinement effect. The PFC and LS-DYNA numerical modelling programs are combined to investigate the effect of blasting-induced stress waves and detonation gas effects. A confinement coefficient in narrow-vein mining is introduced and defined as the ratio of the blasting crater volume or area formed in an infinite free face to that in a confined face. The blasting confinement coefficient is used to rate the confinement severity. On this basis, the effects of minable width and burden on the confinement coefficient are analyzed. The numerical simulation results indicate that the confinement coefficient decreases with increasing minable width for a given burden. The relationship between the minable width and the confinement coefficient can be described by a first-order exponential decay function. For a given minable width, the confinement coefficient increases with increasing burden. The relationship between the burden and the confinement coefficient can be expressed by a first-order exponential growth function. Based on the numerical modelling results, a design chart for the blasting confinement effect in narrow-vein mining is introduced as a guide for preliminary design of narrow vein blasting to optimize production by reducing overbreak (dilution) and underbreak (ore loss).
AB - Due to the limited free face in narrow-vein stoping, blasting is usually subjected to excessive confinement effect that often result in difficulties in ore loss and dilution. The aim of this study is to analyze the blasting confinement mechanism in narrow-vein mining, and to quantitatively define the confinement effect. The PFC and LS-DYNA numerical modelling programs are combined to investigate the effect of blasting-induced stress waves and detonation gas effects. A confinement coefficient in narrow-vein mining is introduced and defined as the ratio of the blasting crater volume or area formed in an infinite free face to that in a confined face. The blasting confinement coefficient is used to rate the confinement severity. On this basis, the effects of minable width and burden on the confinement coefficient are analyzed. The numerical simulation results indicate that the confinement coefficient decreases with increasing minable width for a given burden. The relationship between the minable width and the confinement coefficient can be described by a first-order exponential decay function. For a given minable width, the confinement coefficient increases with increasing burden. The relationship between the burden and the confinement coefficient can be expressed by a first-order exponential growth function. Based on the numerical modelling results, a design chart for the blasting confinement effect in narrow-vein mining is introduced as a guide for preliminary design of narrow vein blasting to optimize production by reducing overbreak (dilution) and underbreak (ore loss).
KW - Blast crater
KW - Blasting confinement effect
KW - Design chart
KW - Narrow-vein
KW - Numerical modelling
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U2 - 10.1016/j.ijrmms.2018.10.010
DO - 10.1016/j.ijrmms.2018.10.010
M3 - Article
AN - SCOPUS:85055348920
SN - 1365-1609
VL - 112
SP - 84
EP - 94
JO - International Journal of Rock Mechanics and Mining Sciences
JF - International Journal of Rock Mechanics and Mining Sciences
ER -