Blasting and preconditioning modelling in underground cave mines under high stress conditions
By E. Córdova, I. Gottreux, A. Anani, A. Ferrada, and J. Contreras
Cave mining operations are typically located deep, under high stresses, and in competent rock masses. This makes initiation and propagation of the caving process harder to manage. Such challenges must be confronted by optimizing the fragmentation of the orebody to achieve smaller size blocks that will produce consistent caving and improve the flow of ore from the drawpoints. The work presented proposes a design for preconditioning in underground mines.
Accretion formation on the refractory lining during the melting of ferrosilicon
By T.M. Nemavhola, T. Coetsee, and A.M. Garbers-Craig
The objective of this study was to investigate the effect of different impurity levels in the ferrosilicon feed material on the extent of accretion formation as well as the effect on the
accretion properties, which influence the ease of accretion removal upon furnace shut-down. It was concluded that the trace elements in the FeSi-75 feed material (Al, Ca, Mn) were mostly responsible for accretion formation, but that rust on the low-carbon steel and oxidation of the steel contributed to accretion attachment to the lining. The total contaminant content, calcium to aluminium ratio in the FeSi-75 feed material, and thereby the liquid to solids ratio in the accretion at temperature determine the strength of attachment as well as growth of the accretion.
A new automated, safe, environmentally sustainable, and high extraction soft-rock underground mining method
By A.J.S. Spearing, J. Zhang, and L. Ma
The exhaustion of surface and other easily mined deposits, together with increasing socio-political pressure, is creating the need to design more environmentally sound, sustainable,
and safe mining practices. The authors have modified a previously designed mining method in order to make it more autonomous, safer, and less costly. This method uses highwall coal mining techniques, adapted for underground applications. Results indicate that the method has more flexibility than longwall mining, the percentage extraction would seem to be in the same range as conventional longwalling, and surface subsidence would not be a major issue due to the use of backfilling.
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