The design & operating philosophies of panel vs block caving

Abstract

The modern trend of designing large underground cave mines according to their desired production throughput rather than utilizing appropriate, geotechnically driven mine design parameters, has caused considerable confusion and ultimately, culminated in poor cave performance. There is a growing tendency for caves with large footprints to be designed as panel caves regardless of their Footprint to Block height ratio. The misconception that a "panel cave" with high block height (Block height / Footprint >2) can be designed and operated no differently to that of a conventional panel cave, with smaller block height (Block height / Footprint < 2) has led to numerous geotechnical problems, including; poor cave propagation and adverse cave shape resulting in ore losses, early dilution entry, large fragmentation, ore recompaction and point loading of the extraction level, to name but a few. This paper serves to define and describe the fundamental design and operating philosophies that are characteristic of successful block and panel caves and highlights the dangers of mixing the two. It further offers an alternative for these horizontal cave layouts, namely the incline cave layout.

Procedure for estimating broken ore density distribution within a draw column during block caving

“…It is used to assess such key mine planning parameters as the draw height, which in turn is used to evaluate the stresses acting on the extraction level pillars, the quantities of caved rock remaining in a draw column, and the degree of secondary fragmentation (Dorador 2016). However, the determination of broken ore density is a very difficult and contentious task as it is virtually impossible to measure in situ (Van As and Van Hout 2008).…”