Comments from George McIsaac
The biggest challenge by far is the length of the stope. Assume that you develop sublevels every 20 metres from floor to floor and that you drive the ramp at 14%, you need 20 m. / 14% = 143 m. of vein. You can have discontinuous mineralization; you just have to identify the waste rounds and store the waste nearby to backfill once you finish the cut.
The next big thing is the dip of the vein; you can’t go at less than 75 degrees or else you’ll start to get in problems stacking the cuts one over the other. Your jumbos and lhds will have a wheel on backfill and one on rock, bad working conditions.
Finally, you want to do this in veins that are not too wide, keep it to less than 5 or 6 metres. The reason is simple: you do cut and fill because of bad ground conditions, so keep your openings under control
RIV C&F is indicated where your strike lengths are very long, as you save a lot on waste development. Also, RIV C&F is great because it requires the same infrastructure as Avoca. That way, your sublevels all look the same, and in good ground conditions, you do avoca, and in bad, you switch to c&f.
Bryant, P.E. (1992) Ramp-in-stope mining at Black Mountain. MASSMIN 92. Johannesburg, SAIMM, pp. 193-198.