Is your time really worth the mighty dollar?
Over the past 25 years, JOHNEX has been in business we have always focused on the direct costs of moving, or in JOHNEX’s opinion, not moving the excess dirt out of any Mine excavation but the one item that we have not paid particular attention to is the cost of time. Of course, this factor will not come into play if the Mine is restricted to only blasting at the end of a shift, or would it? After all, we have got to have our manpower (a very expensive commodity in Australian mining) in the Mine for a set period each shift; does this begin to sound at odds with our goals but close to reality? Productivity is the mantra, how close to actually achieving it are you?
High-speed development is all always about turning around the blasting cycle in the shortest possible time with the maximum advance per blastso moving any excess dirt is going to slow down the entire sequence. Cutting a heading to the designed dimensions is critical to keeping this aspect of blasting under control. There’s a never ending circular relationship with the money lender (how often do you hear of the funding coming out of the Mine owner’s pocket and, if it did, do you think they’d not be concentrating on the rate of return?), ore recovery and the time taken to extract the product – be it gold, diamonds or bauxite.
It all boils down to cash flow; to make money flow into the account one generally needs to spend it in the appropriate places and the time taken between the two needs to be as short as possible. So how do we achieve this, in this mining context, using explosives?
One has to assume that the design has sufficient holes in the heading and that there are trained personnel on the face before we can move into the explosive arena. The standard would be to use ANFO in the face but run up time and detonating pressures play a huge factor in achieving the maximum result from the blast hole; however, this is a discussion for another time. What I am more interested in is the turnaround time experienced from blast to blast.
We believe that with careful attention to details, i.e. drilling accuracy, a Mine can achieve a controlled overbreak of 4 to 5% which is within designed parameters. Until the drill manufacturers can come up with slimline designs, this is not going to change, but once you have gone past the 5%, this is within your area of control.
I think that you will agree with me that as the overbreak increases, so the cost of removal and remediation increases almost exponentially what with the repair work necessary to get the backs/hanging wall into a safe condition. How much of your team’s time is taken up taking the worthless ground out of the Mine? Time lost is never recovered; yes, a concerted effort can pull back some lost time but if you are not putting the collaborative effort in, in the first place – why not?
Time is money and lost time is lost money. If you have got plenty of it to throw around, then this is not for you, but if you are concerned about how the precious dollar is being spent, then you should be talking to us about how to control the spend at the beginning of the mining cycle.
Control your overbreak and save yourself time.
