Hi all, just passing by and gleaned over a few posts, so if I'm missing the point bear with me.
Re the decline discussion, if the reefs are narrow and effectively mined by airleg and scrapper, whether the haulage is via decline or shaft it should not automatically change the level of dilution, the problem arises when a company puts down a decline and tries to utilize the same equipment to 'selectively' mine the ore body.
The actual method of hauling or hoisting the ore is fairly irrelevant to dilution if your airleg crews are using the same stoping methods.
The advantage of a decline (as I see it) is it's normally cheaper to develop and maintain decline,,, and with less specialized labor (once again I'm thinking a sensible size,,,, small), there is a fair bit less compliance and maintenance with a decline, plus a lot more flexibility.
The other mistake I see small miners make is designing too large a decline, time and time again companies are putting in 4.5m, 5m or 6m declines to get 'tonnes' (mine accountants and investors get all gooey as the predicted tonnes go up) but it's horses for courses! Decline sizes must be realisticaly designed to suit the geology it must traverse and the size of the orebody/s.
For instance a 3m or 3.5m decline can easily handle 15 to 20 tonne mine trucks (that would be around say 1.5 - 2 truck loads per airleg stope round (flat backing), give the truck a generous 60min load/haul cycle, you could realisticaly expect in say a 12hr shift to get 7-8 cycles per shift per truck,
One truck could keep several stoping crews busy and probably still haul out a decline development round(waste)as well.
An added bonus of a small decline is that if and when your jumbo breakes down,,,,, and it will,, development can still advance by airlegging it,,, be it at a slightly less rate of advance.
Production and development phases could progress without holding each other up.
It gets crowded juggling dirt in a shaft haulage senario (dosen't matter how well you plan it!)
Ok don't know where I'm heading with all this LOL!! I could probably waffle on about shaft haulage but I think I better quit while I can!
Keep up great posts fellas,
MCO Price at posting:
13.0¢ Sentiment: None Disclosure: Not Held