RE:RE:Vokblvr
VOKBLVER, altho I agree with 98% of the sentiments that you post here, and despite the fact that the reactions to the III tailings breach are being completely overstated , I caution you that a complete absence of a tailings storage facility at Bruce Creek is unlikely. Call it a dam , call it a temporary storage facility , call it a monster steel tank , whatever , but with the proposed mining methods ( blasthole stoping) my gut feel is that I would want about 90 days worth mill tailings available when I need it. There are two reasons for this, unlike cut and fill mining , any given prodction stope has to be 100% mined out befrore filling starts. WE dont know the dimensions of the initial proposed stopes , but 20m x 25 m x 30 m might be a good assumption. At an ore SG of 2.7 , this corresponds to 40,000 tonnes. I would not want to be at the mercy of the mill operators to provide the fill I need, when I need it, and youd be amazed at how far apart these two functions often are.
If I have a small storage pond ( that is not frozen) I can supplement my daily fill material from the mill , with whatever I can pull from my temporary pond. I would hope to pump most of this.
Additionally , as soon as I have a stope available for filling , I better have at least two additional stopes partially mined in order to give me the ability to supply 2700 tonnes , each day , every day. I wont get into the details of production hold ups that can occurr with blasthole stoping , but believe me having an inadequate number of producing stopes is a recipe for disaster. Additionally , once I start filling ,. I need to really fill fast , because there will be a stope on either side of the one being filled, plus one directly above it , none of which I can mine untill the cement in the filled stope has had a chance to set up.
Its all about schedulling , and perhaps I could live with only 60 days storage, but less than that and I could not guarantee adequate mill feed on an uninterupted basis. After Mt Polley it will be interesting to see what precautions are required for even a small dam.