It was floated in a test in 1945 to arrive at the one per cent figure. I wonder whether or not is was taken from a particular area of the mine, as it was only a limited run of 20,000 tons when it was recovered.
The answer is, yes, although the tail is very fine( -200 mesh), gravity could be tried. The gravity con, if it worked on very fine material would be high enuff grade to sell direct or at least be more amenable to acid treatment for upgrade. I know of four or five ways that gravity could be tried. Hy-G Spinners (batch and continuous, back water and none), special rockers, frue vanners, and tables. Possibly even sink-float. If you wanted to increase the recovery in gravity you would mix in a graded coarser sand and perhaps some metal or plastic shot that went to say 80 mesh. This would lift and screen the material allowing better recovery and defeating compacting. At the end of the circuit you could remove the sand by a screen to recirculate.
In the end if gravity worked and was over 70% recovery it may be better to stick with that alone as the organics might totally screw up flotation. I don't know if reverse flotation would work. It does in iron, rejecting the oxide iron to sink to concentrate, while floating the silicates. freepatentsonline.com freepatentsonline.com This might be less sensitive to organics, but when flotation screws up, it generally never favours the con no matter the problem. Organics (dynamite, organic acids, soaps, or other dirt-carbon) cause runs or overflotation as well as de-attachment. This would be bad no matter the direction of the normally intended concentrate travel, sink or float.
Black light would come in handy to be sure. Make it easier to define depth and extent of the tail.
EC<:-} |
