GREY:BKSLF - Post by User
Post by
miningmanon Oct 24, 2014 7:01pm
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Post# 23060013
ahah, now it starts to make sense
ahah, now it starts to make senseFirst off a grab sample at 219g/tonne is pretty well meaningless unless it is reported as xx g/tonne over yy feet. All it really says is that there is some nugget effect within the orebody ( which makes calculating reseves more difficult and can lead to recovery problems). What is interesting is that the NR identifies the SG of this jasperoid material at 2.75 and also states that the DMS plant will not be able to process this. This explains a lot of the previous poor recoveries and implies that the mill process design has not been well thought out at all. Although I am not really a milling guy, I do know that all DMS type plants rely on the difference in SG between the ore and the waste to achieve separation. When I was mining Bayrtes, which has an SG from 4.0-4.2, we were able to separate it from the waste with an SG of around 2.7 quite effectively. When planning a lead/zinc operation , ore SG around 3.2-3.5, my competent milling colleagues were designing a DMS plant to separate the ore from the expected high waste dilution where the waste had an SG of around 2.7. The repeat of 2.7 is not a coincidence. Lacking any specific knowledge of a waste SG , I would always assume 2.7-2.8. Again , unless I had actual measured values , for a quartz type hosted gold orebody, containing pyrites, I would assume 2.8- 2.9. It now appears that DMS is an extremely poor choice for Banks' ore , and the fact that the press release in effect says " Not only has our DMS plant historically been unable to effectively process the Bob zone ore, we know recognize that it is totally incapable of processing the Tel zone"