Wellgreen Project Preliminary Economic Assessment ... - OTCIQ.com

Cu Rec, %
Pt Rec, %
100
95
90
85
80
75
Prophecy Platinum Corporation – Wellgreen Property – Project 50149-001
Cu Rec vs Mass Pull grind/CMC
70
0 5 10 15 20 25
80
70
60
50
40
30
20
10
Wt%
Pt Rec vs Mass Pull grind/CMC
0
0 5 10 15 20 25
Wt%
F3 90
F5 50
F6 144
F8 90-CMC
F3 90
F5 50
F6 144
F8 90-CMC
Ni Rec, %
Pd Rec, %
90
80
70
60
50
SGS Minerals Services
Ni Rec vs Mass Pull grind/CMC
40
0 5 10 15 20 25
Wt%
Pd Rec vs Mass Pull grind/CMC
90
80
70
60
50
40
30
20
10
0
0 5 10 15 20 25
Wt%
Figure 18: Recovery Grind Relationship
The following conclusions can be made from the test results:
F3 90
F5 50
F6 144
F8 90-CMC
F3 90
F5 50
F6 144
F8 90-CMC
• Copper recovery slightly increased with finer grind size over the range tested. The response was
as expected with respect to copper metallurgy in Figure 2, with the grade/recovery relationship
generally improving with finer grind. A maximum rougher recovery of 96% was reached with K80 of
50 µm. A plausible explanation is that at the finer grind, the chalcopyrite is better liberated,
resulting in faster kinetics at the finer grind.
• Effect of grinding on nickel recovery is not similar to copper and finer grinding does not appear to
improve recovery or selectivity, but may even be detrimental to Ni recovery over the range
tested. Nickel metallurgy is shown in Figure 17 where the finer grind resulted in almost the same
recovery as the coarser grind.
• Referring to Table 8 a common trend is noticed, which is not limited to the effect of grind test
series but to all rougher kinetics tests completed, that a final rougher tailings Ni assay value of
~0.11% Ni is often reached. This is because there is some Ni in the silicates as well as some
pentlandite texture/associations which can not be recovered. It also shows that the Pt losses
tend to be highest. The mineralogy by Terra shows that Pt is primarily associated with pyrrhotite.
• Nickel rougher recovery barely reached more than 82%. This is expected since as it was stated
previously, about some of the nickel is expected to be associated with silicate minerals and is not
expected to float. The copper and nickel rougher concentrate grade ranged from 1.5%-1.8% and
25