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

Prophecy Platinum Corporation – Wellgreen Property – Project 50149-001
• In the ground sample, an average of 72% of the chalcopyrite occurs as liberated or free particles.
Based on these analyses, a regrind to ~20 µm should be sufficient. The nickel sulphide is slightly
coarser, but will require regrinding to ~30 µm to achieve greater liberation. This will also be sufficient
to liberate any pyrrhotite reporting to the Cu circuit
• Of the non-liberated chalcopyrite-bearing particles, there is an association between pyrrhotite and
chalcopyrite, and also association with complex gangue particles. Sulphide nickel also occurs as
binary particles with pyrrhotite, as well as with non-sulphide gangue and complex particles.
3. Comminution Testwork
Standard Bond grindability test (BWI) for ball mill grinding and abrasion index test were conducted.
Figures 13 and 14 place the values on histogram plots of the SGS grindability test database. The Bond
ball mill grindability test is performed according to the original Bond procedure. It requires 8 kg of minus 6
mesh material that is preferably prepared at the testing facility. The Bond ball mill work index (BWI) has
been widely used for mill sizing, but is also utilized in computer simulation and variability testing. The BWI
was determined to be 19.7 kWh/t (metric) for the Wellgreen master composite ore. This is considered to
be a hard ore in the context of the SGS BWI database.
The abrasion index fell in the soft range of abrasiveness with a Bond abrasion index of 0.088. Abrasion
Index can be used to determine steel media and liner wear in crushers, rod mills, and ball mills.
Details on grindability testing data and calculations can be found in Appendix C.
Frequency
800
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100
0
Database
Wellgreen
1 3 5 7 9 11 13 15 17 19 21 23 25 27 >28
Bond Ball Mill Work Index - Metric
Figure 13: Histogram of Bond Ball Mill Work Index Distribution
SGS Minerals Services
100
90
80
70
60
50
40
30
20
10
0
Cumulative Frequency (%)
18