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

The feed to the secondary cleaner consists of the primary rougher concentrate and
the primary cleaner concentrate. The secondary cleaner concentrate is the final
concentrate that will be pumped to the concentrate thickener. The overflow from the
concentrate thickener will be recycled as process water where needed. The
underflow from the concentrate thickener will be pumped to a concentrate holding
tank. The final concentrate will be pressure filtered and loaded out for sale and/or toll
smelting. Load out will be done by conveyor directly into 50 t trucks. The secondary
cleaner tail will be sent for magnetic separation prior to being fed to the primary
cleaner.
The primary cleaner feed consists of the secondary cleaner tail, the secondary
rougher concentrate, and the scavenger concentrate. The primary cleaner feed will
be subjected to a high-intensity magnetic separator which will be used to remove the
magnetic pyrrhotite present in the primary cleaner feed. The magnetic pyrrhotite, if
not separated out, would float with the valuable platinum, palladium, nickel and
copper sulphide minerals and lower the grade of the subsequent concentrate. The
magnetic material pulled off by the magnetic separator will be conveyed to the
tailings thickener for disposal in the tailings impoundment. The non-magnetic
material will be pumped as feed to the primary cleaner.
The primary cleaner tail is subject to tertiary grinding in a vertimill. The product from
the vertimill is 80% passing 45 µm. This becomes the feed to the scavenger along
with the secondary rougher tail. The scavenger tail is the final tail which is thickened
and disposed of in the TMF. The overflow from the tailings thickener will become
process water where needed and the underflow will be pumped to the TMF.
As mentioned previously, the primary rougher tail is pumped to a ball mill for
secondary grinding. The ball mill is in closed circuit with a hydrocyclone cluster. The
underflow from the hydrocyclones will be oversize material recycled back to the ball
mill. The overflow will be the 80% passing 75 µm which will be pumped to the
secondary rougher as flotation feed. Pyrrhotite depression will be used in the
secondary rougher to try and create a high grade concentrate.
The MF2 circuit has been used successfully in South African platinum mines (e.g.
UG2 mineralized material) to generate PGE concentrates. Although developed
primarily for UG2 mineralized material, the MF2 configuration offers certain
advantages such as prevention of over-grinding and slimes generation, increased
rejection of talc, chlorite and pyrrhotite and early recovery of PGM. The gradual size
reduction will ensure that the quick floating valuable sulphide minerals are obtained
in the primary rougher, and the secondary and tertiary stages of grinding should
liberate the locked valuable minerals to be floated in later stage concentrates.
Pyrrhotite depression and magnetic separation will be employed to remove some of
the pyrrhotite and try to optimize the final concentrate grade. This is the proposed
ciruit based on the available test work, however the final circuit configuration remains
to be determined.
Prophecy Platinum Corp. 17-3 1193460500-REP-R0001-02
Wellgreen Project Preliminary Economic Assessment,
Yukon, Canada