CG
Another sentence that that is also important from that article
“As part of Stage 2 production at Bald Hill the owners are proposing to treat otherwise stockpiled material that is <1mm fines”.
This got me thinking about the tailings from the previous operators of the tantalum plant (Haddington). I have in the back of my mind that there was a comment made by MC or another poster that there are an estimated 800,000 tonnes of unprocessed spodumene ore that lay in the tailings storage facilities on the project which is not included in any of the reserve updates. I have not been able to reference that information anywhere but my research came up with the following detail.
According to the 16 July 2014AMAL Share Placement Offer p107:
“Under the previous miningoperator, exploration and mining activities had been conducted on the Bald HillTantalite Mine site for approximately four (4) years up until 2006, with1,348,670t of Ore treated and 822,353lbs of Tantalite concentrate produced fromsix (6) separate open pits.”
Those pits were called theNorth , South, West, Hills End, Hill View and Boreline pits.
In August 2002 Haddingtonmade application to use the North pit for in-pit tailings disposal which was estimated to provide storage capacity for 330,000 tonnes of tailings (settled). In June 2004 they made application to use the Hills End pit for in-pit tailings disposal which was estimated to provide storage capacity for 495,000 tonnes of tailings (settled).
The Hill View and Borelinepits are designated as waste dumps. There is also an above ground Tailings Storage Facility (TSF1) that Haddington made appication for back in Feb 2001.
The attached plan shows thelocation of the pits and TSF1 around the main mining area as mined byHaddington.
The Version 2 mining plan lodged in 2017 proposed a single central pit whilst the Version 3 mining proposal lodged in 2018 has now proposed an expanded central pit that will now incorporate the Hills End TSF.
Page 54 of the Version 3 mining plan states the following:
“Hills End Pit, previously backfilled with tailings and rehabilitated, will be re-mined to recover the tailings for re-processing to extract lithium ore.”
The version 3 proposal also goes on to say:
“A lithium ore stockpile (DMS Stockpile) will be located on an area previously approved as a stockpile location. This stockpile will occupy an area of 3.38 ha with a volume of approximately 0.28M m3 (0.6M tonnes). Adjacent to this will be a tantalum ore stockpile occupying 5.24 ha with a volume of approximately 0.24M m3 (0.5M tonnes). Both of these stockpiles are expected to be fed through the processing plant and will be rehabilitated as flat surfaces on completion of the operation.”
‘A reprocessing stockpile will be located in the existing Boreline Extended pit. This will be material that has been processed to extract lithium ore concentrate, but is suitable for reprocessing at a later date. This stockpile will fill the shallow (approximately 5m deep) Boreline Extended Pit and extend as a single stockpile of material up to 15 m tall. The material will be deposited via a mobile stacker. A 1.5m tall bund wall will be installed around the pit to prevent surface runoff transporting silt into the surrounds. The material is expected to be reprocessed in 2019 when planned additions to the lithium processing circuit are undertaken.”
The Hills End pit is only capped by 0.5 metre waste rock and should be free digging material as opposed to the drill, blast and crush method used on the main ore body. If we assume that the Fines circuit handles 100 tonnes per hour for 18 hours a day then there should be enough ore from the Hills End pit to last 275 days of processing even without the DMS stockpiles and reprocessing stockpiles.
Seems to me that our costs of production are going to get a whole lot cheaper when the fines circuit eventually comes on line in 2019.
