Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
- Truck & Shovel / Loader
- Backfill
|
Processing |
- Dry Screening
- Wet Screening
- Gravity separation
- Desand plant
|
Source:
p. 102
Deposit Type
- Bedded Iron (BID)
- Channel Iron (CID)
- Detrital Iron (DID)
Summary:
The Solomon Project area (Firetail, Kings & Queens deposits) is situated approximately 60 kilometres to the north of the Tom Price township in the northern Hamersley ranges. Outcropping geology in the project area is dominated by the Dales Gorge, Whaleback Shale and Joffre Members of the Brockman Iron Formation which hosts large BID throughout the Hamersley Province. The Firetail deposit contains the major tonnages of BID at Solomon, where geological favourable environments have allowed for the formation and preservation of large tonnages of iron mineralisation.
Incised into this bedrock geology are regional palaeochannel systems, predominantly one to two kilometres in width, and stretching for tens of kilometres. During the Miocene period deep chemical weathering and erosion of the generally iron rich material into these fluvial channels formed CID. Through Fortescue’s interpretation of drill hole results, the CID can be subdivided into an upper ‘hard CID’ and a lower ‘ochreous CID’. Clay lenses are observed as semi-discrete bands often several meters thick, sometimes of a poddy nature although often traceable between drill holes. Approximately 40 km of buried CID is preserved in the Kings CID system, with a further 25 km of CID located in the Serenity deposit to the west. Other CID occurrences are also known throughout the Solomon project area. The material overlying the CID (and other areas) has been eroded from adjacent mineralised and un-mineralised bedrock. This clastic material is concentrated into horizons of elevated iron grade termed DID, which forms part of the sequence of overlying late Tertiary aged alluvial and colluvial deposits.
Mining Methods
- Truck & Shovel / Loader
- Backfill
Summary:
Mining Methods
All stages of the mining operations is undertaken by contract mining, under the supervision of Fortescue site mining personnel. Mining uses conventional open pit methods of drill and blast followed by load and haul.
Excavators is employed to dig the material from working mine faces. The excavators load material into haul trucks for transport to either waste dump or ore stockpile locations.
Waste will be transported by haul trucks to waste dumps, located adjacent to the mine pits in the early years, and into mined-out areas of the pits in later years.
Mining is occured at multiple spatially separate pits, each working multiple mining faces simultaneously. The Run of Mine (ROM) ore from each mining area is blended at a number of separate crushing hubs to ensure a consistent mix of ore to achieve the required blend and contaminant levels. Two ROM pads and associated ROM feed bins are proposed at each crushing hub, one each for the CID and the BID/DID products, both of which feed conveyors that is transported ore to the OPFs. In some cases, stockpiles of ROM ore is employed to further enhance the degrees of blending.
The Kings deposit is comprised of four main mine areas - Zion, Valley of the Kings, Trinity and Valley of the Queens. The deposit is located within a broad valley system extending approximately 35 km in length, with a width of 0.5 km to 2 km. The Kings deposit consists of CID with some BID and DID.
Multiple pits within the Kings mine is operated concurrently, with each pit approximately 100 ha in area. The total proposed mining disturbance and infrastructure footprint a ssociated with the Kings mine i s approximately 3,000 ha.
The Kings CID deposit is located below the water table and will require controlled dewatering throughout the life of the mine to achieve and maintain safe, dry mining. Water recovered during dewatering that is excess to mine processing and other uses, will be disposed of via reinjection into the CID aquifer.
Pit Backfilling and Waste Disposal
Overburden from initial mining areas will be transported by haul trucks to permanent external waste dumps until sufficient voids are available for backfilling. In later years of mining, waste will be backfilled into depleted mine voids. Fortescue estimates that approximately 270 Mt of waste will be required to be disposed of to external waste dumps, while 1,730 Mt will be backfilled into mine voids.
The following strategy is envisaged for waste disposal:
- Kings mine (eastern end): Initial waste will be stored at the head of a valley at the eastern part of the deposit. This waste dump is likely to store approximately 100 Mt of waste. Some waste will also be used to construct the tailings embankments for a TSF. On completion of the initial mining stage, waste will be back-filled into previously mined areas to levels resembling the pre-mining topography. The estimated volume of waste to be disposed in-pit is approximately 850 Mt.
- Kings mine (western end): Waste from the eastern end of Valley of the Queens will be stored in-pit as a continuation of the Valley of the Kings mining. Mining within the western end of Valley of the Queens will initially require an external dump for storage of approximately 100 Mt of waste. Once sufficient void space is available, in- pit backfilling will commence and waste will be back-filled into previously mined areas to levels resembling the pre-mining topography. The estimated volume of waste to be backfilled into in-pit dumps is approximately 840 Mt.
Processing
- Dry Screening
- Wet Screening
- Gravity separation
- Desand plant
Source:
Summary:
Ore Processing
The Run of Mine (ROM) ore from each mining area is blended at a number of separate stockpiling areas and crushing huba to ensure a consistent mix of ore to achieve the required blend.
Crushing will involve combinations of primary, secondary and tertiary crushing as well as gravity concentration of the combined with the separation of sand and clay waste material. ROM pads and associated ROM feed bins are proposed at each crushing hub. Ore currently carried from the crushing hubs via conveyors to the OPFs at Kings and Firetail.
The mined ROM ore is transported to elevated pads (ROM pads) for tipping into a ROM feed bin at a number of separate primary crushing hubs. Two primary crushing hubs, with one for the Firetail (for Brockman ore) and one for the Kings (with the one for the Kings project comprising two crushing streams for CID and DID ore, and for the Firetail project comprising a single stream for BID ore). The primary crusher system consis ........

Reserves at June 30, 2020:
Cut-Off Grade of ore reserve (%Fe) ~ 51.5.
Category | Tonnage | Commodity | Grade |
Proven
|
99 Mt
|
Iron (hematite)
|
57.3 %
|
Probable
|
451 Mt
|
Iron (hematite)
|
57.3 %
|
Proven & Probable
|
550 Mt
|
Iron (hematite)
|
57.3 %
|
Measured
|
204 Mt
|
Iron (hematite)
|
55.3 %
|
Indicated
|
1,111 Mt
|
Iron (hematite)
|
55 %
|
Inferred
|
535 Mt
|
Iron (hematite)
|
54.6 %
|
Total Resource
|
1,851 Mt
|
Iron (hematite)
|
54.9 %
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
.......................
|
.......................
|
|
Aug 28, 2020
|
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