Just thought of posting this for any new CYM investors. Some great points from the posters today 
For tinhat; This is an excerpt from the 17//11/21 Resource Upgrade which is also expressed in the restart study.
“Heap leachable Measured, Indicated and Inferred Resource significantly increased to 11.9Mt at 1.1% Cu for ~135,000t of contained copper metal”.
Plus the 91kt of copper metal contained within the existing heaps.
91Kt x 87.3% recovery = 79.4Kt plateable but will be less due to ore sorting losses from undersize material etc. So 2 years worth at least by using 25,000tpa EW
Barry stated in the latest Samso interview highlighting some of the legacy issues with Nifty;
Western Mining truck dumped the ore onto the leach pad then drove over the top of the first 2 pads compressing the ore. Particle size was also too large. Changed practice by pad 3.
This seems pretty stupid when your business model revolves around acid leaching through the crushed ore and your driving trucks over the top compressing it.
As Bayhunter pointed out; Restart Study
"To facilitate the retreat of the historic heaps, the remnant material will be relocated to newly constructed heap leach infrastructure located adjacent to the existing facilities. Material will be reclaimed using front end loaders to a self-contained mobile feeder/stacker unit feeding an overland conveyor transporting to a mobile screening unit to size all material to 20mm.
The sized, crushed and screened material will be transferred to an agglomeration unit via a combination of overland and grasshopper conveyors. Once conditioned, the remnant material will then be moved to a radial stacker, again via a combination of overland and grasshopper conveyors, and stacked to a height of 6m from the front of the heap leach pad cell through to the rear of each cell in an uninterrupted pass."
Also,
The Nifty operation has demonstrated successful treatment of the mineralisation over a period of sixteen years. On this basis, metallurgical testwork is not required on the open pit oxide mineralisation as it is proven and well understood.
Cyprium commissioned ALS Metallurgy Services (ALS) to undertake a metallurgical study to evaluate aged heap leach samples collected during a trenching exercise completed at Nifty during the second quarter of 2021. A 650kg consignment of remnant heap leach pad samples packed into 210-litre plastic lined steel drums was first received at the independent laboratory in May 2021. The contents of the drums were agglomerated and loaded into Perspex columns to complete leaching tests where a testwork regime investigated the extraction potential of the remaining copper via a simulated heap leach process using various reagents as lixiviants.
The testwork targeted copper recoveries of 85%, recovery times of 360 days under actual production leaching conditions, reduced acid consumption and reduced polymer agglomerant consumption.
Four individual column tests (3x2m and 1x6m height) with specific individual objectives and test conditions were conducted during 2021. These test cells have returned results for the finalisation of a system of reagent addition to be used in the treatment of the remnant heap leach pads.
Optimisation testwork, currently underway, will enable a scalable solution to be designed for the agglomeration, curing, stacking and irrigation of the historic heap leach material based on this work.Initial results of the optimisation columns will result in reduced reagents consumptions from those already anticipated in this study.Further optimisation testwork will be conducted on new oxide ore via diamond core drilled in 2021 and currently in the laboratory.
There will be two leach pad circuits on site producing copper in solution to the plant namely, the rehandling, retreatment and stacking of the existing historic leach pads and the mining, crushing, agglomeration and stacking of newly mined oxide material from the expanded historical open pit. (Note: There is no timeline given)
Bayhunter;
Image 5 shows this solution at the pump outlet being discharged to the PLS pond (relatively clean and free of solids). The solution has a grade of +10 gpl copper when compared to a usual solvent extraction (SX) feed grade of 3 to 4 gpl copper. This significant solution inventory of over 500 tonnes of copper is available for project commissioning.
