Significant metallurgical test work has been completed on mineralisation from the Opuwo Project. Good to excellent recovery of cobalt, copper and zinc sulphides has been demonstrated using conventional flotation techniques. Leach extraction test work on Opuwo sulphide concentrates has demonstrated high leach extractions of approximately 95% for the metals of interest, into a sulfuric acid medium, under relatively low pressure and temperature conditions. All work to date has been completed on fresh, unweathered mineralisation, which is the dominant ore type in the Mineral Resource, with test work currently underway on the minor oxide and transition ore types.
update on metallurgy
A series of 10 leaching tests have been completed, with several additional tests in progress. The best leach extraction achieved thus far is as follows: cobalt: 98%, copper: 97%, zinc: 99%, obtained from a concentrate containing 1.17% Co, 3.29% Cu and 2.68% Zn. These high leach extractions suggested that the intensity of the leaching process could be reduced to save on reagent and operating costs. Subsequent leach tests will systematically reduce the leach intensity in order to find the optimal trade-off between concentrate grade, recovery, leaching conditions and operating cost. Initial results for reduced leach intensity have confirmed continued high recoveries and indicate that further reductions in leach intensity (and therefore operating costs) should be possible without any meaningful loss in recovery.
Previous flotation test work has confirmed that the simple sulphide mineralisation comprising the Opuwo deposit can be concentrated using conventional froth flotation techniques, to produce a mixed sulphide concentrate containing a majority of the cobalt, copper and zinc. Closed circuit flotation performance has yielded recoveries of 81% for cobalt (Co), 83% for copper (Cu), and 54% for zinc (Zn) at concentrations of 1.44% Co, 5.50% Cu and 4.37% Zn. These concentrate results were obtained from mixed composite fresh ore samples, gathered throughout the orebody with grades of 0.142% Co, 0.57% Cu and 0.65% Zn. Further optimisation of these results is considered possible.
On this basis, an average estimated 81% Co, 93% Cu and 57% Zn recovery for the sulphide concentrate was applied for the refinery section of the process, including the downstream hydrometallurgical process recoveries. Hydrometallurgical process recoveries are based on mass balance modelling of the unit processes from SENET’s in-house experience. Detailed chemical and mineralogical information from the Opuwo concentrate generated as part of the metallurgical test work program was used in this process.No deleterious elements were identified in the test work that could affect the saleability or price of the products produced.
floation - autoclave - roasting - these look like pretty good numbers to me. we also have anticline - west zone and DOF North - i can only assume the newer near surface finds where mainly done with roasting method as to get them in the update on time - hence the need to test the rest as it could have diluted the numbers a bit ( maybe )
I think this delay was calculated move on cobalt price not so much on met and with the other zones we have open pit - declines and underground with a IMO close to 200mt -
the timing of the finds and constantly having to add and prove up and do met work to the SS pushes out the timeline ( not a bad proplem to have )
as to other battery needed material it was eluded too - I think is vanadium
Drilling to commence at the first five of nine high priority prospects. Phase 1 of the drill program consists of 13 holes for approximately 3,500 metres across five prospects:1. Opuwo Lineament: cobalt, copper, zinc2. Opuwo Corridor West: cobalt, zinc3. Opuwo Corridor South: copper, zinc4. Opuwo Corridor Central: vanadium5. Otjiurunga: lead, silver, vanadium, zinc
i think we done enough drilling for now - so hence the announcement - SS done - update resource done - maybe a bit more work to get all those zones in - contiue with PFS - play with met see if we can do a bit better and do this over a time period where we are not chewing up cash as we watch the cobalt price - bounce back
no one is happy with the events over last few weeks - I’m all in and don’t have any cash now to get my average down - imagine being able to pick up a couple million shares at 2c now
anyway I was going back through some announcements and this is IMO
CLA Price at posting:
1.9¢ Sentiment: Buy Disclosure: Held
(20min delay)
