Kin Mining NL (ASX:KIN) has received positive drilling and metallurgical test work results as part of an ongoing assessment of development proposed at the Cardinia Gold Project near Leonora in Western Australia.
Diamond drilling at the Bruno-Lewis deposits focused on testing the north-trending main contact, northwest trending Bruno lodes and Lewis potassic alteration zones.
This has confirmed the geological interpretation and will be used in an updated estimate of the Bruno-Lewis mineral resource.
Metallurgical test work results for Bruno-Lewis indicate acceptable metallurgical recovery is achievable from fresh rock at relatively coarse grinds of between 16um and 150um in standard CIL laboratory tests.
There were six diamond holes drilled at Bruno-Lewis through February and early March to test two distinct but overlapping styles of mineralisation.
These styles are part of a single large mineralised system spanning in excess of 3 kilometres of strike length.
At Bruno drilling to test the main mineralised contact intersected minor mineralisation including 4 metres at 1.11 g/t gold from 72 metres at the contact.
Also at Bruno, generally thin intersections of 1.2 to 2.2 metres at medium grades of 1.2 to 6.06 g/t were encountered in fresh rock associated with thin quartz veining and porphyry intrusions.
Above the porphyry intrusions and quartz veining, supergene mineralisation was also encountered similar in appearance to mineralisation mined at the Bruno trial pit.
At Lewis, wide zones of 40.5 to 42.3 metres downhole with lower grades of 0.78 to 0.98 g/t were intersected in two holes adjacent to the main Lewis contact.
In the metallurgical tests of Bruno-Lewis master composites illustrated:
- Gravity recovery of about 20% (0.41 g/t gold);
- Acceptable total recovery between 90.2 and 92.6% when using grind size P80 and 150um and standard CN concentrations;
- Relatively fast leaching kinetics with near maximum recovery achieved in less than 24 hours across all grind sizes;
- Minor residue grade sensitivity to finer grind size down to P80 of 75um;
- Leaching rate sensitivity to cyanide concentration; and
- Acceptable cyanide and lime consumption.
The drilling completed at Bruno-Lewis in recent months has allowed a new and updated geological interpretation to be completed with an updated resource estimate expected to be released later this quarter.
Metallurgical test work on variability samples from Bruno-Lewis will take place after the selection of optimal test work conditions following the master composite test work.
The test work and new mineral resource estimate will feed into optimisation, mine design, ore reserve estimation and process plant equipment selection work, which forms part of the pre-feasibility study of the Cardinia project scheduled for mid-year 2019.