De Grey Mining Ltd (ASX:DEG) has revealed an update on drilling results and metallurgical test work from the Mallina deposit at the Pilbara Gold Project in WA.
The Mallina deposit is a large under-explored 5-kilometre long prospective corridor along the Mallina Shear Zone with an existing resource of 3.83 million tonnes at 1.3 g/t gold for 160,700 ounces.
The deposit and surrounding targets have substantial exploration upside and are located only 15 kilometres from the Withnell deposit.
READ: De Grey Mining reveals enhanced exploration potential in Pilbara after identifying multiple new targets
Step out diamond drilling comprising 3 holes, targeting extensions to known gold mineralisation has provided further encouraging results and a further two diamond holes were drilled specifically for metallurgical test work.
Significant intersections
The best intersection is 13.42 metres at 5.12 g/t from 126.58 metres.
Notably, this hole is down dip from a previously reported gold intercepts of 10 metres at 6.09 g/t and 4 metres at 2.71 g/t.
Mallina drilling intersections
Metallurgy
Overall the initial metallurgical test work indicates the oxide ore recovery is expected to average ~86% through a standard CIL processing plant and the fresh sulphide bearing ore is expected to yield ~86% via a sulphide float to produce a sulphide rich concentrate with a mass pull of about 8.6% followed by pressure oxidation of the concentrate.
This processing is in line with the proposed processing flowsheet as designed by GRES and is as expected to be very similar to the Withnell fresh ore processing requirements.