Yandal Resources Ltd (ASX:YRL) has returned high gold recoveries in initial metallurgical test work on oxide and transitional rock samples from the Flushing Meadows deposit within the Ironstone Well project near Wiluna, WA.
Up to 96% gold recovery was achieved from conventional gravity and cyanide leach processing on oxide reverse circulation (RC) drill samples above 80 metres vertical depth.
A transitional RC drill sample from between 89-94 metres vertical depth returned 84% recovery with gold associated with 4% pyrite and minor arsenopyrite.
Managing director Lorry Hughes said: “Samples in the top 80 metres returned on average 94% gold recovery on with samples ground to a standard 80% passing 106 microns.
“These are encouraging initial results that will enable us to effectively plan the next phases of metallurgical testing to be included in open cut mine feasibility studies."
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Samples from six holes
Oxide and transitional composite samples were collected from six RC drill holes within the central and southern parts of the 1.8-kilometre-long mineral resource.
The samples were combined to make three composite samples representative of intense to strongly oxidised gold lodes above 80 metres vertical depth.
Results confirm highly encouraging gold recoveries using conventional gravity and cyanide leach techniques that are in use at third party processing facilities within haulage distance from the deposit.
The overall gold recoveries for the oxide composites were excellent and averaged 94.13% with a maximum gold recovery of 95.62% returned from composite-3, which was sampled from 84-89 metres downhole.
This procedure on the transitional composite returned an overall gold recovery of 77% while a further test on composite-4 at a finer grind increased the overall recovery to 84%.
RC drilling program
Hughes said, “We are currently completing a major RC drilling program to expand the Flushing Meadows resource and explore for high-grade mineralisation at depth.
“If the current RC drilling is successful, a program of diamond drilling will be rolled out to provide representative samples for detailed geological, geotechnical and metallurgical assessment.
“It is important to improve understanding of the geological controls on significant mineralisation existing at depth firstly to identify new resources and secondly to understand the metallurgical characteristics of gold within a number of individual rock types.”
Three-dimensional longitudinal representation of the September 2019 Flushing Meadows mineral resource estimate.
These first-pass metallurgical results will be used as the basis for key inputs in the optimisation work underway and due for completion during October.
A staged program designed to target an expansion of the Flushing Meadows gold deposit as mineralisation comprising about 82 RC drill for 9,000 metres with depths between 30-200 metres has also begun.
The results from this program are expected to allow the company to plan in detail the location of a number of diamond drill holes for inclusion in feasibility level geological, geotechnical and metallurgical studies in the March 2020 quarter.