A resource estimate upgrade has resulted in an 80% increase in the measured category for kaolin which highlights improved confidence in the quality of the resource.
The overall ‘bright white’ kaolinised granite mineral resource has increased by more than 28% to 26 million tonnes.
This in situ kaolinised granite will yield 10.6 million tonnes of minus-45-micron quality kaolin product.
Halloysite content up
Andromeda also reports an increase of around 9% in the halloysite content within the Carey’s Well ‘bright white’ kaolinised granite mineral resource.
The resource at Carey’s Well remains open to the north and northeast.
These improvements in the size and quality of Carey’s Well resource will be incorporated in a pre-feasibility study (PFS) which is scheduled for completion early in the June quarter of 2020.
Carey’s Well resource is one of a number of kaolin prospects included under a joint venture agreement in place between Andromeda and Minotaur Exploration Limited (ASX:MEP).
These prospects include kaolinite and halloysite.
The updated resource replaces previous estimates by Minotaur in 2009 and 2012 reported under JORC 2004 as well as estimates reported by Andromeda in 2018 and 2019 under JORC 2012.
The new kaolinised granite resource estimates for Carey’s Well.
Measured resource increases
The measured resource increased 80% due to 2019 infill drilling while the -45µm recovered material for measured and indicated resources reduced by 5%, with the biggest decrease in the recovery grades associated with inferred material.
Andromeda instigated upgrades to the resource through test work which improved processing of the ore to remove the plus-45-micron fraction.
This included engaging with external laboratories and international kaolin expert consultants on improved processing techniques, along with expanded quality assurance and quality control checks, and independent sign-off on exploration results.
Ongoing exploration and tests have allowed Andromeda to interpret a halloysite zone with the resource including back-calculated kaolinite, halloysite and combined halloysite/kaolinite from the -45-micron fraction.
Halloysite zone interpretation.
The previous resource estimate for the halloysite content was 9.7 million tonnes within Carey’s Well ‘bright white’ kaolinised granite resource, and this new estimate represents an increase of around 9%.
Andromeda’s February 12, 2019 estimate was based on only the halloysite content in the -45 micron fraction for this zone, but in this case, the back-calculation method used adds back the +45 micron fraction of primarily quartz sand grains, which is about 47.4% of the total ore.
The high-grade halloysite material from the recovered -45µm fraction within the halloysite zone.