Castillo Copper Ltd (ASX:CCZ, LSE:CCZ) has taken another key step in assessing the commercial viability of the Broken Hill Alliance (BHA) Project’s East Zone in Far West New South Wales by appointing specialist consultant ANSTO to carry out metallurgical test-work on samples.
The focused test-work will be undertaken on six samples from the Fence Gossan, Reefs and Tors Tanks prospects within the East Zone and results are expected to take 8-10 weeks.
This work will enable Castillo to understand the potential to extract rare earth elements (REE) from shallow clay zones.
Particular focus on MREOs
As such, ANSTO will focus on characterising REE leachability from the samples which comprise fresh pegmatite to highly weathered clay, especially with magnetic rare earth oxide (MREO) grades ranging from 362-603 parts per million (ppm).
Castillo Copper’s chairman Ged Hall said: “The board is delighted ANSTO is conducting specialist metallurgical test-work on samples from the BHA Project’s East Zone.
"Understanding the potential to extract REE mineralisation, especially MREOs, will greatly assist in our efforts to align with a future development partner.”
Hall added: "Pleasingly, the work done to date clearly confirms there is an extensive shallow REE system across the central part of the BHA Project’s East Zone.”
The rare earth elements footprint at the BHA Project's East Zone.
Castillo believes the tests are an important step towards advancing the viability of the BHA Project’s East Zone REE potential and securing interest from prospective development partners.
Strong drill results
This work comes after the company returned strong results from reverse circulation (RC) and diamond drilling across the shallow, clay-hosted REE system, particularly at Tors Tanks and Fence Gossan prospects.
These included:
- 13 metres at 1,550ppm total rare earth oxides (TREO) from 5 metres with MREO content of 38.9% compared to the peer average of 25%;
- 17 metres at 1,605ppm TREO from 2 metres with 28.6% MREO and 1-metre at 3,236ppm TREO from 19 metres with 28.9% MREO;
- 10 metres at 1,013ppm TREO from 49 metres with 24.7% MREO;
- 6 metres at 1,480ppm TREO from 7 metres with 28.9% MREO; and
- 5 metres at 1,598ppm TREO from 14 metres with 29.1% MREO.
Scope of work
The scope of work that ANSTO will carry out includes:
- The potential to extract REE mineralisation from shallow clay zones;
- Characterising the REE leachability from the six samples which comprise fresh pegmatite to highly weathered clay; and
- Separating out high-value MREO (neodymium + praseodymium + dysprosium + terbium) as the grades in the samples range from 362-603ppm MREO.