Positive test results for PMY’s Sorby Hills Project
Pacifico Minerals (ASX:PMY) has today released highly positive results from its Phase I metallurgical test work program at its 75% owned Sorby Hills Lead Silver Zinc Project.
PMY has been developing this large near-surface and flat lying lead-silver-zinc deposit with a focus on simple metallurgy, low cost processing and high recoveries.
It has already delivered a PFS with compelling economics, including modest CAPEX and fast payback, and the current test work is set to support these findings.
Sorby Hills is surrounded by outstanding infrastructure and is significantly de-risked. The latest results, only feed into the positive feeling the company has for the project.
Strong test results
The latest results confirm Sorby Hills’ potential to produce high quality lead concentrate containing appreciable silver credits, which would please JV partner, Henan Yuguang, China’s largest lead smelting and silver producer.
Henan Yuguang has a 25% contributing interest in Sorby Hills.
Current test work being undertaken by PMY, backs up and improves upon historical metalurgical studies that were carried out in the late 1970s and early 1980s, when extensive test work was carried out on core drill samples.
Flotation was the only concentration process tested at the time by the Technical Services Department of Mount Isa Mines Limited (MIM).
In 2018, Minmet Metallurgical Laboratories Pty Ltd (AMML) was commissioned to follow up MIM’s work to confirm the results.
It was found that the AMML test work provided a good correlation with the MIM test work. Another highlight was heavy media test work that proved grade of feed to the concentrator could be increased.
This is important to improving the economics of processing the lower grade areas of the resource.
Further historic results can be found in today’s ASX announcement.
Coming to PMY’s recent test work, the company engaged ALS Metallurgical Services Burnie to assess beneficiation options for Sorby Hills and to confirm the previous flotation performance.
The program included:
- Sample receipt and preparation;
- Optical mineralogy by McArthur Ore Deposit Assessment (MODA);
- Ore sorting by TOMRA Sorting Pty Ltd (TOMRA); and
Highlights of the program include:
- Confirmation of the potential for the Project to produce high quality lead concentrate containing appreciable silver credits.
- Flotation recoveries higher than recent Pre-Feasibility Study (‘PFS’) assumptions:
- Rougher flotation testing with sulphidisation indicates:
- up to 96% Pb and 95% Ag recovery on Fresh composite (T70); and
- up to 91% Pb and 95%Ag recovery on Oxide composite (T76).
- Cleaner flotation testing confirms final concentrate grade of 65% Pb can be produced.
- Further heavy liquid separation testwork (‘HLS’) to upgrade the ores has returned outstanding results with lead losses lower than the 10% assumed in the recent PFS:
- Lead grade upgrade for fresh ore of:
- 1.85x with lead losses of 3.3% at Specific Gravity (‘SG’) 2.75; and
- 3.36x with lead losses of 6.6% at SG 2.93.
- Lead upgrade for oxide ore of:
- 1.22x with lead losses of 4.1% at SG 2.75; and
- 2.15x with lead losses of 9.1% at SG 2.93.
Preliminary ore sorting test work returned 1.3x and 1.4x upgrades respectively for both Pb and Ag using XRT with lead losses of 2-3%.
PMY will now turn its attention to additional test work to support the Optimised PFS to be completed by the end of Q4 2019. The PFS has already confirmed robust financials.
Phase I of metallurgical test work is expected to be completed this month, with Phase II to support the PFS to be undertaken throughout the next two quarters using ore samples from the Phase II drilling program.
Phase III of the test work will be designed to support the Definitive Feasibility Study (DFS).
The DFS is on track for 2020.