Reviewed by Lexie CornerApr 23 2024
Emerita Resources Corp. provided an update on its ongoing metallurgical testing program, along with test results. The program aims to demonstrate the production of commercial-grade concentrates from the Iberian Belt West project (IBW) with potential economic recoveries essential for the planned mill plant design.
According to the preliminary results, IBW can be processed using conventional techniques to produce commercial-grade concentrates at recoveries comparable to those of other Iberian Pyrite Belt operations.
We are very pleased that the carefully executed metallurgical test program has demonstrated grade and recoveries of base metals to concentrates at comparable recoveries to other producing operations in the Pyrite Belt. We view the results contained within this press release as a baseline and look forward to continuous metallurgical performance improvement as we advance IBW towards a production decision.
David Gower, CEO, Emerita Resources Corp.
David Gower adds, “We have taken a very comprehensive approach to get to this point, which has extended the timeline. However, this is a very critical component of developing polymetallic deposits, and it is critical to have optimal results. It is important to note, initial results have indicated opportunities to optimize concentrate grade versus metal recoveries within a future economic model. In March 2024, we announced the addition of Jorge A. Blanco to the Emerita team as Director of Metallurgy.”
Jorge, in a short time, has had a very positive impact on the Project and is currently planning our next metallurgical tests as we wrap up this first phase. Included in future planned programs is to evaluate certain innovative hydrometallurgical processes recently developed in the region, that would allow metal to be produced on site rather than shipping concentrate to a smelter. The focus remains on conventional processing techniques, at this juncture.
David Gower, CEO, Emerita Resources Corp.
Competed tests have yielded zinc concentrates grading 52.4 % Zn with Project average zinc recovery of 84 %. This is around 5–10 % higher than reported results for mines operating in the Iberian Pyrite Belt. The tests conducted on the La Romanera deposit showed a zinc concentrate grade of 49.3 % Zn at 85 % recovery, while tests conducted on the La Infanta deposit yielded a 60 % Zn concentrate grade with 81 % Zn recovery. Testing is ongoing, and the final results will be disclosed upon the completion of this phase of tests.
The La Romanera (0.67 % Cu head grade) and La Infanta (0.86 % Cu head grade) copper-focused tests have demonstrated the production of commercial-grade copper concentrates of 22.26 % Cu and 24.87 % Cu with 69.4 % and 51.69 % copper recoveries, respectively.
These outcomes are comparable to those of mines currently operating in the area, and ore with noticeably higher copper grades should provide better results. La Romanera copper concentrate has a reported gold and silver content of 1.94 g/t Au and 372.8 g/t Ag, while La Infanta copper concentrate has a reported gold and silver content of 7.06 g/t Au and 1534.6 g/t Ag. Testing is still ongoing, with an emphasis on maximizing the recovery of precious metals at La Romanera.
Additionally, test work indicated the possibility of producing a semi-bulk concentrate of Pb and Cu, raising the payable Pb in concentrate and potentially enhancing overall copper recoveries. The average project-wide test results were 7.2 % Cu and 40 % Pb, with semi-bulk concentrate recoveries of 57 % and 36.7 % Pb and Cu, respectively.
These results show comparable higher Pb, Cu grades and higher Pb, Cu recoveries compared to regional operating mines also producing a Cu-Pb bulk concentrate. Tests on the La Romanera deposit separately produced a Pb/Cu semi-bulk concentrate with recoveries of 46.10 % Pb and 37.6 % Cu, containing 38.7% Pb and 7.51 % Cu. With 91.6 % Pb and 52.2 % Cu recoveries, the La Infanta tests yielded concentrate grades of 44.11 % Pb and 6.03 % Cu.
About the Metallurgical Test Program
Wardell Armstrong International Laboratories in the United Kingdom conducted the IBW metallurgical test work. The company hired SRK Consulting to oversee metallurgical matters so that the test program could be finished to the highest possible standard.
The principal aim of this metallurgical testing program was to furnish adequate information regarding the processing properties of the La Romanera and La Infanta deposits’ material to facilitate the completion of a scoping study and a subsequent economic assessment of IBW.
Four composites weighing roughly 100 kg each (three from the La Romanera deposit and one from the La Infanta deposit) were tested. Samples sent in for analysis included:
- La Romanera MET 1: High Gold – Lower Lens;
- La Romanera MET 2: High Copper/Low Zinc – Upper + Lower Lens; and
- La Romanera MET 3: Average Copper/Zinc – Upper + Lower Lens.
- La Infanta MET 4: Semi-Massive Sulphide
Each of the four samples underwent a preliminary characterization study involving chemical analysis and mineralogical investigation of four-sized fractions. To determine the impact of changes in feed grade and ore type on the production of copper, copper/lead, lead, and zinc concentrates, the samples have undergone, or are currently undergoing, a series of rougher, cleaner, and locked cycle flotation tests.