The key findings of an updated independent metallurgical report on the project, situated in the Castilla y León region in north-west Spain, included 83.7% lead (Pb) recovery to a 60.0% Pb concentrate; 87.1% silver (Ag) recovery to 1,350 parts per million (ppm) Ag within Pb concentrate; and 77% zinc (Zn) recovery to a 59.1% Zn concentrate.
The results demonstrate the potential for high-grade saleable and marketable Pb and Zn concentrates, Europa said and were at the higher end of management’s expectations.
“These results show that the amount of lead recovered has remained broadly unchanged versus the lead recoveries obtained from the first locked cycle test; however, there has been a 2.5% increase in the Pb concentrate grade and zinc recovery has increased by 6.3% with a 3.3% increase in Zn concentrate grade,” Europa added in the statement.
Analysis of the final concentrates for deleterious elements highlighted the need for further test-work optimisation in order to keep them below the level that could incur a penalty from off-takers and smelters; however, without a separate marketing study to confirm this, no firm conclusions can be drawn at this stage, the group said.
Additional testing has therefore been recommended by the firm’s consultants to confirm the existence or otherwise of such deleterious elements across other parts of the deposit and, if present, to consider potential methods with which to limit or mitigate their impact.
Europa, however, noted that the concentrates are free from a number of deleterious elements otherwise present in concentrates from the region, including iron, arsenic and bismuth.
The company said it intends to immediately commence an analysis of ore sorting as a specific optimisation route, which has presented itself as a viable possibility from the findings of the metallurgical testing. Accordingly, mineralisation in the upper portion of the ore body will now be tested using XRT (X-ray transmission) ore sorting techniques to assess its amenability to pre-concentration and to determine the viability of XRT within the process route by using existing samples from distinct lithological areas already sampled from holes TOD-024 and TOD-025.
"The second phase metallurgical programme at Toral has proven to be successful with both Pb and Zn concentrates showing healthy recoveries and grades, with Ag being complementary to the Pb content. The programme has also provided some insight into possible areas for improvement and optionality that requires further work,” said Myles Campion, Europa's technical director in the statement.
“Such additional activities will include an assessment of the amenability of the lower grade mineralisation, present in a distinct lithological unit in the upper portion of the deposit, via the application of XRT ore sorting technology. We will also undertake a new round of metallurgical work on the high-grade intersection from hole TOD-025, thereby supplying spatially distinct data and further concentrate analysis, which will enable the company to further assess the process flow-sheet,” he added.
Meanwhile, Laurence Read, Europa's executive director, described the latest results as “excellent”.
“We are particularly pleased with the increase in zinc recovery versus the first set of results and the significant silver credit,” Read said.
“We believe that Toral has the potential to be a near term producer of silver, lead and zinc but that further work must be carried out on the flow-sheet before looking to move towards future development. In addition, importantly, chemical analysis has allowed Europa Metals, for the first time, to look at potential smelter suitability for the project, although additional assessment is required, as part of the overall flow-sheet optimisation process, to reduce by-product elements," he added.