JOHANNESBURG (miningweekly.com) – ASX-listed Alta Zinc, formerly Energia Minerals, has updated the mineral resource estimate for the Colonna Zorzone deposit at its Gorno zinc project, in northern Italy.
The resource estimation revision, which was commissioned to include all drilling results obtained to date, primarily focused on using the resource estimation to inform metallurgical and mining studies on the project and to improve the level of geological knowledge in the resource.
Alta said on Friday the updated estimate underpinned the revised project configuration study, which was based on the Colonna Zorzone resource.
The outcomes of the study have not been released yet, but the company said at the end of November that the revised study should deliver an improved understanding of an underground processing facility in proximity to the mine, including the capital expenditure and operating expenditure requirements, environmental impacts and simplified permitting pathways, as well as information on the geotechnical environment for underground plant construction.
Alta stated the revised mineral resource estimation had resulted in the overall zinc grade rising slightly (0.1%), lifting the total contained zinc metal by 3 000 t.
The new indicated and inferred estimate, using a 1% zinc cutoff grade, is estimated at 3.3-million tonnes, grading 4.9% zinc for 163 000 t of zinc, 1.3% lead for 43 000 t of lead and 27.2 parts per million silver for 2.9-million ounces of silver.