No details on the study were released - presumably due to it being non-JORC - with the company saying it had "focussed on the potential for application of safe, low cost mining methods to the ore bodies based on their geometry and observed geotechnical conditions".
Nearly 18 months ago, Zinc of Ireland said the resource's "thick, flat lying zone (in excess of) 20m (is) amenable to efficient mining methods", with metallurgical work around the same time reported to have shown "exceptional metallurgy".
Meanwhile the Richard Monti-chaired company has increased the resource to 11.3 million tonnes grading 9% zinc and lead.
The maiden estimate of the resource was in June 2017 and totalled 5.2Mt at 8.6% zinc and lead.
Monti has been with Zinc of Ireland since May 2018.
Work at the project has been impacted in recent months by COVID-19 restrictions.
Zinc of Ireland had cash on hand at the start of the quarter of about A$1 million.
Staff and corporate costs totalled just $103,000 last quarter, broadly similar-to another ASX-listed European zinc hopeful, Ironbark Zinc.
The latter has made even slower headline progress at its Citronen pre-development project in Greenland given its been working on that opportunity since 2007.
Shares in Zinc of Ireland last traded at 4.2c, capitalising the company at $5.1 million.