Ironbark Zinc continues to optimise Citronen Zinc-Lead Project with positive metallurgical review results

Ironbark Zinc Limited (ASX:IBG) continues to optimise the Citronen Zinc-Lead Project in Greenland with a metallurgical review of the historic test-work and process flowsheet returning positive results. This work by Mineralis Consulting in Brisbane continues to support Ironbark's progress in refreshing the Citronen feasibility study (FS) with phase I results leading to a decision to begin a phase II study. The subsequent study is expected to be commissioned shortly with the expectation of results being available in the fourth quarter of 2020. Key findings Mineralis has confirmed that: The Citronen ore body sits firmly within the well-understood family of Stratiform Sedex Zinc-Lead deposits for which processing risks are well-studied and understood (the majority of the world’s largest historic and currently operating zinc mines consist of these types of deposits); Previous test-work was confirmed to be of high quality; Improvements to processing technology (especially flotation since the original Citronen FS test-work was completed) offer the opportunity to further optimise metallurgical performance; and Opportunities to streamline the process flow sheet were identified, in particular, the primary comminution and concentrate regrind circuits. Mineralis is one of the world’s pre-eminent consultants in the metallurgical processing of Sedimentary Exhalative (Sedex) Zinc-Lead ore bodies.  Phase II plans Ironbark has engaged Mineralis to complete a phase II study which will focus on: Refining the proposed flotation circuit with a focus on the drivers of metallurgical performance; Increase focus in circuit on zinc recovery (vs lead); Undertake limited new confirmatory metallurgical test work for any proposed circuit modifications - which will be done with existing core currently stored in Perth, Western Australia; and Update the process design to facilitate preliminary engineering. It is anticipated that this work will further increase confidence levels in the proposed Citronen development, reflecting best in class thinking and technology in 2020.