European Metals Holdings Limited announced the successful production of lithium hydroxide monohydrate from pregnant leach solution manufactured during the recent larger-scale Cinovec pilot programme. Highlights: The pilot programme has confirmed the viability of the Lithium Chemical Plant (LCP) process flowsheet for the industrial-scale production of either lithium carbonate or lithium hydroxide. Crude lithium carbonate from the pilot programme has been converted into exceptionally clean battery-grade lithium hydroxide monohydrate at laboratory scale.

The pilot programme processed ore is fully-representative in all respects of the run-of-mine for the first seven years of mining planned at Cinovec, including average grade and expected rock-type mix from the bulk mining. The Cinovec LCP flowsheet produces a high purity lithium sulphate solution which is capable of being used to produce either lithium carbonate or lithium hydroxide. The first stage (un-reprocessed) crude lithium carbonate produced is very close to battery grade and easily upgraded to battery grade in a single bicarbonation step (see the Company's ASX/AIM announcement of 9 November 2023 Successful Battery-Grade pilot programme for Cinovec Lithium Project").

The Cinovec LCP flowsheet lends itself to producing battery-grade lithium hydroxide monohydrate either directly, or indirectly via re-processing the first stage crude lithium carbonate. The project team has assessed the relative industrial process risks of manufacturing battery-grade lithium hydroxide monohydrate using both methods. It was concluded the indirect method was regarded as the lower-risk method, when considering process risks and costs.

This method of production of lithium hydroxide monohydrate has been tested as part of the pilot programme and has successfully produced battery-grade lithium hydroxide monohydrate at a laboratory scale. European Metals has previously produced battery-grade lithium hydroxide monohydrate (see the Company's ASX/AIM announcement of 8 April 2019 Cinovec Project Update - Battery Grade Lithium Hydroxide Sample Produced). The principal differences between the previous and current samples produced are that the current sample has come from the much larger-scale batch-continuous pilot programme for the revised LCP flowsheet commenced in 2023; and that the assaying requirements have been more extensive, to a better-developed reference standard published in 2020 (see further below).

The revised substantially simpler LCP flowsheet was announced by the Company on 31 October 2022 - see the Company's ASX/AIM announcement Simplified Extraction Process Delivers Exceptionally Clean Battery Grade Lithium Product with Improved Economics"). Cinovec battery-grade lithium hydroxide monohydrate contains a higher carbonate level than specified in the reference standard because it has been prepared at laboratory scale. Lithium carbonate crystallises simultaneously with lithium hydroxide monohydrate; conditions are optimised to reduce the production of lithium carbonate to a minimum.

In an industrial-scale plant, the lithium carbonate, which is produced in much finer crystals than the lithium hydroxide monohydrate, is separated from the end-product by the physical process of elutriation in solution. Elutriation is a process for separating the finer lithium carbonate particles, using a stream of solution flowing in the opposite direction to the sedimentation of the larger lithium hydroxide monohydrate crystals. This process is not possible in laboratory-scale tests.

Acid solubles were not measured as there was not enough sample for this test. Magnetic metal particles were also not measured due to the large sample that is required as well as pilot plant equipment being materially different to the commercial plant and there being far less contact with metal components in the pilot plant.