Key Highlights

  • Geomet, which holds the Cinovec lithium project, gave in-principle approval to adopt a single tunnel kiln in place of two gas-fired rotary kilns.
  • The approval is conditional on testwork contracts and a preliminary market consultation, and the choice between gas and electric heating has not been made.
  • Phase 2 testwork reported 93.4 per cent roast and leach recovery, and Phase 3 testwork is due to start in November 2026.

European Metals Holdings (ASX:EMH) has reported that Geomet s.r.o., the company that holds the Cinovec lithium project in the Czech Republic, has given in-principle approval to adopt tunnel kiln technology. The kiln would replace the two gas-fired rotary kilns assumed in the December 2025 definitive feasibility study (DFS) with a single kiln that could be heated by either gas or electricity. Geomet is 49 per cent owned by European Metals and 51 per cent by CEZ a.s. through SDAS.

The company said the approval is not final. It is conditional on satisfactory agreement of testwork contracts and on a preliminary market consultation under the Czech Public Procurement Act. A final choice between gas and electric heating has not yet been made.

Reasons for the change

The DFS roasts zinnwaldite concentrate and reagents in the lithium chemical plant, followed by water leaching at 60 degrees Celsius, with testwork reporting 93.2 per cent lithium extraction into the pregnant leach solution. European Metals said the tunnel kiln could lower processing-plant Capital and operating costs, mainly through a lower roasting temperature and the option of electric heating. It also said the design may remove dependence on gas, potentially allowing the plant to run solely on green power from CEZ.

Other features cited by the company include temperature control of plus or minus 10 degrees Celsius, which it said avoids vitrification of the product, less dust and off-gas, and heat recovery from hot solids. It added that modular, ground-level construction may shorten build time and reduce capital needs, and that the kiln fits within the footprint of the existing rotary kiln process train, so no major site redesign outside pyrometallurgy is needed. On emissions, the company pointed to 2024 testwork that estimated a reduction of about 50 million normal cubic metres, roughly 98,000 tonnes, of CO2 a year if electric heating is powered by renewables. The company described these as its own expectations rather than confirmed project outcomes.

Testwork and operating parameters

The tunnel kiln is expected to operate at a maximum solids temperature of about 850 degrees Celsius, with gas temperatures of about 870 to 880 degrees. Testwork showed that 850 degrees held for 30 minutes delivered lithium recovery equal to or slightly better than the rotary kiln benchmark, and it found no statistically significant difference between 30 and 60 minutes, so residence time may fall below the one hour assumed in the DFS.

Phase 1 testwork in 2024 recorded 93.2 per cent lithium recovery at 850 degrees for one hour and judged a single tunnel kiln feasible. Phase 2, which began in the third quarter of 2025 and is now complete, reported 93.4 per cent roast and leach recovery, confirmed the 850-degree target, and included pilot briquetting of 1,500 kilograms of roast charge. The company said recycling mixed-salt by-product from the lithium phosphate reactor into the kiln charge was viable, with improved recovery and reduced by-product mass, and that reagent quantities can be reduced. Equipment manufacturers supplied DFS-level budget quotes. The announcement also cites a 925-degree rotary kiln temperature in one section.

Timeline and permitting

European Metals (ASX:EMH) does not expect the change to affect the project timetable, and said tunnel kiln design and construction are simpler and modular. It also said the change does not affect the Environmental Impact Assessment permitting statement or timeline, because it considers all of the kiln's environmental impacts positive.

Next steps

Detailed design will lead into execution-level engineering. Phase 3 testwork is due to start in November 2026, using a shuttle kiln with two kiln cars and 1.5 tonnes of briquettes per test. Objectives include optimising the roast mix, time-temperature profile and reagent use, possibly raising lithium extraction by several percentage points, and confirming heat requirements, briquetting alternatives, materials of construction, fan power and kiln furniture design.