DLE Pilot Plant Update

CleanTech Lithium PLC (AIM:CTL, Frankfurt:T2N, OTCQX:CTLHF), an exploration and development company advancing sustainable lithium projects in Chile, announces it has completed due diligence on the use of industrial forward osmosis (iFO) as an alternative to using a standard thermal evaporator for eluate concentration in it´s pilot plant conversion stage. iFO provides several benefits to optimise the downstream process to produce battery-grade lithium carbonate.

Highlights:

• CTL has investigated utilising iFO for eluate concentration, the first step in the downstream conversion process, with the method achieving higher water recovery and up to 60% lower energy consumption and CO2 emissions compared to using conventional thermal evaporators
• iFO also has high efficiency when utilising solar thermal for power supply
• An iFO demonstration unit, provided by Forward Water Technology based in Canada, is preparing for shipment from Toronto to the facilities of Conductive Energy in Chicago, USA
• Conductive Energy will convert the eluate produced from our DLE pilot plant in Copiapó, Chile, using feed brine from Laguna Verde, into battery grade lithium carbonate
• The Company is assessing both iFO and conventional thermal evaporators for the concentration stage for the Laguna Verde PFS, which is currently underway
• An initial volume of 88m3 of concentrated eluate, equal to approximately one tonne of lithium carbonate equivalent (LCE), is at Conductive Energy´s facility, with transport and commissioning of the iFO unit expected to take approximately two weeks
• This progress continues to make CleanTech Lithium a leader in exploration and development of a DLE-based project in Chile and will provide the ability to produce large test samples of lithium carbonate to potential offtake partners seeking product qualification

Steve Kesler, Executive Chairman and Interim CEO, of CleanTech Lithium PLC, said:

"Our team has undertaken a tremendous amount of work on selecting and optimising the DLE process for the Laguna Verde project, and this has extended to the downstream conversion process where we are working with Conductive Energy. Previous test-work confirmed that a downstream process has been developed that will efficiently produce battery-grade lithium carbonate for the Laguna Verde project at pilot scale, including use of Forward Osmosis which we are investigating as an alternative for eluate concentration. This has the potential to lower energy consumption, CO2 emissions and both capital and operating costs."

CleanTech Lithium has engaged Conductive Energy for the conversion of lithium chloride eluate, produced using feed brine from Laguna Verde at our DLE pilot plant in Copiapó, Chile, into battery-grade lithium carbonate. Four containers of eluate with a total volume of 88m3 have been received by Conductive Energy at its Chicago, USA, facility with conversion to begin in October 2024. Conductive Energy´s conversion process is shown in Figure 1 which is based on standard industry process steps, other than the trialing of Forward Osmosis in the eluate concentration stage as an alternative to using a relatively more energy intensive thermal evaporator.

Figure 1: Conductive Energy Conversion Process

As due diligence in investigating alternative technologies capable of improving process performance, iFO was trialed in process test-work on a 200L sample of eluate undertaken at Conductive Energy´s facilities in Q2 2024. The full results of this test-work, which produced a sample of battery grade lithium with a purity of 99.75% lithium carbonate, was reported to the market on July 22, 2024. Results of the iFO stage of the test work achieved very good performance supporting the replacement of a thermal evaporator in concentrating eluate, with the key parameters and results provided in Table 1:

Table 1: Results from concentration of Laguna Verde eluate through R/O followed by iFO

A concentration of 18,000mg/L Li was set as the target concentration during iFO testing, representative of a typical lithium concentration used in the carbonation conversion process. Based on the Laguna Verde eluate, iFO can concentrate lithium up to 50,000 mg/L Li. Total water recovery of 94% was achieved during the eluate concentration, with the remaining 6% recycled or returned in the process. The DLE adsorbent used to produce the concentrated eluate achieved very high impurity rejection rates, except for boron, as previously reported (RNS July 22, 2024).

iFO testing was optimised for boron removal resulting in a 55% reduction based on weight. The achieved boron reduction is significant enabling improved process efficiency and product quality, while reducing energy consumption and operating costs associated with removal of boron using Ion Exchange (IX), which is the last process step prior to carbonation. In the Laguna Verde PFS currently underway, recovering this boron as a saleable by-product is being investigated.

Other benefits of iFO use include a 60% reduction in energy consumption compared to conventional thermal evaporators, and up to 80% if operated using a renewable energy source such as solar thermal as depicted in Figure 2 below. iFO´s low energy use when compared to thermal evaporation enables CO2 emission reduction by up to 60%, underscoring the sustainability benefits of this innovative technology.

Figure 2: Depiction of commercial scale iFO plant with solar thermal power supply

As a result of iFO performance during testing, CTL requested Conductive Energy to replace the thermal evaporator with iFO during the downstream conversion process for the next stage of conversion test-work, in which additional iFO operating information can be obtained such as energy requirements. A iFO demonstration unit with the capacity to process 35 m3/day of concentrated eluate will be supplied by Forward Water Technologies, which is shown in Figure 3 below, when final commissioning was underway. The unit is now ready for shipment from Toronto, Canada, and is expected to arrive at the Conductive Energy facility in Chicago, USA, in approximately one week. A further one week of on site commissioning is planned before the eluate conversion process will commence.

Figure 3: iFO demonstration unit with capacity to process 35 m3/day of eluate in final commissioning

Competent Persons

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