Introducing L‑Max® and LOH‑Max®
Our patented L‑Max® and LOH‑Max® technologies extract lithium from lepidolite, other lithium mica minerals and the high-grade lithium phosphate mineral, amblygonite. They open up a much needed and far less contested mineral supply than traditional spodumene and brine sources.
These processes operate at atmospheric pressure and modest temperature, importantly with no requirement for roasting. As a result, our development and operating risks are far lower than conventional hard rock lithium chemical production methods that employ high temperature and/or high pressure processes. We are set to deliver lithium hydroxide or carbonate as well as other in-demand strategic metals sustainably and at competitive cost with no solid process waste, in contrast to conventional hard rock processes that are more energy intensive and generate substantial quantities of waste.
Greenhouse gas emissions
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What is L‑Max®?
L‑Max® is our patent-protected process for converting lithium-mica minerals to lithium and other useful by-products.
The mica is concentrated using a conventional flotation process and then subjected to leaching, a process by which the concentrated ore is treated with sulphuric acid. Sulphuric acid is one of the most commonly used chemicals employed in industry and takes the contained lithium and other metals into solutions as salts.
These salts are soluble, whilst the remaining part of the concentrate is not. The metal salts are then selectively extracted by precipitation from the solution by adjusting temperature and pH. Which means we can then wash out the lithium as a sulphate at the end of the process.
The L-Max® system is a low energy process and only uses low-cost, conventional reagents – predominantly sulphuric acid and lime - as well as steam and employs common use industrial equipment. Pilot scale tests have proven it delivers battery grade material. Its other outputs manufactured by a compatible patented process owned by Lepidico include silica, SOP – a fertiliser – caesium, rubidium and a gypsum rich residue product.
What is LOH‑Max®?
Our second patent protected technology, LOH‑Max®, produces high quality lithium hydroxide from lithium sulphate. This is significant as many end-customers have an emerging preference for lithium in its hydroxide, rather than carbonate, form.
Use of LOH‑Max® also significantly reduces capital and operating costs in the metal’s production versus conventional methods. This means LOH‑Max® is attractive for the final processing of a broad range of lithium concentrates - from hard rock, including spodumene, and sedimentary hosted deposits. Which is why we see opportunities for licensing it to the growing number of lithium chemical producers. Furthermore, unlike conventional processes LOH-Max does not produce sodium sulphate disposal of which is problematic due to its high solubility – this is seen as a significant emerging issue for the lithium and lithium-ion battery industries.
For those who want more detail on our technology
The L‑Max® process leaches the lithium and other metals from the mica mineral concentrate feed without an energy intensive thermal treatment before the leach, which is typical of other hard rock conversions. In fact, very little energy is required to keep the process at temperature. Optimising the leaching conditions has been an important part of L‑Max® development.
Handling of the leached slurry is embedded into the L‑Max® intellectual property. The slurry is filtered at a relatively modest temperature to yield a solution containing the valuable monovalent metals - and a silica-rich filter cake. Effective washing of this cake achieves high lithium recovery and produces the first process by-product, amorphous silica.
The filtered aluminium-rich leach liquor is cooled, resulting in the crystallisation of an alum solid. This separates the lithium from the other monovalent cations. Potassium, rubidium and caesium all form alums, whereas lithium does not.
The remaining lithium-rich liquor is treated through a series of pH controlled precipitation stages, with limestone or lime, to remove the remaining impurities - iron, aluminium, manganese, and magnesium. The resulting lithium sulphate solution allows the recovery of a high specification lithium product.
Production of lithium hydroxide is achieved without the co-production of sodium sulphate, using the proprietary LOH-Max® process. The unique chemistry of this process produces high purity lithium hydroxide monohydrate and efficiently remove even high concentrations of residual impurities in a cost effective manner. The process takes the lithium sulphate liquor produced from the L-Max® process as feed and involves hydrometallurgical reactions to produce lithium hydroxide and a gypsum containing residue when used in tandem with L‑Max®.