The Project is located in the southern Central Zone (“sCZ”) of the Damara Belt.

The pegmatites within EPL 5439 form part of the Karibib Pegmatite Belt and are hosted in biotite schists and carbonate lithologies of the Karibib Formation, in quartzites of the Chuos Formation, in basement gneisses of the Abbabis Complex and in Damaran aged (500-530 Ma) granites. The licence includes the Rubicon mine which comprises three pits (Rubicon I, II and III), the Helikon 1-5 pegmatites as well as a number of associated smaller pegmatites.

Two types of pegmatitic granites are recognised within the Property:
- a porphyritic biotite granite, light orange in colour with centimetre-size perthitic K- Feldspar and a finer grained phase of the same composition. Most of the pegmatites associated with this type of porphyritic granite are zoned and with lepidolite±petalite, beryl, and columbo-tantalite mineralization like the Rubicon pegmatite;
- a porphyritic leucogranite often associated with black tourmaline (var. schorl). Pegmatites associated with this granite are un-zoned and not mineralized.

The Rubicon pegmatites.
Large parts of the area around the Rubicon Mine are also covered by thick alluvium and calcrete which makes it difficult to ascertain the exact orientation of the main pegmatite. However, the main pegmatitebody forms a prominent ridge which strikes northwest and dips between 20º and 65º northeast; in the Rubicon I pit the dips are average about 46° and flatten to about 18-25° at depth, in the Rubicon II pit the dips are ~30° and flatten to about 8-12° at 20 m depth.

The main Rubicon pegmatite consists of two ellipsoidal well zoned, Li-mineralized bodies developed around two quartz cores and surrounded by a zone of quartzo-feldspathic pegmatite. The two bodies are exposed in the Rubicon I and II pits over a strike length of approximately 700 m, are 25-35 m thick and intruded into a pegmatitic two-mica granite. The pegmatitic granite is also intruded into Okongava Diorite. The Okongava Diorite is intruded into the metasedimentary lithologies of the Karibib Formation (Damara Supergroup).

The Helikon pegmatites.
The Helikon group of pegmatites is located approximately 7 km north of Rubicon and comprises at least 7 zoned pegmatites namely Helikon 1 to 7 of which Helikon 1 to 5 have been mined in the past with Helikon 1 the most productive. Helikon 6 does not occur within the Karibib (Rubicon-Helikon) area.

The Helikon 1 Pegmatite is the largest pegmatite of this group and forms a ~400 m long lens shaped body oriented east-west and dipping at between 60°-70° to the north to subvertical in places with an average width of ~60 m. It is hosted in marbles dominated by calc-silicate felses, of the Karibib Formation, which strike east-west and dip ~45° to the south.

The Helikon 2-5 pegmatites outcrop in the hills 800 m to the north of Helikon 1 along an east- west strike for approximately 1,600 m and average 9-15 m thick. The Helikon 2-4 pegmatites outcrop as a series of semi- continuous dyke-like bodies and strike east- west over approximately 1,000 m. Helikon 5, which not been exploited, is the west most pegmatite, is a separate intrusion about 100 m to the west of Helikon 4 outcrops discontinuously over approximately 500 m. The Helikon 2-4 pegmatites are referred to as six “sections” within a larger (Helikon 2) pegmatite.

The host rocks are marbles, calc-silicates with isolated intercalations of biotite schists of the Karibib Formation, which strike east-west and dip 20°-45° to the south and are cross-cut by the pegmatites which dip at between 30° south to vertical, averaging 55°-80° to the south at Helikon 2-5.

The mineralization of economic interest is found in zoned complex petalite-lepidolite- amblygonite bearing LCT pegmatite sills and dykes. The pegmatites also contain minor amounts of niobium and tantalum, caesium and rubidium mineralization. The main lithium minerals present are lithium micas (comprising lepidolite and/or zinnwaldite) and petalite which are restricted to the intermediate and core zones of the pegmatites.

The dip, geometry and near surface location of the mineralised zones at the Karibib Project are suitable for conventional open pit truck and shovel operations with drilling and blasting required to fragment both mineralised rock and waste rock. An industry standard approach to mine planning has been undertaken.

Pit wall slopes are based on a geotechnical assessment by Pells Sullivan and Meynink engineers. The geotechnical assessment was based on dedicated geotechnical drilling in final pit walls, mapping of fault structures, core assessment and physical rock testing and failure modelling. Inter ramp angles are 55° based on 15m high benches with 8m berms.

The Rubicon pit design has been completed in four stages and Helikon 1 two stages. The stages have been selected based on value, grade, and strip ratio criteria.

Mining operations at the Karibib Project are characterised by hard rock materials requiring: blasting; the selective mining of a sloping orebody; operation over and around remnant underground workings; and the need for water management at depth.

Ore will be transported to run-of mine crusher stockpiles, with various grades of ore requiring individual stockpiles. The rehandling of ore from stockpiles is required to balance ore feed to the concentrator. A fleet of one 50-tonne excavator and 35 tonne trucks can adequately support the mining schedule for the majority of the mine life. Later in the project life, as substantial quantities of waste removal is required to cut the Rubicon pit back, a local mining contractor will be employed to manage this peak material movement phase.

The Helikon 1 deposit is mined as a satellite pit located approximately 7km from the concentrator. The haul road from Helikon 1 to Rubicon is already developed and road trucks will be used for haulage.

Mine waste ex-Helikon 1 pit will be placed into the Helikon 1 Waste Management Area (“WMA”), constructed immediately to the south of the open pit and up dip of the pegmatite structures to avoid sterilisation of any deposit extensions.

Mine waste ex-Rubicon pit will be placed in the Rubicon WMA immediately to the east of the open pit. There it will be co-disposed with filtered tailings from the mineral concentrator and used to construct the walls and to cap the facility at closure. The benign concentrator tailings will be trucked to the WMA. The tailings are then co-disposed with waste rock from the mining and covered continuously to ensure dust mitigation and that no unstable pockets are left in the overall dump matrix. During periods when there is insufficient rock from the mining operation to co-mingle with the tailings then barren rock from later mining stages will supplement the cover requirement.

The target ore zones are within pegmatite sills formed in granite host rock. The Rubicon orebody dips at 20° to 30° to the north east. The Helikon 1 orebody dips at 50° to 60° to the NNE. Rubicon ore grade zones have true widths of 5 to 15 metres. Helikon 1 ore true widths are 5 to 20 metres. TheRubicon pit will mine the orebody over a strike length of 750 metres and at Helikon 1 ore will be mined over a 360 metre strike length.

Karibib is fully permitted for the re-development of two open pit mines feeding lithium mica ore to a central mineral concentrator that employs conventional flotation technology.

Concentrate is shipped to a chemical conversion plant to be built in the Khalifa Industrial Zone Abu Dhabi (KIZAD) that employs Lepidico’s proprietary process technologies. Main products of lithium hydroxide monohydrate (“lithium hydroxide” or “LiOH”), caesium formate and rubidium sulphate are augmented by bulk by-products of SOP fertiliser and amorphous silica, with the latter used as a partial supplement for cement which attracts a significant carbon credit.

Abu Dhabi is the world’s largest producer of sulphur, used in the manufacture of sulphuric acid, which is a key reagent in the proprietary L-Max® process. It is planned that acid will be purchased for the first three years of operation prior to a dedicated acid plant being built, which will also generate power from waste heat. L-Max® is a hydrometallurgical process that is much less power intensive than convention chemical conversion of spodumene, allowing the Phase 1 Project to have a modest carbon intensity versus the industry.

The mineral concentrator will use conventional crushing, grinding, desliming and froth flotation processes followed by dewatering of concentrate and tailings streams.

The lithium principally occurs in lepidolite, amblygonite and lithian muscovite although zinnwaldite is also recovered through the froth flotation process. The overall recovery of lithium to the lithium concentrate is 80-90%, at a concentrate grade of 2.9%-4.2% Li2O. These values vary according to the mineralogy.

The concentrator has been designed to process 333,000tpa (dry basis) of ore for the first four years (“Stage 1”) and 541,000tpa (dry basis) from Year 5 of production (“Stage 2”). Stage 2 requires the addition of a second smaller ball mill, reconfiguration of the flotation circuit and the installation of a second tailings filter. The plant will be debottlenecked in Year 7 to cater for a declining head grade.

Chemicals Conversion
The L-Max® process has been developed over a six year timeframe through an extensive program of laboratory, mini-plant and pilot plant programs. Coupled with extensive flowsheet modelling and vendor testwork, a robust process has evolved that produces lithium hydroxide, high value by- product chemicals of caesium and rubidium (extracted by a separate proprietary process) and a range of bulk by-products, in an efficient low energy approach.

A unique aspect of the L-Max® process is the direct leaching of the lithium bearing mineral from the feed without the need for an energy intensive thermal treatment step preceding the leach, which is employed by many other hard rock lithium conversion processes. The leach conditions are such that very little energy is required to keep the process at temperature. Optimising the leaching conditions has been an important part of the development process.

Handling of the leached slurry is a key part of the L-Max® process and the embedded intellectual property. The slurry is filtered at elevated temperature to yield a solution containing the valuable monovalent metals and a silica-rich filter cake. Effective washing of this cake is required to achieve high lithium recovery to the liquor moving downstream.

The filtered leach liquor, which is rich in aluminium, is cooled resulting in the crystallisation of an alum solid. This alum crystallisation step achieves the separation of lithium from the other monovalent cations. The monovalents, potassium, rubidium and caesium all form alums, whereas lithium does not. Filtering the alum slurry results in the potassium, rubidium and caesium, and most of the aluminium reporting to the solids, and a liquor containing the lithium and small amounts of other impurities. The alum solids are further treated to yield potassium, caesium and rubidium products.

The impure lithium-rich liquor is treated through a series of pH controlled precipitation stages, with limestone and lime, to sequentially remove the remaining impurities, namely iron, aluminium, manganese, and magnesium. The resulting lithium sulphate solution is of sufficient quality to allow 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 has been able to directly produce high purity lithium hydroxide monohydrate 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.

The chemical plant is designed to process 56,700tpa (dry basis) of lithium mica/amblygonite concentrate at a feed grade of 4.0% Li2O for production capacity of 5,600tpa of lithium hydroxide. The by-products include caesium, rubidium, amorphous silica, SOP, and gypsum residue. The overall lithium recovery to lithium hydroxide is estimated at 90%.

The L-Max®/LOH-Max® processes consist of just five main processing steps for the recovery of lithium hydroxide: feed preparation, leaching, impurity removal, sulphate removal and lithium recovery. A further three processing steps are included for the recovery of SOP, being alum dissolution, aluminium removal and SOP crystallisation. A further three processing steps are included for the recovery of rubidium and caesium products, being rubidium-alum crystallisation and re-pulp, aluminium precipitation and rubidium crystallisation.