The geological setting of the lithium-tin- tungsten deposit Zinnwald is characterized by the appearance of two main lithologies, the Teplice Rhyolite (TR) and the Zinnwald Albite Granite (ZG).

The ZG is regarded as highly altered albite granite which intruded the volcanic pile of the Teplice rhyolite. The ZG intrusive body covers an ellipsoid N-S-striking outcrop area of 1.4 km x 0.4 km and straddles the border between Germany and Czech Republic.

The volcanic rocks of the Teplice rhyolite, covering a large area at the eastern margin of the Altenberg Block, extend for about 22 km in NNW-SSE direction. Within the property the TR represent the most dominant country rock and exhibit a wide textural variability. They are generally reddish grey to dark red in colour. Based on their textural appearance three subdomains / varieties can be distinguished: (I) A dominant phenocryst rich rhyolite.
(II) A subordinate phenocryst poor, ignimbritic rhyolite.
(III) A vein-like, coarse-grained, porphyroidic granite.

The ZAG ( zinnwaldite-albite-granite ) was found up to a depth of 730 m. From 390 to 540 m major zones of alternating ZAG and porphyritic zinnwaldite-microgranite (PZM) occurred.

Greisen type mineralization at the Zinnwald / Cínovec deposit is related to flat dipping, sheet-like greisen ore bodies and veins in the apical part of a geochemically highly evolved granitic intrusion. Lithium, tin, and tungsten mineralization is potentially economic and occurs mainly as quartz-mica greisen.

Exploration at Zinnwald has defined a Li-Sn-W greisen deposit in several stacked continuous bodies with a dimension of 1.6 x 1.5 km on the German territory. The deposit reaches from 200 m a.s.l. up to 850 m a.s.l..

Individual greisen beds show a vertical thickness between less than 1 m and more than 40 m.

The Zinnwald / Cínovec greisen deposit and subordinately the Teplice Rhyolite can be characterized by a number of different mineralization styles. The most important include:
I. Independent or vein adjoining greisen bodies;
II. Flat dipping veins (so called “Flöze”);
III. Subvertical dipping veins (so called “Morgengänge”);
IV. Metaalbite granite Sn-W-(Nb-Ta) mineralization.

Independent or vein adjoining greisen bodies.
The lithium ore mineralization of the Zinnwald property is closely linked to the existence of metasomatic greisen ore bodies that are located at the endo-contact of the uppermost parts of the ZG stock (style I). They form curved, stacked and lensoidal compact greisen bodies that can be highly irregular in shape but commonly exhibit a larger horizontal and limited vertical extend. However, maximum intersected greisen thickness is about 44 m. This style of greisen mineralization occurs in the central uppermost part and along the flanks of the ZG and follows with subparallel dip the morphology of the granite’s surface. Frequency and thickness generally decrease with depth. True thickness of greisen bodies is consequently consistent with the vertical depth for the central parts where the dip angle is less than 10°. Towards the gently inclined (10° - 30°) flanks of the N, E and S and a steeply inclined (40° - 70°) W-flank the true vertical thickness needs to be recalculated, respectively. On average, thickness of potentially mineable greisen bodies in the property area is between 2 m and 15 m.

The Zinnwald greisen contains variable amounts of quartz, Li-Rb-Cs-bearing mica named zinnwaldite, topaz and accessory minerals. Among the greisens of a granitic protolith three ideal end members can be inferred:
I. Quartz greisens - (quartz 85 to 100 %);
II. Mica greisens - (zinnwaldite 85 to 100 %);
III. Topaz greisens - (topaz 85 to 100 %).

Where as monomineralic greisen mineralization is of subordinate significance further subtypes with different proportions of quartz-mica-topaz are described for the deposit. The most abundant types and its average composition are the following:
IV. Quartz-mica greisens - (quartz 65 %, zinnwaldite 25 %, topaz 5 %);
V. Mica greisens - (quartz 50 %, zinnwaldite 40 %, topaz 5 %);
VI. Quartz-poor mica greisens - (quartz 15 %, zinnwaldite 75 %, topaz 5 %);
VII. Quartz-topaz greisens - (quartz 80 %, zinnwaldite 5 %, topaz 10 %);
VIII. Topaz-mica greisens - (quartz 65 %, zinnwaldite 20 %, topaz 10 %).

Other greisenized lithologies.
In terms of volume the ZAG is by far the most influenced lithology. Progressive greisenization produced an enormous amount of greisenized ZAG that exhibits typical features, e.g. beginning replacement of feldspar by the growth of metablastic quartz and zinnwaldite as well as advanced argillic, sericitic and haematitic alteration.

Greisenization can also affect the wall rock (TR). Unlike the medium-grained zinnwaldite albite granite, which shows strong greisenization in the upper part, the TR is only affected along flat or steep zones / cracks and along the contact between TR and ZAG, which were potential paths for the hot and pressurised fluids. Greisenized TR can be characterized by a prominent dark colouring due to the presence of fine-grained micas (muscovite and zinnwaldite) dispersed in the matrix of the TR. The original texture of the protolith is still recognisable. Thickness of greisenized TR can reach up to 5 m in direct vicinity of the contact towards the ZAG but tends to be less than 10 cm. Greisenized joints are commonly mineralized in the centre by quartz, zinnwaldite and / or topaz.

Metaalbite granite Sn-W(-Nb-Ta) mineralization. Moderate to intermediate greisenization of albite granite associated with significant mineralization of Sn-, W- and Nb-Ta-oxides (style IV) represents an unusual mineralization style of the Zinnwald deposit. Spatially independent from major greisen ore bodies this style is characterised by greisenized albite granite of common appearance but with a disseminated ore mineralization.

A continuous body of metaalbite granite Sn-W(- Nb-Ta) mineralization with 20 m (depth from 299 to 319 m). The mean ore grades are 0.26 wt.% Sn, 520 ppm W, 130 ppm Nb and 40 ppm Ta. Maximum grades amount to 0.39 wt.% Sn, 1200 ppm W, 160 ppm Nb and 50 ppm Ta. Located below a stacked quartz-mica greisen ore body of exceptional thickness and grade (50 m at 0.47 wt.% Li).

Ore Grades.
The differentiation of potential economically interesting ore types was based on mean lithium grades and aspects of ore processing. According to these criteria two ore types can be distinguished:
“Ore Type 1”: greisen;
“Ore Type 2”: greisenized albite granite und greizenized microgranite.

The weighted lithium grades for “Ore Type 1” vary from about 1,000 ppm to 8,100 ppm (0.10 % –0.81 %). The quartz-mica-greisen with a mean of about 3,400 ppm Li (0.34 %) represents the most prevalent petrographic sub-type within this group. It is assumed that this sub-type mainly determines the overall mean Li grade of the ore deposit.

The lithium grade of greisenized albite granite – and of subordinate greisenized microgranite – (“Ore Type 2”) ranges from 1,500 ppm to 2,000 ppm (0.15 % - 0.20 %). This clearly reflects the lower degree of greisenization intensity.

The “greisenized zones” are thought to envelop the greisen beds and reaching 810 m a.s.l. in the southern part and 350 m a.s.l. in the northern part of the modelled deposit.

The mining operation for the Project is planned as an underground mine development using a main ramp for the access to the mine and for ore transportation from the mine to the surface and straight to Freiberg, 50 km away from Zinnwald. The mine technology will be a common load-haul- dump (LHD) room and pillar technology with subsequent backfill using self-hardening material.

Simplifying, the deposit structure represents an anticline, at the flanks of which the ore bodies plunge below 400 m a.s.l.. The main ramp reaches the deposit in the north at +560 m a.s.l. in the foot wall of the anticline vertex. The deposit itself will be developed via short ramps and sublevels with a spacing of 8 m, initially focussing on the deeper portions of the deposit.

Development and extraction take place in the following order:
1. North field +560 m level
2. East field +560 m level
3. North field (below +560 m a.s.l.)
4. East field (below +560 m a.s.l.)
5. North field (above +560 m a.s.l.)
6. East field (above +560 m a.s.l.)
7. West field
8. Central field.

The inclined development ramps are planned with a cross section of 5.0 by 4.5 m and will be constructed along the footwall boundaries of the ore bodies by conventional drilling and blasting technology. The different sublevels are planned in a vertical distance of 8.0 m. At first, a sublevel crosscut will be prepared through the ore body up to its hanging wall boundary. With respect to the mining technique, turning radii are to be met for the development ramps with an inner radius of not less than 6 m and an outer radius not less than 11 m. In the extraction level the inner radius should not be below 5 m.

Mining consists of two extraction steps:
- 1st Extraction Step: Construction of pillar roads with a standard cross section of 5.0 by 4.0 m with permanently stable dimensioning (e.g. 5.0 m width on +560 m level) and a horizontal roof pillar thickness of 4.0 m. This extraction step is still accompanied with 70 % systematic mining losses.
- 2nd Extraction Step: Systematic reduction of pillars and horizontal roof pillars depending on the local conditions (deposit shape, geotechnical conditions, etc.) to a dimension of up to 7,0 by 7,0 m. Thus, it is possible to reduce the systematic mining losses down to 30 %.

The first extraction step can be downward and upward directed, whereas the second step has to be upward directed beginning at the deepest part of the deposit.

For an optimal development of the mine and a steady output of ore material, the initial development of the mine within the first years will be focused onto the deeper ore bodies (below +560 m) of the north and east field. The deepest planned sublevels are in the north field at +392 m (ore slice +388 to +396 m level) and in the east field at +360 m (ore slice +356 to +364 m level). The uppermost mineable sublevel will be at +688 m (ore slice +684 to +692 m level), to guarantee a minimum distance towards the historic mine workings. Furthermore, as long as a safety pillar of at least 25 m towards the historic mine workings is maintained, it is also possible to mine the ore bodies above the +688 m sublevel.

Loading of the chutes will be done by LHD technique. To ensure a daily output of 2,088 t, about 5 extraction workings, which will be mined in parallel, are necessary. Therefore, three wheel loaders with a payload of about 7 t are planned for the transport of the ore to the chutes. Surface haulage and transport of the ore from the mine site directly to the external processing done will be done by dump trucks with about 30 t loading capacity.

Selective Mining:
Preferred mining considers only the high grade ore blocks of the respective sublevel. These ore blocks represent to 80 % blocks with a productivity of = 24 [ppm*m], 30 % with a productivity of = 16 [ppm*m] and 20 % of the remaining masses. The preferential extraction initially considers only the first extraction step. The resulting openings (5 m x 4 m) are permanently stable and are kept open for a longer period until the second stage of extraction will take place during the subsequent mining.

Subsequent Mining:
The subsequent mining considers the remaining ore blocks that are not mined during the preferential mining. These ore blocks represent to 20 % blocks with a productivity of = 24 [ppm*m], 68 % with a productivity of = 16 [ppm*m] and 78 % of the remaining masses. The subsequent mining now only includes the second extraction step where the existing champers are expended to their final dimension of 7 m x 7 m. Immediately after extraction, this chamber has to be re-filled with backfill.

Complete Mining:
Complete mining refers to the total extraction of the ore reserves from the sublevel, excluding the volumes which are blocked by the preparatory openings. These ore blocks represent to 100 % blocks with a productivity = 24 [ppm*m], 98 % of blocks with a productivity = 16 [ppm*m] and 98 % of the remaining masses.

The mineral processing, consisting of
- jaw crusher;
- cone crusher;
- ball mill;
- dry magnetic separation, and;
- fine grinding;
is very robust. The lithium recovery assumed in the FS is 92 %.

- The pyrometallurgy test work has confirmed a robust roasting recipe consistently achieving > 85 % lithium extraction in the leach.

- The hydrometallurgical test work confirmed, that impurity removal successfully reduced calcium and magnesium contaminants in the pregnant leach solution (PLS). The precipitation by adding potassium fluoride has resulted in a battery-grade lithium fluoride with 99.5 % purity with a recovery rate of 95 %.

- The overall recovery rate from ROM to end product (LiF) is 76 %.

The FS is based on an average annual mine production over 30 years of the mine plan of approx. 573,362 t greisen ore containing an average grade of 0.31 wt.% Li. In the mineral processing unit, the ore is beneficiated to approx. 124,420 t/a zinnwaldite concentrate with up to 1.33 wt.% Li, which is extractable in a dry magnetic separation process. The subsequent metallurgical / chemical processing starts with a roasting process in a rotary kiln on the chemical site by adding limestone and anhydrite / gypsum. The roasted zinnwaldite- limestone-anhydrite mixture is than leached with hot water. In this process lithium and potassium are converted into water soluble lithium and potassium sulfates, which can be separated by several crystallization cycles. This is followed by various purification steps. Finally, 5,112 t/a of high purity lithium fluoride can be produced from the solution, which corresponds to 7,285 t/a lithium carbonate equivalent (LCE). As a by-product of this production process, approximately 32,000 t/a of potassium sulfate is expected to be produced. This co-product will be sold to chemical companies in Germany as a fertilizer product.

The forecast operating schedule for the mine in Zinnwald and the mineral processing unit in Freiberg is 24 hours from Monday to Friday and 6,000 hours per annum. The weekends will be used for maintenance. The chemical plant will run 24/7 and 8,000 h/a. The designed plant availabilities are typical 83 % for mine, mineral processing unit and pyrometallurgical plant.