Cinovec Lithium / Tin Project
The Cinovec project is located 100 km NW from Prague on the border with Germany. It is part of the historic Cinovec-Zinnwald mining district. Over the past 600 years more than 40,000 tonnes of tin has been extracted in this area.
Tin has been mined in the Cinovec district from the 14th century. Modern UG mining ceased in 1972 in the central part of the Cinovec district, where near surface flat lying quartz-cassiterite-wolframite veins were mined UG with a shaft access. As the high grade ore was running out, the Czech State Company initiated an extensive UG exploration program southward of the Central Mine. Extensive UG drilling and tunneling defined significant blind tin-tungsten-lithium mineralization associated with greisenitization and silicification. About half a million tonnes of ore was test-mined in the 1980s and a feasibility study was completed. All operations ceased with the demise of the centralized economy in 1990.
The northern part of the Czech part of the Cinovec district is less understood but known for extensive mining in the 18th and 19th century.
Old processing plant
The Erzgebirge region is situated in a NW part of the Bohemian Massif in the Saxothuringian zone of the European Variscides. The deposit itself is related to post-orogenic granite intrusion, which intrudes rhyolites. The pervasively altered and greisenised lithium-albite granite (with quartz, topaz,zinwaldite and cassiterite) in the upper part of the cupola hosts flat veins surrounded by greisens and steep quartz veins with wolframite. The main minerals are cassiterite, wolframite, scheelite, zinwaldite, topaz and fluorite.
The Inferred JORC-compliant resource based on 846 diamond drillholes for 83,466m, and 21.5km of underground development tunnels is:
- 28Mt at 0.4% Sn (28Mt at 0.6% Sn equivalent - allowing for lithium and tungsten credits)
- 37Mt @ 0.38% Li
Metallurgical pilot testing of the Cinovec South ore in the 1970s achieved good recoveries (96% Sn and 84% W) using gravity and gravity/flotation flow sheets. Lithium is contained in lithium micas (mainly zinwaldite) and therefore concentrates in the gravity reject, from which the Li-micas can be concentrated by magnets. Lithium carbonate was produced on industrial scale during mining in the 1970s.