Bernic Lake ( Eng. Bernic Lake ) - a lake and the same name unique composition of the rare pegmatite metals, located in the southeast of Manitoba , Canada . The deposit contains ores of tantalum , cesium and lithium , discovered at the beginning of the 20th century.
Feature
The deposit is represented by a series of pegmatite bodies lying in amphibolitic diabases and andesites of the late Archean . The main body of the ellipsoidal shape gently plunges north under the level of Lake Bernik. Plagioclase-microcline pegmatites with a complex of tantalum, cesium, lithium and beryllium minerals.
The association of tantalum minerals includes tin tantalite ( vodhenite ), tapiolite , microlite and pseudo-xiolite; lithium minerals are represented by spodumene , lepidolite , amblygonite and petalite ; cesium is concentrated in pollucite ; Beryl , cassiterite , columbite , molybdenite , etc. are also found.
Reserves: tantalum ores 0.9-1.3 million tons with a Ta 2 O 5 content of 0.15-0.22%; lithium - 5.1 million tons (mainly in spodumene and small amounts in lepidolite), beryllium - 0.9-1.0 million tons with a BeO content of 0.22%. The total reserves of pollucite 450 thousand tons
The Bernik Lake deposit contains 70% of the world's cesium reserves.
Development Technology
The field is developed underground (up to 200 m deep); includes a tantalum mining and processing plant and a processing plant for the processing of spodumene ores. Processing of ores with fine crystalline tantalite, as well as the production of lithium, cesium and beryllium concentrates, is envisaged. The extraction of tantalum from ores 80%. Tantalum concentrate contains 50-52% Ta; 3.5% Nb 2 O 5 and 9% SnO 2 .
Literature
- Hirnichy encyclopedic vocabulary: in 3 volumes / as amended. V.S. Bіletsky. - D.: Skhidny vidavnichy dim, 2004. - T. 3. - 752 p. - ISBN 966-7804-78-X .