Blind River

BLIND RIVER, Algoma (EN: Blind River, Algoma; RU: Блайнд-Ривер, Алгома) is the large uranium ore region within Canada (the Ontario province). It has been discovered during the 1948; all industrial deposits have been identified during the 1953.

Blind River has the length of more than 150 kilometres; they distinguish within it the Quirk, Nordic, and Pronto ore zones. The reserves of the U3O8 are estimated at 250-300 thousand tonnes (1980). The uranium-bearing property is associated with the layers of the quartz-pebble conglomerates within the thick (up to 1050 metres) stratum of the Lower Proterozoic rocks (quartzites, arkoses, greywackes, argillites), which have been crumpled into folds and broken by numerous dip-slip faults. The ore bodies of the lenticular and tabular shapes are confined to the lower part of the large transgressive series, which is embedded with the sharp angular unconformity on the complicately dislocated and metamorphosed complexes of the Archean (the length is more than 2 kilometres, the thickness is 1.5-12 metres, the angles of the dip are 20-85 degrees). The ore mineralization is confined to the cement of conglomerates. The uranium minerals, namely, brannerite, uraninite, uranothorite, coffinite, and tucholite, associate with monazite, zircon, orthite, sulphides of iron, molybdenum, cobalt, and lead. The average content of U is 0.08%, of Th is 0.02-0.04%. The development of the deposits is performed by the underground method (the depth is 200-600 metres). The system of development is room and pillar (the width of the chambers is 20 metres, the width of the virgin pillars is 7.5 metres), the extraction of the ore is 67%. There is used the self-propelled equipment, the delivery of the ore is performed by conveyor. The average productivity of the labour of the worker is 115 tonnes of the rock mass per working shift. The total productive capacity of the mines is 40 thousand tonnes of the ore per day (1978). They extract the non-significant quantity of uranium (approximately 270 tonnes per year) by the method of the underground leaching. The beneficiation of the ore is performed according to the sulfuric acid scheme with the ion exchange reaction at the Denison (the daily productive capacity is 7100 tonnes), Algoma Nordic (3 thousand tonnes), Pronto Uranium (1500 tonnes), and other hydrometallurgical plants.