Angara-Pit iron ore basin

ANGARA-PIT IRON ORE BASIN (RU: Ангаро-Питский железорудный бассейн) is situated at the south of the Krasnoyarsk territory of the RSFSR, between the Angara and Big Pit rivers. Within the limits of the region, there have been explored for approximately 100 kilometres of length the Nizhneangarskoe, Udorongovskoe, and Ishimbinskoe deposits, and there have been identified several ore manifestations of the hematite ores. The deposits have been discovered in 1946-49.

The Angara-Pit iron basin represents itself as the large synclinal fold of the north-western strike, which is complicated by the folds of the higher orders. According to its genesis, it belongs to the group of the marine slightly metamorphosed sedimentary deposits. The depositions of the hematite ores are confined to the bottoms of the Upper Proterozoic terrigenous ore-bearing stratigraphic suite. The ore horizon (50-80 metres on average) consists of 11 packs, each of which is formed by the ore and non-ore layers (0.4-20 metres), which are extending from 0.3 to 14 kilometres. The ore depositions are of the layered shape with the angles of the dip of 45-65 degrees. The main ore minerals are hydrohematite, hematite, and goethite. The ores contain neither harmful nor alloying admixtures.

The large part of the ores requires gravity-flotation or roasting-magnetic benefication with the usage of the local lignites as reductant. The reserves of the ores (of the A+B+C1 categories) are 755 million tonnes with 36-40% average content of Fe; one third part of the ores of the Nizhneangarskoe deposit may be developed by the open pit method with the stripping ratio of 2.9 tonnes per tonne. The Angara-Pit iron basin is the reserve iron ore base.