The Kachkanar-Gusevogorsk iron (V, PGE) ore field is located in the central Urals, Yekaterinburg Oblast, of the Russian Federation, 120 km north of Nizhny Tagil. The Middle Silurian (~428 Ma) Kachkanar Complex (Reshit'ko, 1967) is an example of an Alaska-Urals type concentrically differentiated mafic-ultramafic complex; presumed to be a magma chamber feeding eugeoclinal mafic island arc volcanism.
The Kachkanar Complex comprises a group of three lenticular massifs emplaced into a shear zone in Ordovician-Silurian eugeoclinal meta-volcanics (metamorphosed to amphibolite and chlorite schist). The cores of the massifs are occupied by dunite which grades outwards into peridotite, olivine pyroxenite, clinopyroxenite, olivine gabbro, gabbronorite, diorite and syenite.
The Kachkanar-Gusevogorsk ore field has provided iron ore concentrate (61% Fe) for the Nizhny Tagil smelters since the mid-1900s, despite an extremely low average grade of iron (15-16.5% soluble iron in magnetite). The operation is said to be currently (2006) profitable due to large-scale bulk mining of very uniform ore. Production to date (2006) is from the Gusevogorsk (eastern) sub-area (3-4 open pits) where disseminated magnetite is coarser than that found in the Kachkanar sub-area to the west, which is unmined. Interstitial xenomorphic titanium-magnetite with subordinate ilmenite is found densely disseminated in layers of diallag pyroxenite (20-30% magnetite). Past production totals 1.5 Bt with reserves of 14.7 Bt of ore containing 2.43 Bt iron. Recoverable vanadium grades 0.084% for a total of 13.61 Mt V. Titanium content is 1-2%.
Platinum, together with iridium, osmium but little paladium has, in the past, been won from alluvial placers. It is also found in trace amounts in the iron ore and in olivine pyroxenite and wehrlite. Platinum alloys form small scattered disseminated grains in olivine pyroxenite and wehrlite, whereas platinum-paladium sulphides prefer diallagite and magnetite-rich pyroxenite. The former minerals were won from alluvial placers, the latter can be recovered by magnetic separation. Kachkanar holds the greatest share of the known Uralian PGE resource (some 700 t plus of PGE).
(Source: Peter Laznicka, 2006)
