Weathered skin on olivines of the Kovdorsk massive as possible source of refractory raw materials

Conclusions

Laboratory technological investigations of the weathered skin of olivines from the Kovdorsk massive (Northern Mountain) showed that it is possible in principle to obtain standard forsterite (grade FKh) refractories with an addition of chromite corresponding to ST SÉV 5366-85. They have a moderate porosity, high compressive strength, high refractoriness, and low thermal conductivity. In their properties they are practically as good as refractories made from raw olivine rock. The reduction in the thermomechanical factors of specimens of compositions Nos. 1, 2, 4, and 5 is due to the increased contents (up to 14.4%) of iron oxide (instead of 8% for the traditonal magnesia-silicate raw material, for example dunites).

The favorable grain-size composition and the low value of Δm_calc (loss on ignition) means we can use the raw material without preliminary crushing, which ensures a lower cost than for dunite and crystalline olivine.

The possibility of using the weathered skin as a raw material for manufacturing olivines opens up prospects for geological development work at the Northern Mountain in order to increase the reserves of olivines. The weathered olivines in this case should be classified as an independent type of rock.