PROBLEMS IN INTEGRATED GARNET ORE PROCESSING

References: 16th International Multidisciplinary Scientific GeoConference SGEM 2016, www.sgem.org, SGEM2016 Conference Proceedings, ISBN 978-619-7105-56-8 / ISSN 1314-2704, June 28 - July 6, 2016, Book1 Vol. 2, 1167-1174 pp

ABSTRACT
There is a definite geological localization of occurrences of potentially commercial garnet in the Republic of Karelia related, first of all, to separate parcels of one of mezo-structures of the Belomorian mobile belt. Commercial garnets, with exception of precious stones, belong to metamorphogene minerals, the formation of which was determined by conditions of amphibolite facies of metamorphosis of kyanite or kyanite-sillimanite type. Metamorphic conditions of medium temperatures and high pressures were especially favourable. Metasomatism connected with acidic alkalinization in conditions of kyanite-muscovite and quartz-muscovite facies was another important factor. A sequence of accompanying ferro-magnesian metasomatism in the earlier metamorphogene formations had provoked the formation of garnet ores in the result of intensive metasomatism on this territory. For practical reasons, garnet metasomatites including granatites, garnet-containing amphibolites and gneisses of the Belomorian mobile belt are of special interest. The maintenance of rock-forming minerals in this rocks varies: garnet 10-60%, quartz - 15-60%, muscovite - to 10% , biotite - to 20%, staurolite - to 17%, plagioclase - to 30%, amphibole - to 60%, kyanite - to 10%.
Preliminary results of laboratory technological tests testify a possibility to dress the ores to produce garnet concentrate. But there are some factors interfering receiving high-quality mineral products: fine-embedded inclusions in minerals; presence of minerals with similar physical and chemical properties (for example staurolite and amphibole).
An alternative problem solving is to produce the combined (garnet-staurolite, garnet-amphibole, quartz-plagioclase) concentrates. It is also possible to improve the separation by modifying mineral properties in the desired way. The next step will be to carry out some special tests to evaluate the abrasive properties of the combined garnet-staurolite concentrates and to work out the technical specifications for them.

Keywords: Garnet ores, quartz, enrichment, technological properties