FELDSPAR RAW MATERIAL IN THE REPUBLIC OF KARELIA AND ITS TECHNOLOGICAL ASSESSMENT

Abstract

The article provides a brief overview of the state of the mineral resource base of feldspar rocks in the Republic of Karelia. Karelia ranks first in Russia in terms of proven reserves of ceramic pegmatites. The feldspar industry is interested the most in potassium and potassiumsodium feldspar (microcline, microcline-pertite, orthoclase, plagioclases), used mainly for the glass and ceramic industries. Rocks and industrial minerals of the Republic of Karelia are of practical interest as a promising mineral raw material for the manufacture of a wide range of porcelain, faience and other types of ceramic products, including various technical silicate materials. Industrial types of feldspar raw material deposits in Karelia are represented by granite pegmatites, rapakivi granites, alaskanites, nepheline and alkaline syenites, acidic volcanic and subvolcanic formations, and anorthosites. Most of the pegmatite deposits have been actively exploited, and some objects with measured reserves are kept as standby reserves. The mineral and technological features of nontraditional feldspar raw materials were studied the most thoroughly for rapakivi granites (Salma massif), overburden rocks of the Kostomuksha iron ore district, quartz porphyry (Rosa-Lamрi), syenites (Eletyozero and Elisenvaara) and anorthosites (Nizhnee Kotozero). The geological and technological study of various objects bearing feldspar raw materials has shown that the textural and structural characteristics and mineral composition of the rocks are mainly conducive to enrichment. Enrichment using magnetic separation methods yields conditioned microcline, quartz-feldspar, nepheline-feldspar concentrates of varying quality, applicable in the faience, electrical, glass and other industries. The integrated approach to the study of mineral raw materials will enable us to assess the feasibility of processing not only feldspar, but also other types of minerals, including waste dumps of large exhausted deposits. Transport accessibility, moderately harsh climatic conditions, and profound knowledge of the mineral resource base opens up broad prospects for the revival and further development of the mining sector in Karelia.