Technological Features of Quartz from Muscovite Pegmatite Mining Wastes of North Karelia (Russia)

Abstract

Quartz from pegmatite mining wastes in North Karelia (Russia) were studied using atomic emission spectroscopy with inductively coupled plasma, IR spectroscopy, and optical and scanning electron microscopy to reveal the main technological characteristics of quartz that determine the possibility of utilizing it as a promising raw material for high-purity quartz concentrate production. It was shown that mineral inclusions in quartz were mainly represented by feldspars, muscovite, calcite, iron oxides, and borosilicate, which was confirmed by the trace element composition of quartz dominated by Al, Ca, K, and Na. Quartz contains OH-complexes associated with structural impurities of Al, Li and B along with molecular water, which was a part of gas–liquid inclusions. A quartz concentrate with a total impurity content of 160 ppm was obtained by unsorted quartz processing that included electromagnetic separation, microwave exposure, and acid pickling. Production of high-purity quartz concentrate with a total impurity content of <50 ppm in quartz grit with a fineness of 0.5–0.1 mm turned out to be difficult because of micron-sized mineral inclusions, gas–liquid inclusions, and structural impurities that were hard to remove during enrichment.