Contrast Characteristics of the Muscovitic Quartzite from Karelia, Russia - Determining the Possibility of Intensification of the Beneficiation Process

Abstract

The use of muscovite is determined by its industrial look and quality. Sheet mica is traditionally used as electrically insulating material. Crushed mica dry or wet grinding and scrap (waste from the production of sheet mica) are used as electrical insulating material (for example, mica paper), filler in the manufacture of various kinds of fillers, grout and paint etc. In addition, today there is a steady demand for micronized muscovite for the production of decorative coatings and cosmetics.On the territory of the Republic of Karelia (Russian Federation) there is a significant number of deposits and occurrences moscoviticarum rocks. Promising target small iron-poor Muscovite is the manifestation of the Eastern Hitware identified in 1999. The average mineral composition of rocks of the productive series: quartz – 10-71%; Muscovite – 8-42%; plagioclase – 1,5-28%; kyanite – 2-13,5%; biotite, and 0.1-8%; ore (pyrite, sphalerite) and 1.5 – 11%.Enrichment of this type of mineral raw materials may be carried out using traditional methods – gravity, magnetic separation, flotation. Textural-structural and mineralogical features, a high degree of secondary changes (thin intergrowths of muscovite with graphite, ferritization, the decrease of the strength characteristics) and the availability of areas and dedicated silicification abundant pyrite mineralization and its vein type significantly impoverish muscovite ore, necessitate the adjustment of technological schemes and modes of enrichment. Possibilities of improvement of processes of pretreatment and subsequent enrichment is possible using the methods of pre-sorting that represent rational and cost-effective alternative to traditional beneficiation processes. To explore the possibility of using the optical methods being preconcentration, experimental study of the contrast of properties of samples of the original ore. The study was carried out on crushed material, graded by size: -10+5; -20+10; -40+20 -60 and+40 mm. the results revealed the main search area colour shades in images of mineral samples in the colour system HLS – grey, brown, bright yellow-orange and purple. The correlation between the colour characteristics of the individual pieces and the content of muscovite. To implement the sort method of photometric separation, the threshold separation can be determined by one of the highlighted areas of the gamut or in their entirety. Next, the sorted ore with the same mineralogical and structural properties can effectively be enriched with gravitational methods. In the complex process of enrichment, it is possible to obtain, in addition to muscovite, quartz and kyanite products, which undoubtedly will increase the output of marketable products.