ASSESSMENT OF CRYSTALLINITY DEGREE OF QUARTZ RAW MATERIALS

Abstract

Link for citation: Korovkin M.V., Ananyeva L.G., Zherlitsyn A.A., Kondratiev S.S., Savinova O.V., Kurskaya V.S. Assessment of crystallinity degree of quartz raw materials. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 8, рр. 59-67. In Rus. The relevance of research is determined by the need to assess the degree of transformation of quartz raw materials in its natural occurrence, as well as, changes in the properties of raw materials and products are exploited under various operating conditions. X-ray diffraction and Infrared spectroscopy was used to assess the degree of crystallinity of various crystalline quartz materials and products made of silicon dioxide, which showed satisfactory convergence of results and can be recommended for use in world practice. Objects: artificially grown quartz, including samples of synthetic quartz with an admixture of aluminum, zone-colored single crystal of quartz with an admixture of two and ferric iron; natural crystals of amethyst, smoky quartz, optical quartz; samples of fused quartz, products made of technical and optical quartz and silicate glass; as well as fine-grained samples of quartzites, including their micro- and nano-sized fractions. Methods: optical and electron scanning microscopy, X-ray spectral and analysis, infrared spectroscopy, X-ray diffraction. Results. The paper shows that the degree of crystallinity of quartz raw materials and products based on it is determined by the presence of a structural ordering in the near zone that characterizes the crystalline state corresponding to the a-quartz phase, which is confidently recorded by XRD and FTIR methods. The local disorder of high-purity quartz or quartzites having various impurities or defects in their structure that arise under the influence of external influences or exploitation causes deterioration of their properties and decrease in the degree of crystallinity.

Keywords

• quartz
• quartzites
• silicon dioxide
• quartz glass
• crystallinity index
• x-ray diffraction method