Transformations of Uzbekistan Quartz Raw Materials – Quartzites of the Dzherdanak Deposit and Vein Quartz of the Nurota Deposit Under Thermal Impact

The aim of the work is to study the transformations of quartz raw materials as a result of high-temperature exposure. The objects of the study were quartzite from the Dzherdanak deposit in the Surkhandarya region and vein quartz from the Nurota deposit in the Samarkand region. The mineralogical composition of natural raw materials and phase and structural transformations during high-temperature exposure to 1430 ° C were studied using X-ray and differential thermal analysis. Based on the results of physicochemical analysis methods, it was found that vein quartz consists entirely of quartz and, therefore, it can be assumed that impurity elements are in the structure of the mineral. Quartzite contains inclusions of siliceous cementing substance, less than 2% of clay substance and inclusions of ore minerals less than 0.1%. The presence of impurities in quartzite reduces the temperatures of phase transformations and the temperature of cristobalite formation.