Dynamics of Physical-Chemical Transformations at Eastern Donbass Siltstones Firing

摘要

The article presents the results of studies on the dynamics of phase transformations occurring during firing of processing screenings of Eastern Donbass spoil tips, represented by siltstones, and which are promising raw materials for the production of various types of building ceramics - ordinary, face and clinker bricks, high-performance ceramic stones, ceramic tiles and siding. It is established that the screenings are raw material of low-temperature sintering. Depending on the degree of grinding, raw material can belong to the group of medium-or high-sintering raw materials. The screenings have a rather narrow sintering range - no more than 50 oC, which, as it seems to us, can be expanded by increasing the content of fine fractions in the preparation of screenings. Main mineral phases at the firing temperature of 1000-1100 oC are quartz, feldspars, ferrous silicates and aluminium silicates (fayalite, hypersthene, etc.), hematite. Features of dynamic phase and mineralogical transformations allow us to recommend firing products based on screenings at temperatures of 1000 °C and above, namely: in the production of ordinary bricks and stones based on screenings, it is necessary to focus on the temperature of 1000-1050 °C, in the production of clinker bricks and tiles at temperatures of 1050-1100 °C. When choosing corrective additives for screenings, it is necessary to pay attention to complex additives that increase the connectivity and plasticity of molding compositions, as well as expand the sintering range.