VOL 87, No. 3 (2014)

The indicators of long-term strength (time and deformation to failure) of dense-sintered oxide ceramics in the temperature range 1400 - 1600 ° C at loads up to 60 MPa have been determined. There is a relationship between the characteristics of creep and ductile fracture: regardless of the crystal size in ceramics and the test conditions, the product of the steady-state creep rate and the time to fracture is constant, i.e. deformation to failure is constant. Thus, from the results of measurements of the creep rate, the durability of the materials can be established.

Current trends in the study of the fine structure of ?-Al ₂ O ₃ single crystal fibers obtained by pulling from the melt onto a seed (EFG) and by thinning a feeder using laser heating (LHPG) are presented. ). Studies of the crystallographic orientation of ?-Al ₂ O ₃ single crystal fibers have been carried out on an optical and scanning electron microscope. The use of X-ray diffraction topography for studying the perfection of the obtained single-crystal ?-Al ₂ O ₃ fibers and observing the boundaries of blocks and single dislocations is proposed.

Studies have shown that mullite gives the main strength characteristics to the ceramic bricks of the Astrakhan Kremlin. Crystallization of mullite in the sample under study indicates that the brick firing temperature was not less than 1000 - 1050 ° C.

The use of waste from a fiberglass plant allows not only to solve a serious environmental problem, but also to improve the quality of building ceramics produced at brick factories.

The possibility of obtaining ceramics for construction purposes from the dumps of coal mines, in particular, waste heaps of the Kizelovsky coal basin of the Perm Territory is shown. The use of oligopeptides contributes to an increase in the aggregate stability of dispersed systems and waste heaps, consisting of burnt and unburned ceramic rocks with enhanced physical and mechanical properties.

The possibility of producing paving elements from glass waste and quartz dust is shown, which in terms of operational properties are not inferior to clinker paving elements and are significantly superior to paving elements based on fine-grained concrete.

The results of studies on the effect of oxides of group II elements, jointly introduced into the glaze mixture, on the properties of pyroxene glasses are presented. It is shown that the simultaneous introduction of two oxides of group II elements improves the adhesive properties of glasses, reduces their melting point and LTEC. The resulting glazes can be used to cover decorative ceramic items.

The modern methods of fine grinding and air classification of materials by dry method are presented, providing accurate particle size limitation, as well as clean processing of the original product without impurities. The special wear-resistant design of the working units allows for fine grinding and classification of even the hardest materials, including up to 10 units on the Mohs scale.

Some systems for cleaning conveyor belts are considered and factors influencing the efficiency of cleaning and operational reliability of cleaning devices are determined. Improvements are proposed for scraper and screw cleaners designed to remove abrasive and strongly adhering raw materials from the idle strand of the belt.