M. Balakhashvili, Z. Kovziridze, N. Nizharadze, N. Darakhvelidze , V. Qinqladze
Georgian Technical University, Institute of Bionanoceramic and Nanocomposite

Technology.

69 Str. Kostava, 0160Tbilisi, Georgia.
E-mail: m.balakhashvili@gtu.ge

Summary: Purpose: The purpose of the work obtaining high-refractory clinker dolomite -
khrol sand - magnesite shards on the base. Method: The study of physical and technical
properties, the evaluation of the process of mixing and phase formation of materials was
carried out by determining the limit of porosity, density and compressive strength, also by
differential-thermal, X-ray structural analysis, electron-microscopic analysis methods.
To obtain high-refractory clinker the mixtures were prepared as an aqueous suspension. The
suspension was dried in a thermostat at 110 °C and rehydrated by adding 10 mass % water,
semi-dry method of sample to form. The samples were formed under hydraulic pressure, with
a diameter of 20 mm and a height of 20 mm. The forming pressure was 25 MPa. Results:
After the decomposition of dolomite at 900 0 C, above 1000 0 C the process of mineral formation
begins. Finally, annealing takes place at 1450 0 C and the samples acquire operational
properties. Tensile strength - 480 MPa, density -3.69 gr/sm 3 , total porosity -1.85%. The
roasting mode was selected accordingly: the rate of temperature rise from 0-1000 °C was 10
°C/min. Up to 1000-1400 0 C at 6 0 C/min. The last temperature delay was 1 and 4 hours. At
different values ??of the saturation coefficient-KH, the content of free unwanted CaO in the
material changes. At different values of the saturation coefficient-KH, the content of free
unwanted CaO in the material changes. The intensive baking process takes place at 1450-
1500 0 C with a delay of 4 hours. It is at this temperature range that complete bonding of
calcium oxide with silicate and formation of tricalcium silicate ends, as well as crystallization
of periclase.
Conclusion: In the process of roasting Dolomite - Chrol sand - magnesitic shards, as a
result of chemical interaction, new phases are formed: periclase and alite. At a mixture ratio
of 4:1, complete bonding of calcium oxide with silicon dioxide of fine sand is taking place,
forming tricalcium silicate, and high-quality well-baked clinker is obtained by firing at 1450-
1500 0 C.
A high-quality well-baked clinker without free calcium oxide is obtained, which is confirmed
by physical-technical properties and electron-microscopic analysis.