EFFECT OF CERIUM OXIDE AND BASICITY OF SLAGS ON THEIR VISCOSITY AND CRYSTALLIZATION START TEMPERATURE

Abstract

The study of the influence of the content of cerium oxide and the basicity of the slag on the viscosity and temperature of the onset of crystallization of the CaO–SiO2–Ce2O3 system containing 15% Al2O3 and 8% MgO was carried out using the simplex-lattice method of experiment planning, which makes it possible to obtain mathematical models describing the dependence of the property on the composition as a continuous function. Using the experimental data, we built mathematical models that describe the relationship between the temperature of a given viscosity and the composition of the oxide system. Then, by combining the obtained composition-temperature diagrams of a given viscosity on the isothermal section of the composition-viscosity diagram, a set of viscosity isolines was obtained. Generalization of the results of mathematical modeling and graphical display on the isothermal section of the composition-viscosity diagram made it possible to obtain new data on the viscosity of the CaO–SiO2–Ce2O3 oxide system containing 15% Al2O3 and 8% MgO, in the range of basicity 2–5 and the content of 0–15% Ce2O3. Experimental data show that the slags of the studied oxide system, which do not contain cerium oxide, are characterized by an increased crystallization temperature and viscosity in the studied range of basicity. The presence of cerium oxide in the slags of the studied oxide system provides a rather low viscosity and crystallization start temperature in the temperature range of 1500–1550°C. An increase in the content of cerium oxide in slags with a basicity of 2–3 from 1 to 15% is accompanied by a decrease in the crystallization onset temperature from 1490 to 1410°C. Increasing the basicity to 5.0 leads to an increase in the temperature of the onset of crystallization to 1520°C. At a temperature of 1500°C, the viscosity of slags with a basicity of 2.0–3.0, containing 7–15% Ce2O3, varies within 0.2–0.3 Pa · s. An increase in slag basicity to 3.0–5.0 at a fixed Ce2O3 content of 7–15% is accompanied by an increase in slag viscosity up to 1.0 Pa · s and reaches 2.0 Pa · s with a decrease in Ce2O3 to 1–6%. An increase in temperature to 1550°C and a fixed basicity of 3–5 is accompanied by a significant decrease in viscosity, which does not exceed 0.35 Pa · s at a Ce2O3 content of 1–15%.