KARAKTERISASI MATERIAL REFRAKTORI JENIS SILIKA DENGAN BERBAGAI VARIASI TEMPERATUR SINTERING

Abstract

Finding some difficulties to obtain coke as a fuel of blast furnace makes metal melting industry in Ceper Klaten decided to using induction furnace as the primary metal melting equipment. Usage of induction furnaces is a new technology for them. So, there are less knowledge about induction furnace mainly about lining material like silica. This research aimed to determine the physical properties of refractory include chemical composition, grain shapes, distribution size of powder, density, porosity and microstructure. Result of this research is expected to minimize of errors in the usage of refractory material. In this research, refractory powders printed using a mold with diameter of 17.8 mm and height of 50 mm with a compacting pressure of 240 MPa. Sintering process was done by varying the temperature 1200oC, 1250oC, 1300oC, 1350oC, 1400oC and 1450oC with heating rate of 100C/min and cooling rate of 200C/min. Result of the tests showed that the composition contained in the raw material powder is quartz low (SiO2), while in the specimens that have been sintered at 1400oC, phase changed into cristobalite (SiO2) of 26.53% and increased in specimens that have been sintered at 1450oC by 54.89%. The grains shape of silica is sub-rounded and distribution of powder size spread evenly on the entire mesh. Values of density in a row are 2.10 g/cm3; 2.06 g/cm3; 2.22 g/cm3; 2.26 g/cm3; 2.24 g/cm3; 2.15 g/cm3 and porosity are 18.47%; 18.43%; 18.25%; 17.62%; 16.62%; 16.40%. Microstructure analysis showed that the pores of refractories has narrowed in line with increasing sintering temperature.