APPLICATION OF SILICON CARBIDE CRUCIBLE FOR GEMSTONE HEAT TREATMENT IN MICROWAVE OVEN
Keywords:Gemstones, Heat treatment, Microwave, Silicon Carbide, Dielectric, Zircon
This research was developed to reduce cost of gemstone heat treatment, defined as a common process to improve a quality of gemstones, for local gem burners by using an interaction of a dielectric material in a microwave oven which can be applied as alternative method to use instead of an electric and a gases furnace. The objectives of the study were (1) to examine the trend of the relationship between times, temperature, and power (2) to find out the best composition between SiC and heat-transfer mediums. After the result was formulated, a research prototype was created by remodeling the crucibles with SiC and the heat-transfer mediums, then heated the system using the microwave oven. Based on the findings of this investigation it was concluded that temperatures can hit the peak at 840˚C for oxidation and 1000˚C for reduction which is proved by the colour enhancement of zircon. The final model based on this study can be practically used for burn reddish brown zircon (collected from Ratanakiri, Cambodia) to becomes sky blue (reduction) and colorless (oxidation).
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