A PROCESS FOR PRODUCING COLORED CUBIC ZIRCONIA BY A SKULL MELTING METHOD OF HIGH FREQUENCY INDUCTION HEATING

摘要

PURPOSE: Provided is a process for producing a colored cubic zirconia of high value, which has beautiful color and gloss like natural jewelry and excellent durability, in large quantities with a low cost. CONSTITUTION: The process for producing a colored cubic zirconia by high frequency induction heating method comprises the steps of: mixing 75 to 85 wt% of ZrO2 with 15 to 20 wt% of Y2O3 based on the total weight of the mixture and a small amount of rare earth metal elements, and filling the mixture into a scull equipped with an inside heater; positioning the scull charged with the raw materials in a high frequency induction heating device, heating the heater by the high frequency of 25 to 150 kHz to melt the raw materials; maintaining the melted product at the temperature of about 3,000 deg.C to form initial crystal seeds; moving an induction coil gradually at the outside of the high frequency induction heating device with the speed of 3.0-6.0 mm/hr from bottom to top of the scull to grow the cubic zirconia single crystals; cooling the crystals for 24 hours or more after the completion of the crystal growth; separating the product from the scull, cooling the product for 24 hours or more under the ambient atmosphere, and isolating the single crystals from the product.