- Lime Fusion Method
In this process the naturally available Zircon and pure limestone with 2% Calcium Chloride are mixed together in a blending mill for better mixing and the mixed material is shifted to a crucible. The crucible is heated to a temperature of 1400 0C in a furnace and the maximum temperature is maintained for 2 hours for ensuring perfect sintering. The sintered material is taken out from the crucible and is leached with a solution of 5% hydrochloric acid and 2% sodium hydroxide. Multiple leaching is done to get pure zirconia powder. This is then dried for obtaining final powder.
In the next process, the natural zircon is mixed with dolomite and 2% calcium chloride for an hour in a blending mill. The mixed material is shifted to a crucible and is heated to a temperature of 1400 0C in a furnace. The maximum temperature is maintained for 2 hours for ensuring perfect sintering. The sintered material is leached with a solution of 5% hydrochloric acid and 2% sodium hydroxide. Multiple leaching is done to get pure zirconia powder. This is then dried for obtaining final powder.
The second method is preferred since it yields 100% fully stabilised zirconia.
To be contd….
