Melted Aluminum Oxide Ingots

RHT offers alternatives to the traditional crystal feedstock obtained through the Verneuil process - the so-called “compacting” method. The method is based on high-frequency aluminum oxide melting in a cool container. The thin layer of initial powder (lining, or garnissage) stays between the water-cooled wall of the container and melted aluminum oxide, thus preventing any possibility of polluting the melt. The technology of aluminum oxide compacting gives a high-purity poly- crystal feedstock, a cylindrical ingot that fills the volume of the growing furnace wolfram crucible in the most efficient way. By changing container geometry, it is possible to obtain ingots of more complicated shapes, such as prisms for HDSM.

The advantages of the compacting method are: High purity of ingots obtained (up to 99.998%). High capability of synthesis results (chemical composition of leuco sapphire manufactured) to be reproduced. High productivity. One compacting furnace outputs about 10 kg of compacted powder per hour (with density ~ 3,3 g/sm3). The opportunity to choose the geometry and size of ingot, which is important for certain customers. The simplicity and low cost of the process compared to Verneuil production method (energy consumption for 30 kg ingot is 80 kW per hour).

Not only do we offer compacted aluminum oxide ingots themselves, but also the equipment and technology required for their manufacturing.

Aluminum oxide
"Kristall" growth furnace