Technological capability of synthesis of inorganic oxides in water fluid in neighborhood of critical point

This technology is based on the use of water fluid as a reaction medium for synthesis of fine-crystalline oxides. The production of fine-crystalline oxides in a pilot plant using the industrial autoclaves has demonstrated the economical expediency and environmental safety of manufacturing of various fine-crystalline oxides by this method. The synthesis is performed at temperature in the range 380–410 °C and pressure of the water fluid 10–30 MPa in a high-pressure apparatus (reactor, autoclave or gasostat).Both the simple and mixed oxides with crystal sizes ranged from 100 nm to 400 μm were synthesized including quartz, corundum, zincite, aluminates of alkaline earth and rare earth elements, barium hexaferrite and yttrium-aluminum garnet.