Alumina hollow ball products are made of high-purity alumina hollow ball by high-temperature sintering. The products have the advantages of low bulk density, high compressive strength, low thermal conductivity, and high operating temperature. They can be widely used in synthetic ammonia liquefaction furnaces, ethylene production The lining of high temperature furnaces such as gas furnaces has strong resistance to corrosive gases and slag, and the operating temperature is below 1800 °C.
Alumina hollow ball is a new type of high-temperature heat insulating material, which is smelted and blown with industrial alumina in an electric furnace, and its crystal form is α-Al2O3 microcrystal. With alumina hollow ball as the main body, it can be made into products of various shapes. The use temperature is 1800 ℃. The mechanical strength of the products is high, which is several times that of ordinary lightweight products, and the bulk density is only one-half of corundum products. It has been widely used in high temperature and ultra-high temperature furnaces such as petrochemical industrial gasifiers, carbon black industrial reaction furnaces, and metallurgical industrial induction furnaces, and has achieved very satisfactory energy-saving effects.
The working layer of alumina heat-insulating refractory bricks that can directly contact the flame can also be used as a heat-insulating layer. It is widely used in ceramics, refractory kilns, powder metallurgy sintering furnaces, semiconductor components sintering kilns and kilns with hydrogen and reducing atmosphere.
The production method of alumina hollow ball is to add alumina raw material into a pouring electric furnace and melt it into a liquid, and then pour the furnace at a certain angle to make the solution flow out from the pouring tank at a corresponding speed, so that the liquid flows through the stream at a 60° -90° flat nozzle, blow out and form alumina hollow ball with high-speed airflow with a pressure of 0.6-0.8MPa, and then mix the alumina hollow ball, sintered alumina fine powder and binder according to a certain proportion, form, and dry, fired to obtain alumina hollow spherical bricks.
Alumina hollow ball have obvious thermal insulation properties and low thermal conductivity, which can play a good thermal insulation effect, reduce heat dissipation, and improve thermal efficiency, thereby saving energy. The energy saving effect can reach more than 30%.
