Study progress in preparation of high-purity alumina powder
Refers to the purity of 99.99%, higher purity alumina ultrafine powders with uniform size, is definitely the biggest production value production in 21st century one in the most higher, by far the most extensively utilized and sophisticated supplies. High purity fine alumina with higher hardness, high strength, put on resistance, corrosion resistance, heat resistance, oxidation resistance, insulation resistance, surface area, tiny thermal expansion coefficient, thermal shock resistance, low dielectric loss properties of, widely employed in insulation supplies, electronic merchandise and aerospace supplies, corrosion resistant materials which include high-tech cutting edge sector. Alumina alumina-oriented products in China, fine alumina specifically low sodium, Superfine and high purity alumina production has not but reached the level of industrialization, merchandise primarily depend on imports. With the development of domestic high-tech business, increasing demand for high-grade, multiform alumina. For that reason, to study prospects for production of high-grade aluminium.
Since 1984, Germany scientists H.Gleite Nano-alumina powder is prepared for the very first time due to the fact researchers all over the world began on the preparation of nanometer alumina powders by a broad and deep investigation, presents a number of preparation procedures. At present, high-purity alumina powders ready by pyrolysis, pyrolysis of ammonium aluminium carbonate hydroxide ammonium aluminum sulfate, liquid phase deposition, sol-gel, and organic aluminum alkoxide system.
Hydrochloric acid ammonia making high purity alumina powder
On analysis of preceding function and comparison from the different techniques of study on preparation of high-purity alumina powder around the basis of new preparation strategy is proposed, namely ammonia hydrochloride preparation of high-purity alumina powder.
Hydrochloride ammonia water preparation high pure alumina powder is will industrial aluminum hydroxide or partial aluminum acid sodium and hydrochloride Yu sealed of reaction slot within reaction, get three chloride aluminum remedy; 3 chloride aluminum resolution filter Hou, by evaporation, and Crystal generated has six water three chloride aluminum Crystal; six water 3 chloride aluminum Crystal in hydrogen chloride gas of protection Xia high temperature dehydration, get no water 3 chloride Aluminum powder, 3 chloride Aluminum powder in vacuum furnace inside for sublimation purification, get purity over 99.999% of 3 chloride aluminum; high pure three Qi of aluminum dissolved Yu ammonia answer, following concentrated, and Upon crystallization, filtration, drying, high-purity aluminum hydroxide crystals; aluminum hydroxide crystals at high temperature calcined later became the purity of 99.999%, with an average particle size of 0.three ?? m, surface area 21 high-purity alumina powder.
Relative for the hydrochloric acid ammonia, at present the primary production method of high-purity alumina thermal decomposition and organic aluminum alkoxide solution there's a complicated procedure, technical circumstances and difficult to control, larger fees and critical shortcomings, such as pollution. As China's financial improvement, higher purity alumina demand will continue to improve, whilst the production of environmental specifications is going to be higher and higher, green and efficient preparation of higher pure hydrochloric acid ammonia alumina production technology will be widely made use of.
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