Korchuganova E. A active alumina preparation by the nitrate - urea method

The results of the experimental study of the homogenous aluminums hydroxide precipitation are presented. Conclusions regarding about the possibility of the aluminums hydroxide (boehmite crystal mode) preparation from the aluminum nitrate-urea system are made. It is shown that the active alumina production is possible by the sediments calcinations without the previous sediments washing. As a result of the thermo gravimetric investigations of calcinations processes of aluminum nitrate, ammonia nitrate, aluminum hydroxide, urea and deposits containing aluminum hydroxide and received by precipitation with urea from a solution of aluminum nitrate, which are carried out the mathematic model was obtained. The mathematic model describes the calcinations processes with the required precision. The speed constants of aluminum nitrate, ammonia nitrate, aluminum hydroxide and urea were determined. Recommendations of the calcining gases in this technology at the aluminum nitrate production stage are presented. The results of the original chemisorption's process experimental study are presented. The 70% of the nitrate component of the row materials is recycled according to offered technology. The technological scheme was described. It consist of technological stages: TAH dissolving in the nitric acid; homogenous precipitation from the aluminum nitrate solution with the urea; deposits calcinations; chemisorption's proces