ALUMINATE SOLUTION CARBONIZATION AND ITS USE TO PRODUCE HIGH DISPERSITY MATERIALS

The PURPOSE of the paper is experimental study of the carbonization of alkaline aluminate solutions and search for the region of available technological regimes to obtain the precipitation of a high dispersity aluminum hydroxide. METHODS. The study uses the following analysis methods: multifactorial experimental study of the carbonization indices of aluminate solutions and calcination of their decomposition products, laser microanalysis of particle size and size distribution, spectral analysis of gas-air mixture composition, electron microscopy of precipitation composition and chemical analysis of solutions, mathematical processing of results. RESULTS. The process temperature and solution neutralization rate are shown to be of decisive importance when obtaining the products of high dispersity. The dependence of the average median diameter of precipitate particles for aluminum hydroxide crystallization in the form of bayerite and gibbsite has been obtained in the form of a second-order polynomial. It has been determined that the average size of gibbsite particles changes at the stage of high-temperature calcination depending on the heating rate and isothermal temperature that is accompanied by slight agglomeration and an increase in their size. CONCLUSION. Technological principles of obtaining finely dispersed materials under nepheline raw materials processing formulated in the article provide the opportunity to adapt the carbonization process for the production of non-metallurgical products.

alumina production, alkaline aluminate solutions, aluminium hydroxide and alumina, size, precipitation patterns, experimental studies

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