The materials physical and chemical analysis of the reasons of instability particle size distribution of productional of aluminum hydroxide in the processing of bauxite by Bayer process. Shown that the frequency of changes in the properties precipitate Al(OH)3, formed during the precipitation of aluminate solutions determined by the dependence of the growth processes on the relative supersaturation of the system per unit area of the seed. Found determines the influence of concentration injected seed aluminum hydroxide and its active surface (which varies under the influence of impurities in the aluminate solution) on the parameters of the periodic changes in the properties of sediment.
The results of the technical and mineralogical studies of washability of low quality bauxites of North Onega deposit are presented. The experiments of determination of the grindability of raw materials including without ball grinding and assessment washability bauxite by magnetic separation and flotation were conducted. These ores are very complex object for enrichment, as characterized by extremely thin impregnated aluminum-containing minerals, as well as the similarity of their properties. Further work of to conduct experiments using chemical enrichment (as soon as the chemical enrichment, and in combination with the physical methods of enrichment) is planned.
Materials of calculation of solubility of aluminum hydroxide in the system Na2O – K2O – Al2O3 – H2O, by data of the solubility in the private sections of this system for a wide range of compositions aluminate solutions by the content of alkaline components are presented. It is shown that the solubility of aluminum hydroxide in the range of concentration of alkaline components from 1,29 mol/l to 1,94 mol/l is a linear function of the mol fraction of one of them. The results of experimental researches on decomposition of aluminate solutions are given. Significant increase of the degree of decomposition of aluminate solutions in per cents of the theoretical values with growth of mol fraction of K2O in a mixture of alkaline components has been established.