Moroz I. Re-dispersion of metal carbonate powders and structural features of their sedimental precipitations

The thesis analyzes the results of the investigation of the re-dispersion of metal carbonate powders in liquids of various chemical nature (water, 1,4-dioxane, isopropyl alcohol, isobutyl alcohol), in surfactant solutions (TRITON X-100, ATLAS G-3300 and HYAMINE 1622), in water with pH range from 5,7 to 11,0 and its effect on the aggregation stability and topological structure of the dispersions of copper and nickel basic carbonates and manganese and cobalt carbonates. It was shown for the first time that the aggregation and sedimentation stability of the suspensions of investigated metal carbonates depends on the degree of powder re-dispersion in which two consecutive processes are distinguished: the first, spreading of a liquid on the particle surface through open polydisperse pores, and the second, seeping of a liquid into closed pores. The role of each process in the destruction of the primary particle aggregates during the preparation of the suspensions was discussed, and conflicting effects were shown that result in the eventual re-dispersion degree. It was established that the effect of investigated surfactants on the re-dispersion ability of the medium depends on the powder dispersity (the size of pores that exist in powders). It was found that the spatial structures formed by the particles of the powders of investigated carbonates are non-uniform, and that the average particle packing density depends of the primary and the secondary density of their packing. It's shown the influence of conditions for preparing of the metal carbonates powders mixture on their thermal decomposition and solidphase fusion