Zbadano wpływ temperatury, czasu dehydratacji oraz głównych zanieczyszczeń (Mg, Al, Fe(III)) na kondensację kwasu fosforowego(V). Badania prowadzono na układzie modelowym oraz rzeczywistym. Stwierdzono, że największy wpływ na proces kondensacji fosforanów(V), z analizowanych zanieczyszczeń, mają jony Al i Fe(III). Zależność tę zaobserwowano zarówno w odniesieniu do układu modelowego, jak i ekstrakcyjnych kwasów fosforowych. Ustalono również, że na zawartość polifosforanów(V) w produktach kondensacji większy wpływ ma temperatura niż czas dehydratacji.
EN
Condensation of extractive phosphoric acids based on the Al₂O₃, Fe₂O₃ and MgO-contg. phosphorites was carried out in a glass reactor placed inside a tubular vertical furnace. The heated reactor allowed for condensation of acids at 200-300°C and dehydration times 45-135 min. The increasing content of pollutants resulted in a decrease of polyphosphate content in products. The presence of Al ions resulted in a decrease of the condensation in the highest extent. The increase in condensation temp. and dehydration time resulted in an increase of polyphosphate fraction content in products, but the temp. effect was higher than those of the dehydration time.
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General properties of aqueous solutions of sodium silicates as a function of most important parameters, such as: silicate modulus, concentration, temperature, pH, ageing time, presence of electrolytes and technology of their preparation, are presented in this work. At the same time the proposition of treating these systems as mixtures of silicic acid and silicates, buffer mixtures and inorganic colloids, was given. The history of studies of the properties and molecular composition of water glasses solutions, both in Poland and abroad, was included in this work. Because of the complexity of the discussed systems, arising from the diverse levels of condensation of both silicic acids and silicate ions, a review of most frequently used and most useful methods and experimental techniques for the evaluation of molecular composition of aqueous solutions of silicates, was conducted. Such diversity of experimental techniques is a consequence of the fact that water glasses and systems in which they occur, having such versatile applications in many branches of the economy, still do not have complete and uniform literature study. It is the reason why in this article general conclusions based on experimental results received with the discussed methods are presented.
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