The problem of hydrothermal mass transfer and deposit of tantalum and niobium during the formation of their deposits (according to experimental data)статьяЭлектронная публикация
Дата последнего поиска статьи во внешних источниках: 24 июля 2024 г.
Аннотация:Experimental data on the solubility of columbite (Mn, Fe) (Nb, Ta)2 O6, pyrochlore (Сa, Na)2(Nb, Ta)2O6(O, OH, F), tantalum oxides (Ta2O5) and niobium (Nb2O5) inacidic, neutral and alkaline aqueous solutions: fluoride, chloride, mixed (mHF + mHCl), carbonate Na2CO3 and (Na2CO3 + NaF), alkaline NaOH and (NaOH + NaF) in theconcentration range from 0.01 to 2.0 mol/kg H2O at a temperature of 300 – 550oC, a pressure of 50 - 100 MPa at f(O2) given by Co-CoO and Ni-NiO buffers have been obtained. It has been established that the solubility of the minerals pyrochlore and columbite is incongruent, while thesolubility of pyrochlore is higher than that of columbite. The presence of the F-ion has a positive effect on the solubility of minerals and oxides, and the complex formation of Nb is much more pronounced than that of Ta. The role of temperature and pressure is secondary
