On the basis of the data of the chemical composition of wolframite rocks of the Sherlovaya Gora deposit, a model of their oxidation in an aqueous medium under standard conditions in the Selector PC is constructed. For Bi, Sb, Se, Te and U, equilibrium mineral phases and compounds are presented depending on the redox conditions of the “water-rock” systems.

— Based on the known thermodynamic characteristics, changes in the standard Gibbs energies Δ ƒ G ° and enthalpies Δ ƒ H ° of formation, standard values of entropies S ° at a temperature of 298.15 K of hydrate sulfates of divalent metals (Ca, Mn, Cd, Fe, Zn, Cu, Mg, Ni, Co, and Be), equations of linear dependences of the values of the thermodynamic functions of the compounds on the content of crystallization water were obtained using the least squares method. Comparison of the estimates with the multidimensional correlation analysis method shows a higher accuracy of calculations with the considered approach. A correlation has been revealed between the thermodynamic properties of the hydrates and the crystallographic radii of the cations. The derived equations are used to calculate unknown properties of some hydrates. Comparison of the calculations of the thermodynamic equilibria of the MeSO 4 –H 2 O systems by the Selector PC showed a good agreement with the experimental diagrams of the solubility of salts in water.

Linear programming is used to decompose potentials with respect to oxide components for a series of synthetic compounds of uranoarsenates of different metals, based on standard Gibbs energies of formation (ΔfG°) from the elements. The resulting system of additive contributions is used to calculate unknown ΔfG° of minerals of the class of uranoarsenates.

The relevance of the research is caused by insufficient knowledge about behavior of rare earth elements in hypergene zone of sulfide deposits. Sulfide oxidation leads to formation of highly reactive acid waters and active migration of metals, including rare earth elements. Formation of secondary minerals on different types of geochemical barriers is an intermediate stage in rare earth elements transport. The main aim of the research is the establishment of the role of new mineral formation associations in migration and distribution of rare earth elements in the conditions of hypergene zone. Object of the research is mineral of rozenite group of the Sherlovogorsk tin/polymetallic deposit. Methods. Mineral composition of solid samples was determined by x/ray method on diffractometer DRON-3 in the Cu Ka radiation by powder method. Chemical composition of minerals was determined by atomic emission spectrometry with inductively coupled plasma on the Perkin Elmer Optima 5300DV (USA) and mass spectrometry on the spectrometer Perkin Elmer NexION 300D (USA). Total and sulfate sulfur was determined by infrared absorption on the analyzer LECO CS230 SHHS. Results. According to the carried out analyses it is determined that the bedrock, ore and hypergene minerals are largely enriched in lanthanides of yttrium group and exceed Clarkie of the earth crust several times. For surface waters the concentrations of rare earth elements are higher by orders than for average ones of river waters. It was revealed that the newly formed minerals are concentrators of rare earth elements and the source of their secondary migration in dissolved form in the hypergene zone. Waters ponds with high contents of rare earth elements can be considered as a potential liquid ore of these elements.

Mine water at some mineral deposits in Transbaikalia contains valued metals commercially recoverable from solutions using zeolite rocks. Experimental impregnation of metal-bearing mine water from Sherlovaya Gora and Bom-Gorphon areas with sodium and ammonium kinds of clinoptilolite rocks from shivyrtuin deposit has been carried out. In the laboratory conditions, metals adsorbed by zeolite rocks are extracted by means of displacement by concentrated ammonium salts with further calcinations of the filtrate up to 500 °С. The metal content of the obtained cakes is conditioned by metal concentrations in solutions, by methods of impregnation and by the eluents applied. Saturation of ammonium types of zeolites with mine water solutions from the Sherlovaya Gora lake and further extraction of adsorbed metals by ammonium acetate yields the recovery of lantanoids of 73%. The obtained results, considering multiple recycling of the sorbent, can be used in development of an efficient technology for extraction of rare earth elements from mine solutions.

The standard thermodynamic potentials of natural zeolites in universal stoichiometric representation are computed. The enthalpies are estimated using linear deconvolution into chemical elements for calibration minerals. The entropies are computed using the additive scheme for oxide components; the Gibbs free energies are computed based on the calculated standard thermodynamic functions and entropies of thermochemically simple compounds.

Рассчитаны стандартные энтальпии, энтропии и энергии Гиббса образования из элементов соединений системы Al–S–O–H. На основе анализа ошибок расчетов рекомендованы значения термодинамических характеристик минералов – сульфатов и гидроксосульфатов алюминия с кристаллизационной водой. Проведено тестирование достоверности полученных значений в сравнении с экспериментальными данными растворимости сульфата алюминия.

The standard enthalpies, entropies, and Gibbs energies of formation from elements were calculated for compounds in the Al-S-O-H system. The thermodynamic parameters of minerals, aluminum sulfates and hydroxide sulfates with water of crystallization, were recommended on the basis of analysis of calculation errors. The reliability of the resulting values was tested compared to the solubility experimental data of aluminum sulfate.