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An effect of mechanical activation on reaction capacity of tinstone under its dispersion with the minerals with different hardness and in the presence of reducing agents was investigated. Dependence of degree of SnO₂ dilution in HCl on the hardness of the added under grinding mineral and on redox capacity of used reagents was fixed. It was determined that an activation barrier decreases with increasing reaction capacity.

The bromine and iodine content and distribution in the soils and natural waters of the south of West Siberia are studied. Questions associated with the pattern of accumulation and migration of halogens in the soil profile, and with the conditions in natural waters contributing to, or hindering the accumulation of halogens in them, are discussed.

The effect of mechanical activation of well crystallized zirconium oxide of monoclinic modification in a centrifugal planetary activator mill and in vibratory mill on the characteristics of fine crystalline structure and phase transformation depending on the treatment environment and mechanical loading is investigated. It is established that the mechanical action in the centrifugal planetary mill stimulates dispersion processes, accumulation of microdeformations, and phase transition of the oxide into the tetragonal form. The rate of processes depends on the environment of treatment: for mechanical activation of the dry powder, the phase transition occurs within 15 min, the rate of the process decreases in the presence of water as additive. Treatment in vibratory mill causes mainly crushing of the particles and accumulation of microdeformations. After 2 h, the size of crystallites decreases to 38 nm and remains unchanged during further treatment; gradual accumulation of microdeformations and amorphization of structure occur. After 15 h, the fraction of the crystalline phase was 15 %; no formation of other crystalline phases was observed. The formation of a metastable tetragonal form of ZrO₂ in the activator apparatus can be due to the pulsed character of powerful mechanical action, which causes intense crushing of the crystallites (20 nm) and can create local conditions favourable thermodynamically and kinetically for the phase transition in separate regions of the solid.

Thermochemistry of the decomposition reactions of Sm_{1 + x}Ba_{2 - x}Cu₃O_y solid solutions (x = 0-0.8) has been studied by solution calorimetry (2M HCl, 23.15 K). Dependences of the formation enthalpies of these compounds on the samarium content have been obtained. Analysis of the experimental data shows that the Sm_{1 + x}Ba_{2 - x}Cu₃O_y phases can decompose into mixtures of variable composition in both inert and oxygen atmospheres. In an inert atmosphere, decomposition reactions can form mixtures of solid solutions with high samarium contents and barium cuprate. Under oxygen, decomposition can lead either to mixtures of phases with higher and lower samarium contents or to mixtures with high samarium contents and barium cuprate. Decomposition reactions of solid solutions are assumed to increase the critical current. For samples prepared under oxygen, the critical current is admitted to be stronger than for samples synthesized under an inert atmosphere. The results of thermochemical studies will permit optimization of the solution-free process for sample preparation from SmBa₂Cu₃O_y, which is currently the most promising and widely used technology.

Reactions of FeCl₃ with MBH₄ (M = Li, Na, K) which take place during mechanical activation (MA) of mixtures of crystalline substances in a vibratory vacuum mill have been studied. The reactions form diborane(6) or B₂H₆; the product yields depend on the nature of MBH₄, on the molar ratio of reagents, and on the mechanical activation time. Under optimal conditions, the yield of B₂H₆ is 81.5, 79.5, and 73.5% when LiBH₄, NaBH₄, and KBH₄, respectively, are used. When mixtures of FeCl₃ with MBH₄ are heated without MA, reactions occur with liberation of H₂, while B₂H₆ is not formed.

The results of tests of the laboratory prototype of adsorption chiller based on ecologically sound working pair "water - SWS-1L adsorbent" are presented. The adsorbent relates to the family of selective water sorbents and is a mesoporous silica gel KSK modified with calcium chloride. The device produces cold water at a temperature of 5-10 ^oC, which can be used in air conditioning systems, to store food, etc. High coefficient of performance reaching 0.6 for low temperature of water desorption (90-95 ^oC) was obtained during the test of the device. This allows the investigated adsorbent to become a real alternative for traditional materials (silica gel, zeolites) for use in ecologically pure adsorption systems involving low-potential heat (T100 ^oC)

The effects of nonferrous metals on extraction of the ruthenium form [RuNO(NO₂)₄OH]^2- (An^2-), prevailing in weak acid solutions, by mixed-radical phosphine oxide (L) are investigated from the viewpoint of extraction of fission ruthenium. The synergic effect has been found to be high (n10³) because [RuNO(NO₂)₄OHML_m] heterometallic complexes are formed (M = Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺; m = 1-3). Extraction constants have been determined for the complexes, and conditions of their formation and extraction from nitrate solutions have been optimized. An approach to ruthenium extraction by nitration the starting solution to convert various forms of ruthenium into the An^2- form and by extracting Ru in the form of Ru/M complexes has been verified experimentally. The suggested method for extracting ruthenium was tested on real high-level waste.

The problem of contamination of chlorophenolic biocides with polychlorinated dibenzo-n-dioxines and dibenzofurans formed as admixtures in the process of preparation synthesis is considered. Results of assay of chloroorganic admixtures in the sodium pentachlorophenolate synthesized in this country are presented. A high toxicity of the preparation determined by the content of less chlorinated congenerics of polychlorinated dibenzo-n-dioxines is demonstrated.

Indirect oxidation of maleic acid by Fenton's reagent with electrochemical generation of hydrogen peroxide from oxygen in a carbon hydrophobized electrode in 1M Na₂SO₄ solution is studied. It is established that the process goes on destructively through a number of intermediates with mineralization to CO₂ and H₂O. Succinic, malic, oxalic acids and anhydrides of ketoacids were detected among the intermediates. The rate of mineralization depends on the current density and on the concentration of Fe²⁺ ions.

The behaviour of gallium, aluminium, and zinc in the course of reagent carbonization of alkaline solutions is described. It is shown that gallium and zinc may be separated, and separation conditions have been studied. Gallium may be concentrated by co-precipitation with the basic aluminium carbonate to give rich aluminium-free gallate solutions.