Home – Home – Jornals – Advanced Search

Physicochemical and adsorption properties of natural zeolites of the Sakhaptinsk (Krasnoyarsk Territory), Kholinsk (Chita Region) and Khonguruu (Yakutia) deposits have been studied. Changes in the zeolite characteristics in contact with alkaline and acid solutions have been established. The efficiency of the zeolites studied in the process of adsorption of petroleum products from gaseous and aqueous media has been compared. A correlation between the adsorption activity and efficiency of natural adsorbent zeolites with Na, K-components and molar Si/Al ratio in their composition has been found. The results obtained have made it possible to recommend the zeolites studied for development of adsorbent materials.

Possibility of obtaining a composite material from the wastes of yeast hydrolysis product

An amorphous compound, obtained by mechanical activation of a mixture of hydrated zirconium and titanium dioxides, under annealing at 600 °C forms crystalline zirconium titanate. Similarity between the soft mechanochemical synthesis and sol-gel procedure for obtaining dispersed zirconium titanate is demonstrated.

The possibilities of the application of mechanochemical method for performing dechlorination process with chlorinated aromatic compounds and polyvinylchloride are considered. On the basis of spectral investigations, we proposed possible mechanism and the composition of products of mechanochemical dechlorination of chlorinated aromatic compounds. Mechanochemical transformation of hexachlorobenzene, 1,4-dichlorobenzene and octachloronaphthalene, o-nitrochlorobenzene in the presence of alkaline agents proceeds with the formation of phenols and naphthols. This process can be represented as nucleophilic substitution in the aromatic ring. It is demonstrated that the intensity of mechanical action affects the relations between the main products of o-nitrochlorobenzene transformation. Under high-intensive mechanical action, the major product of the interaction of o-nitrochlorobenzene is 2-nitro-3-chlorophenol; under soft conditions, it is o-nitrophenol.

A technology for recycling of chromic waste to obtain abrasive material for polishing has been proposed whose introduction will efficiently solve the ecological problem of the region. The abrasive material obtained has a polishing ability which exceeds by 5

The investigation of obtaining thermoexpanded graphite from native graphite samples of four deposits in Russia and Ukraine involving various procedures of intercalation and pyrolysis is described. It is established that the most promising raw material for the production is graphite from Zavalye (Ukraine) and Kyshtym (Russia). Intercalation of these samples with chloric, nitric, acetic acids and chromic anhydride followed by thermal treatment in the steady mode allows obtaining carbon materials with the bulk density about 1 kg/m³. It is demonstrated that pyrolysis of the same intercalated samples in a flow reactor results in obtaining carbon materials with substantially smaller specific volume, but they possess a number of technological advantages in comparison with those obtained under steady conditions.

Ecologically safe methods of obtaining high-purity liquid organosilicon compounds containing Si

Development of functional electronics as an alternative to the circuit engineering is tightly connected with solution of a number of problems in the field of material science and technology. Semiconductor complex oxides, magnetic, sensor and radiation-generating materials, ferro-, piezo- and pyroelectrics acquire a great importance in the modern world, since they play the role of "clever" materials. Their necessity is increasing as the most advanced branches of science and technology, in particular electronics, computer engineering, medicine, laser and photochemical engineering, are developing. Among the methods of obtaining complex oxide materials, very promising are those of solutions to which the sol-gel method belongs. Mixing the initial components in a solution and their subsequent thermal treatment result in obtaining homogeneous materials and decreasing the temperature and temporal parameters of synthesis. This makes it possible to introduce chemically active and easily fusible components, e. g., lead and bismuth, into the complex oxide composition. An important role in the stabilization of the characteristics of functional materials is played by their purity factor. The absence of admixtures and the homogeneity of phase composition ensure the maximal characteristics and brusque transitions realized in the work of functional materials. In order to obtain homogeneous, pure and morphologically uniform functional oxide materials, the authors propose an extraction-pyrolytic technology.

A technology for obtaining magnesium oxide from brines on the background of prevalent amount of calcium chloride is proposed. The possibility of a combined obtaining magnesium and calcium compounds in the form of magnesia and calcium chloride hexahydrate is demonstrated. It is recommended to use concentrated calcium chloride solutions for preparation of drilling fluids.

Among the mineral phases composing human uroliths, the most widespread are spherulite aggregates of calcium oxalate monohydrate (CaC₂O₄ ^. H₂O). The morphology of these aggregates and their formation conditions have been studied. They are regular products of crystallization under the conditions of high supersaturation existing in the kidney. Formation of CaC₂O₄ ^. H₂O crystals takes place mainly by means of heterogeneous nucleation, and their growth goes in kinetic regime. Destruction of oxalate concrements by means of distance shock-wave lithotrypsy (DSWL) creates many problems to medical men and patients due to anatomic peculiarity of the spherulite aggregates. In these, nuclei of two types