Home – Home – Jornals – Chemistry for Sustainable Development 2010 number 3

The use of the products formed in combustion of the mineral part of coal (cenospheres) that are close in the ratio SiO₂/Al₂O₃ to crystalline aluminosilicates of the structural type of rock-forming granitoid minerals, in processing and burying radioactive wastes (RAW) allows one to solve the problems of waste minimization both in nuclear and fuel power engineering. Due to the application of microspehric zeolites and porous materials based on cenospheres of the ash from the combustion of the Kuznetsk coal for solidification of liquid RAW containing cesium and strontium radionuclides, it becomes possible to obtain glass crystal compounds under rather soft conditions (750-900 °С). Under these conditions, mineral-like phases of feldspar and feldspathoids fixing radionuclides in their lattice are formed. The target phases content reaches 66-80 %.

Sorption of methylene blue, vitamin B₁₂ and gelatine on the enterosorbent made of the bast of birch bark from aqueous solutions modeling the medium of stomach and intestines was investigated. The corresponding kinetic curves allowing one to estimate the completeness of the use of the sorption potential of enterosorbent in differentmodel media were obtained. Efficient curative and prophylactic action of the enterosorbent for the therapy of esherichiosis in mice was demonstrated.

Features of physicochemical processing of the natural gas of Eastern Siberia for the purpose of obtaining valuable products are considered. Special attention is paid to the processes based on the microspherical components of energy ash: non-cryogenic process of helium isolation using cenospheres, and the process of oxidative dimerization of methane (ODM) into ethane and ethylene in the presence of ferrospheres. A scheme of natural gas processing taking into account the features of composition and involving the stages of ODM is proposed.

Results of investigations, carried out at the Institute of Chemistry and Chemcial Technology SB RAS, concerning the problem of search and development of methods to synthesize new complex compounds of platinum possessing biological activity are presented. Two series of compounds representing the analogues of cisplatin and oxplatin, respectively, are presented. New efficient synthesis procedures were developed, X-ray structural studies of the majority of compounds were performed. Thernal stability and solubility of compounds were established. The data obtained may serve as the basis for the industrial production and arrangement of the modern physicochemical monitoring of the composition and properties of these preparations.

Results of investigations carried out in the Institute of Chemistry and Chemcial Technology in the area of mastering the technologies for obtaining synthetic solid, gaseous and liquid fuel from the brown Kansk-Achinsk coal are generalized. The technologies under development are based on the processes of autothermal pyrolysis and gasification of brown coal in the reactors with the boiling bed of catalytically active slag, and on the processes of thermal dissolution of coal and its mixtures with carbon-contaiing wastes in the presence of activated iron ore catalysts that provide obtaining liquid fuel and binders for road construction.

Results of the investigation of composition features of brown coal from Siberian deposits and the major factors determining its structural properties are presented. Methods of stimulating destructive reactions of hydrogenation into liquid hydrocarbons by means of preliminary activation tratment and the use of catalysts are considered. Investigation was carried out with different coal samples from the Kansk-Achinsk and Lensk basins; for comparison, the data on brown coal from the large deposit Yallourn (Australia) are described. The general regularities of the changes of structural properties are established, as well as the features of the interaction with solvents depending on the content of ion-exchange cations among which calcium cations are prevailing and play the part of ion cross-links in the structure. It is shown that cation removal with diluted HCl solutions, mechanochemical treatment and irradiation with accelerated electrons under optimal conditions allow one to enhance the activity int eh interaction with solvents and to elevate the reactivity during hydrogenating destruction into liquid hydrocarbons.
Results of the investigation of the effect of conditions of mechanochemical treatment of iron ore concentrates on their phase composition and parameters of the fine crystal structure are presented. The conditions of the preparation, on this basis, of dispersed active hydrogenation catalysts providing thorough decomposition of the organic mass of brown coal to form liquid hydrocarbons were developed. The individual and group composition of the obtained light-coloured hydrocarbon fractions of coal hydrogenates was determined. The data were compared with the composition of the corresponding fractions of oil from the major promising deposits of Eastern Siberia. Suitability of liquid coal hydrogenates for obtaining synthetic motor fuel, other oil products and their use as petrochemical raw material was substantiated.

Results of systematic investigation of the physicochemical features of the formation and isomerizing activity of catalysts based on zirconium dioxide modified with sulpahte and tungstate anions and various trivalent cations, depening on the composition and preparation conditions, are presented.

Methods of synthesis of betulin diacetate and dipropionate from birch bark are proposed. The methods are based on combined extraction of betulin from birch bark and its acylation with acetic and propionic acids. The structure of the resulting betulin derivatives was confirmed by means of chromatography - mass spectrometry, FTIR and NMR spectroscopy.

Problems connected with processing of underground polycomponent brines of the Krasnoyarsk Territory are to a large extent due to the remoteness of deposits and the absence of developed infrastructure. The version involving direct extraction recovery of valuable elements in the form of salts is considered. It is shown that the highest salt concentrating degree may be achieved for extraction of calcium bromide and lithium chloride (by a factor of 20 and 40, respectively). A scheme of extraction recovery of calcium bromide with a mixture of tributylphosphate and molecular iodine is proposed. Problems of lithium chloride extraction are considered. For the example of extraction of lithium tetraphenylborate, LiFeCl₄ and Li(ClI₂) in the systems with tributylphosphate, it is established that the growth of steric hindrance for the formation of extracted complexes promotes the recovery of lithium from calcium chloride brines.

Technological problems of processing rare metal ores of the Chuktukon deposit (Krasnoyarsk Territory) are considered. Oxide ferrimanganese ores contain 3-7 % earth oxides in the form of phosphates (monazite, florencite) and 0.5-1 % niobium oxide (chalcolamprite) and are practically undressable. The possibility of their direct chemical processing was studied. A scheme including autoclave nitric acid leaching and extraction of rare earth elements, reductive treatment of leaching tailings and isolation of niobium concentrate into the non-magnetic fraction was proposed. According to this scheme, nitrate solutions are subjected to thermal decomposition in order to recover nitric acid. The pyrometallurgical process of ore reduction leading to cast iron and rare metal products was analyzed. Process realization requires solution of complicated technological problems in obtaining high-quality products.

For the synthesis of palladium acetate [Pd(CH₃COO)₂]₃ as example, the features of the behaviour of pallaium nitrate solution as a precursor for the technology of industrial synthesis of palladium salts without chlorine-containing reagents aer studied. It is discovered that the oxygenated compounds of nitrogen that are present in the solution affect branching of the syntheis trajectory. It is shown that the formation of the final products proceeds through a series of intermediate stages at which new and already known chemical compounds were isolated: [Pd₃(CH₃COO)₆], [Pd(NO)₂O], [Pd(NO)NO₂], [Pd₂(CH₃COO)₂(NO)₂]₄, [Pd₆O₂(CH₃COO)₃(NO₂)_{6 - x}(NO)_x](H₃O)(H₂O)₅ (x = 0-3), [Pd₃(CH₃COO)₅NO₂], катена-[Pd(CH₃COO)₂]_n, catena-[Pd(HCOO)₂]_n, catena-[Pd(NO)₂Cl₂]_n, catena-[Pd(NO)X]_n (X = Cl or Br). Isolation and investigation of intermediate products allowed us to propose a scheme of the transition of the nitrate coordination surroundings of palladium into the acetate one. Side processes realized in the system are initiated, as a rule, by nitrosation reactions. On the basis of the data obtained, a set of industrial methods of obtaiing palladium acetate was developed.

Extraction processes developed and introduced by the authors at the Norilsk Mining and Smelting Plant (at present ZF OAO GMK "Norilsky Nikel") during the years 1979 to 2009 are considered.

Results of the investigation of reagent regimes and technological operations of gold recovery into concentrates from the ores of parent deposits and technogenic gold-containing raw material of the Krasnoyarsk Territory. Investigations were carried out at the Institute of Chemsitry and Chemcial Technology SB RAS and at the Institute of Nonferrous Metals and Materials Science of the Siberian Federal University during the recent decade. Dependencies of ore concentrability on the mineral and granulometric composition were established. Ways to impromenet of the quality of gold-containing concentrates are shown, new floatation agents are recommended along with new operations of fine gold concentrating, including afterconcentration of old dumps and tailings. Technological operations for the treatment of different hypergene deposits based on stagial combination of various mining and concentrating technologies were rpopsoed for the first time.

Results on the methods of obtaining and the properties of ultrahigh-molecular polyethylene (UHMP) are presented. Items made of this material survive rigid performance conditions, unlike for usual grades of the polymer. It was demonstrated that modification of UHMP by introducing ultrafine particles of inorganic materials promotes enhancement of the performance characteristics of the items made of UHMP. Results of investigations in the area of the development of technologies for obtaining items made of the composite materials based on modified UHMP. New rubber-polymer materials based no modified UHMP, butadiene-nitrile, cis-isoprene and divinyl caoutchouc were obtained. Due to extremely low abradability and increased performance resources of the items made of the developed materials under extremal performance conditions, the materials may win broad range of applications in various areas of technology.

Features of the treatment of non-yielding materials in open and closed systems are considered. The possibility to increase the efficiency of decomposition of difficultly processable ores and concentrates of precious metals in open systems with the use of low-temperature alkaline fusion and acidic oxidative treatment in closed systems - in autoclaves using the microwave radiation is demonstrated.

Possibility of the polymerization of α-angelicalactone (5-methylfuran-2(3H)-one) via two major routes - by opening the olefin bond and/or opening of the lactone bond - is demonstrated. Polyesters of α-angelicalactone were obtained on basic catalysts. Liquid and solid polymers with the molecular masses (MM) 840 to 100 000 were synthesized. It was shown by means of NMR that the fraction of polyester intermonomer bonds in them is 60-68 %. Copolymers of α-angelicalactone with styrele additives were obtained; their ММ was about 200 000-500 000. It was shown that the obtained polymers are subject to biodegradation by different microorganisms within a time interval from a month to half a year.

High-calcium volatile ash of brown coal from the Berezovsky open-pit mine of the Kansk-Achinsk basin selectively sampled from different points in the ash-collecting installation at BSRES-1 (convective pit, prechamber, and each of the four fields of electrofilters) was studied. Differences between these middlings in chemical composition, dispersity, binding properties were established. The types of volatile ash samples were determined in the system of their chemical classification. It was shown that the ash samples of Beresovsky, Nazarovo coal from the 1^st - 4^th fields of electrofilters differ from all the known kinds of ash by the maximally high calcium content. It follows form the phase diagram of the system СаО-Al₂O₃-SiO₂ that hydraulically active phases similar to the basic phases of the Portland cement clinker may be formed from the ash of electrofilters. Due to differences in the composition of ash samples, the ratio of these phases will be changed, too. Along with differences in particle size, this allows one to obtain Portland cement with special properties on this basis. Six fractions of magnetic microspheres of high purity were obtained; their chemical, quantitative phase composition and morphology were studied, including the contribution from globules of different kinds and the structural texture features of the material; methods of application were determined; the trends of changes in composition and morphology with changes in fraction size were established.