Modeling the compositions of slime waters in the tailing dumps of the Central and Krasnorechensk concentrating mills at the Dal’negorsk district in the positive temperature range

The paper describes the physicochemical modeling of slime water formation in the dried tailing dumps of the Central and Krasnorechensk concentrating mills in the positive temperature range. The Eh and pH parameters of the equilibrium solutions, quantitative element compositions of the latter, and the compositions of the crystallizing hypergene and technogenic minerals were determined. The modeling was carried out on the basis of the averaged chemical compositions of the tailings. The resulting data point to a possible hydrosphere pollution with slime waters containing elements of sulfide ores and enclosing rocks, which may occur over the entire considered temperature range, both before hypergene mineral deposition and after that.     

Physico-chemical parameters of the formation of supergene and technogenic minerals in the mining technogenic systems of Russian Far East

The physico-chemical parameters of crystallization (genesis) of 30 supergene minerals from the mine, slime, and drainage waters in the mining technogenic systems of sulfide-containing deposits of the Far East of Russia are presented. The data have been obtained using Selektor software complex allowing modeling the sulfides oxidation under the hypergenesis and technogenesis conditions. We have determined the temperature ranges of formation and association of the primary and secondary minerals.     

Initial magnetic susceptibilities of iron and nickel aerosol powders

The dependence on angle is considered for the hysteresis-free initial susceptibilities _a and _ar together with the initial susceptibility _o for iron and nickel aerosol powders, as well as the effects on these characteristics from changes in powder packing density. Estimates are made of the negative-interaction fields, and a quantitative comparison is made between the observed _ar() and theoretical values by means of the pair model. The correlation between the experimental and theoretical relationships confirms the concepts used on the predominant effects from magnetostatic interaction in the mechanism for magnetization reversal in powders of materials with low anisotropy.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, pp. 40–43, July, 1984.     

Synthesis of esters of metallocene alcohols and 4,5-dichloroisothiazol-3-carboxylic and 5-arylisoxazole-3-carboxylic acids

Acylation of alkyl- and 1,1′-dialkylferrocene alcohols and diols as well as (3,4,4-trichlorobut-3-ene-1-ol-1-yl)-4,5-cymantrene with dichloroisothiazole- and 5-arylisoxazole-3-carbonyl chlorides has afforded esters containing 1,2-azoles fragments. Some of the obtained compounds have exhibited potentiating action in the binary mixtures with insecticides.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>’-substituted derivatives of 5-(4-methylphenyl)isoxazole-3-carbohydrazonamide

Condensation of aromatic, isoxazole, and ferrocene aldehydes as well as 1,1’-diacetylferrocene with 5-(4-methylphenyl)isoxazole-3-carbohydrazonamide afforded various N-substituted azines with molecular fragments of the corresponding aldehydes or diacetylferrocene.     

Carbon nanotubes as a support for Pt-and Pt-Ru-catalysts of reactions proceeding in fuel cells

Comparative study of two types of single-wall carbon nanotubes and standard carbon black Vulcan XC-72 as supports for catalysts of reactions proceeding in fuel cells is carried out. The nanotubes were prepared by arc method; they differed in the degree of their purifying from amorphous carbon and metal impurities. The structure and hydrophobic-hydrophilic properties of these carbon supports are studied by etalon porosimetry. The effect of the supports’ specific surface area on the deposited catalyst particles size and specific surface area is studied. The catalysts (Pt-Ru and Pt) were deposited from aqueous solutions of their salts. Platinum was also deposited by thermal decomposition of ethoxy clusters. It is shown that in methanol oxidation reaction at the Pt-Ru catalysts the current values per unit true surface area do not depend on the support nature, provided the catalyst loading is equal and the particle size is similar. When oxygen is reduced at platinum deposited onto purified nanotubes and the carbon black Vulcan XC-72, specific kinetic currents also are close to each other. It is shown that the degree of nanotubes purification and their structure affect the kinetics of this reaction significantly.     

Stieltjes differential method in the modeling of an irregular system on a geometric graph

We analyze a SD-equation on a graph from the viewpoint of variational laws and generalize the mathematical modeling on space grids to the case of an irregular object. We take into account the possible appearance of the delta-function phenomenon even at the grid nodes.     

Behavior of Sulfide Ore Elements in the Oxidation of Concentration Tailings under Cryogenic Conditions (Dalnegorsk District,Far East)

Russian Journal of General Chemistry - Oxidation processes in the sulfide component of the concentration located in the Dalnegorsk district were modeled in the range from–25 to 0°C. The...