Stirring of a dispersed material in a pin granulator was examined on the basis of the accumulation and restoration theory of random processes. A mathematical description was given for stirring along the apparatus, which yields a function for distribution of the material over time for a granulator with a multifunctional rotor using experimental values of the mean time and distribution of time in the unit cells of the granulator.
The adsorption of platinum chloride complexes by synthetic activated SKN carbon is studied at various acidities and for various supporting salt electrolytes and it is shown that, upon going from strongly acidic to weakly acidic media, not only the quantitative indices of adsorption change but the mechanism of absorption of platinum by carbon changes as well. With the help of XPS, the formation of the surface complexes and the reduced forms of platinum are identified. The heat effects which are accompanied by the absorption of platinum ions on activated carbon are measured and the fractions of heat corresponding to the formation of the metallic phase are separated. A general scheme is suggested for the adsorption processes of platinum chloride complexes on activated carbon and the essential role of the electrochemical mechanisms is shown.
The results of testing of two methods of sorption leaching of zinc ions out of the oxide using the ion-exchange resin KU-2 - in the presence of direct contact of the solid phases and leaching through mesh - were compared, and the advantage of the latter method was demonstrated. As a result of an investigation of the influence of the rate of sorption dissolution of zinc and copper oxides on the nature of the functional groups of the sorbent, it was established that the leaching rate is sharply reduced (virtually to zero) with increasing pH of the cation-exchange resin. A study of the influence bf the degree of regeneration and washing of the ion-exchange resin KU-2-8 free of acid on its ion-exchange properties in the leaching of zinc showed that reducing the regeneration stages to three to four and washing to a pH of the last wash water equal to 3 do not decrease the rate of sorption dissolution of zinc oxide.
The hardness, mechanical strength, and corrosion resistance of lead alloys containing 2.7-3.0% antimony and up to 4.7% tin have been studied. The addition of tin increases the mechanical strength and corrosion resistance of the alloy without having noticeable effects on the hydrogen and oxygen overpotentials. An optimum alloy composition is proposed, whose mechanical properties equal those of Pb-Sb alloys, but whose corrosion resistance and anodic film cohesive properties significantly exceed those of the simpler system.
The effect of ammonium sulfate on the solubility of carbamide in sulfuric acid has been studied. A sharp fall in its solubility was noted in the presence of (NH4)2. SO4. The only crystalline phase in the concentration range 0-10 mass % (NH4)2SO4 is (NH2)2CO.H2SO4.
It was proposed that a two-electrode system be used for determining the efficiency of metal-corrosion inhibitors by setting the linear potential scan to 100 mV. The advantages of using the two-electrode system in comparison to a three-electrode system and the polarization resistance method were investigated. It was shown in examples of inhibitor protection of carbon steel in neutral and acid media that the inhibition coefficients are close to those obtained from ordinary polarization curves.
A study was carried out on the feasibility of using a copper-containing, chemically oxidized polycaproamide for initiating the graft polymerization of potassium p-styrenesulfonate. A marked positive effect in the initiation of graft polymerization was observed in the heterogeneous oxidation of polycaproamide by a hydrogen peroxide solution in an alkaline medium with catalytic amounts of a copper complex in the fiber. This complex may be introduced into the fiber both in the polymer synthesis step or upon surface treatment of the prepared fiber by a solution of a copper-containing complex of a triisoindolebenzene macrocycle. A correlation was found between the oxidation of polycaproamide treated with H2O2 with the efficiency of graft polymerization initiation in the absence of polymerization for polycaproamide subjected to thermal oxidation.
The dependence of electrical conductivity of a porous glass on the amount of heteropoly acids added to it and relative humidity is investigated. It is determined that the main contribution to the conductivity comes from the form of the acid molecularly distributed in the pore region. The porous glass-silicotungstic acid system is recommended as an electrometric humidity sensor.
A method is given for determining the parameters in clustering accompanying water absorption, which is based on electrochemical relaxation. Coatings have been ranked in hydrophilicity, water permeability, and associate dimensions. The correlation between the parameters indicates that the approach is correct.
The structural-formation processes are studied in solutions of hydroxypropylcellulose in trifluoroacetic acid over a wide range of concentrations.
A mathematical model has been developed for the process of chemical cutting of crystals. It has been shown that the reciprocal of the rate of chemical cutting in the case of first-order chemical reactions is equal to the sum of the reciprocals of the limiting rates of the chemical reaction, the supply of etchant, and the diffusion of the reactant molecules. Satisfactory agreement has been obtained between experimental and theoretical results in the example of cutting a crystal of indium antimonide. The model can be used in optimizing the process of chemical cutting and in equipment design.
The structural characteristics of a phosphorus-containing fibrous polyligand based on polyvinyl alcohol and polyacrylonitrile and its compounds with the transition metal ions copper(II), iron(III), cobalt(II), nickel(II), and lead(II) were studied by IR and EPR spectroscopy and by chemical methods. The results indicated the formation of coordination compounds of the above-mentioned metals with active groups of the modified copolymer containing two metal atoms and one twice-deprotonated phosphonic group.
Quantitative parameters have been examined for forecasting metal oxidation types. The oxidation (barrier or porous types) is governed by a criterion dependent on the molar volumes of the metal or metal oxide, the proportion of the metal ions entering the solution, and the total number of them passing from the metal to the oxide.
A generalized quantitative method of describing conversion processes is reported. The method is based on the phenomenological generality of these processes which is determined by the possibility of representing any conversion processes by a trajectory of differentiated masses in space. This leads to common parameters for any process - the stoichiometric coefficient and degree of conversion. Generalized equations for calculating the changes in the mass and composition of a substance are reported.
Isotherms of the adsorption of copper(II) from aqueous solutions of copper(II) chloride by four samples of carbon fiber materials were obtained. The influence of cHClO4 and (c)HCl on the adsorption of copper(II) by samples of CFM-1, which are characterized by the presence of acidic and basic functional groups, was studied. It is concluded that the adsorption of copper(II) proceeds according to an ionic adsorption mechanism and a hydrogen-bond mechanism.
Anion-exchange extraction of butyl, hexyl, octyl, decyl, and dodecyl sulfate by solutions of trinonyloctadecylammonium, dicetyloctadecylammonium, and octyloctadecylammonium salts in various solvents is studied. The effect of the extractant and solvent nature on the anion-exchange extraction of alkyl sulfates is examined. Hydration energies of the alkyl sulfates are found.
To increase the accuracy of the determination of the acidity of industrial cracking catalysts, the acidity of an aluminosilicate catalyst, kaolin, and their mixtures were studied chromatographically with respect to the reversible adsorption of pyridine. It was shown that a correct evaluation of the economic effect of the catalyst requires a determination of the total acidity with respect to reversibly and irreversibly chemisorbed titrants.
The transformation and transport processes in polycrystalline systems, which lead to a plastic deformation of the material, have been discussed. Correlations have been derived which relate structural, mechanical, and transformation parameters to the creep rate. The correlation between the creep rates during stretching and compression of the material has been determined.
Analysis of the experimental data on the heat capacity of liquids encompassing 350 inorganic molecular liquids yielded the atomic heat capacity fractions for 58 elements. Data are given on the precision of the heat capacity calculation using the Neumann-Kopp rule and the recommended atomic fractions C(p). For the Kelly rule, we established that the proportionality coefficient between the heat capacity with the number of atoms in the molecule, in the general case, depends on the type of anion and coordination of the compound. The values of the coefficient are given for halides with different coordination. The Neumann-Kopp and Kelly rules provide entirely satisfactory predictions of the heat capacity of molecular inorganic liquids using the extremely available data on the compound studied.
