Problems of Chemistry and Chemical Technology

Influence of the Middle Magnetic Field on the Disperse Iron-Oxygen Mineral Phase Formation by Applyng the Rotation-Corrosion Dispergation Method

The purpose of this work was to investigate the process of the disperse iron-oxygen mineral phase formation by applying the rotation-corrosion dispergation method when the middle magnetic field affected the system. The rotation-corrosion dispergation method is based on the principle of iron (steel) electrode corrosion when its surface contacts either with air or dispersion medium. The constant magnetic field was influencing the system during the process of the phase formation. The magnetic field intensity was 0,6—1,9 kOe and remanent magnetic induction was 0,7—1,3 T.

Germanium-Silicate UTL Structure Zeolites with Extra Large Pores

The review contains literature data and the authors own research on methods for the synthesis of element-containing germanium-silicate zeolites with extra large pores.

Influence of Bast Fibers Treatment Stages on Microcrystalline Cellulose Indices

The process of obtaining microcrystalline cellulose from non-wood plant bast fibers (flax, hemp, kenaf) with using preliminary acid hydrolysis, alkaline sulfite -alcohol method delignification and oxidation-organosolvent processing was investigated. It is established that the conduct preliminary acid hydrolysis in the first step of obtaining microcrystalline cellulose can significantly reduce the mineral content (at 62–75 %), partly yield of pulp (at 9–12 %) and residual lignin content (at 20–30 %) compared of feedstock.

Application of Modified Hooke–Jeeves Method for Multi-Objective Optimization

The task of multi-objective constrained optimization of chrome tanning of semi-finished leather applying the Hooke–Jeeves method is solved. The optimality criterion is formulated in the form of a generalized additive objective function. Local criteria for the objective function are normalized and nondimensionalized. The weighting parameters are obtained on the basis of professional assessments. The algorithm of the modified Hooke–Jeeves method is the basis for the software module, which is implemented using object-oriented programming language Visual Basic for Application.

Sorption of Phosphates by Iron (III) Oxyhydrates with Various Crystalline Structures

By means of precipitation method (amorphous ferric oxyhydrate), - (goethite) and - (lepidocrocite) have been synthesized. Physical-and-chemical parameters of the synthesized compounds have been characterized using X-ray diffraction, porosity studies, pH titration. With the aid of XRD it was found that - and - have crystalline structure, while is amorphous. The sorption affinity of ferric oxyhydrates of various crystalline structure towards phosphate ions has been studied.

Modelling of Organic Compounds Adsorption on Metals Based on the HSAB Concept

The adsorption process of surfactants on metals from the perspective of the charge-transfer complexes formation and their stabilization by charging and electronic (orbit) interaction is discussed. The expediency of Lewis-Usanovych acid-base balance and coming out of it principle of Pearson’s “hard” and “soft” acids and bases (HSAB) application in modelling of adsorption processes is shown. Equations that corresponds to the electrode adsorption equilibrium, conditioned by charging, electronic and charge-electron interaction are derived and qualitatively validated.

Causal Diagrams Constructing for Sealed Electrochemical Devices on the Method of Ascent from the Abstract to the Concrete

The sequence of actions to build generalized causal diagrams for sealed electrochemical devices, which can be sealed primary and secondary chemical sources of electric power, ultracapacitors, electrochemical sensors and others device based on the specified settings, was described. Diagram allows visualizing the relationship of various factors affecting electrochemical devices and their stability during storage and use.

Copper Production from a Carbonate Ores by Electrowinning Method

A process of compact copper electrowinning from the solution obtained by leaching copper from the ore by sulfuric acid was discussed. It was shown that the ore leaching is advisable to carry out with 10 % hydrochloric acid for 30–40 minutes with intensive stirring of the mixture. Copper electrowinning process was done from a concentrated solution with a stepped reduction of the current density which was proportional to the copper ion concentration decreasing during the process. The comparison of the parameters of the real and theoretical calculated processes was performed.

The Development of the Electrochemical Methods for the Corrosion Rate Determination of Scientific School of L.I. Antropov

The development of scientific bases of electrochemical methods for the determination of the corrosion rate, which were originated under the guidance of outstanding electrochemists L.I. Antropov and continued by his followers’ school, was investigated. Accuracy aspects of the corrosion rate determination by polarization resistance (R p) method were discussed. It was shown that application of the two-electrode cell significantly decreases R p determination error.

Influence of Electroosmotic Phenomena on Transient Duration in Amperometric Gas Sensors

The work is dedicated to the 100th anniversary of the birth of great scientist-electrochemist, corresponding member of USSR SA L.I. Antropov and continues series of studies of transients processes in amperometric sensors. Reasons of differences in the duration of transient processes in the measurements, differentiated break from several minutes to several hours, allowing time for the values of the output current signal by 10 and 50 % of its stationary value to estimate the expected value of reliable sensor signal prior to its stabilization were revealed.