Preliminary Purification Research Articles

Preparation of LiNi0.8Co0.1Mn0.1O2 cathode materials from the hydrochloric acid leaching of laterite: A short and low-cost process

The direct preparation of LiNi0.8Co0.1Mn0.1O2 (LNCM811) cathode materials from the hydrochloric acid leaching of laterite are promising; however, there are Cl− ions and other impurities in the hydrochloric acid leaching solution, thereby limiting the commercial application of LNCM811. In this study, we compared the LNCM811 prepared from Cl−- and SO42−- ion precursor solutions, and observed that the existence of Cl− ions could result in agglomerate disjointed and the primary particles grew separately during the sintering process, further deteriorating the electrochemical performance. Therefore, the initial raw Ni/Co solid residues were washed with deionised water and leached with 25 wt% H2SO4 solution to obtain an enriched Ni/Co solution with SO42− anions. Furthermore, considerable impurities in the enriched Ni/Co solution caused primary particle separation during the sintering process and led to the LNCM811 having poor electrochemical properties. Therefore, it was further purified by extraction with Cyanex272 to obtain a pure NiSO4 solution. The impurities in the NCM811 precursor prepared from this pure NiSO4 solution were below standard limits, the corresponding lithiated cathode delivers an initial reversible capacity of 192.1 mAh g−1 at 0.1C with an initial Coulombic efficiency of 86.5%; it retains 85.1% of its capacity after 100 cycles at 1.0C in 2.8–4.3 V, thereby achieving the standard of commercial LNCM811. On this basis, combined with the previous research of our group, high-value utilisation of laterite for preparing cathode materials includes the following processes: hydrochloric acid leaching, preliminary purification, alkaline oxidation precipitation, conversion of the Cl− solution system to the SO42− ion solution system, extraction, solution-phase synthesis, and calcination. Moreover, compared with the conventional process of preparing NCM811 from metal sulfates, the cost saving through the proposed process was found to be approximately 265.8 $/ton.

A Highly Efficient Waste-Free Technology of Water and Fuel Preparation for Thermal Power Stations

A highly efficient, economical, and waste-free technology for the purification of natural waters for thermal power plants has been developed. The preliminary purification of water involved microfiltration on tubular ceramic membranes made of clay minerals according to a technology developed at the Dumansky Institute of Colloid Chemistry and Water Chemistry, NAS of Ukraine; the degree of retention of suspended solids and iron and manganese compounds on the membranes was 99.9, 99.8, and 60%, respectively. The high separation capacity of such membranes is due to the modification of their surface by water contaminants with the formation of a self-organizing dynamic membrane that serves as an additional barrier. The dynamic membrane formation contributed to the retention of up to 24.0% of the co-occurring ions, Ca2+ in particular; this is typical for ultrafiltration membranes. Further desalination was performed with low-pressure reverse osmosis membranes; two stages of reverse osmosis turned out necessary to achieve a total ion content of 0.5 mg/dm3 in the make-up water of a steam turbine unit of a thermal power plant (TPP). The retentate of the second stage of reverse osmosis, for which the total ion content is 50–60 mg/dm3, can be used for technical purposes at TPPs. The salt content of the retentate formed after the first stage of reverse osmosis was ~3 g/dm3, and thus insufficient for further transformation into secondary material resources; however, the introduction of waste recycling systems is considered to be the modern direction in protecting the environment from technological influence. The retentate of the first stage of reverse osmosis was concentrated using an original concentrating electrodialyzer developed at the Dumansky Institute of Colloid Chemistry and Water Chemistry, NAS of Ukraine; some design modifications that distinguish this electrodialyzer from the conventional ones were proposed and patented. Electrodialysis treatment of the retentate for 2.5 hours at a current density of 2.5 A/dm3 enabled the production of a solution with the ion content of ~105 g/dm3. This brine can be converted into sodium hypochlorite or caustic soda and hydrochloric acid by electrolysis. The diluate with a mineralization of ~200.5 g/dm3 and a total organic carbon content of ~148.3 g/dm3 can be used for the preparation of coal-water slurry fuels for power generation and metallurgy. The basic technological schemes of make-up water purification for the needs of thermal power plants and the preparation of slurry fuel systems based on coal and reverse osmosis waste that contains organic substances are proposed.

Siderophore Production by Rhizosphere Biological Control Bacteria Brevibacillus brevis GZDF3 of Pinellia ternata and Its Antifungal Effects on Candida albicans.

Brevibacillus brevis GZDF3 is a gram-positive, plant growth-promoting rhizosphere bacterium (PGPR) isolated from the rhizosphere soil of Pinellia ternata (an important herb in traditional Chinese medicine). The GZDF3 strain produces certain active compounds, such as siderophores, which are the final metabolite products of non-ribosomal peptide synthetase (NRPS) and independent non-ribosomal peptide synthetase (NIS) activity. With the present study, we attempted to investigate the siderophore production characteristics and conditions of Bacillus sp. GZDF3. The antibacterial activity of the siderophores on pathogenic fungi was also investigated. Optimal conditions for the synthesis of siderophores were determined by single factor method, using sucrose 15 g/l, asparagine 2 g/l, 32°C, and 48 h. The optimized sucrose asparagine medium significantly increased the production of siderophores, from 27.09% to 54.99%. Moreover, the effects of different kinds of metal ions on siderophore production were explored here. We found that Fe3+ and Cu2+ significantly inhibited the synthesis of siderophores. The preliminary separation and purification of siderophores by immobilized-metal affinity chromatography (IMAC) provides strong antibacterial activity against Candida albicans. The synergistic effect of siderophores and amphotericin B was also demonstrated. Our results have shown that the GZDF3 strain could produce a large amount of siderophores with strong antagonistic activity, which is helpful in the development of new biological control agents.

Matrix Effect in the Isolation of Breast Cancer-Derived Nanovesicles by Immunomagnetic Separation and Electrochemical Immunosensing-A Comparative Study.

Exosomes are cell-derived nanovesicles released into biological fluids, which are involved in cell-to-cell communication. The analysis of the content and the surface of the exosomes allow conclusions about the cells they are originating from and the underlying condition, pathology or disease. Therefore, the exosomes are currently considered good candidates as biomarkers to improve the current methods for clinical diagnosis, including cancer. However, due to their low concentration, conventional procedures for exosome detection including biosensing usually require relatively large sample volumes and involve preliminary purification and preconcentration steps by ultracentrifugation. In this paper, the immunomagnetic separation is presented as an alternative method for the specific isolation of exosomes in serum. To achieve that, a rational study of the surface proteins in exosomes, which can be recognized by magnetic particles, is presented. The characterization was performed in exosomes obtained from cell culture supernatants of MCF7, MDA-MB-231 and SKBR3 breast cancer cell lines, including TEM and nanoparticle tracking analysis (NTA). For the specific characterization by flow cytometry and confocal microscopy, different commercial antibodies against selected receptors were used, including the general tetraspanins CD9, CD63 and CD81, and cancer-related receptors (CD24, CD44, CD54, CD326 and CD340). The effect of the serum matrix on the immunomagnetic separation was then carefully evaluated by spiking the exosomes in depleted human serum. Based on this study, the exosomes were preconcentrated by immunomagnetic separation on antiCD81-modified magnetic particles in order to achieve further magnetic actuation on the surface of the electrode for the electrochemical readout. The performance of this approach is discussed and compared with classical characterization methods.

Effective Purification of Germanium Obtained from Mineral Raw Materials

By studying the heat treatment of metallic germanium obtained from mineral raw materials, in is experimentally established that germanium heating in a certain narrow temperature range leads to a significant decrease in the concentration of uncontrolled impurities. The use of such a heating as a preliminary germanium purification makes it possible to increase significantly the efficiency of subsequent germanium purification by a zone melting method.

Microbiological Air Quality and Drug Resistance in Airborne Bacteria Isolated from a Waste Sorting Plant Located in Poland-A Case Study.

International interests in biological air pollutants have increased rapidly to broaden the pool of knowledge on their identification and health impacts (e.g., infectious, respiratory diseases and allergies). Antibiotic resistance and its wider implications present us with a growing healthcare crisis, and an increased understanding of antibiotic-resistant bacteria populations should enable better interpretation of bioaerosol exposure found in the air. Waste sorting plant (WSP) activities are a source of occupational bacterial exposures that are associated with many health disorders. The objectives of this study were (a) to assess bacterial air quality (BAQ) in two cabins of a WSP: preliminary manual sorting cabin (PSP) and purification manual sorting cabin (quality control) (QCSP), (b) determine the particle size distribution (PSD) of bacterial aerosol (BA) in PSP, QCSP, and in the outdoor air (OUT), and (c) determine the antibiotic resistance of isolated strains of bacteria. Bacterial strains were identified on a Biolog GEN III (Biolog, Hayward, CA, USA), and disc diffusion method for antimicrobial susceptibility testing was carried out according to the Kirby–Bauer Disk Diffusion Susceptibility Test Protocol. A large share of fecal bacteria, Enterococcus faecalis and Alcaligenes faecalis spp. feacalis, was found in the tested indoor air, which is a potential health hazard to the workers of the monitored WSP. Our results demonstrate the necessity to take into account fecal air pollution levels to avoid making erroneous assumptions regarding the environmental selection of antibiotic resistance. Total elimination of many anthropogenic sources is not possible, but important findings of this study can be used to develop realistic management policies methods to improve BAQ.

Extraction and preliminary purification of polysaccharides from Camellia oleifera Abel. seed cake using a thermoseparating aqueous two-phase system based on EOPO copolymer and deep eutectic solvents

A thermoseparating aqueous two-phase system (ATPS) based on ethylene oxide-propylene oxide (EOPO) copolymer and deep eutectic solvents (DES) was developed for the extraction and preliminary purification of polysaccharides in Camellia oleifera Abel. seed cake. DESs were used as the extraction media for obtaining the crude extract. The maximum extraction yield (Y) of polysaccharides was 152.37 mg/g in the crude extract. Then the crude polysaccharides were extracted and preliminary purified by EOPO/DES ATPS. The maximum extraction efficiency (E.E.) of polysaccharides was 86.91% in EOPO-rich phase by the first ATPS extraction. The EOPO-rich phase was separated and the polysaccharides were recovered by temperature-induced phase separation. The maximum recovery efficiency (R.E.) was 84.92% in aqueous phase by the second ATPS extraction. This thermoseparating ATPS possesses the merits of good environment-friendlies, simple operation, and easy recovery of components, which can be used as an efficient method for the extraction and separation of polysaccharides.

Analytical Method Development and Validation of Paliperidone: A Review

A Simple, precise, Sensitive, rapid, specific and accurate analytical HPLC method have been developed for the estimation of paliperidone in Bulk & Pharmaceutical dosage forms. Paliperidone is atypical antipsychotic. The methods can be used for routine analysis for the estimation of paliperidone in formulations. Hence, this technique would be applied used for quantification of paliperidone in bulk and solid dosage formulation. The projected method was validated for various ICH parameters like linearity, limit of detection, accuracy, precision, ruggedness, robustness and system suitability. The RP-HPLC method was developed for determination of drug in pharmaceutical formulation. The presented study is simple, since samples are directly used without any preliminary chemical dramatization or purification steps. Generally a RP-HPLC assay utilize Symmetry C18 or equivalent with mobile phase composition of pH 7 buffer: acetonitrile [40: 60] was used, and flow rate was 0.8 ml min-1 with UV detection at 285 nm.

Sewage cleaning by using a phase separator

This article proposes a solution to the urgent problem of treating oil-, fat-containing wastewater. A phase separator of dispersions for preliminary purification of industrial wastewater contaminated with fats is proposed, its effectiveness in the treatment of wastewater at local treatment facilities of an industrial plant for the production of sunflower oil is tested. In order to reduce the cost of acquiring reagents and increase the efficiency of purification of fat-containing wastewater, the use of carbide sludge and sodium hydroaluminate was studied. Laboratory studies conducted by the method of an active experiment.

Determination of veterinary drug/pesticide residues in livestock and poultry excrement using selective accelerated solvent extraction and magnetic material purification combined with ultra-high-performance liquid chromatography–tandem mass spectrometry

An ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) method based on selective accelerated solvent extraction and magnetic material purification was established to analyze the residues of various veterinary antibiotics and agricultural fungicides and insecticides in livestock and poultry excrement. Methanol–acetonitrile (4:1, V/V) was used as the extraction solvent and static extraction was conducted three times in 5 min. Preliminary purification was achieved by adding 0.5 g acidic alumina–florisil (1:1, W/W) to the extraction cell while the extraction was conducted. This preliminarily-purified extract was further purified using magnetic material, then analyzed using UPLC–MS/MS. Under optimal conditions, 33 types of antibiotics, including 3 amphenicols, 8 macrolides, 17 sulfonamides and 5 nitroimidazoles, as well as 37 types of pesticides, including 27 insecticides and 10 fungicides, were detected. Recoveries ranged from 60.3% to 110.0% at three spiked concentrations (10 μg/kg, 20 μg/kg and 50 μg/kg), the detection limits ranged from 0.2 to 3.5 μg/kg and the quantitative limits ranged from 0.5 to 11.5 μg/kg. This newly-established method was tested using 30 livestock and poultry excrement samples and confirmed its use for determining veterinary drugs and pesticides in practical samples.

METHOD OF PHOSPHORIC ACID PRODUCTION BY SORPTION CONVERSION OF APATITE CONCETRATE IN PRESENCE OF SULPHOCATIONITE IN SODIUM OR POTASSIUM FORMS

The aim of the work is the continuation of the development of a new efficient hydrochemical technology for the processing of apatite concentrate, which makes it possible to produce phosphoric acid with a reduced content of impurities as a product, to use all the valuable components of apatite concentrate. The dependence of the efficiency of decomposition of apatite concentrate with a phosphate acid solution at a temperature of 20 and 50 °C in the presence of sulfate cationite КУ-2-8чС in Na+- and K+ - forms was studied. The influence of the decomposition conditions (expense and form of sorbent, the ratio of liquid: solid, the interaction temperature) on the degree of decomposition of the concentrate, the completeness of absorption by the sorbent of the metallic cations of the concentrate, the content of impurities in the resulting phosphate-acid solution, and the composition of undissolved residues are studied. The possibility of achieving a high degree of decomposition of the concentrate (up to 99.5 %) is established. High sorption efficiency of calcium and strontium (up to 90.2 and 93.4 % respectively) is shown. The sorption of REE of the cerium group was better than the REE of the middle and yttrium groups. Increasing the temperature from 20 to 50 °C reduced REE sorption by 14-170%. Aluminum, thorium and uranium were the most difficult to sorb. It has been found that effective purification of phosphoric acid from the impurity of fluorine is achieved directly in the process of decomposition. The efficiency of purification from fluorine when using a sorbent in the K+ - form is greater than when using a sorbent in the Na+- form. It is shown that the obtained acid can be purified from sodium or potassium by the electrodialysis method in a two-chamber electrodialyzer equipped with a cation exchange membrane. It is found that before electrodialysis, preliminary purification of the phosphate solution from calcium, which is obtained during the decomposition of apatite concentrate, is necessary. To this purpose, an additional purification of the phosphoric acid solution by sulphocathionite sorption has been investigated. The lower sorption from the phosphoric acid solution of Al, Ti, Fe, Th, and U is explained by the formation of stable anionic complexes or undissociated molecules by these elements. The developed technology for the production of phosphoric acid from the apatite concentrate does not require the use of sulfuric acid, has a number of other advantages. The content of impurities in the resulting phosphoric acid is much less than in the extraction phosphoric acid produced by the sulfuric acid processing of apatite concentrate.

"Fishing and Hunting"-Selective Immobilization of a Recombinant Phenylalanine Ammonia-Lyase from Fermentation Media.

This article overviews the numerous immobilization methods available for various biocatalysts such as whole-cells, cell fragments, lysates or enzymes which do not require preliminary enzyme purification and introduces an advanced approach avoiding the costly and time consuming downstream processes required by immobilization of purified enzyme-based biocatalysts (such as enzyme purification by chromatographic methods and dialysis). Our approach is based on silica shell coated magnetic nanoparticles as solid carriers decorated with mixed functions having either coordinative binding ability (a metal ion complexed by a chelator anchored to the surface) or covalent bond-forming ability (an epoxide attached to the surface via a proper linker) enabling a single operation enrichment and immobilization of a recombinant phenylalanine ammonia-lyase from parsley fused to a polyhistidine affinity tag.

Double Purification Technique for Crude Yellowcake: Selective Dissolution of Impurities and Liquid-Liquid Extraction from Acetate Media

Innovated two-stage technique was developed for the uranium purification starting from Egyptian crude yellowcake. Preliminary purification using urea-tetrahydrofuran system allowed removal of large amounts of undesirable gangues. The second purification stage using acetate aqueous liquor/Alamine 308 solvent extraction system allowed removal of the remaining gangues from the semirefined cake. The maximum loading capacity of the organic solvent was 42 gU L-1 after five contacts between the two phases under the optimized conditions: 10% solvent concentration in kerosene, 5 min shaking time, aqueous feed pH 0.25, and 1 : 1 organic to aqueous ratio. Uranium stripping was done using ammonium carbonate solution. The final purified uranium peroxide cake (66.2% U) of nuclear purity, meeting the ASTM C788-03 standard, was obtained from the stripping solution after hydrogen peroxide precipitation.

In Situ Characterization of Fe-N-C Electrocatalysts Synthesis By XPS and XRD

As one of the most promising candidates to replace Pt-based electrocatalyst for oxygen reduction reaction in fuel cell, Metal-Nitrogen-Carbon (M-N-C) catalysts, especially Iron-Nitrogen-Carbon (Fe-N-C) materials, have attracted massive research interests in recent years. Typically, there are three main categories of synthesis approaches for Fe-N-C electrocatalyst, based on what chemicals are used as iron and nitrogen precursors: macrocyclic iron complexes, metal-organic frameworks, and various heterocyclic compounds. Despite these different approaches, it is found that numerous purified preliminary Fe-N-C products need further heat treatment to achieve better electrocatalysis performance. However, the reason why heat treatment is efficient, as well as the best parameters such as atmosphere, time and temperature, are still unclear and require intensive characterization for elucidation. Here, we report in situ XPS for the investigation how carbon environment and nitrogen moieties change, in addition to in situ XRD, on a specific atomic-dispersed Fe-N-C material (made from nicarbazin via sacrificial support method[1]) during high temperature heat treatment. Figure 1 shows the change of surface contents via XPS C 1s and N 1s under ultra-high vacuum. It is found by rising the temperature from room to 750 °C, the graphitic C with a characteristic peak around 284.5 eV decreases from ~50 atomic % to ~20 %, resulting in a more fragmented carbon structure, while sp3 carbon and nitrogen-carbon have an obvious increase. After flash heating to 950 °C (the typical point used in 2nd heat treatment for this electrocatalyst synthesis) and followed cooling back to 150 °C, there is no reversibility of graphitic carbon. For N 1s shown in Figure 1B, comparing initial 150 °C and final 150 °C after cooling, it is found that pyridinic-N content drops from ~20 atomic % to 15%, and pyrrolic-N decreases from ~40 % to 30 % respectively. Meanwhile, metallic/amine nitrogen increases from ~10% to ~15% while graphitic-N/N+ grows from ~7 % to 20 %, resulting in a more efficient Fe-Nx bonding and surface ionic conduction. In addition, in situ XRD shows that there is no obvious crystalline formed during high temperature treatment, indicating that there is no agglomeration of iron particles. These in situ XPS and XRD results elucidate that extra heat treatment of Fe-N-C electrocatalyst after preliminary synthesis and purification is an essential procedure and can improve the electrochemical performance efficiently. [1] M. J. Workman, M. Dzara, C. Ngo, S. Pylypenko, A. Serov, S. McKinney, J. Gordon, P. Atanassov, K. Artyushkova, J. Power Sources 2017, 348, 30-39. Figure 1

Purification of water sources from oil contamination by hydrophobic carbonate sludge

The paper presents laboratory and experimental studies on the purification of surface water sources from oil contamination by sorption material on the basis of production waste. Energy waste is a slurry of chemical water treatment, which is formed during liming and coagulation at the stage of preliminary purification of natural water. Based on the sludge, the hydrophobic sorption material “MGSM” was developed. The following requirements are imposed on the sorption materials that allow, at low costs, the most effective cleaning of the water surface from petroleum products: hydrophobicity, oil capacity, buoyancy, ease of utilization from the water surface, efficient work in a different temperature range, resistance to water disruption, non-toxicity, optimal price. The material obtained has these requirements. The technical characteristics of the developed sorption material were determined: oil capacity, wetting contact angle, an express analysis of the quality of the aqueous extract of the hydrophobic sorbent developed for the acute lethal toxicity of fish of the Poecilliareticulata Pet. and crustaceans Daphniamagna Str. A technological scheme for utilization of oil-contaminated hydrophobic sorption material as a secondary energy resource in industrial enterprises is proposed, a calculation of the volume of air and combustion products during its combustion, calculation of harmful emissions, thermal calculation, and prevented environmental damage.

Methods for High-Purity Aluminum Oxide Production for Growth of Leucosapphire Crystals (Review)

Methods for the preparation of raw materials to produce leucosapphire are considered. It is shown that the main directions in the production of high-purity aluminum oxide raw materials are: electrochemical oxidation of aluminum, decomposition of alkoxides, high-temperature treatment of aluminum oxide in a halogen-containing atmosphere, and preliminary purification of aluminum-containing compounds followed by their decomposition. It is shown that methods of the purification of aluminum hydroxide and oxide obtained by the Bayer process are the most promising for industrial use. These methods include the complex purification and simultaneous preparation of ceramic preforms starting from aluminum hydroxides or oxides by their treatment in subcritical or supercritical steam and the following heat treatment in a halogen-containing medium.

Continuous synthesis of high purity KNO3 through electrodialysis metathesis

The traditional metathesis (double replacement) method for preparing the chlorine-free fertilizers has its shortcomings, such as high energy consumption and limited conversion degree. Here, the environmental-friendly and economical electrodialysis metathesis (EDM) process was developed to synthesize the potassium nitrate of high purity continuously. The experiments were carried out by using an EDM membrane module of 200 cm2 effective membrane area with 5 repeating units. Effects of operating parameters, current density, initial KNO3 concentration and water flow rate of the KNO3 tank, on EDM performance (energy consumption and current efficiency) and KNO3 quality were investigated. Results showed that the lowest energy consumption (0.165 kWh/kg KNO3) can be attained, while the current efficiency and K2O content in the final product can be high to 94.10% and 44.61 wt%, respectively. After a preliminary and simple purification, the products can meet the requirements of the Chinese national standard GB/T20784-2006. What is more, results of the economic evaluation showed that the total process cost of the continuous EDM system is 0.119 $/kg KNO3, which is lower than that of batch mode (0.160 $/kg KNO3). In addition, the production cost of KNO3 is about 622.10 $/t KNO3, which is lower than the commercial product price (705 $/t KNO3). To sum up, the above results suggest that the continuous EDM process for generating KNO3 of high purity is economically feasible and has great potential to be industrialized.

Universal Research Cryogenic Unit for Xenon Production

Xenon is a cryogenic product that is currently in short supply. Requirements for its purity are increasing. Its consumption in microelectronics, medicine, and space technology and for high-energy particle physics research is rising. The permissible impurity contents in Xe for various applications were analyzed. A universal research cryogenic unit for Xe production of throughput up to 10 Nm3/h of feedstock mixture was designed. A scheme with separation by rectification and preliminary catalytic and adsorptive purification of the feedstock was chosen. The unit was built in blocks so that processing schemes for Xe production from various mixtures, e.g., Kr–Xe, Xe–N2, Xe–O2, could be studied. Trace impurities in Xe were analyzed by gas chromatographs with thermal conductivity (TCD), He-ionization (HID), and flame-ionization detectors (FID). Water vapor in the analyzed gases was measured using laseroptical and coulometric hygrometers. The first runs showed that the unit could produce Xe of purity up to 99.9999 %. Experimental data for rectification of Xe to a purity of 99.999 % are presented. Xe could be purified experimentally from traces of CF4, C2F6, SF6, hydrocarbons, CO2, and H2 to 0.05; O2 and N2, 0.1; Kr, 0.01; and water vapor, 0.2 ppm.

Heavy metals and Zn isotope ratios in the snow of the Karabash copper smelting area (Southern Urals, Russia)

This work presents the first results of winter fieldworks aimed at the assessment of heavy metal content and Zn isotope composition in the snow cover of a smelting area in South Ural. Twenty one snowpacks were sampled at the end of the winter 2018 in the vicinity (1.0-95 km) of the copper smelter of the Karabash town (South Ural, Russia). The snow samples were analyzed for major and trace element composition using ICP-MS and ICP-OES techniques. Zn isotope analysis was performed by MC-ICP-MS with preliminary chromatographic purification. pH and water hardness values were obtained as well. Zn, Cu, Pb, Cd and Sr enrichment factors were calculated. The contaminant particles in snow were established to have been derived from the technogenic source through the distances up to 95 km from the industrial smelting area.

Combined processing of channels in ceramic parts

Abstract The paper examines the technology of manufacturing through and blind channels of various sections and axis profiles in ceramic filters and nozzles, applied in heat engines and current generator drives for supplying and purifying liquid fuel. The article presents the data on the manufacture of ceramic nozzles and filters, designed for preliminary and fine purification of liquid fuels, having increased thermal and chemical resistance when operating in the hot zone of aircraft and rocket engines. We show the possibility of their use in power machines and installations, operating at high pressure drops during the purification of corrosive media and in conditions of product vibration. New technological methods have been developed and implemented for combined manufacture of long channels with small sections, having various configuration and position of hole axes, which improve the performance parameters of parts. At the level of invention, new methods and devices have been created for combined processing of through and blind channels with anodic dissolution of metal inserts under the impact of an ultrasonic beam, locally amplifying the mass transfer from the zone of channel formation. The article shows the advantages of combined processing, using ultrasonic vibrations to intensify the process of manufacturing through and blind holes in ceramics, which successfully substitutes the previously applicable technological methods and means of technical equipment, and broadens the opportunities of technologists for manufacturing nozzles and filters, complying with the operational requirements for products of new-generation equipment, created and mastered by domestic industry. We disclose the ways of improving the structure and technology of combined processing of perspective types of ceramic products, with account of their use in mechanical engineering.