Structure and properties of iron-chromium-nickel powders obtained via electrodispersing of metal wastes of the alloy Kh25N20 in distilled water

Purpose. Investigation of the composition, structure and properties of powder materials obtained by electrodispersion of tungsten waste of the VA brand in an oxygen–containing medium - distilled water. Methods. To determine the composition, structure and properties of powder materials, samples of powders obtained from waste tungsten of the VA brand were studied. The powder material was obtained by electroerosive dispersion in distilled water. Microanalysis of powder particles was carried out using a scanning electron microscope, analysis of the size distribution of powder particles was obtained using a particle size analyzer, X-ray spectral microanalysis of powder particles was carried out using an energy dispersive X-ray analyzer integrated into a scanning electron microscope, analysis of the phase composition of powder particles was carried out using X-ray diffraction on a diffractometer. Results. During the study, it was revealed that the shape of the particles obtained from powdered tungsten materials is spherical and elliptical, and agglomerates of smaller particles are also marked on magnification. Oxygen and tungsten are present in the composition of powder materials, while there are no joint structural components. The phases of pure tungsten in α and β modifications are noted in the phase composition. It follows from the analysis of the granulometric histogram that the particle size spread varies in the range of 0.092–62.59 microns, while the average particle diameterwas 5.73 microns. Conclusion. The obtained research results can be used to develop a new heavy pseudo-alloy using metal waste of expensive raw materials by the method of electroerosive dispersion with subsequent improvement and optimization of the composition and structure of the alloy.

Extensive use of electroerosion dispersion (EED) method to recycle metal discard into powders for their re-use in additive technologies is limited by a lack of complete data on the effects of the initial composition, production modes and media on the properties of produced powders and their application technologies. Hence there is a need in new re-use technologies for alloy-powder produced from nichrome scrap and in the assessment of their efficiency, which in its turn requires integrated theoretical and experimental studies. The goal of the presented work was to investigate morphology and element composition of cobalt-chromium alloy-powders that had been produced for additive technologies by eletroerosion dispersion of CCh alloy in distilled water. Research and test material was cobalt-chromium scrap of “TSELIT” alloy grade. The working medium was distilled water. To produce cobalt-chromium powders by electroerosion dispersion an EED plant for current conducting materials. Metal scrap was charged into the reactor filled with working medium, distilled water; the process was run at the following parameters: energy discharge capacitor capacity was 28 mcF, voltage 110 V pulse frequency 100 Hz. The results of the research of the morphology and component composition of cobalt-chromium powder-alloys that had been produced for additive technologies by electroerosion dispersion of cobalt-chromium TSELIT alloy scrap in distilled water demonstrated that the majority of particles in the powder had regular sphere or oval shape, with large amount of surface oxygen, which required additional chemical treatment before use in additive technologies.

Purpose. Investigation of the composition, structure and properties of powder materials obtained by electrodispersion of nickel waste of the PNK-0T1 brand in an oxygen-containing medium – distilled water.Methods. To determine the composition, structure and properties of powder materials, samples of powders obtained from waste nickel grade PNK-0T1 were studied. The powder material was obtained by electroerosive dispersion in distilled water. Microanalysis of powder particles was carried out using a scanning electron microscope, an analysis of the size distribution of powder particles was obtained using a particle size analyzer, an X-ray spectral microanalysis of powder particles was carried out using an energy-dispersive X-ray analyzer embedded in a scanning electron microscope, an analysis of the phase composition of powder particles was carried out using X-ray diffraction on the diffractometer.Results. During the study, it was revealed that the shape of the particles obtained from nickel powders is spherical and elliptical, and agglomerates of smaller particles are also noted on the increase. Oxygen and nickel are present in the composition of powder materials. The phases of pure nickel and nickel oxide NiO are marked in the phase composition. From the analysis of the granulometric histogram, it follows that the particle size spread varies in the range of 0.26...18.62 microns, the average volume diameter of the particles was 5.2 microns.Conclusion. The obtained research results can be used to develop a new heavy pseudo-alloy using metal waste from expensive raw materials by the method of electroerosive dispersion, followed by improvement and optimization of the composition and structure of the alloy.

Рurpose of this work was to optimize the process of obtaining powder materials for the production of carbide cutting tools by electrodispersing metal waste of TN20 alloy in water.Methods. To carry out the planned studies, waste of sintered tungsten-free hard alloy of the TN20 brand was selected. Distilled water was used as the working fluid. On an experimental patented installation for the production of powders from conductive materials, waste of a tungsten-free hard alloy TN20 was dispersed in distilled water with a loading weight of 500 g. The following electrical parameters of the installation were used: capacitance of capacitors 60.0...62.5 UF; voltage at the electrodes from 120...140 V; pulse repetition frequency 120...140 Hz. The study of the shape and morphology of the surface of particles obtained by EED of waste of a tungsten-free hard alloy TN20 was carried out on an electron-ion scanning (scanning) microscope with field emission of electrons "QUANTA 600 FEG" (the Netherlands). The average particle size of titanium powder was studied using the Analysette 22 NanoTec laser particle size analyzer (Germany). Optimization of the processes of dispersion of waste of tungsten-free hard alloy TN20 was carried out by setting up a complete factorial experiment on the average particle size of the resulting erosive particles according to block diagrams.Results. Analysis of the particle shape parameters of the carbide powder from images from a scanning microscope suggests that the electroerosive particles are mainly spherical in shape and agglomerates. It has been experimentally established that the average particle size of a carbide powder of 24.4 microns is obtained with a discharge capacitor capacity of 63 UF, an electrode voltage of 200 V, and a pulse repetition frequency of 200 Hz.Conclusion. Carrying out the planned measures will solve the problem of recycling waste from TN20 alloy and their reuse in the production of cutting tools.

The purpose of this work was to study the fire resistance of technical materials treated with flame retardants based on electroerosion powder of Aluminum hydroxide.Methods. Aluminum metal wastes of the AD0E brand were dispersed in distilled water at a loading weight of 250 g at an experimental installation. The resulting electroerosive aluminum powder was studied by various methods. The microanalysis was performed on a QUANTA 600 FEG microscope. The phase composition was studied using a Rigaku Ultima IV diffractometer. The fire resistance of the treated fabric was studied according to the following method: a strip of fabric 5 cm wide and 10 cm long was suspended in an upright position by one end in a tripod clamp (the other end remains hanging freely). The flame of an alcohol burner was placed under the lower end of the sample for 12 seconds (according to a stopwatch). After the specified time, the flame of the burner was removed and the burning and smoldering time of the sample was noted after the flame ceased to act. Gorenje After the end of the experiment, the area of the charred part of the sample was measured.Results. Experimental studies of the fire resistance of textile materials treated with flame retardants have shown high efficiency of using an electroerosive aluminum hydroxide powder for these purposes. Aluminum hydroxide powder was obtained in distilled water from electrical aluminum metal waste. The peculiarity of the use of the obtained aluminum hydroxide is due to the fact that it provides a difficult-to-ignite fabric, reduces the ability of the material to ignite, localizes the flame; provides a long-term flame retardant and at the same time antiseptic effect; treated fabrics are odorless, harmless to humans and animals; consumption for impregnating fabrics: 100-250 g/m2, depending on the density of the fabric.Conclusion. The effectiveness of flame retardants based on electroerosive Aluminum hydroxide powder is confirmed by the fact that cheap metal waste and progressive environmentally friendly (without wastewater and emissions), low- energy technology (up to 5 kWh/kg) are used for its production.

A study of the phase composition of powder materials obtained by the electroerosion dispersion of BrC30 lead-bronze metal waste in distilled water is carried out. The preparation of metal materials of microfractions and nanofractions is carried out using an electroerosion-dispersion unit. The filings are placed in the reactor of the installation, which is filled with distilled water (an oxygen-containing medium). The following operating modes of the installation are set: pulse repetition rate of 95−105 Hz, voltage applied to the electrodes of 190−200 V, capacitor capacitance of 65.5 μF. At the places where the discharges occur, the temperature increases, and the materials melt and evaporate, which leads to the formation of fine particles. The phase composition of the powders is studied by X-ray diffraction on a Rigaku Ultima IV diffractometer. It is established that the main phases in the resulting electroerosion materials are Cu, Pb(Cu2O2), Pb5O8, Pb. The resulting powder materials can be used for metallization and galvanic coatings.

The efficacy of copper shavings (Cu(0)) for the removal of Hg2+ from aqueous solution by amalgamation is demonstrated. Two kinds of copper shavings were investigated: (a) chemically processed shavings (Fluka) and (b) recycled shavings from scrap metal. Batch sorption experiments yielded very high retardation coefficients of 28 850-82 830 for the concentration range studied (1-10 000 microg/L Hg2+ dissolved in distilled water or in a 0.01 M CaCl2 matrix solution). Sorption data were well-described bythe Freundlich isotherm equation. Kinetic batch sorption experiments showed that 96-98% of Hg2+ was removed within 2 h. Column experiments were performed with a mercury solution containing 1000 microg/L Hg in a 0.01 M CaCl2 matrix with a flow rate of 0.5 m/d. No mercury breakthrough (c/c(0) = 0.5) could be detected after more than 2300 percolated pore volumes, and the high retardation coefficients determined in the batch studies could be confirmed. Copper was released from the shavings due to the amalgamation process and to copper corrosion by oxygen, resulting in concentrations of mobilized copper of 0.2-0.6 mg/L. Due to their high efficiency in removing Hg2+ from aqueous solution, the use of copper shavings for the removal of mercury from contaminated water is suggested, employing a sequential system of mercury amalgamation followed by the removal of mobilized copper by an ion exchanger such as zeolites. Possible applications could be in environmental technologies such as wastewater treatment or permeable reactive barriers for in situ groundwater remediation.

Freshwater scarcity and growing vitality essential are among the most important issues around the world. In the current work, an effort is made to improve the yield of existing single-slope single-basin solar still (SS) with basin area of 1 m2 using various energy absorbing material such as black granite stone, metal scrap of mild steel and nanoparticle Al2O3 in the water basin, and the freshwater yield was compared with and without the energy storing material (ESM) for the water depth of 0.01 m. Yield of freshwater augmented by 11.6%, 25.1% and 33.5% by using metal scrap, black granite and nanofluid Al2O3 inside the water basin, respectively, and the full day efficiency augmented by 15.5%, 26.8% and 33.6% as compared to the conventional SS. It was concluded that the solid nanometric size particle Al2O3 inside the water basin helps in achieving the maximum yield of the freshwater. SS is also proficient to eliminate the impurities of brackish water and convert it to pure and distilled water with PPM ranging below 50 and makes it ideal for the rural Indian villages with economical and hygienic point of view.

Purpose. Investigation of morphology, determination of material balance and dynamics of accumulation of electroerosive nickel powders.Methods. To analyze the shape and morphology of the surface of nickel powder particles, as well as to compile the material balance and dynamics of their accumulation, electroerosion nickel powders were obtained by electroerosion dispersion from PNK-0T1 nickel waste in two different dielectric media: aviation kerosene and distilled water. The operating values of the EED parameters are: voltage at the electrodes 115-120 V for kerosene and 98-105 V for water, respectively; capacitor capacity 44.0–45.5 UF for kerosene and 60.0–62.0 UF for water, respectively; pulse frequency 60-65 Hz for kerosene and 100-110 Hz for water, respectively. Microanalysis of the powder particles was performed using a QUANTA 600 FEG scanning electron microscope.Results. Morphological studies aimed at determining the shape of the surface of the EENP particles made it possible to establish that the particles are characterized by a spherical and, more rarely, an elliptical shape, and the formation of aggregates from particles of the smallest diameter was also noted. The maximum loss of material in the EED process is 0.7% of the total mass. The efficiency of the nickel waste EED process is 4.3 g/hour for distilled water and 2.3 g/hour for aviation kerosene.Conclusion. The obtained research results can be used to develop a new heavy pseudo-alloy using metal waste from expensive nickel raw materials by electroerosion dispersion with subsequent improvement and optimization of the alloy composition and structure to achieve the necessary characteristics of a new heavy pseudo-alloy.

Characterization of metal finishing sludges: influence of the pH

Comparison of leaching characteristics of heavy metals in APC residue from an MSW incinerator using various extraction methods

The presence of heavy metals in solid and liquid wastes is a significant issue in terms of the environment degradation. These are one of the most serious environmental pollutants, and reaching dangerous levels will need more investigation. Chromium, in particular, has become a global environmental problem among heavy metals. This research looked at the effects of Cr207 stress on Dolichos biflorus L., a kind of horse grain that plays an essential role in Indian agriculture. D. biflorus seeds were cultivated in the dark under laboratory conditions with a Sodium chromate concentration of (0-3.0mg/L). The control treatment was distilled water. Seven-day-old seedlings were utilized to study the effects of chromate stress on peroxidase activity and chlorophyll content. The findings showed that when the quantity of Sodium chromate increased, the chlorophyll content of D. biflorus seedlings increased considerably (p 0.9). Increased polyphenyloxiase and peroxidase activity indicated the appearance of a scavenging mechanism in plants under heavy metal stress, whereas increased peroxidase quantity indicated the generation of free radicals. The drop in chlorophyll concentration indicates that the plants' development has slowed, resulting in a fall in production.

The article discusses a topical issue of scrap metal recycling, in particular BrS30 alloy scrap recycling, into powders for their repeated use to fabricate and harden machine parts. Nowadays, one of the most promising method of processing any conductive material is electro-erosion dispersion, which is non-waste, eco-friendly and energy-efficient. The paper presents the findings of a research of porosity of products, sintered from leaded bronze pressed powders, obtained by electro-erosion dispersion in distilled water. It was determined that in uniaxial pressing of the powder using a desktop hydraulic press, and in isostatic pressing of the powder using an isostatic press, and further sintering of the obtained samples in a folding tube furnace, the porosity was 0.61% and 1.44%, respectively.

Neurobehavioral assessment of Danio rerio intoxicated by sodium arsenate and the use of Arsenicum Album to reverse the condition of anxiety

Environmental contamination with heavy metals and radionuclides remains a major problem worldwide. The current clean-up methodologies are based on energy-intensive engineering processes, which are disruptive and costly. A new universal technology targeted for the permanent enclosure and fixation of nuclear and other extreme hazardous metallic wastes in subsurface sites is needed. Such technology will be useful in treating contamination at many sites in the U.S., with specific applications to Department of Energy (DOE) sites. Biopolymers are potential tools for such an innovative technology. Biopolymers have repeated sequences, and therefore provide ample opportunity for chemical reactions with metals, soil particles, and other biopolymers. They also have the additional ability of creating cross-linking interpenetrating networks that can encapsulate the contaminants. Based on this concept, in the present work five biopolymers (xanthan, chitosan, polyhydroxy butyrate, guar gum, polyglutamic acid) were investigated for potential use in the stabilization of metals in the subsurface. The effects of these biopolymers (used alone and in combinations) on soil characteristics (permeability, shear strength) and their metal uptake ability have been studied using laboratory drainage flow systems. Biopolymer solutions were run through the experimental sandpack columns, followed by copper solution and leaching agents (distilled water and hydrochloric acid). The permeability and shear strength of sand were evaluated. Copper uptake capacity of each biopolymer and combination of biopolymers was also studied along with subsequent leaching. All biopolymers tested improved sand characteristics (by decreasing permeability and increasing shear strength) and had good metal uptake ability (60–90%) with relatively low leachability (10–22%). While biopolymers used alone were more efficient in metal uptake, the combination of two biopolymers (xanthan and chitosan) had an increasing plugging effect. These results show the potential of using biopolymers in subsurface metal stabilization.