Alloy Waste Research Articles

Single-step synthesis of MgAl2O4/MgO nanocomposites from MgAl scraps by thermal plasma technique for bi-functional applications of supercapacitor and waste-water treatment

Plasma-based methods present a highly efficient approach for reclaiming valuable metals and nanoparticles from discarded metal scraps and minerals. In this research, we employed the thermal plasma arc discharge (TPAD) method to synthesize mixed-phase spinal-type magnesium aluminate and magnesium oxide (MgAl2O4/MgO) nanocomposites ranging in size from 10 to 120 nm, using discarded MgAl alloy waste scraps as the primary material. By employing comprehensive characterization techniques such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDS), we successfully confirmed the formation of highly crystalline MgAl2O4/MgO nanocomposites, showcasing a nearly spherical morphology. The surface area of the prepared nanocomposites was investigated using Brunauer-Emmett-Teller (BET) analysis; the values are 51.3 m2g-1. The synthesized MgAl2O4/MgO nanocomposites displayed exceptional photocatalytic activity toward industrial wastewater and commercial dye. Moreover, investigated the storage properties of MgAl2O4/MgO nanocomposites as an electrode material, revealing a good specific capacitance of 379.2 F/g at a current density of 1 A/g, demonstrating pseudocapacitive behavior. These results offer valuable insights into sustainable waste utilization and the development of high-performance nanomaterials for practical applications in various fields.

Anions regulation strategy in simulated seawater: A sustainable and efficient approach for on-site hydrolysis hydrogen generation from Mg alloy waste

This innovative study addresses a critical gap in ‘Green hydrogen’ technology by examining the impact of anions on the hydrolysis of residuary waste AZ91D alloy (Rw-AZ91D) in simulated seawater. Despite seawater's potential as an abundant resource for hydrogen production, its complex anionic composition presents efficiency challenges. Through meticulous regulation of anion types and concentrations, the results demonstrate that under ideal conditions (0.5 M NaCl at 298 K), Rw-AZ91D yields a remarkable hydrolysis capacity of 727.0 mL g−1, with a rapid onset (0.42 min) and low activation energy (27.8 kJ mol−1). Intriguingly, oxygenated acid anions notably impede both kinetics and yield. In 0.5 M NaCl solution respectively mixed with 0.1 M Na2SO4, Na2CO3 and NaNO3 solution, the hydrolysis capacities of Rw-AZ91D increase to 409.5, 514.4 and 118.6 mL g−1. When the concentration of employed anions decreases to 0.02 M, 516.5, 621.0 and 480.5 mL g−1 H2 can be obtained. Microstructural and thermodynamic assessments indicate that anions affect hydrolysis via their ionic size, chemistry, induced acidity, and solubility of Mg2+-complexed metallic compounds. This work introduces a cost-effective and eco-friendly method to manage anions during hydrogen production, thereby bolstering the feasibility of portable hydrogen generators and advancing sustainable seawater utilization in Mg alloy waste-based hydrogen generation systems.

Research on Fe Removal, Regeneration Process, and Mechanical Properties of Mg Alloy AM50A

In recent years, the widespread application of Mg alloy casting and Mg alloy products has generated a large amount of Mg alloy waste. This experiment used a single factor experimental analysis method to study the optimal process for removing Fe from Mg alloy AM50A waste, and developed an efficient Fe removal and regeneration process for Mg alloy AM50A. It was found that the optimal refining temperature for removing Fe ions was 670 °C, the optimal refining (RJ-2) agent mass ratio was 1.5%, and the optimal refining time was 40 min. Regenerated J40-1.5-AM50A Mg alloy was prepared using the best refining process, and its composition and mechanical properties were tested and analyzed. The experimental results show that the composition of the regenerated J40-1.5-AM50A Mg alloy prepared by this method is consistent with AM50A, with an Fe removal rate of 96.2%. The mechanical properties were improved compared to the original AM50A sample, with a maximum tensile strength increase of 1.611 KN and a tensile strength increase of 26.333 MPa. The elongation after fracture is 2.25 times that of the original sample. Research has shown that the RJ-2 refining agent can provide mechanical properties of magnesium alloys during the refining process. By analyzing the composition, XRD, SEM, and EDS of AM50A (Fe) and J40-1.5-AM50A, it was found that the refining process accelerates the removal of Fe in the form of Fe deposition.

Improving damping characteristics of epoxy by adding copper alloy wastes

Purpose The purpose of this study is to get benefits from manufacturing harmful wastes is by using them as a reinforcement with epoxy matrix composite materials to improve the damping characteristics in applications such as machine bases, rockets, satellites, missiles, navigation equipment and aircraft as large structures, and electronics as such small structures. Vibration causes damaging strains in these components. Design/methodology/approach By adding machining chips with weight percentages of 5, 10, 15 and 20 Wt.%, with three different chip lengths added for each percentage (0.6, 0.8 and 1.18 mm), the three-point bending and damping characteristics tests are utilized to examine how manufacturing waste impacts the mechanical properties. Following that, the optimal lengths and the chip-to-epoxy ratio are determined. The chip dispersion and homogeneity are assessed using a field emission scanning electron microscope. Findings Waste copper alloys can be used to enhance the vibration-dampening properties of epoxy resin. The interface and bonding between the resin and the chip are crucial for enhancing the damping capabilities of epoxy. Controlling the flexural modulus by altering the chip size and quantity can change the damping characteristics because the two variables are inversely related. The critical chip size is 0.8 mm, below which smaller chips cannot evenly transfer, and disperse the vibration force to the epoxy matrix and larger chips may shatter and fracture. Originality/value The main source of problems in machine tools, aircraft and vehicle manufacturing is vibrations generated in the structures. These components suffer harmful strains due to vibration. Damping can be added to these structures to get over these problems. The distribution of energy stored as a result of oscillatory mobility is known as damping. To optimize the serving lifetime of a dynamic suit, this is one of the most important design elements. The use of composites in construction is a modern method of improving a structure's damping capacity. Additionally, it has been demonstrated that composites offer better stiffness, strength, fatigue resistance and corrosion resistance. This research aims to reduce the vibration effect by using copper alloy wastes as dampers.

Thermal pre-treatment of reactive aluminium alloy waste powders

AbstractThis study focussed on assessing the efficiency of thermal pre-treatment of Al alloy waste powders to facilitate their subsequent treatment and disposal. Five samples originating from aluminium surface finishing industries underwent thermogravimetric analyses and were subjected to a laboratory tub furnace. Four set temperatures (450, 475, 500, 525 °C) for the tubular furnace were selected based on the TG results. Using sequential images of the sample inside the tubular furnace, the ignition delay time was calculated. In addition, the efficiencies of medium-temperature thermal pre-treatment were determined using the gas volume method. The shot blasting samples (S1 and S2) exhibited shorter ignition delay times compared to the sandblasting (S3) and one of the polishing samples (S4). The influence of ZnO alloy content on the ignition delay time was investigated, revealing that the ignition delay time decreased with an increase in ZnO alloy content. The raw and pre-treated materials were analysed for morphology, composition and reactivity. The pre-treatment efficiency of the samples improved, especially with a retention time longer than the ignition delay of the samples. Recommendations for the storage and handling of pre-treated products were provided.

Performance of catechin as a sustainable-green inhibitor to inhibit the hydrogen production of Al alloy waste dust

Al alloy products produce hazardous waste dust during machining and surface treatment. Although the risk of dust explosion can be avoided by using the wet dust collector system, potential hydrogen explosion arises when Al alloy waste dust reacts with water. In this paper, catechin (CA) was selected to inhibit the hydrogen production of Al alloy waste dust and the hydrogen production curves of 6 different concentrations of CA were obtained. Characterization experiments were conducted on Al alloy waste dust before and after hydrolysis reaction through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The inhibition mechanism of CA on hydrogen production was discussed by in the light of hydrolysis kinetics and adsorption models. The results show that the hydrolysis process of Al alloy waste dust is in line with the nucleation-growth model. When the CA concentration is 0.35 wt%, almost no hydrogen is produced. SEM-EDS shows that the surface of the hydrogen-inhibition product is smooth and dense. Given the reduction in metal hydroxide content, as indicated by XRD results, this confirms that CA is effective in inhibiting the hydrogen production of Al alloy waste dust. FTIR results show that the adsorption mechanism of CA includes chelation and electrostatic adsorption, and the formation of a passivation film on the surface of Al alloy waste dust to prevent the metal particles from contacting water, thereby inhibiting hydrogen production. This study offers a more sustainable solution for inhibiting hydrogen production of Al alloy dust in the wet dust collector system to ensure both production safety and environmental protection.

Vitrification of lead–bismuth alloy nuclear waste into a glass waste form

AbstractLead–bismuth eutectic (LBE), a promising coolant in advanced nuclear systems, can be activated by neutrons during nuclear reactor operations. The decommissioning of nuclear facilities would generate lead–bismuth (Pb–Bi) alloy‐contaminated nuclear waste. The current metallic nuclear waste treatment approach involves remelting followed by cementitious solidification. This increases the waste volume and the risk of radionuclide migration in groundwater. Therefore, this study developed a method for vitrification of Pb–Bi alloy waste. Different amounts of SiO2 were added at 750–1100°C in the air to turn the simulated LBE waste into glass waste form. The values of the normalized elemental leaching rates (Pb, Bi, Si, Te, and Ni) determined using the 28‐day static leaching test were less than .2 g m−2 d−1 and varied with SiO2 addition. Furthermore, a three‐stage evolution of the glass structure with SiO2 addition was proposed according to the structural analysis performed using Raman and X‐ray photoelectron spectroscopies. The evolution stages were as follows: (i) the stage of heavy metal transition from covalent to ionic heavy metals (7.5 wt% < SiO2 < 15 wt%), (ii) the stage of increase in bridging oxygen (15 wt% < SiO2 < 20 wt%), and (iii) the stage of domination of the Si–O network (20 wt% < SiO2 < 25 wt%). The evolution of the glass structure resulted in varying glass chemical durability. Finally, the glass‐forming region of (20–48)PbO–(35–70)Bi2O3–(7.5–25)SiO2 (wt%) and the temperature needed to melt those glasses were determined through the melting test, where radionuclides and toxic heavy metals showed undetectable volatilization during vitrification. Hence, turning LBE waste into glass waste form will be a potential approach for treating Pb–Bi alloy nuclear waste.

Annealing crystallization control mechanism of catalytic degradation properties of Fe-based amorphous ribbons

Amorphous alloys are meta-stable materials with long-range disordered atomic structure, which have excellent catalytic degradation performance and are also susceptible to crystallization, but the mechanism of the effect of crystallization on their catalytic properties has not been clarified. Therefore, the effect of the annealing crystallization process on the microstructure of Fe-Si-B-Cu-Nb industrial amorphous ribbons and their catalytic degradation properties for acid orange 7 are investigated in this work. It is found that the catalytic degradation performance of the ribbons decreases dramatically after having been annealed at 460–580 ℃ , and its reaction rate constant is less than 0.01 min<sup>–1</sup>. The main reason is the formation of <i>α</i>-Fe precipitation phase in the ribbons after having been annealed at high temperatures and the destruction of the substable amorphous structure. These reduce the rate of hydroxyl radical formation. In contrast, the catalytic degradation performance of the 650–700 ℃ annealed ribbons increases significantly, which increases to 3.77 times the degradation rate of the as-cast ribbons. The decolorization rate of acid orange 7 by the annealed ribbons reaches 99.22% within 15 min, which is 1.12 times that of the as-cast ribbons. The improvement of the catalytic degradation performance is attributed to the primary cell effect between the crystalline phase and the metal compounds and the substitution reaction between the Cu-enriched clusters and zero-valent iron. In this study, the influence mechanism of annealing crystallization on the performance of Fe-Si-B-Cu-Nb industrial amorphous ribbons for degrading azo dyes is revealed, which provides theoretical and experimental support for using aged iron-based amorphous ribbons to purify printing and dyeing waste-water and achieve “purification of waste-water by using alloy waste”.

Closed-loop recovery of molybdenum and value-added reuse of tungsten from alloy waste in additive manufacturing

As metal additive manufacturing (MAM) technology is booming in the aerospace sector, alternatives to the traditional production methods of metals such as mining, processing, and refining with severe emissions are urgently needed. This study proposed a closed-loop route for efficient recovery of molybdenum (Mo) and value-added reuse of tungsten (W) from Cr–Co–Ni–Mo–W alloy waste in MAM. The results showed that the leaching efficiency of Mo and W reached 99.3% and 99.9%, respectively, using the dual chemical-physical means of mixed-alkali roasting and leaching by microwave heating, while the discharge of waste liquor containing Cr6+ was reduced. Leaching kinetic studies revealed that the metal leaching process was controlled by chemical reaction mechanism. Moreover, the 10%N1923 (primary amine)–5%TRPO (tri-alkyl phosphine oxide)–kerosene extraction system exhibited a synergistic extraction effect on Mo and W. After purification, Mo was recovered as Mo powder for MAM. Simultaneously, the recovered product of W, MnWO4, was applied as a photocatalytic material with excellent degradation of methylene blue dye. Ultimately, the proposed method obtained recovery efficiencies of 98.4% and 99.3% for Mo and W, respectively, achieving efficient and environmentally-friendly reuse of these key metals.

Method to predict alloy yield based on multiple raw material conditions and a PSO-LSTM network

The production of ferroalloys accounts for a large proportion of the total energy consumption of the steelmaking industry. Accurately predicting alloy element yields is the key to reducing alloy waste, but there are significant differences in alloy yield under different conditions using ferroalloy raw materials during steelmaking. Therefore, this paper proposes a multi-model alloy element yield prediction method based on a particle swarm optimization (PSO) hyperparameter-optimized long short-term memory (LSTM) network and raw material condition classification. The accuracy of the PSO-LSTM prediction model was verified through simulations and was significantly higher than that of other network models when using the same raw material conditions. The average absolute error of predictions using raw materials with a low drum index was 0.4485, and it was 0.6162 under a high drum index, which was significantly lower than that (0.7077) under the condition without classification. This demonstrates the rationality of classifying working conditions according to the raw material conditions of ferroalloys. In addition, this paper combines the prediction model with a linear programming algorithm to develop a ferroalloy operating system and uses it in a steel plant to guide workers to complete an alloying operation. After four months of industrial testing, the internal control rate of finished steel composition increased from 91–94 % to 95–98 %. According to statistical analysis, the optimized HRB400E threaded steel consumed 1.23 kg less silicon-manganese per ton of steel, reduced the cost of steel alloy per ton by 8.6 yuan, and significantly reduced the waste of ferroalloys during steelmaking.

Optimization of the Technological Process of Dispersing Brass Waste in a Carbon-Containing Environment by Setting up a Full Factorial Experiment

Purpose of research. Optimization of the technological process of dispersing brass waste in a carbon-containing environment by setting up a full factorial experiment.Methods. The electroerosion process of LS58-3 alloy waste was carried out on a patented device, LS58-3 alloy waste (GOST 15527-2004) was used as metal waste. Isopropyl alcohol (GOST 9805-84), which is a carbon-containing medium, was chosen as the working fluid (dispersing medium).Variable parameters during operation of the installation were: the voltage supplied to the electrodes (100...200 V); capacity of discharge capacitors (25...65 μF); discharge frequency 50...100 Hz.When an electric discharge occurs, the electrodes and wastes are instantly destroyed and the smallest powder particles are formed. The granulometric composition of the obtained powder was carried out using the Analysette 22 NanoTec particle size analyzer. The development of a mathematical model of the process of obtaining lead brass powder was carried out by conducting a full factorial experiment of type 23.Results. As a result of mathematical calculations, the maximum value of the optimization output parameter (average particle size) was determined, which was 23.8 μm at the following values of the factors (dispersion modes): the voltage supplied to the electrodes is 200 V, the discharge frequency is 100 Hz, and the capacity of the discharge capacitors is 65 μF.Conclusion. On the basis of the obtained results of studies and calculations, it is possible to conclude that by changing the operating modes of the EDM installation, it is possible to obtain powders of different sizes. The voltage applied to the electrodes and the capacity of the discharge capacitors have the greatest influence on the particle size of the resulting charge. When the values of these parameters increase, the mass yield of the powder increases, which directly depends on the size of the obtained particles.The obtained regression equation makes it possible to determine at which operating modes of the installation it is possible to obtain powder of a given particle size.

Composition, Structure and Properties of Hard Alloy Components Made of Electroerosive Powders Prepared from Solid T5K10 Alloy Waste in Water

Composition, Structure and Properties of Hard Alloy Components Made of Electroerosive Powders Prepared from Solid T5K10 Alloy Waste in Water

WEAR-RESISTANT POWDER MATERIALS FOR PLASMA-POWDER SURFACING

Among powder surfacing materials with high hardness and resistance to abrasive wear, powders based on WC-TiC-Co systems, which are the basis of hard alloys, are among the most promising. (Research purpose) The research purpose is investigating wear-resistant powder materials for plasma-powder surfacing by electrodispersing solid alloy waste of the T30K4 brand in kerosene. (Materials and methods) We chose substandard carbide plates of the T30K4 brand as the starting material; lighting kerosene as the working fluid. We solved the tasks set in the work on the study of the composition, structure and properties of the obtained carbide powders using modern equipment and complementary methods of physical materials science. Electrodispersion of solid alloy waste was carried out on the original installation; the shape and morphology of the particle surface were studied on an electron-ion scanning microscope with field emission of electrons QUANTA 600 FEG; particle size composition ‒ on a laser particle size analyzer Analysette 22 NanoTec; X-ray spectral microanalysis of particles was carried out on an energy dispersive X-ray analyzer of EDAX company, integrated into a scanning electron microscope QUANTA 200 3D; phase analysis of particles was performed on an X-ray diffractometer Rigaku Ultima IV. (Results and discussion) A new technology for producing a carbide electroerosive powder suitable for plasma-powder surfacing has been developed and investigated, the effectiveness of which is confirmed by the properties of the proposed powder material: the spherical shape of powder particles; the average size of powder particles is 58.4 micrometers; powder particles with a uniform distribution of alloying elements: C, Co, Ti and W; powder particles include phases of carbides WC and TiC. (Conclusions) The conducted studies have shown that it is possible to obtain a wear-resistant powder alloy with a uniform distribution of alloying elements by the method of electroerosive dispersion of solid alloy waste of the T30K4 brand.

IMPROVING THE EFFICIENCY OF RESTORATION AND HARDENING OF THE WORKING BODIES OF TILLAGE MACHINES BY PLASMA-POWDER SURFACING OF CARBIDE ELECTROEROSIVE MATERIALS

The use of powders obtained from solid alloy waste as a highly solid dispersed component of the composition for plasma-powder surfacing will improve the quality, reliability and durability of plasma coatings of working bodies of tillage machines with a minimum of costs for powder materials. However, the properties of these plasma coatings have not been studied enough, so it is necessary to conduct comprehensive studies. (Research purpose) The research purpose is improving the technology of restoration and hardening of the working bodies of tillage machines by plasma-powder surfacing of powder materials obtained by electroerosive dispersion of solid alloy waste T30K4. (Materials and methods) Carbide powders made by electrodispersing solid alloy waste T30K4 in kerosene were used to obtain plasma coatings. We chose for the renovation object a pointed cultivator paw made of 40XC rolled steel. The obtained plasma coatings were studied using modern equipment and complementary methods of physical materials science. (Results and discussion) We have developed, tested and investigated a new technology for restoring and strengthening the working bodies of tillage machines using the example of a pointed cultivator paw by plasma-powder surfacing of carbide electroerosive powder materials. The effectiveness of the development was confirmed by the properties of plasma coatings: the microstructure of the coating has a fine-grained structure, without inclusions, uniform phase distribution and the absence of pores, cracks and discontinuities; elements W, Ti and Co in the coating are evenly distributed; phases of carbides WC and TiC are present; the grain size of the coatings is about 0.3 micrometers; the microhardness of the coatings is about 14245 megapascals. (Conclusions) The results of field tests showed that the resource of the working bodies of tillage machines, restored and strengthened with carbide electroerosion materials, is 1.25 times higher than the resource of new parts.

Optimization of the Process of Obtaining a Charge of Lead-Antimony Alloy SSu3 by the Electroerosion Method in Distilled Water

The purpose of this work was to optimize the process of obtaining a charge of lead-antimony alloy SSu3 by the electroerosion method in distilled water according to the criterion of average particle size.Methods. At the experimental facility for the production of lead-antimony powders from conductive materials, the waste of the SSu3 alloy was dispersed in distilled water at a loading weight of 250 g. The following electrical parameters of the installation were used: voltage at the electrodes from 100–200 V; capacitance of capacitors 25–65 UF; pulse repetition frequency 25–50 Hz. The average particle size was studied using the Analysette 22 NanoTec plus laser particle size analyzer. The determination of the optimal parameters of the EED installation was carried out by setting up a complete factorial experiment (PFE) on the average particle size of the obtained electroerosive materials. The parameters of the EED installation operation were selected as factors: the voltage at the electrodes, the capacitance of the discharge capacitors and the pulse repetition rate.Results. According to the conducted series of experiments, the results of which are presented in the table, the limiting values of the optimization parameter y (the average size of electroerosive particles) were determined, which amounted to: 44 microns with a capacity of 65.5 UF discharge capacitors, a voltage at the electrodes of 200 V, a pulse repetition frequency of 75 Hz.The conducted studies have shown that by the method of electroerosive dispersion of SSu3 alloy waste in distilled water, it is possible to obtain an alloy powder with a uniform distribution of alloying elements.Conclusion. Optimization of the process of obtaining the charge of lead-antimony alloy SSu3 by the electroerosion method in distilled water according to the criterion of the average particle size was carried out. The results obtained can be used by enterprises of the industrial sector for the production of lead-antimony powder.

Charge Obtained by Electrodispersing Waste of the LS58-3 Alloy in Distilled Water

The purpose of this study was to conduct metallographic studies of the composition of the charge obtained by the method of electrodispersion of lead brass waste in distilled water.Methods. Waste electrodispersion of lead brass brand LS58-3 was carried out on an experimental setup. Metallographic studies of charge samples from LS58-3 alloy waste were performed using the equipment of FGBOU VO SWGU and NRU BelGU: the shape, size and structure of charge particles, as well as its granulometric composition.Results. On the basis of the conducted experimental studies aimed at studying the composition, structure and properties of the charge obtained from the waste of the LS58-3 alloy in distilled water, the high efficiency of using the electrodispersion technology is shown, which provides, at low power costs, the production of new copper-lead powders suitable for industrial use. materials. It is noted that the powder materials obtained by electroerosion of lead brass waste of grade LS58-3 in distilled water have the following characteristics: the geometric shape of the charge particles is mainly spherical; particle sizes from 0.45 to 29.63 microns; the volume average particle diameter is 7.1 μm.Conclusion. The research carried out will allow for a gradual transition to advanced production technologies and materials through the use of progressive, environmentally friendly, low-tonnage and waste-free technology of electroerosive dispersion in the production of new copper-lead powder materials from LS58-3 alloy waste.

Kinetics and Optimization of Metal Leaching from Heat-Resistant Nickel Alloy Solid Wastes.

Recycling waste from the production and consumption of heat-resistant alloys to return them to production is an urgent task due to the high cost of the components contained in these alloys. The kinetics and conditions of the acid leaching process of the grinding waste of a heat-resistant nickel alloy are studied depending on the composition of the acid solution (H2SO4, HCl, HNO3, and their mixtures) at room temperature to boiling point temperature and various acid concentrations (1.5 to 3.0 mol/L), ratios of waste to solution (1:10 to 3:10), fraction sizes (0.04-1 mm), and contact duration (1 to 120 h). The linearization of experimental data by the Gray-Weddington, Gistling-Brownstein, and Kazeev-Erofeev equations showed that the rate of the leaching process was influenced by both the chemical reactions between sulfuric acid and metals included in the grinding waste and the diffusion of reagents through the film of reaction products and undissolved impurities. Optimal conditions for acid dissolution of the grinding waste have been established to obtain the maximum degree of extraction of the main component of the alloy, nickel. The processing of powder particles with a size of less than 0.1 mm should be carried out in a solution of sulfuric acid with a concentration of 3.0 mol/L at a temperature of 100 °C for 6 h with a ratio of solid to liquid phases of 1:10. The reported results are very important for industry personnel to recover metals and for environmentalists to treat the alloy waste.

Repair of Worn-Out Parts of Auger Presses by Surfacing Method

In the briquetting process of various finely dispersed materials using the auger pressing method, an important issue is extending the service life and repairing worn-out elements, such as the auger, die, and lining. This study provides a literature review and industrial experience in repairing worn-out parts of industrial presses. It formulates the main approaches for restoring abrasive surfaces and presents the results of experimental studies aimed at prolonging the lifespan of augers in briquette presses using surfacing methods, including using powders obtained from solid alloy waste.

Production of Open-Cell Metal Foams by Recycling of Aluminum Alloy Chips.

In this paper, an innovative sustainable method of producing metal foams was presented. The base material was aluminum alloy waste in the form of chips obtained by machining process. The leachable agent, used to create pores in the metal foams, was natrium chloride, which was later removed by leaching, resulting in metal foams with open cells. Open-cell metal foams were produced with three different input parameters: volume percentage of natrium chloride, compaction temperature, and force. The obtained samples were subjected to compression tests during which displacements and compression forces were measured to obtain the necessary data for further analysis. To determine the influence of the input factors on the selected response values such as relative density, stress and energy absorption at 50% deformation, an analysis of variance was performed. As expected, the volume percentage of natrium chloride was shown to be the most influential input factor because it has a direct impact on the obtained metal foam porosity and thus on the density. The optimal values of the input parameters with which the metal foams will have the "most desirable" performances are a 61.44% volume percentage of natrium chloride, a compaction temperature of 300 °C and a compaction force of 495 kN.

Rhenium recovery from highly concentrated sulfuric media using AMR anionite in column mode

The paper deals with the study of rhenium recovery by AMR anionite from model high-acidic sulfuric solution as well as its desorption by ammonia solution in column experiments. Total dynamic exchange capacity was calculated. Experimental data were processed using the Thomas, Yoon-Nelson and Bed Depth Service Time models, basic parameters were calculated. It was found that total dynamic exchange capacity calculated by Thomas fit was the closest to the experimental value. Rhenium desorption was examined using ammonia solution. Rhenium recovery degree and concentration factor were calculated. The elution curve featured a clear peak that allows producing eluate with high rhenium concentration. The presented results may be used when designing technologies for rhenium sorption from different process solutions and during recycling rhenium-containing alloy wastes.