Copper ferrite obtaining from microelectronics waste

Relevance. The need to develop new methods for metal waste disposal. This direction, with the participation of various intensifying influences, refers to resource-saving, technological, minimizing the volume of capital costs for raw materials, production and subsequent sale. Aim. To obtain copper ferrite from iron and copper waste of microelectronics. Copper ferrite is a useful and highly demanded product in this branch of domestic industry, especially now, when many sanctions have been imposed on our country, including in terms of microelectronics. To study its magnetic properties and draw a conclusion about the possibility of its application. Objects. Samples of iron and copper waste in the form of plates, wire and shavings. Methods. Volumetric analysis, electron microscopy, X-ray phase analysis, study of magnetic susceptibility. Results. The authors have produced finely dispersed iron (III) oxide from iron-containing microelectronics waste. This oxide is used in electrical engineering as part of high-voltage resistors for grounding the neutral of networks, lithium-ion batteries, as a carrier of analog and digital information. In the radio engineering industry it is used as part of low-voltage resistors, high-frequency chokes, small-sized pulse transformers. The authors produced finely dispersed copper (II) oxide from copper-containing waste. This oxide is used in production of phosphors and dry batteries – in batteries with liquid cells as a cathode, with lithium as an anode and dioxalane mixed with lithium perchlorate as an electrolyte. In addition, it finds application as a p-type semiconductor, since it has a narrow bandgap of 1.2 eV, and manufacturing photovoltaic cells in solar panels. Copper ferrite was synthesized from the obtained oxides by sintering. Rings made of such alloy serve as a core in transformers. The part increases the magnetic field strength by several thousand times, making the devices transmit more power than they could with a non-ferrite core. Ferrite ring cores are found not only in transformers, but also in other electronics (e.g. magnetic memory)

MODIFICATION OF NON-AUTOCLAVED FOAM CONCRETE WITH PEAT ADDITIVE TMT600

The authors have studied the effect of a thermally modified additive based on peat TMT600 on the properties and structure of foam concrete of non-autoclave hardening and proposed a model of a fragment of the structure of the gas–solid–liquid interface and a model for the formation of a porous structure of foam concrete of non-autoclave hardening. The paper reveals the mechanism of the role of the foaming agent in formation of the porous structure of foam concrete. Tomography methods have shown that the real structure of foam concrete corresponds to the proposed models, as well as the achievement of a uniform distribution of pores by volume. It was established that in hydration after the dissolution of tobermorite and ettringite, the cement particles are recharged, and, consequently, the electrokinetic potential changes from positive to negative values. The mass transfer of particles is carried out not only by diffusion, but also by convection during foam formation. The accelerated movement of particles can also be carried out due to the electrostatic interaction of charges both on the surface of the foam and the peat additive. The geometry of the structural cells of the foam has the form of polygons, consisting mainly of hexagons and pentagons. As a result of the ongoing processes, a complex hierarchical structure is formed, in which the Plateau–Gibbs channels in the foam are calmed (clogged), forming a stronger skeleton, and after cement hydration, due to the recharging of the surface of the latter, an interpore partition of increased strength is eventually formed with a simultaneous uniform distribution of pores in foam concrete structure. The developed wall material has not only high strength, frost resistance, but also increased thermal insulation properties. The foam concrete obtained with the use of the TMT600 additive fully meets the seven fundamental criteria of the modern concept of building materials science, such as: technological availability and efficiency, energy and resource saving, environmental safety and natural compatibility, economic feasibility, ethical acceptability of practical application, aesthetic expressiveness and social orientation

Quantitative and Qualitative Analysis of Hydrogen Accumulation in Hydrogen-Storage Materials Using Hydrogen Extraction in an Inert Atmosphere

Currently, standard samples with high hydrogen concentrations that meet the requirements of hydrogen extraction in an inert atmosphere are not currently available on the market. This article describes the preparation of Ti-H standard samples and the calibration of RHEN602, a hydrogen analyzer, using LECO (LECO, Saint Joseph, MI, USA). Samples of technically pure titanium alloy were chosen as the material for sample production. The creation procedure includes five main steps: sample preparation (polishing to an average roughness of 0.04 μm using sandpaper), annealing, hydrogenation, maintenance in an inert gas atmosphere, and characterization of the samples. The absolute hydrogen concentration in the samples was determined by two methods: volumetric and mass change after the introduction of hydrogen. Furthermore, in-situ X-ray diffraction, temperature programmed desorption (TPD) analysis, and thermogravimetric analysis were used during measurements to investigate the phase transitions in the samples. As a result of this work, a series of calibration samples were prepared in a concentration range up to 4 wt % hydrogen, optimal parameters for measuring high concentrations of hydrogen. The calibration line was obtained and the calibration error was 10%