Structure and hyperfine interactions in Aurivillius Bi9Ti 3Fe5O27 conventionally sintered compound

The structure and hyperfine interactions in the Bi9Ti3Fe5O27 Aurivillius compound were studied using X-ray diffraction and Mössbauer spectroscopy. Samples were prepared by the conventional solid-state sintering method at various temperatures. An X-ray diffraction analysis proved that the sintered compounds formed single phases at temperature above 993 K. Mössbauer measurements have been carried out at room and liquid nitrogen temperatures. Room-temperature Mössbauer spectrum of the Bi9Ti3Fe5O27 compound confirmed its paramagnetic properties. However, low temperature measurements revealed the additional paramagnetic phase besides the antiferromagnetic one

The effect of organic acids as leaching agents for hydrometallurgical recovery of metals from PCBs

The hydrometallurgical treatment, compared to other recycling processes, is of great interest due to its higher efficiency and better economy. In hydrometallurgy, popular agents used in the leaching processes of e-waste include inorganic acids, ammonia, chlorides, thiourea, thiosulphates. Organic acids are also becoming more and more popular. The article presents an overview of possible paths of the metal recovery from e-waste with the use of various organic acids. The results of own research on the leaching of printed circuit boards with the use of organic acids including citric acid, oxalic acid, acetic acid, formic acid, malic acid, lactic acid are also presented.Web of Science613-461260

Research of Leaching of the Printed Circuit Boards Coming from Waste Mobile Phones

The continuous changing technologies of electronic devices, mainly mobile phones cause that their life is shorten from year to year (even to 8-12 months); that is way there is a constantly increasing amount of generated waste. Such waste treatment to recover mainly copper and other base metals should be really profitable. The process of metals recovery could be done using different methods including pyro- and hydrometallurgical process. The paper describes the research of leaching process of Printed Circuit Boards (PCB) coming from waste mobile phones. As a leaching agent sulfuric acid was used with addition of hydrogen peroxides. Experiments were carried out for different temperature, acid concentration and addition of hydrogen peroxide. As a result the concentration of copper, zinc, iron and aluminium in the obtained solution was measured. The results were discussed

Role of Oxidizing Agents in Leaching Process of Electronic Waste

New technologies and the globalization of the electrical and electronic equipment market cause a continuous increase in the amount of electrical and electronic waste. They constitute one of the waste groups that grows the fastest in quantity. The development of the new generation of electrical and electronic devices is much faster than before. Recently attention has been concentrated on hydrometallurgical methods for the recovery of metals from electronic waste. In this article the role of an oxidizing agent, mainly ozone and hydrogen peroxide was presented in hydrometallurgical processes. Leaching process of printed circuits boards (PCBs) from used cell phones was conducted. The experiments were carried out in the presence of sulfuric acid and ozone as an oxidizing agent for various temperatures, acid concentration, ozone concentration. As a result, the concentrations of copper, zinc, iron and aluminum in the obtained solution were measured. The obtained results were compared to results obtained earlier in the presence of hydrogen peroxide as an oxidizing agent and discussed

Problems of Processing and Separation of Multi-Material Electronic Waste in Terms of Circular Economy

The article presents current methods used for the recovery of metals from used electronic equipment. The analysis of the composition and structure of the material was made on the example of one of the most popular and widespread e-waste - used cell phones. The article was address the problems of processing and separation of individual components included in these heterogeneous wastes. The main purpose of the conducted research was to prepare the tested material in such a way that the recovery of metalsin the further stages of its processing was as effective as possible. The results of attempts to separate individual material fractions with magnetic, pyrometallurgical or hydrometallurgical methods will be presented. An analysis of the possibilities of managing electronic waste in terms of the circular economy will be made

Effects of V2O5 Additive on Structure and Dielectric Properties of BiNbO4 Ceramics

Celem niniejszej pracy było zbadanie wpływu dodatku V2O5 na strukturę i właściwości dielektryczne ceramiki BiNbO*. Do wytworzenia ceramiki zastosowano metodę reakcji w fazie stałej i spiekanie swobodne w atmosferze powietrza. Cera- mikę poddano badaniom morfologii (SEM). składu chemicznego (EDS) oraz rentgenowskiej analizie fazowej i strukturalnej. Właściwości dielektryczne w domenie częstotliwości (v =10Hz-lMHz) i temperatury (T =RT-550°C) zbadano przy pomocy spektroskopii impedancyjnej. Stwierdzono, że dodatek V2O5 powoduje niewielką zmianę parametrów komórki elementarnej, zmniejsza porowatość ceramiki oraz pozwolił zaobserwować zjawiska relaksacyjne występujące w dwóch zakresach częstotli- wości: v = 102-I03Hz oraz v =105-106Hz w temperaturze T>285°C

Structure and Hyperfine Interactions in Aurivillius Bi9Ti3Fe5O27Bi_{9}Ti_{3}Fe_{5}O_{27} Conventionally Sintered Compound

The structure and hyperfine interactions in the $Bi_{9}Ti_{3}Fe_{5}O_{27}$ Aurivillius compound were studied using X-ray diffraction and Mössbauer spectroscopy. Samples were prepared by the conventional solid-state sintering method at various temperatures. An X-ray diffraction analysis proved that the sintered compounds formed single phases at temperature above 993 K. Mössbauer measurements have been carried out at room and liquid nitrogen temperatures. Room-temperature Mössbauer spectrum of the $Bi_{9}Ti_{3}Fe_{5}O_{27}$ compound confirmed its paramagnetic properties. However, low temperature measurements revealed the additional paramagnetic phase besides the antiferromagnetic one

Właściwości dielektryczne kompozytów ceramicznych żelazianu bizmutu-tytanianu bizmutu

n this paper the BiFeO3//Bi4Ti3O12 (BF//BiT) ceramic-ceramic composites with 0-3 connectivity were prepared from BiFeO3 and Bi4Ti3O12 ceramic powders by free sintering method at T=900°C, for different concentration of the BF ceramic phases. Bi4Ti3O12 and BiFeO3 ceramic powders were synthesized by the conventional mixed oxide method (MOM). Synthesized BF powder was dispersed in a BiT solution and next such composite was pressing and sintering. Crystalline structure was studied by X-ray diffraction method. The dielectric properties of the BF//BiT ceramic composites were also investigated. Temperature dependence of dielectric permittivity of BF//BiT composites was measured in the frequency range of f=10kHz-100kHz. It was found, that properties of the ceramic-ceramic composite are not a simple sum of properties of the phases constituting the composite but they depend on both the way of connectivity and mutual influence of the phases on each other. The abrupt increase in permittivity may indicate an excess of the percolation threshold, so the ceramic composite for the concentrations of the BF ceramic phase cV 10% nie mogą być indeksowane jako kompozyty o sposobie łączenia faz 0-3

Influence of Processing Conditions on Crystal Structure of Bi6Fe2Ti3O18 Ceramics

Aim of the present research was to apply a solid state reaction route to fabricate Aurivillius-type ceramics described with the formula Bi6Fe2Ti3O18 (BFTO) and reveal the influence of processing conditions on its crystal structure. Pressureless sintering in ambient air was employed and the sintering temperatures were 850 and 1080 °C. It was found that the fabricated BFTO ceramics were multiphase ones. They consisted of two Bim+1Fem-3Ti3O3m+3 phases, namely the phase with m=5 (i.e. the stoichiometric phase) and m=4 (i.e. the phase with a reduced number of layers in the slab). Detailed X-ray diffraction patterns analysis showed that both phases adopted the same orthorhombic structure described with Fmm2 (42) space group. The ratio of weight fractions of the constituent phases (m=5): (m=4) was ~30:70