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1

Potassium chloride recovery from mechanically activated microcline through the chlorination roasting and leaching route

Alyosif Bahaa, Uysal Turan, Erdemoğlu Murat

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 167500

EN

In this study, effects of mechanical activation in the chlorination roasting and water leaching route known as CaCl2 process and developed for the production of potassium chloride (KCl) from potassium feldspar ores were studied. A microcline containing K-feldspar ore with 10.89% K2O was first intensively dry milled by a planetary ball mill and mixed with calcium chloride (CaCl2) and then roasted at temperatures up to 1000°C to obtain KCl that will be finally dissolved by the water leaching. Potassium recovery by water leaching increased rapidly up to 800°C. At higher temperatures, the recovery decreased fast due to the evaporation of KCl. According to the K recovery values per unit energy consumed, the optimum roasting temperature was determined as 750°C and the milling time was 15 min. It was concluded that intensive milling causes mechanical activation of the microcline to reduce the chlorination roasting temperature, which triggers a rise in the K recovery by the water leaching.

2

Waste Water Purification from Metal Ions by Ultra-Dispersed Natural Sorbents

Yerbolov Sezim, Daumova Gulzhan

Journal of Ecological Engineering

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2022

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Vol. 23, nr 1

43--50

EN

This work is devoted to mine wastewater purification from metal ions, such as copper, zinc, lead, cadmium, iron, and manganese. The rationale was provided for the possibility to purify the wastewater from metal ions with nonactivated and ultra-dispersed natural sorbents. The adsorption capacity of bentonite clay from Tagan deposit and shungite from Koksui deposit of the Republic of Kazakhstan was studied on the basis of its fraction composition. It was found that the most effective method of sorbents modification was mechanical activation. The comparative studies of metal ions adsorption efficiency were carried out with mechanically activated and ultra-dispersed bentonite clay and shungite. The experiment enabled to find out that ultra-dispersed bentonite clay is prospective for use in order to deeply purify multicomponent mine wastewater. The highest degree of metal ions extraction was achieved due to 30-minutes contact of wastewater.

3

The effectiveness of modified sodium bicarbonate in the purification of exhaust gases from HCl and HF

Wysocki D., Szymanek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 114, nr 2

57--66

EN

Purpose: The effectiveness of gas purification depends on the sorption properties of sorbents. The aim of the research was to determine the ability of sodium sorbents to remove gaseous pollutants such as HCl and HF. Design/methodology/approach: The research used baking soda subjected to mechanical and thermal activation, which was introduced into the hot flue gas circuit, similar to the dry flue gas cleaning method used in all kinds of boilers. Findings: In almost all cases, mechanical and thermal treatment of baking soda allowed for a significant improvement in the reduction of hydrogen chloride and hydrogen fluoride concentrations in the exhaust gases produced during the combustion of polyethylene terephthalate (PET) bottles. Research limitations/implications: The preparation of sorbents must consider the optimum development of the material's specific surface area, especially during thermal activation, to prevent pores from sintering. Practical implications: In wet and dry flue gas cleaning processes, sodium compounds are used in the power industry. Appropriate preparation of the sorbent allows for improving the effectiveness of reducing the concentration of harmful substances and reducing investment and operating costs. Originality/value: From the point of view of process optimisation, the results obtained will contribute to the identification of optimal operating conditions in dry sorbent injection systems to prevent the pores on the surface of the sorbent from clogging when injected into hot flue gases.

4

Effect of mechanical activation on carbothermic reduction and nitridation of titanomagnetite concentrates

Wen Xiaojin, Yu Wen, Zeng Danliang, Zhu Liang Liang, Chen Jiangan

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 5

33--45

EN

The carbothermic reduction and nitridation process of titanomagnetite concentrates with the help of mechanical activation were investigated by particle size analysis, thermodynamic calculation, thermogravimetric analysis, X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive spectroscopy analysis. The thermogravimetric and X-ray diffraction results indicated that either the reduction of iron oxide or the reduction and nitridation of M3O5 to TiN could be promoted significantly with the increase in activation time. The results obtained from scanning electron microscopy and energy-dispersive spectroscopy showed that, when samples were not activated, chunks of and thin M3O5 were derived from the reduction of ilmenite and titanomagnetite. They were severely sintered with impurities to form a dense structure. As a result, M3O5 was difficult to be converted to TiN, especially chunks of M3O5. However, when samples were activated, the sintering degrees of the impurity and M3O5 were mitigated, and the particle size of the iron as a medium for delivering C to M3O5 was decreased in the roasted product. This condition enhanced the diffusion of C to the surface of M3O5. Meanwhile, the bulk of ilmenite was broken in the activation process, which prevented the formation of chunks of M3O5. Thus, the conversion of M3O5 to TiN was promoted.

5

Influence of mechanical activation and heat treatment on surface development and oxide layer thickness of Ti6Al4V ELI alloy

Szota M., Łukaszewicz A., Bukowska A.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 97, nr 2

69--76

EN

Purpose: The paper presents the results of mechanical activation of the surface on oxide layer thickness after heat treatment of TU6Al14V ELI alloy. Design/methodology/approach: Specimens were made from 5 mm diameter rod cut into semicircular slices. The samples were mechanically activated throughout mechanical treatment of the surface: one sandblasted with glass beads during 5 minutes and other ground with sandpaper grit 40, 180, 220 and 800 during 7.5 and 15 minutes. Findings: Then microstructure of specimens etched with Kroll solution was observed using an optical microscope and roughness parameters of the surface were measured. Research limitations/implications: Afterwards heat treatment (550°C, 5 hours) was conducted, then roughness parameters and thickness of the oxide layer were measured by means of a scanning microscope. Practical implications: The conducted research showed up that mechanical activation of the surface which cause an increase of surface development results in greater thickness of the oxide layer which is formed during heat treatment. Nevertheless, mechanical activation that results in a decrease of surface development, such as polishing, results in a decrease of oxide layer thickness. Originality/value: The results of the research can be used to obtain the desired thickness of the oxide layer in the production of the elements that require increased wear and corrosion resistance.

6

Fabrication of Fe-TiB2 Nanocomposites by Spark-Plasma Sintering of a (FeB, TiH2) Powder Mixture

Huynh X.-K., Kim B.-W., Kim J.-S.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 2

1043--1047

EN

Fe-40wt% TiB2 nanocomposites were fabricated by mechanical activation and spark-plasma sintering of a powder mixture of iron boride (FeB) and titanium hydride (TiH2). The powder mixture of (FeB, TiH2) was prepared by high-energy ball milling in a planetary ball mill at 700 rpm for 3 h followed by spark-plasma sintering (SPS) at various conditions. Analysis of the change in relative sintered density and densification rate during sintering showed that a self-propagating high-temperature synthesis reaction occurs to form TiB2 from FeB and Ti. A sintered body with relative density higher than 98% was obtained after sintering at 1150°C for 5 and 15 min. The microstructural observation of sintered compacts with the use of FE-SEM and TEM revealed that ultrafine particulates with approximately 5 nm were evenly distributed in an Fe-matrix. A hardness value of 83 HRC was obtained, which is equivalent to that of conventional WC-20 Co systems.

7

Copper Leaching from Chalcopyrite: Mechanochemical Approach

Tesinsky M., Balaz P.

Inżynieria Mineralna

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2017

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R. 18, nr 1

1--5

EN

In the presented work, possibilities of intensification of copper leaching from chalcopyrite CuFeS2 induced by mechanical activation was studied. In this article, the influence of mechanical activation time on copper leaching efficiency is compared. This study also shows how mechanical activation time influences selectivity of copper and iron leaching. For mechanical activation, planetary mill Fritsch Pulverisette 6 at 400 rpm and room temperature was used. Grinding chamber (250 cm3 in volume) and 50 balls (10 mm in diameter) made of tungsten carbide were used. Specifically, the effect of mechanical activation time (4, 20, 30 minutes), the effect of temperature (40, 60, 80°C) on the copper recovery by leaching and the effect of the leaching atmosphere (air, argon) were examined. The results showed that the highest possible recovery of copper from chalcopyrite was obtained after 20 minutes of milling and leached in hydrochloric acid at 80°C, with air atmosphere without any oxidizing reagents.

PL

W artykule przedstawiono możliwości intensyfikacji procesu ługowania miedzi z chalkopirytu CuFeS2 za pomocą aktywacji mechanicznej. Zbadano wpływ czasu aktywacji mechanicznej na efektywność ługowania miedzi. Wyniki badań pokazały również wpływ czasu na selektywność rozdziału miedzi i żelaza. Do aktywacji mechanicznej wykorzystani młyn planetarny Fritsch Pulverisette 6, aktywację prowadzono przy obrotach 400 rpm, w temperaturze pokojowej. Do badan wykorzystano komorę mielenia o objętości 250 cm3 i 50 kul o średnicy 10 mm wykonanych z węglika wolframu. Określono wpływ czasu aktywacji mechanicznej (4, 20, 30 minut), wpływ temperatury (40, 60, 80°C) na odzysk miedzi w procesie lugowania w atmosferze powietrza i argonu. Wyniki wskazują, że najwyższy możliwy odzysk miedzi z chalkopirytu uzyskano po 20 minutach mielenia i ługowaniu w kwasie solnym w temperaturze 80°C, w atmosferze powietrza, bez jakichkolwiek czynników utleniających.

8

Effect of Mechanical Activation on the in situ Formation of TiB2 Particulates in the Powder Mixture of TiH2 and FeB

Huynh X.-K., Kim B.-W., Kim J. S.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2B

1393--1398

EN

The in situ formation of TiB2 particulates via an interface reaction between Ti and FeB powders was studied. The effects of mechanical activation by high-energy milling on the decomposition of TiH2 and the interface reactions between Ti and FeB powders to form TiB2 were investigated. Powder mixtures were fabricated using planetary ball-milling under various milling conditions. The specific ball-milling energy was calculated from the measured electrical power consumption during milling process. High specific milling energy (152.6 kJ/g) resulted in a size reduction and homogeneous dispersion of constituent powders. This resulted in a decrease in the decomposition temperature of TiH2 and an increase in the formation reaction of TiB2 particulates in the Fe matrix, resulting in a homogeneous microstructure of nanoscale TiB2 evenly distributed within the Fe matrix. In contrast, the powder mixture milled with low specific milling energy (36.5 kJ/g) showed an inhomogeneous microstructure composed of relatively large Fe-Fe2 B particles surrounded by a thin layer of Fe-TiB2 within a finely dispersed Fe-TiB2 matrix region.

9

Control of Natural Zeolite Properties by Mechanical Activation in Stirred Media Mill

Bohács K., Faitli J., Bokányi L., Mucsi G.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2B

1399--1406

EN

Due to the special characteristics of zeolites, they can be applied in a very wide range of industries, i.e. agricultural, environmental or water treatment purposes. Generally, high added value zeolite products are manufactured by micro- or nanogrinding. However, these processes require high energy input and cause significant wearing of the mill parts. Therefore, the optimization of zeolite grinding, as well as the control of its properties are of a great importance. In the present paper a Hungarian natural zeolite was mechanically activated in stirred media mill for various residence times in distilled water, meanwhile the particle size distribution and the grinding energy were measured. Additionally, on-line tube rheometer was used to study the rheology of the suspension during the grinding process. The particle interaction and the suspension aggregation stability were detected by zeta-potential measurements. Structural changes due to the mechanical activation process were monitored by FTIR. It was found that the material structure of the zeolite, as well as the rheological behaviour of the zeolite suspension and its aggregation stability had been altered due to the mechanical activation in the stirred media mill. It can be concluded that the zeolite product properties can be modified by mechanical activation in order to produce a high added value tailored material.

10

Improvement of the mass transfer processes efficiency by means of mechanical activation of homogeneous and heterogeneous systems

Blinichev V., Postnikova I., Krawczyk J.

Czasopismo Techniczne. Mechanika

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2016

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Y. 113, iss. 2-M

33--42

EN

In this paper, the ways of intensification of technological processes by means of powerful short pulses of energy in activation machines in solid phase and water systems are considered. The mechanism of accumulation and relaxation of energy for the substances subjected to mechanical activation is shown.

PL

W pracy omówione zostały metody intensyfikacji procesów technologicznych w ciałach stałych i cieczach przy użyciu krótkotrwałych impulsów energetycznych. Przedstawiono mechanizmy akumulacji i relaksacji energii w substancjach poddanych mechanicznej aktywacji.

11

Structure and Magnetic Properties of Bi5Ti3FeO15 Ceramics Prepared by Sintering, Mechanical Activation and Edamm Process. A Comparative Study

Jartych E., Pikula T., Mazurek M., Franus W., Lisinska-Czekaj A., Czekaj D., Oleszak D., Surowiec Z., Aksenczuk A., Calka A.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2A

869--874

EN

Three different methods were used to obtain Bi5Ti3FeO15 ceramics, i.e. solid-state sintering, mechanical activation (MA) with subsequent thermal treatment, and electrical discharge assisted mechanical milling (EDAMM). The structure and magnetic properties of producedBi5Ti3FeO15 samples were characterized using X-ray diffraction and Mössbauer spectroscopy. The purest Bi5Ti3FeO15 ceramics was obtained by standard solid-state sintering method. Mechanical milling methods are attractive because the Bi5Ti3FeO15 compound may be formed at lower temperature or without subsequent thermal treatment. In the case of EDAMM process also the time of processing is significantly shorter in comparison with solid-state sintering method. As revealed by Mössbauer spectroscopy, at room temperature theBi5Ti3FeO15 ceramics produced by various methods is in paramagnetic state.

12

Structure and Mössbauer spectroscopy studies of mechanically activated (BiFeO3)1-x-(BaTiO3)x solid solutions

Malesa B., Antolak-Dudka A., Oleszak D., Pikula T.

Nukleonika

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2015

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Vol. 60, No. 1

109--114

EN

(BiFeO3)1-x-(BaTiO3)x solid solutions with x = 0.1–0.4 and 0.7 were investigated. The ceramics were prepared by mechanical activation technology and subsequent heat treatment. As was proved by X-ray diffraction, increase of BaTiO3 concentration causes a change in the crystalline structure from the rhombohedral structure characteristic of BiFeO3 to a cubic one. 57Fe Mössbauer spectroscopy allowed observation of a gradual transformation from an ordered spin structure of Fe3+ ions to the paramagnetic state with an increase of x.

13

Investigation of Structure and Physico-Mechanical Properties of Composite Materials Based on Copper - Carbon Nanoparticles Powder Systems

Kovtun V., Pasovets V., Pieczonka T.

Archives of Metallurgy and Materials

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2015

|

Vol. 60, iss. 1

51--55

EN

Physico-mechanical and structural properties of electrocontact sintered copper matrix- carbon nanoparticles composite powder materials are presented. Scanning electron microscopy revealed the influence of preliminary mechanical activation of the powder system on distribution of carbon nanoparticles in the metal matrix. Mechanical activation ensures mechanical bonding of nanoparticles to the surface of metal particles, thus giving a possibility for manufacture of a composite with high physico-mechanical properties.

PL

Materiały kompozytowe o osnowie miedzi zawierające nanocząstki węgla wytwarzano metodą spiekania elektrostyko-wego. Spieki poddano badaniom właściwości fizyko-mechanicznych oraz badaniom strukturalnym. Obserwacje przełomów za pomocą mikroskopu skaningowego wykazały korzystny wpływ mechanicznej aktywacji mieszanki proszków na rozmieszczenie nanocząstek węgla w osnowie metalowej. Aktywacja prowadzona w wysokoenergetycznym młynie wibracyjnym doprowadza do mechanicznego połączenia nanocząstek węgla z powierzchnią cząstek miedzi, dzięki czemu możliwe jest wytworzenie spiekanego kompozytu o wysokich właściwościach fizyko-mechanicznych.

14

Comparative analysis of process parameters of talc mechanical activation in centrifugal and attrition mill

Andric L., Terzic A., Acimovic-Pavlovic Z., Pavlovic L., Petrov M.

Physicochemical Problems of Mineral Processing

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2014

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Vol. 50, iss. 2

433--452

EN

The efficiency of talc mechanical activation by means of two different mechano-activators - centrifugal and attrition mill is investigated in this study and the comparative analysis of the characteristics of obtained talc powders is presented. A new approach for obtaining high-grade talc concentrate with low Fe2O3 content is achieved through effect of mechanical activation of talc accompanied by hydrometallurgical process. The applied mechanical activation process conditions of ultra-centrifugal mill were defined by number of rotor revolutions, sieve mesh size, and current intensity. These operating parameters of the ultra-centrifugal mill were variable. Ultra fine grinding of talc in attrition mill (attritor) was carried out in various time intervals - from 5 to 15 min. The following technological parameters of the mechanical activation were monitored: time of mechanical activation, circumferential rotor speed, capacity of ultra-centrifugal mill, and specific energy consumption. The investigation was based on a kinetic model. The structure and behavior of activated samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and differential thermal analysis (DTA).

15

Structure and hyperfine interactions in multiferroic Aurivillius Bi m+1Ti3Fe m−3O3m+3 compounds prepared by mechanical activation

Mazurek M., Oleszak D., Czekaj D.

Materials Science Poland

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2014

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Vol. 32, No. 4

676--681

EN

The aim of the study was to determine the structure and hyperfine interactions of Bim+1Ti3Fem−3O3m+3 multiferroic Aurivillius compounds prepared by mechanical activation process. X-ray diffraction and Mössbauer spectroscopy were applied as complementary methods. After the process of mechanical milling, desired Aurivillius phases were not formed, thus, thermal treatment needed to be applied. Heating the product of mechanical activation up to 993 K allowed to obtain Aurivillius phases with relatively large amount of non-reacted hematite. However, after the material was annealed at an elevated temperature of 1073 K, the content of not fully synthesized hematite was significantly reduced. Mössbauer spectroscopy confirmed that Aurivillius compounds remain in paramagnetic state at room temperature.

16

Oddziaływania nadsubtelne w ceramice (BiFeO3)0.9-(BaTiO3)0.1 wytworzonej przez aktywację mechaniczną

Malesa B., Mazurek M.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2014

|

nr 2

16--19

PL

W pracy przedstawiono wyniki badań strukturalnych i magnetycznych dla ceramiki (BiFeO3)0.9-(BaTiO3)0.1 otrzymanej w procesie aktywacji mechanicznej. Badania struktury i oddziaływań nadsubtelnych przeprowadzono odpowiednio metodami dyfrakcji promieniowania X oraz spektroskopii efektu Mössbauera.

EN

In this work the results of structural and magnetic investigations for (BiFeO3)0.9-BaTiO3)0.1 ceramics prepared by mechanical activation are presented. The structural analysis and hyperfine interactions investigations were performed by X-ray diffraction and Mössbauer spectroscopy.

17

Structure and hyperfine interactions of multiferroic Bim+1Ti3Fem-3O3m+3 ceramics prepared by mechanical activation

Mazurek M., Jartych E., Oleszak D.

Nukleonika

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2013

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Vol. 58, No. 1

143-147

EN

The structure and hyperfine interactions in the Bi5Ti3FeO15, Bi6Ti3Fe2O18 and Bi7Ti3Fe3O21 multiferroic ceramics were studied using X-ray diffraction and Mössbauer spectroscopy. Samples were prepared by mechanical activation process in a high-energy ball mill from a mixture of TiO2, Fe2O3 and Bi2O3 oxides as polycrystalline precursor materials. The mechanical milling process was completed by thermal processing. A pure single-phased material was obtained in the case of Bi7Ti3Fe3O21 compound. The proposed mechanical activation technology allows to produce the Aurivillius compounds at lower temperature, by about 50 K, as compared to the solid-state sintering method.

18

Comparative X-ray diffraction and Mössbauer spectroscopy studies of BiFeO3 ceramics prepared by conventional solid-state reaction and mechanical activation

Jartych E., Lisinska-Czekaj A., Oleszak D., Czekaj D.

Materials Science Poland

|

2013

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Vol. 31, No. 2

211--220

EN

The aim of this work was to prepare BiFeO3 by modified solid-state sintering and mechanical activation processes and to investigate the structure and hyperfine interactions of the material. X-ray diffraction and Mössbauer spectroscopy were applied as complementary methods. In the case of sintering, BiFeO3 phase was obtained from the mixture of precursors with 3 and 5 % excess of Bi2O3 during heating at 1023 K. Small amounts of impurities such as Bi2Fe4O9 and sillenite were recognized. In the case of mechanical activation, the milling of stoichiometric amounts of Bi2O3 and Fe2O3 followed by isothermal annealing at 973 K resulted in formation of the mixture of BiFeO3, Bi2Fe4O9, sillenite and hematite. After separate milling of individual Bi2O3 and Fe2O3 powders, mixing, further milling and thermal processing, the amount of desired BiFeO3 pure phase was significantly increased (from 70 to 90 %, as roughly estimated). From Mössbauer spectra, the hyperfine interaction parameters of the desired BiFeO3 compound, paramagnetic impurities of Bi2Fe4O9 and sillenite were determined. The main conclusion is that the lowest amount of impurities was obtained for BiFeO3 with 3 % excess of Bi2O3, which was sintered at 1023 K. However, in the case of mechanical activation, the pure phase formed at a temperature by 50 K lower as compared to solid-state sintering temperature. X-ray diffraction and Mössbauer spectroscopy revealed that for both sintered and mechanically activated BiFeO3 compounds, thermal treatment at elevated temperature led to a partial eliminating of the paramagnetic impurities.

19

Mössbauer studies of Bi5Ti3FeO15 electroceramic prepared by mechanical activation

Mazurek M., Jartych E., Oleszak D.

Przegląd Elektrotechniczny

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2012

|

R. 88, nr 9b

256-258

EN

The present work involves the structure analysis and the determination of hyperfine interactions parameters of multiferroic Bi5Ti3FeO15 electroceramic, prepared by high-energy ball milling of polycrystalline precursors (mixture of the Bi2O3, TiO2 and Fe2O3 simple oxides). This analysis was performed by X-ray diffraction and Mössbauer spectroscopy.

PL

W pracy przedstawiono wyniki badań dla multiferroicznej elektroceramiki Bi5Ti3FeO15 otrzymanej podczas procesu aktywacji mechanicznej (mielenie wysokoenergetyczne polikrystalicznych proszków Bi2O3, TiO2 i Fe2O3). Badania struktury i oddziaływań nadsubtelnych przeprowadzono metodami dyfrakcji promieniowania X oraz spektroskopii efektu Mössbauera.

20

Hyperfine interactions in multiferroic mechanically activated BiFeO3 compound

Jartych E., Oleszak D., Mazurek M.

Przegląd Elektrotechniczny

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2012

|

R. 88, nr 9b

242-244

EN

In this work the results of structural and magnetic investigations for multiferroic BiFeO3 compound prepared by mechanical activation are presented. The structural analysis and hyperfine interactions investigations were performed by X-ray diffraction and Mössbauer spectroscopy, respectively.

PL

W pracy przedstawiono wyniki badań strukturalnych i magnetycznych dla multiferroicznego związku BiFeO3 otrzymanego w procesie aktywacji mechanicznej. Badania struktury i oddziaływań nadsubtelnych przeprowadzono odpowiednio metodami dyfrakcji promieniowania X oraz spektroskopii efektu Mössbauera.