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  1. 9 Physicochemical Problems of Mineral Processing
  2. 6 Materials Science Poland
  3. 5 Polimery
  4. 3 Hutnik, Wiadomości Hutnicze
  5. 3 Journal of Ecological Engineering
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  1. 3 Gomelya Mykola
  2. 3 Gwoździk M.
  3. 3 Masłowski M.
  4. 3 Shabliy Tetyana
  5. 3 Zaborski M.
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  1. 3 2023
  2. 1 2022
  3. 5 2021
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1
Content available Novel multicomponent functionalized biopolymers with enhanced thermal and dielectric properties
Rani Sanjeeta, Ali Syed Kashif, Kumar Pawan, Anugrah Kunwar Sugam, Saya Laishram, Gambhir Geetu, Gautam Drashya, Hooda Sunita, Verma Manisha
Polimery
|
2023
|
Vol. 68, nr 7-8
386--395
EN
A new functionalized biopolymer was obtained by modifying chitin using ethylenediaminetetraacetic acid and magnetite nanoparticles (Fe3O4). Thermogravimetric analysis was performed, and dielectric properties were examined. The obtained biopolymer showed better thermal stability, as evidenced by a higher onset temperature. The activation energy calculated using imaginary impedance data and Nyquist plots was found to be consistent. Moreover, the dielectric permittivity decreased rapidly with increasing frequency. At high frequencies, there was no dependence of dielectric loss on temperature and frequency. The obtained biopolymer can be used in many applications such as microwave devices, deflection yoke, high-frequency capacitors, sensors, etc.
PL
Otrzymano nowy funkcjonalizowany biopolimer poprzez modyfikację chityny przy użyciu kwasu etylenodiaminotetraoctowego i nanocząstek magnetytu (Fe3O4). Przeprowadzono analizę termograwimetryczną i zbadano właściwości dielektryczne. Otrzymany biopolimer wykazywał lepszą stabilność termiczną, o czym świadczyła wyższa temperatura początku rozkładu. Wykazano zgodność energii aktywacji obliczonej z wykorzystaniem danych dotyczących urojonej impedancji oraz na podstawie wykresów Nyquista. Przenikalność dielektryczna zmniejszała się gwałtownie wraz ze wzrostem częstotliwości. Przy wysokich częstotliwościach nie stwierdzono zależności stratności dielektrycznej od temperatury i częstotliwości. Otrzymany biopolimer można wykorzystać w wielu zastosowaniach, takich jak urządzenia mikrofalowe, jarzmo odchylające, kondensatory wysokiej częstotliwości, czujniki itp.
2
Content available Mineralogical characteristic and beneficiation evaluation of rare earth carbonate wall rock
Gao Chunqing, Yan Guoying, Wang Hailiang, Luo Hongzhen, Zhang Lin, Yang Hanxu, Xu Jian
Physicochemical Problems of Mineral Processing
|
2023
|
Vol. 59, iss. 1
art. no. 161300
EN
In order to rationalize the development and utilization of the wall rock discarded during rare earth mining, chemical analysis, inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction analysis, artificial panning, optical microscope analysis, mineral liberation analysis and energy-dispersive spectroscopy were used to study the process mineralogy of the wall rock. The results show that the main useful elements in the rare earth wall rock were iron, light rare earth elements, fluorine and niobium. Iron was mainly occurrence as magnetic iron in magnetite, rare earth elements in bastnaesite and monazite, fluorine as a independent mineral in fluorite and niobium in columbite. The main useful minerals were finely disseminated, with magnetite (48.16%), bastnaesite (49.04%), monazite (42.18%), fluorite (39.30%) and columbite (63.26%) distributed in -0.030 mm particle size. The useful minerals were evaluated separately for beneficiation based on the process mineralogical characteristics of the rare earth wall rock, and the results showed that magnetite, rare earth and fluorite resources could be effectively recovered using magnetic separation, flotation, gravity concentration and leaching enrichment methods. The sequential recovery of iron, rare earth, fluorine and niobium elements produces iron concentrate (65.40% TFe at recovery of 38.03%), rare earth concentrate (50.66% REE at recovery of 62.73%), fluorite concentrate (95.23% CaF2 at recovery of 40.34%) and niobium iron ore concentrate (1.63% Nb2O5 at recovery of 5.56%). This study provides recommendations for the rational development and utilization of rare earth wall rock and provides reasonable levels of recovery predictions.
3
Content available Magnetosorption Purification of Water from Petroleum Products
Vozniuk Marta, Shabliy Tetyana, Gomelya Mykola, Sirenko Ludmila, Sidorov Dmytro
Journal of Ecological Engineering
|
2023
|
Vol. 24, nr 11
155--162
EN
In this work, the processes of purification of oily waters using magnetites were investigated: magnetite synthesized according to the classical method and magnetites modified with hydrophobizing agents (sulfonol or alkylimidazolin). It was shown that magnetite modified with alkylimidazolin in doses of 50–200 mg/dm3 provides a high degree of oil removal from waters of various mineralization. The degree of water purification reaches 97.5–99.8%. Sulfonol-modified magnetite shows greater efficiency than conventional magnetite only at high concentrations (200 mg/dm3) and only in fresh water. Three hours is enough to ensure the maximum degree of purification of water-oil solutions. Changing the amount of hydrophobizing agent (alkylimidazolin) during the synthesis of magnetite reduces the effect of pH on the purification of both fresh and mineralized waters.
4
Content available Enhanced effect of fine magnetite on the flotation performance of fine hematite in sodium oleate system
Pei Bin, Luo Ximei, Yang Wen, Wei Dayong, Li Chao, Wang Yunfan
Physicochemical Problems of Mineral Processing
|
2022
|
Vol. 58, iss. 4
art. no. 149673
EN
In this work, the effect of magnetite with different particle sizes on the flotation performance of both coarse and fine hematite particles were investigated by using sodium oleate as a collector. The results showed that the magnetite particles with different particle sizes showed a negative effect on hematite (-106+45 μm) recovery, but the addition of magnetite with the same particle sizes as hematite during the direct flotation of -45 μm hematite was beneficial to improve the recovery of micro-fine hematite and the Fe grade of concentrate. The finer the magnetite particle was, the more obvious the agglomeration effect of hematite was. Therefore, the beneficial effect could be achieved by adjusting the particle sizes of particles. Moreover, sodium oleate was beneficial to promote the agglomeration of micro-fine magnetite and hematite. The results from the microscopic analysis, laser particle size analysis, and EDLVO calculation proved that there was an effective aggregation between fine magnetite and fine hematite particles, which increased the apparent size of hematite particles and the probability of the mineral particles adhering to bubbles, thus improving the hematite recovery.
5
Content available The effect of various surfactants on fatty acid for apatite flotation and their adsorption mechanizm
Liu Shuyong, Han Baisui, Zhao Tonglin
Physicochemical Problems of Mineral Processing
|
2021
|
Vol. 57, iss. 5
46--56
EN
The synergistic effect of surfactants, i.e., Tween-80 (polyethylene glycol sorbitan monooleate), Span-80 (sorbitanoleate), and MES (fatty acid methyl ester sulfonates), on fatty acid collectors were investigated using single mineral flotation experiments, surface tension measurement, Fourier transform infrared spectrum, and contact angle measurements. The single mineral flotation experiments showed that it was possible to efficiently separate apatite from magnetite, quartz, and biotite by mixing fatty acids with surfactants. The surface tension measurement showed that the surfactants could significantly reduce the surface tension and Critical Micelle Concentration (CMC) of fatty acids. Fourier transform infrared spectroscopy analysis indicated that all of the surfactants did not react with the fatty acids, but only physically adsorbed on the surface of apatite, thus promoting the chemical adsorption of fatty acids on apatite. However, the surfactant chemisorbed on magnetite and competing with a fatty acid, which led to a decrease in the flotation recovery. The results for contact angle measurement showed that the contact angle difference between apatite and magnetite increased with the addition of surfactant, and resulted in an efficient separation.
6
Content available Usage of Sorbent-Catalyst to Accelerate the Oxidation of Manganese
Gomelya Mykola, Tverdokhlib Mariia, Shabliy Tetyana, Linyucheva Olga
Journal of Ecological Engineering
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2021
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Vol. 22, nr 4
232--239
EN
The processes of manganese (II) ions removal from water using sorbent catalysts and ion exchange materials modified with iron oxides were studied. It was shown that manganese ions oxidize very slowly in artesian water, even when the pH is adjusted to 9.0. Intensive aeration of solutions due to stirring also does not promote the oxidation of manganese (II) ions. The degree of manganese extraction due to oxidation is reduced from 20–30% for solutions with a concentration of manganese ions of 1 and 5 mg/dm3 to 11–15% for solutions with a concentration of 15 and 30 mg/dm3. A significant increase in the oxidation efficiency of manganese ions was achieved by using magnetite as a sorbent catalyst. The efficiency of water demanganization increases along with the intensity of water aeration when mixing solutions. It was established that strongly acid cation exchangers provide efficient extraction of manganese ions from water. At the same time, a high exchange capacity of strong acid cation exchange resin KU-2–8 in acid and salt form was noted. It was shown that the capacity of manganese ions of this cation exchange resin in the Ca2+-form is slightly lower. When using the KU-2–8 in Ca2+-form of cation exchange resin to remove manganese ions from the solution already in the first samples, the leakage of manganese ions at the level of 10 mg/dm3 and above was observed. This indicates that this form of ion exchanger is not suitable for deep purification of water from manganese (II) ions. In order to increase the efficiency of manganese ion extraction from water, increase the duration of the filter cycle, magnetite and magnetite-modified KU-2–8 cation exchange resin were used as a sorbent-catalyst. It was shown that the cation exchange resin modified with magnetite provides the removal of a significant part of manganese ions due to catalytic oxidation on magnetite. The conditions of effective manganese extraction under static and dynamic conditions are determined.
7
Content available Sorbent-Catalyst for Acceleration of The Iron Oxidation Process
Gomelya Mykola, Tverdokhlib Mariia, Shabliy Tetyana, Radovenchyk Vyacheslav, Linyucheva Olga
Journal of Ecological Engineering
|
2021
|
Vol. 22, nr 3
221--230
EN
In this work, the process of water deironing by using magnetite as a catalyst to accelerate the oxidation of iron ions in an aqueous medium was investigated. It was shown that the efficiency of iron ion extraction depends on the solution concentration, sorbent dose and contact time. In all cases, the use of magnetite accelerated the process of extraction of iron by more than an order of magnitude in comparison with similar experiments on the oxidation of iron without the addition of a catalyst. At the pH values greater than 6, the use of magnetite as a catalyst contributes to the deep purification of water from iron ions.
8
Content available remote Równoczesne tłumienie promieniowania gamma i neutronów w jednowarstwowej osłonie betonowej
Safamehr Majid, Izadinia Mohsen, Hashemi Seyed Hamid, Hoseini Seyed Jalil
Cement Wapno Beton
|
2021
|
R. 26, nr 6
503--514
PL
Dzięki możliwości zastosowania różnych połączeń, beton jest jednym z najbardziej odpowiednich materiałów do konstruowania osłon przed promieniowaniem. W niniejszych badaniach kruszywo hematytowe i magnetytowe zastąpiło kruszywo zwykłe, oddzielnie i całkowicie w dwóch etapach. Dodatkowo zastępowano 2,5, 5 i 10% masowych cementu węglikiem boru. Przeprowadzono badanie gęstości, tłumienia promieniowania gamma z użyciem źródła Co 60 i promieniowania neutronowego z użyciem Am-Be 241. Zgodnie z wynikami, zastąpienie kruszywa zwykłego kruszywem hematytowym, poprawiło liniowy współczynnik tłumienia i makroskopowy przekrój czynny absorpcji neutronów betonu odpowiednio o 17% i 73%. Właściwości te poprawiły się odpowiednio o 37% i 105%, przy zastosowaniu kruszywa magnetytowego. Ponadto, przy dodaniu do składu betonu maksymalnie 10% węglika boru, makroskopowy przekrój czyny wzrósł o 120%, jednak liniowy współczynnik tłumienia zmniejszył się tylko o 5-8%. Oznacza to, że możliwe jest uzyskanie odpowiedniego tłumienia promieniowania gamma i wiązek neutronów jednocześnie, w jednej warstwie betonowej osłony. Ponadto stwierdzono dobrą zgodność wyników badań i symulacji Monte Carlo.
EN
The ability to create various compounds has made concrete one of the most suitable materials for constructing radiation shields. In this investigation, hematite and magnetite aggregates were used to replace ordinary aggregate, separately and completely in two stages. Boron carbide was also substituting cement at percentages of 2.5, 5, and 10 by mass. The density test, gamma irradiation with Co 60 and neutron irradiation with Am-Be 241 were performed. According to the results, the replacement of ordinary aggregates with hematite aggregates in concrete, improved the linear attenuation coefficient and macroscopic cross section by 17% and 73%, respectively. These parameters increased by 37% and 105%, respectively, by the use of magnetite aggregates. Moreover, with the addition of a maximum of 10% boron carbide to the concrete, the macroscopic cross-section increased by 120%, however, the linear attenuation coefficient decreased by between 5% and 8%. This means that it is possible to have a suitable attenuation of gamma ray and neutron beams in a single layer of concrete shield simultaneously. In addition, the results of the tests and Monte Carlo simulation were found to have good consistency.
9
Content available remote Rola nanokrzemionki w betonie zawierającym kruszywo hematytowe i magnetytowe oraz węglik boru jako osłony przed promieniowaniem gamma
Safamehr Majid, Izadinia Mohsen, Hashemi Seyed Hamid, Koohestani Saeideh
Cement Wapno Beton
|
2021
|
R. 26, nr 3
218--232
PL
W artykule opisano wyniki badań dwóch betonów ciężkich, pierwszy zawierający kruszywo hematytowe i drugi magnetytowe. Węglik boru wprowadzono jako zamiennik cementu w ilościach 2,5; 5 i 10% masowych. Następnie w tych mieszankach ilość cementu zmniejszono o 5% i zastąpiono nanokrzemionką. Zbadano także właściwości betonu: wytrzymałość na ściskanie, szybkość przejścia fali ultradźwiękowej i gęstość, a także napromieniowano próbki kobaltem 60, w celu określenia współczynnika tłumienia liniowego. Zastosowanie kruszyw zawierających tlenek żelaza, a zwłaszcza magnetyt, było korzystne dla wszystkich wymienionych właściwości, natomiast odwrotnie było w przypadku dodania do mieszanki węglika boru. Dodatek nanokrzemionki skompensował spadek wytrzymałości betonu na ściskanie spowodowany dodatkiem węglika boru, ale zmniejszył współczynnik tłumienia liniowego o około 4%. Jednak właściwości mieszanek zawierających węglik boru i nanokrzemionkę były zawsze lepsze niż w przypadku betonów zwykłych. W celu określenia współczynnika tłumienia liniowego przeprowadzono symulacje Monte Carlo, których wyniki okazały się zgodne z wynikami uzyskanymi w trakcie badań doświadczalnych.
EN
Two families of heavy concrete were investigated in this project, the first containing hematite and the second magnetite aggregates. Boron carbide also replaced cement in mass of 2.5, 5 and 10%. Once again, in these compounds the content of cement was reduced by 5% and replaced by nanosilica. Such parameters as compressive strength, ultrasonic pulse velocity and density were investigated, and the specimens were irradiated with cobalt 60, to quantify the linear attenuation coefficient. Using iron ore aggregate, especially magnetite, was advantageous for all the above-mentioned parameters, while the opposite was true, when boron carbide was added to the mix. The addition of nanosilica compensated the decrease in compressive strength of concrete due to the presence of boron carbide, but reduced the linear attenuation coefficient by about 4%. However, the properties of the mixes containing boron carbide and nanosilica, were always better than those of conventional concretes. To quantify the linear attenuation coefficient, Monte Carlo simulations were performed, and their results turned out to be in good agreement with those obtained by the experimental measurements.
10
Content available Electromagnetic system for improving the adhesion of wheels to rails
Osenin Yurij, Antoshkina Lidiya, Sosnov Igor, Shapran Evgeniy, Chesnokov Aleksei
Transport Problems
|
2019
|
T. 14, z. 1
59--67
EN
The article describes the design of a system used for the improvement of the adhesion of locomotive wheels to rails; the principle of which is based on the electromagnetic feeding of the contact area with the bulk material that has magnetic properties and high hardness (iron scale Fe3O4 and magnetite FeO×Fe2O3). The experimental results of laboratory and bench tests confirming the effectiveness of the proposed system compared with the existing devices using quartz sand to improve the adhesion of wheels to rails are presented. It is concluded that the use of an electromagnetic system for improving the particle supply to the wheel/rail interface is promising.
11
Content available The mechanism study on aryl-substituted aromatic acid ionic liquid as the collector for quartz flotation
Li Haonan, Mei Guangjun, Yu Mingming, Cheng Qian, Zhu Guobin
Physicochemical Problems of Mineral Processing
|
2019
|
Vol. 55, iss. 5
1239--1249
EN
An aryl-substituted aromatic acid ionic liquid (M-X) was synthesized through hexadecyl trimethyl ammonium bromide and sodium salicylate, and it was employed as a flotation collector for the separation of quartz from magnetite. Laboratory flotation studies of magnetite and quartz were conducted using the M-X and dodecylamine (DDA) as collector. The results showed that the M-X has a stronger collecting ability and selectivity for quartz without starch. The adsorption mechanism of M-X on quartz and magnetite surfaces was studied by Fourier transform infrared spectroscopy (FTIR), zeta potential and X-ray photoelectron spectroscopy (XPS) analysis. Results indicated that the adsorption of M-X on the quartz surface was more efficient than that on the magnetite surface. And the salicylate anion in M-X was found to have depression effect to magnetite.
12
Content available The phase separation phenomenon in the Na2O–B2O3–SiO2–Fe2O3 glass-forming system and its application for producing porous glasses
Konon Marina, Antropova Tatyana, Polyakova Irina, Anfimova Irina, Dikaya Lidiya, Semenova Ekaterina, Kurilenko Ludmila
Optica Applicata
|
2019
|
Vol. 49, nr 3
437--444
EN
Glasses in the Na2O–B2O3–SiO2–Fe2O3 system with a constant SiO2 content 70 mol% were synthesized using conventional melting in platinum crucibles in SiC-furnace in air. After synthesis and annealing, glasses were heat treated at 550°C for 96–144 hrs to promote phase separation. A tentative region of phase separation for this temperature was outlined. X-ray powder diffractometry results showed three iron-containing phases (Fe3O4, FeSiO3 and β-Fe2O3) forming in the investigated glasses with magnetite being the main phase as it is observed in most of the glasses. Chemical durability studies showed that compositions of phase-separated glasses suitable for synthesis of porous glasses, both iron-free and iron-containing lie in between 4 and 8 mol% of Na2O. Bulk samples of porous glasses were obtained within the chosen region having the following parameters: specific surface area 40–185 m2/g, porosity 30%–45%, pore diameter 3–14 nm. The parameters of porous structure of iron-containing porous glasses are of the same order of magnitude as the porous glass used for the multiferroic nanocomposite synthesis.
13
Content available Analysis of crystallite size changes in a hematite and magnetite formed on steel used in the power idustry
Gwoździk M.
Technical Sciences / University of Warmia and Mazury in Olsztyn
|
2018
|
nr 21(1)
65--73
EN
The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.
14
Content available Selective agglomeration of magnetite in entlandite-serpentine system and implication for their separation
Lu J., Yuan Z., Liu J., Li L., Wang N., Meng Q.
Physicochemical Problems of Mineral Processing
|
2017
|
Vol. 53, iss. 2
943--955
EN
In nickel sulfide processing, magnesium silicates (serpentines) can easily form slime coatings or hetero-aggregation on pentlandite surfaces, and hence decrease the pentlandite flotation rate and recovery. In this work, magnetic separation of pentlandite from serpentine using selective magnetic coating through adding magnetite fines as magnetic seeds was investigated. Interactions of magnetite-pentlandite and magnetite-serpentine were calculated by the DLVO (Derjaguin-Landau-Verwey-Overbeek) theory. The results show that the interaction of magnetite-pentlandite was obviously stronger than that of magnetite-serpentine with an external weak magnetic field (4776 A/m-1). Therefore, fine magnetite fractions selectively adhered to the pentlandite surfaces and enhanced its magnetism, resulting in being separated from serpentine by magnetic separation, which was further verified by magnetic coating-magnetic separation and SEM observations.
15
Content available Photon attenuation properties of concretes containing magnetite and limonite ores
Gur A., Artig B., Cakir T.
Physicochemical Problems of Mineral Processing
|
2017
|
Vol. 53, iss. 1
184--191
EN
In this study, gamma shielding properties of concretes containing magnetite and limonite ores at different ratios (5%, 10%, 15%, 20%, and 30%) were investigated by using a 60Co (1.25 MeV) radioactive source which was built in Thratron 1000E™ device used for radiotherapy purposes. Then, the photon transmission values (I/I0) were measured by 0.6 cm3, farmer type, PTW™ ion chamber. The dose readings (I0 and I), made by PTW™ Unidose Electrometer, were used to calculate the linear attenuation coefficient (, cm-1), the mean free path (, cm), and the mass attenuation coefficient (, cm2/g) by the Lambert equations, and the results were compared with the calculations obtained using the WinXCom computer program. The findings from this study revealed that the concretes containing magnetite and limonite ores were more effective than the ordinary concrete in the attenuation of gamma rays. It was determined that the values of the mean free path decreased with the increasing concentrations of magnetite and limonite ores while the linear attenuation coefficients for 10 concrete blocks increased with the increasing magnetite and limonite ore concentrations. A comparison of the theoretical values obtained from the WinXCom computer program and the experimental results revealed a good level of conformity.
16
Wstępne wyniki zastosowania magnetytu w oczyszczaniu ścieków z przemysłu kosmetycznego
Maksymiec J., Marcinowski P., Bogacki P., Zapałowska E., Dzienio K.
Gaz, Woda i Technika Sanitarna
|
2017
|
Nr 8
336--339
PL
Ścieki technologiczne pobrane z zakładu produkującego kosmetyki poddano oczyszczaniu z wykorzystaniem procesu Fe3O4/H2O2. Stosowano różne proporcje i dawki reagentów. Najlepsze wyniki oczyszczania uzyskano dla dawki magnetytu 4000 mg/l oraz dla dawki nadtlenku wodoru 1200 mg/l. Po 120 min prowadzenia procesu uzyskano zmniejszenie wartości ChZT od wartości początkowej, 1200 mg/l do 409 mg/l, co stanowi obniżenie o prawie 70%. Największe spadki wartości ChZT obserwowano w ciągu pierwszych 5min prowadzenia procesu. Wydłużanie czasu trwania prowadzi do dalszego ubytku wartości ChZT, przy czym intensywność zachodzenia procesu jest już wyraźnie mniejsza. Ze względu na minimalną rozpuszczalność katalizatora, zmniejszenie zawartości zanieczyszczeń należy wiązać z zachodzeniem procesu heterogenicznej katalizy a nie z homogeniczną reakcją Fentona czy koagulacją.
EN
The wastewater used in the experiments was collected from cosmetic factory. Fe3O4/H2O2. process was applied for wastewater treatment. Different Fe3O4/H2O2. reagents doses and H2O2/COD weight ratios were chosen. The highest COD removal was obtained for magnetite 4000mg/l and hydrogen peroxide 1200 mg/l doses, in a H2O2/COD weight ratio 1:1. After 120min of the process, the minimum COD value 409 mg/l (70% removal, from 1200 mg/l) was achieved. The rapid COD removal for shorter process time (5 min) was observed. Further COD removal for longer time was still observed, but then the rate of decline decreased. Due to minimal catalyst solubility, the decrease in contaminations amount in the wastewater should be connected with heterogeneous catalysis process rather than homogeneous Fenton process or coagulation.
17
Content available Bakterie magnetotaktyczne i ich minerały
Sawłowicz Z.
Przegląd Geologiczny
|
2016
|
Vol. 64, nr 5
328--337
EN
Magnetotactic bacteria (MTB) produce magnetic minerals, magnetite (Fe3O4) and greigite (Fe3S4) in their cells. These magnetosome crystals form chains which allow bacterial cells to align with the Earth magnetic field. Magneto-aerotaxis allows bacteria to find optimal growth conditions in the water column. MTB species and their habitats are described, along with the description of minerals and the origin of magnetosomes. Fossil MTB are used to solve different geological problems they especially influence rock magnetism. Cultured magnetotactic bacteria and their nanominerals find more and more applications in many disciplines.
18
Content available Wpływ cieczy jonowych na wybrane właściwości kompozytów magnetycznych napełnionych cząstkami tlenku żelaza (Fe3O4) o wymiarach mikrometrycznych
Masłowski M., Strąkowska A., Pingot M., Zaborski M.
Polimery
|
2016
|
T. 61, nr 2
117--124
PL
Na bazie kauczuków: etylenowo-propylenowego (EPM), butadienowo-akrylonitrylowego (NBR) i silikonowego (MVQ) otrzymano mieszanki kauczukowe zawierające 60 phr mikrometrycznego tlenku żelaza Fe3O4. Zbadano wpływ dodatku cieczy jonowej z grupy soli alkiloamoniowych do takich mieszanek kauczukowych na właściwości reometryczne, gęstość usieciowania oraz wytrzymałość mechaniczną wulkanizatów. Stwierdzono, że dodatek cieczy jonowej powoduje wzrost stopnia zdyspergowania cząstek magnetytu w elastomerowym ośrodku, co prowadzi do zwiększenia momentów obrotowych w czasie sieciowania i skrócenia czasu jego trwania. Wytworzone kompozyty wykazywały większą gęstość usieciowania niż kompozyty napełnione mikrometrycznym Fe3O4, ale niezawierające cieczy jonowej. Zaobserwowano także polepszenie właściwości mechanicznych wulkanizatów z dodatkiem cieczy jonowych, przejawiające się zwiększeniem wartości naprężenia przy wydłużeniu 100 % oraz wytrzymałości na rozciąganie. Świadczy to o zwiększonej w wyniku dodatku cieczy jonowej aktywności cząstek napełniacza, który w warunkach większego zdyspergowania tworzył własną sieć przestrzenną, przenikającą się z siecią elastomeru i wpływającą tym samym na wytrzymałość materiału.
EN
Rubber blends based on ethylene-propylene (EPM), acrylonitrile-butadiene (NBR) and silicone (MVQ) rubbers containing 60 phr micro-sized iron oxide Fe3O4 were prepared. The effect of the addition of an ionic liquid selected from the group of alkylammonium salts on the rheometric properties, crosslinking density and mechanical strength of vulcanizates was studied. It was found that the ionic liquid additive increased the dispersion degree of magnetite particles in the elastomer, which leads to an increase in torque during the vulcanization and reduces the cure time. The produced vulcanizates showed higher crosslinking density than the composites filled with micro-sized magnetite Fe3O4 alone. Also, an improvement of mechanical properties of the vulcanizates with ionic liquid additives was observed, namely an increase in the stress at 100 % elongation and tensile strength. This indicates that the addition of ionic liquid results in an increased activity of the filler particles, which, due to their better dispersion, form their own, spacial network interpenetrating the elastomer network and influencing the material strength.
19
Content available remote Electromagnetic Radiation Generated by Acoustic Excitation of Rock Samples
Yavorovich L. V., Bespalko A. A., Fedotov P. I., Baksht R. B.
Acta Geophysica
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2016
|
Vol. 64, no. 5
1446--1461
EN
The paper presents an experiment on acoustic excitation of electromagnetic radiation (EMR) signals in skarn, sandstone, and magnetite ore samples. For the skarn and sandstone samples, the EMR signal amplitude was observed to decrease with increasing ultimate strength. Supposedly, this effect can be explained by assuming that EMR is generated when an acoustic wave propagates through an electrical double layer. The presence of piezoelectric inclusions (e.g., quartz) in the magnetite ore enhances the analog EMR signal and its spectral components.
20
Content available remote Wielofunkcyjne nanokompozyty magnetytu : wytwarzanie, właściwości i zastosowania
Dzido G., Markowski P., Jarzębski A. B.
Przemysł Chemiczny
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2015
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T. 94, nr 2
147-153
PL
Dokonano przeglądu literatury dotyczącej metod wytwarzania, właściwości i zastosowania wielofunkcyjnych połączeń nanokompozytowych, których jednym ze składników jest Fe₃O₄.
EN
A review, with 68 refs., of methods for manufg., properties, as well as medical and industrial applications of multifunctional Fe₃O₄-contg. nanocomposite materials.
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