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In this study, we synthesized MnFe2O4 solid nanospheres (MSN) calcined at different temperatures (200–500 °C) and MSN-based materials mixed with carbon black, for their use as electrocatalysts in the oxygen reduction reaction (ORR) in alkaline medium (0.1 M KOH). It was demonstrated that the calcination temperature of MSN material determined its chemical surface composition and microstructure and it had an important effect on the electrocatalytic properties for ORR, which in turn was reflected in the performance of MSN/CB-based electrocatalysts. The study revealed that the presence of Mn species plays a key role in the ORR activity. Among tested, MSN200/CB and MSN350/CB exhibited the best electrochemical performances together with outstanding stability.

In this study, we synthesized MnFe2O4 solid nanospheres (MSN) calcined at different temperatures (200–500 °C) and MSN-based materials mixed with carbon black, for their use as electrocatalysts in the oxygen reduction reaction (ORR) in alkaline medium (0.1 M KOH). It was demonstrated that the calcination temperature of MSN material determined its chemical surface composition and microstructure and it had an important effect on the electrocatalytic properties for ORR, which in turn was reflected in the performance of MSN/CB-based electrocatalysts. The study revealed that the presence of Mn species plays a key role in the ORR activity. Among tested, MSN200/CB and MSN350/CB exhibited the best electrochemical performances together with outstanding stability.

Adsorbents based on magnetic materials are the subject of numerous researches. Beside good magnetism and functional surface, manganese ferrite is unstable and prone to form low mechanical strength agglomerates, which necessitate its deposition on the substrate surface. Expanded vermiculite outer surfac, is a useful medium for the deposition of nanoparticles whereas intercation layer is suitable for holding cation species (distance of 2:1 layers may be greater than 10 Å). Due to its relatively high surface area, cation exchange capacity and natural abundance of vermiculite, this mica mineral and its composites could be valorized as potentially low-cost adsorbents. In this study, manganese ferrite/expanded vermiculite (MnFe2O4/EV) composite was prepared by in-situ method. Deposited manganese ferrite particles on the surface of EV were formed in the solvothermal reaction using suitable reagents. Both composite and base material are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface area (SSA), cation exchange capacity (CEC) and pH point of zero charge (pHPZC) determination. The adsorption properties of MnFe2O4/EV and EV have been investigated in a batch system at pH close to the pHPZC for the removal of Ni (II) from water. Considering process parameters such as contact time, adsorbent dosage and temperature: adsorption type, isotherm parameters (Langmuir and Freundlich) and rate of adsorption parameters were determined. Results of the kinetic studies gave fine correlations with pseudo – second order and Weber – Morris model. Taking into consideration fact that EV had low CEC values and SSA, obtained composite have high adsorption capacity (more than 30 mg Ni g-1). Also, X-ray diffractograms showed alteration of biotite vermiculite (formed during solvothermal action) into phlogopite (formed after adsorption process and aging). The methodology, Adsorbenti na bazi magnetičnih materijala su predmet brojnih istraživanja. Osim dobre magnetičnosti i funkcioncionalnoj površini, mangan ferit je nestabilan i teši formiranju aglomerata niske mehaničke čvrstine, čime se iziskuje njegova depozicija na površini supstrata. Spoljna površina ekspandovanog vermikulita je korisni medijum za depoziciju nanočestica dok interkalacioni sloj je podesan za zadržavanje katjonskih vrsta (rastojanje između slojeva može biti iznad 10 Å). Zahvaljujući relativno visokoj površini, kapacitetu katjonske izmene i prirodnoj zastupljenosti vermikulita, ovaj mineral liskuna i njegovi kompoziti mogu biti valorizovani kao potencijalni povoljni adsorbenti. U ovoj studiji, kompozit mangan ferita/eksapndovanom vermikulitu (MnFe2O4/EV) pripremljen je in-situ metodom. Deponovane čestice mangan ferita na površini EV formirane su u solvotermalnoj reakciji korišćenjem podesnih reagenasa. Kompozit kao i bazni materijal karakterizovani su: infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR), difrakcijom X-zraka na prahu (XRPD), skenirajućom elektronskom mikroskopijom (SEM), specifičnom površinom (SSA) određenom metodologijom po BET-u, kapacitetom katjonske izmene (CEC) i pH tačke nultog naelektrisanja (pHPZC). Adsorpciona svojstva MnFe2O4/EV i EV istražena su u šaržnom sistemu na pH vrednosti bliskoj pH tački nultog naelektrisanja za uklanjane Ni (II) iz vode. Uzimajući u obzir procesne parametre kao što su vreme kontakta, masa adsorbenta i temperatura određeni su: tip adsorpcije, izotermski parametri (Lengmir i Frojndlih) kao i parametri brzine adsorpcije. Rezultati kinetičkih studija dobro se korelišu pseudo – drugom redu reakcije i Veber – Morisovim modelom. Uzevši u obzir činjenicu da je uzorak EV imao malu vrednost CEC i nisku specifičnu površinu, dobijeni kompozit ima visok adsorpcioni kapacitet (preko 30 mg Ni g-1). Osim toga, difraktogrami X-zraka pokazali su alteraciju biotitskog vermikulita (formiranog solvotermalnom akcijom) u f

Adsorbents based on magnetic materials are the subject of numerous researches. Beside good magnetism and functional surface, manganese ferrite is unstable and prone to form low mechanical strength agglomerates, which necessitate its deposition on the substrate surface. Expanded vermiculite outer surfac, is a useful medium for the deposition of nanoparticles whereas intercation layer is suitable for holding cation species (distance of 2:1 layers may be greater than 10 Å). Due to its relatively high surface area, cation exchange capacity and natural abundance of vermiculite, this mica mineral and its composites could be valorized as potentially low-cost adsorbents. In this study, manganese ferrite/expanded vermiculite (MnFe2O4/EV) composite was prepared by in-situ method. Deposited manganese ferrite particles on the surface of EV were formed in the solvothermal reaction using suitable reagents. Both composite and base material are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface area (SSA), cation exchange capacity (CEC) and pH point of zero charge (pHPZC) determination. The adsorption properties of MnFe2O4/EV and EV have been investigated in a batch system at pH close to the pHPZC for the removal of Ni (II) from water. Considering process parameters such as contact time, adsorbent dosage and temperature: adsorption type, isotherm parameters (Langmuir and Freundlich) and rate of adsorption parameters were determined. Results of the kinetic studies gave fine correlations with pseudo – second order and Weber – Morris model. Taking into consideration fact that EV had low CEC values and SSA, obtained composite have high adsorption capacity (more than 30 mg Ni g-1). Also, X-ray diffractograms showed alteration of biotite vermiculite (formed during solvothermal action) into phlogopite (formed after adsorption process and aging). The methodology

Adsorbents based on magnetic materials are the subject of numerous researches. Beside good magnetism and functional surface, manganese ferrite is unstable and prone to form low mechanical strength agglomerates, which necessitate its deposition on the substrate surface. Expanded vermiculite outer surfac, is a useful medium for the deposition of nanoparticles whereas intercation layer is suitable for holding cation species (distance of 2:1 layers may be greater than 10 Å). Due to its relatively high surface area, cation exchange capacity and natural abundance of vermiculite, this mica mineral and its composites could be valorized as potentially low-cost adsorbents. In this study, manganese ferrite/expanded vermiculite (MnFe2O4/EV) composite was prepared by in-situ method. Deposited manganese ferrite particles on the surface of EV were formed in the solvothermal reaction using suitable reagents. Both composite and base material are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface area (SSA), cation exchange capacity (CEC) and pH point of zero charge (pHPZC) determination. The adsorption properties of MnFe2O4/EV and EV have been investigated in a batch system at pH close to the pHPZC for the removal of Ni (II) from water. Considering process parameters such as contact time, adsorbent dosage and temperature: adsorption type, isotherm parameters (Langmuir and Freundlich) and rate of adsorption parameters were determined. Results of the kinetic studies gave fine correlations with pseudo – second order and Weber – Morris model. Taking into consideration fact that EV had low CEC values and SSA, obtained composite have high adsorption capacity (more than 30 mg Ni g-1). Also, X-ray diffractograms showed alteration of biotite vermiculite (formed during solvothermal action) into phlogopite (formed after adsorption process and aging). The methodology, Adsorbenti na bazi magnetičnih materijala su predmet brojnih istraživanja. Osim dobre magnetičnosti i funkcioncionalnoj površini, mangan ferit je nestabilan i teši formiranju aglomerata niske mehaničke čvrstine, čime se iziskuje njegova depozicija na površini supstrata. Spoljna površina ekspandovanog vermikulita je korisni medijum za depoziciju nanočestica dok interkalacioni sloj je podesan za zadržavanje katjonskih vrsta (rastojanje između slojeva može biti iznad 10 Å). Zahvaljujući relativno visokoj površini, kapacitetu katjonske izmene i prirodnoj zastupljenosti vermikulita, ovaj mineral liskuna i njegovi kompoziti mogu biti valorizovani kao potencijalni povoljni adsorbenti. U ovoj studiji, kompozit mangan ferita/eksapndovanom vermikulitu (MnFe2O4/EV) pripremljen je in-situ metodom. Deponovane čestice mangan ferita na površini EV formirane su u solvotermalnoj reakciji korišćenjem podesnih reagenasa. Kompozit kao i bazni materijal karakterizovani su: infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR), difrakcijom X-zraka na prahu (XRPD), skenirajućom elektronskom mikroskopijom (SEM), specifičnom površinom (SSA) određenom metodologijom po BET-u, kapacitetom katjonske izmene (CEC) i pH tačke nultog naelektrisanja (pHPZC). Adsorpciona svojstva MnFe2O4/EV i EV istražena su u šaržnom sistemu na pH vrednosti bliskoj pH tački nultog naelektrisanja za uklanjane Ni (II) iz vode. Uzimajući u obzir procesne parametre kao što su vreme kontakta, masa adsorbenta i temperatura određeni su: tip adsorpcije, izotermski parametri (Lengmir i Frojndlih) kao i parametri brzine adsorpcije. Rezultati kinetičkih studija dobro se korelišu pseudo – drugom redu reakcije i Veber – Morisovim modelom. Uzevši u obzir činjenicu da je uzorak EV imao malu vrednost CEC i nisku specifičnu površinu, dobijeni kompozit ima visok adsorpcioni kapacitet (preko 30 mg Ni g-1). Osim toga, difraktogrami X-zraka pokazali su alteraciju biotitskog vermikulita (formiranog solvotermalnom akcijom) u f

Starting hematite (Fe2O3), zinc oxide (ZnO) and manganese carbonate (MnCO3) powders were homogenized in a planetary ball mill in stainless steel bowls with stainless steel balls for 15 min, calcined in air at 1000 C for 2 h, milled in a planetary ball mill for 30 minutes, followed by 4 h in an aghate mill, sieved through a 325 mesh to form four starting powders: MnFe2O4, ZnFe2O4, Mn0.5Zn0.5Fe2O4 and a two-phase mixture of zinc and manganese ferrite. Structural properties of the obtained powders were analyzed using XRD, SEM and EDS. Electrical properties of disk shaped samples were measured at room temperature on an impedance analyzer in the frequency range 100 to 40 MHz, enabling determination and comparison of dielectric permittivity and complex impedance. Complex relative permeability of toroid shaped samples was measured on an impedance analyzer in the frequency range from 1 MHz to 500 MHz.

Starting hematite (Fe2O3), zinc oxide (ZnO) and manganese carbonate (MnCO3) powders were homogenized in a planetary ball mill in stainless steel bowls with stainless steel balls for 15 min, calcined in air at 1000 C for 2 h, milled in a planetary ball mill for 30 minutes, followed by 4 h in an aghate mill, sieved through a 325 mesh to form four starting powders: MnFe2O4, ZnFe2O4, Mn0.5Zn0.5Fe2O4 and a two-phase mixture of zinc and manganese ferrite. Structural properties of the obtained powders were analyzed using XRD, SEM and EDS. Electrical properties of disk shaped samples were measured at room temperature on an impedance analyzer in the frequency range 100 to 40 MHz, enabling determination and comparison of dielectric permittivity and complex impedance. Complex relative permeability of toroid shaped samples was measured on an impedance analyzer in the frequency range from 1 MHz to 500 MHz.

Starting hematite (Fe2O3), zinc oxide (ZnO) and manganese carbonate (MnCO3) powders were homogenized in a planetary ball mill in stainless steel bowls with stainless steel balls for 15 min, calcined in air at 1000 C for 2 h, milled in a planetary ball mill for 30 minutes, followed by 4 h in an aghate mill, sieved through a 325 mesh to form four starting powders: MnFe2O4, ZnFe2O4, Mn0.5Zn0.5Fe2O4 and a two-phase mixture of zinc and manganese ferrite. Structural properties of the obtained powders were analyzed using XRD, SEM and EDS. Electrical properties of disk shaped samples were measured at room temperature on an impedance analyzer in the frequency range 100 to 40 MHz, enabling determination and comparison of dielectric permittivity and complex impedance. Complex relative permeability of toroid shaped samples was measured on an impedance analyzer in the frequency range from 1 MHz to 500 MHz.

Starting hematite (Fe2O3), zinc oxide (ZnO) and manganese carbonate (MnCO3) powders were homogenized in a planetary ball mill in stainless steel bowls with stainless steel balls for 15 min, calcined in air at 1000 C for 2 h, milled in a planetary ball mill for 30 minutes, followed by 4 h in an aghate mill, sieved through a 325 mesh to form four starting powders: MnFe2O4, ZnFe2O4, Mn0.5Zn0.5Fe2O4 and a two-phase mixture of zinc and manganese ferrite. Structural properties of the obtained powders were analyzed using XRD, SEM and EDS. Electrical properties of disk shaped samples were measured at room temperature on an impedance analyzer in the frequency range 100 to 40 MHz, enabling determination and comparison of dielectric permittivity and complex impedance. Complex relative permeability of toroid shaped samples was measured on an impedance analyzer in the frequency range from 1 MHz to 500 MHz.

Starting hematite (Fe2O3), zinc oxide (ZnO) and manganese carbonate (MnCO3) powders were homogenized in a planetary ball mill in stainless steel bowls with stainless steel balls for 15 min, calcined in air at 1000 C for 2 h, milled in a planetary ball mill for 30 minutes, followed by 4 h in an aghate mill, sieved through a 325 mesh to form four starting powders: MnFe2O4, ZnFe2O4, Mn0.5Zn0.5Fe2O4 and a two-phase mixture of zinc and manganese ferrite. Structural properties of the obtained powders were analyzed using XRD, SEM and EDS. Electrical properties of disk shaped samples were measured at room temperature on an impedance analyzer in the frequency range 100 to 40 MHz, enabling determination and comparison of dielectric permittivity and complex impedance. Complex relative permeability of toroid shaped samples was measured on an impedance analyzer in the frequency range from 1 MHz to 500 MHz.

Recently, potential applications of the magnetic heating for heterogeneous catalysis or organic synthesis have been reported. As these new applications are not limited by biocompatibility requirements, a wide range of possibilities for non-aqueous colloidal nanoparticles with enhanced magnetic properties is open. In this work, manganese and cobalt ferrite nanoparticles are synthesized by co-precipitation method with average particle size around 12 nm. The particles are either coated with tetramethylammonium hydroxide (TMAOH) and dispersed in water or with oleic acid (OA) and dispersed in hexane to produce aggregated or disaggregated nanoparticles, respectively. It is observed that the particle disaggregation improves significantly the heating efficiency from 12 to 96 W/g in the case of cobalt ferrite, and from 120 to 413 W/g for the manganese ferrite. The main responsible for this improvement is the reduction of hydrodynamic volume that allows a faster Brownian relaxation. This work also discusses the relevance of the size distribution.

In this work, nano-sized manganese ferrite (MnFe2O4) was synthesized through the decomposition of the mixed oxalates. The formation of the spinel manganese ferrite was confirmed by X-ray diffraction analysis. The morphology of the ferrite products was studied by scanning electron microscopy. The particle size, which was determined using the Scherrer formula, ranged from 25 to 30 nm. Magnetic properties of the manganese ferrite were analyzed using a vibrating sample magnetometry technique; a narrow hysteresis loop indicated the MnFe2O4 obtained was a soft ferromagnet. Magnetic properties of the manganese ferrite produced were in agreement with those reported in literature for MnFe2O4 nanoparticles prepared by conventional methods, including co-precipitation and mechanochemical processes. By plotting a series of literature data determined by different authors and techniques, a correlation between saturation magnetisation and particle size has been noted regardless of the synthesis methods. In general, the oxalate method seems to be able to produce nano-manganese ferrite in a shorter time (2-3 h) as compared to other conventional techniques reported in literature (up to 54 h)., QC 20160207

The catalytic effects of MnFe2O4 nanoparticles on the dehydrogenation properties of NaAlH4, prepared by ball milling, are investigated. The onset temperatures for NaAlH4 + 7 mol% MnFe2O4 are 95 C, 152 C and 327 C for the three dehydrogenation steps, significantly lower compared with as-received NaAlH4. The isothermal dehydriding kinetics shows that adding MnFe2O4 to NaAlH4 could significantly enhance the desorption kinetics of NaAlH4, 7 mol% MnFe2O4-doped sample also displays the well-maintained kinetics and only a slight capacity loss for the three cycles. From the differential scanning calorimetry and the Kissinger desorption kinetics analysis, the apparent activation energy of the 7 mol% MnFe2O4-doped sample for the three steps is 57.74 kJ mol(-1), 75.06 kJ mol(-1) and 117.22 kJ mol(-1), resulting in 56.05 kJ mol(-1), 67.53 kJ mol(-1) and 59.12 kJ mol(-1) reduction, respectively, compared with the as-received NaAlH4. Based on the Fourier Transform Infrared Spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, Fe0.9536O and amorphous Mn or Mn-containing species together play a synergistic role in remarkably improving NaAlH4 dehydriding properties, Peer Reviewed, Postprint (published version)

In the modern practice, a sustainable development strategy in a domain of wasteutilization is shifting its focus from a general completeness of recycling to a morespecific attention to efficiently utilize elements in the wastes. This is well-illustrated bythe steelmaking slag industries. The major waste product from the steelmaking practiceis slag and its main constituents are: CaO, SiO2, Al2O3, MnO, FeO and so on. The mainfield of application for the steelmaking slags is civil engineering, especially for road andwaterway construction. However, a significant amount of the slag remains in the dumps,damaging the environment as well as requiring a land for secure storage. Efficientrecycling of these materials is of increasing interest worldwide as a result of increasingsustainability in processes with respect to increasing raw material costs and wastereduction.In order to find a practical solution, joint efforts are currently made at the RoyalInstitute of Technology, Sweden and National Metallurgical Academy of Ukraine. Theconcept is based on transformation of non-magnetic wüstite (FeO) to magneticmagnetite (Fe3O4) using an oxidizing atmosphere was proposed.In order to verify the feasibility of the proposed way of slag utilization, experiments onthe ternary CaO-FeO-SiO2 and quaternary CaO-FeO-SiO2-MnO slags systems,accompanied by thermodynamic and kinetic modelling, were performed. The crystalprecipitation during synthetic slag oxidation was observed by Confocal Scanning LaserMicroscopy (CSLM). Precipitated phases were found to be magnetite and manganeseferrite in the spinel form.Obtained magnetite and manganese ferrite can be separated from the slag by magneticseparation.The formation of nanosize manganese ferrite from the CaO-FeO-SiO2-MnO slag systemduring oxidation was investigated. Experiments were conducted in a horizontalresistance furnace in an oxidizing atmosphere (air). The final product was analysed by Xraydiffraction (XRD). The particles size of the manganes, QC 20100916

In the modern practice, a sustainable development strategy in a domain of wasteutilization is shifting its focus from a general completeness of recycling to a morespecific attention to efficiently utilize elements in the wastes. This is well-illustrated bythe steelmaking slag industries. The major waste product from the steelmaking practiceis slag and its main constituents are: CaO, SiO2, Al2O3, MnO, FeO and so on. The mainfield of application for the steelmaking slags is civil engineering, especially for road andwaterway construction. However, a significant amount of the slag remains in the dumps,damaging the environment as well as requiring a land for secure storage. Efficientrecycling of these materials is of increasing interest worldwide as a result of increasingsustainability in processes with respect to increasing raw material costs and wastereduction.In order to find a practical solution, joint efforts are currently made at the RoyalInstitute of Technology, Sweden and National Metallurgical Academy of Ukraine. Theconcept is based on transformation of non-magnetic wüstite (FeO) to magneticmagnetite (Fe3O4) using an oxidizing atmosphere was proposed.In order to verify the feasibility of the proposed way of slag utilization, experiments onthe ternary CaO-FeO-SiO2 and quaternary CaO-FeO-SiO2-MnO slags systems,accompanied by thermodynamic and kinetic modelling, were performed. The crystalprecipitation during synthetic slag oxidation was observed by Confocal Scanning LaserMicroscopy (CSLM). Precipitated phases were found to be magnetite and manganeseferrite in the spinel form.Obtained magnetite and manganese ferrite can be separated from the slag by magneticseparation.The formation of nanosize manganese ferrite from the CaO-FeO-SiO2-MnO slag systemduring oxidation was investigated. Experiments were conducted in a horizontalresistance furnace in an oxidizing atmosphere (air). The final product was analysed by Xraydiffraction (XRD). The particles size of the manganes, QC 20100916

In the modern practice, a sustainable development strategy in a domain of wasteutilization is shifting its focus from a general completeness of recycling to a morespecific attention to efficiently utilize elements in the wastes. This is well-illustrated bythe steelmaking slag industries. The major waste product from the steelmaking practiceis slag and its main constituents are: CaO, SiO2, Al2O3, MnO, FeO and so on. The mainfield of application for the steelmaking slags is civil engineering, especially for road andwaterway construction. However, a significant amount of the slag remains in the dumps,damaging the environment as well as requiring a land for secure storage. Efficientrecycling of these materials is of increasing interest worldwide as a result of increasingsustainability in processes with respect to increasing raw material costs and wastereduction.In order to find a practical solution, joint efforts are currently made at the RoyalInstitute of Technology, Sweden and National Metallurgical Academy of Ukraine. Theconcept is based on transformation of non-magnetic wüstite (FeO) to magneticmagnetite (Fe3O4) using an oxidizing atmosphere was proposed.In order to verify the feasibility of the proposed way of slag utilization, experiments onthe ternary CaO-FeO-SiO2 and quaternary CaO-FeO-SiO2-MnO slags systems,accompanied by thermodynamic and kinetic modelling, were performed. The crystalprecipitation during synthetic slag oxidation was observed by Confocal Scanning LaserMicroscopy (CSLM). Precipitated phases were found to be magnetite and manganeseferrite in the spinel form.Obtained magnetite and manganese ferrite can be separated from the slag by magneticseparation.The formation of nanosize manganese ferrite from the CaO-FeO-SiO2-MnO slag systemduring oxidation was investigated. Experiments were conducted in a horizontalresistance furnace in an oxidizing atmosphere (air). The final product was analysed by Xraydiffraction (XRD). The particles size of the manganes, QC 20100916

In the modern practice, a sustainable development strategy in a domain of wasteutilization is shifting its focus from a general completeness of recycling to a morespecific attention to efficiently utilize elements in the wastes. This is well-illustrated bythe steelmaking slag industries. The major waste product from the steelmaking practiceis slag and its main constituents are: CaO, SiO2, Al2O3, MnO, FeO and so on. The mainfield of application for the steelmaking slags is civil engineering, especially for road andwaterway construction. However, a significant amount of the slag remains in the dumps,damaging the environment as well as requiring a land for secure storage. Efficientrecycling of these materials is of increasing interest worldwide as a result of increasingsustainability in processes with respect to increasing raw material costs and wastereduction.In order to find a practical solution, joint efforts are currently made at the RoyalInstitute of Technology, Sweden and National Metallurgical Academy of Ukraine. Theconcept is based on transformation of non-magnetic wüstite (FeO) to magneticmagnetite (Fe3O4) using an oxidizing atmosphere was proposed.In order to verify the feasibility of the proposed way of slag utilization, experiments onthe ternary CaO-FeO-SiO2 and quaternary CaO-FeO-SiO2-MnO slags systems,accompanied by thermodynamic and kinetic modelling, were performed. The crystalprecipitation during synthetic slag oxidation was observed by Confocal Scanning LaserMicroscopy (CSLM). Precipitated phases were found to be magnetite and manganeseferrite in the spinel form.Obtained magnetite and manganese ferrite can be separated from the slag by magneticseparation.The formation of nanosize manganese ferrite from the CaO-FeO-SiO2-MnO slag systemduring oxidation was investigated. Experiments were conducted in a horizontalresistance furnace in an oxidizing atmosphere (air). The final product was analysed by Xraydiffraction (XRD). The particles size of the manganes, QC 20100916

The influence of long-term milling of a mixture of MnCO3 and alpha-Fe2O3, and of MnO2 and alpha-Fe2O3 powders in a planetary ball mill on the reaction synthesis of nanosized MnFe2O4 ferrites was studied. The mechano-chemical reaction leading to formation of the MnFe2O4 spinel phase was followed by X-ray diffraction. The spinel phase was first observed after 10 h of milling and its formation was completed after 20 h in case of the MnCO3 - alpha-Fe2O3 mixture. The synthesized MnFe2O4 ferrite has a nanocrystalline structure with a crystallite size of about 28 nm. The thermal treatment of the as-milled powder at 400 degrees C for 4 h led to formation of the MnFe2O4 crystalline phase in case of the mixture of MnCO3 and alpha-Fe2O3, but in MnO2 alpha-Fe2O3 case thermal treatment at temperatures of 400 degrees C and higher leads to formation of (Mn,Fe)203 and separation of Mn2O3 and Fe2O3.

The influence of long-term milling of a mixture of MnCO3 and alpha-Fe2O3, and of MnO2 and alpha-Fe2O3 powders in a planetary ball mill on the reaction synthesis of nanosized MnFe2O4 ferrites was studied. The mechano-chemical reaction leading to formation of the MnFe2O4 spinel phase was followed by X-ray diffraction. The spinel phase was first observed after 10 h of milling and its formation was completed after 20 h in case of the MnCO3 - alpha-Fe2O3 mixture. The synthesized MnFe2O4 ferrite has a nanocrystalline structure with a crystallite size of about 28 nm. The thermal treatment of the as-milled powder at 400 degrees C for 4 h led to formation of the MnFe2O4 crystalline phase in case of the mixture of MnCO3 and alpha-Fe2O3, but in MnO2 alpha-Fe2O3 case thermal treatment at temperatures of 400 degrees C and higher leads to formation of (Mn,Fe)203 and separation of Mn2O3 and Fe2O3.

The influence of long-term milling of a mixture of MnCO3 and alpha-Fe2O3, and of MnO2 and alpha-Fe2O3 powders in a planetary ball mill on the reaction synthesis of nanosized MnFe2O4 ferrites was studied. The mechano-chemical reaction leading to formation of the MnFe2O4 spinel phase was followed by X-ray diffraction. The spinel phase was first observed after 10 h of milling and its formation was completed after 20 h in case of the MnCO3 - alpha-Fe2O3 mixture. The synthesized MnFe2O4 ferrite has a nanocrystalline structure with a crystallite size of about 28 nm. The thermal treatment of the as-milled powder at 400 degrees C for 4 h led to formation of the MnFe2O4 crystalline phase in case of the mixture of MnCO3 and alpha-Fe2O3, but in MnO2 alpha-Fe2O3 case thermal treatment at temperatures of 400 degrees C and higher leads to formation of (Mn,Fe)203 and separation of Mn2O3 and Fe2O3.

In the patent magnetic manganese ferrite and manganese-magnesium ferrite films of high compositional purity can be made by a relatively short and simple technique. The technique involves the dissolving of ferric nitrate and either manganese nitrate, or manganese nitrate and magnesium nitrate, in alcohol at room temperature; immersing the surface of a substrate in the solution; preliminarily firing the coated substrate at 400C to 700C and successively cooling to room temperature between coats. After weighing on a balance to determine exact amounts of material deposited, the coated substrate is fired at 800C to 1000C in an inert atmosphere for one to four hours to align the oxides formed to the spinel structure of the ferrite.