scholarly journals Effects of sodium silicate, calcium carbonate, and silicic acid on ammonium nitrate degradation, and analytical investigations of the degradation process on an industrial scale

2015 ◽  
Vol 21 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Ahmet Gezerman ◽  
Burcu Çorbacıoğlu
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Ammonium Nitrate ◽  
Sodium Silicate ◽  
Silicic Acid ◽  
Degradation Process ◽  
Inorganic Chemical ◽  
Subsequent Storage ◽  
Nitrate Degradation ◽  
Scanning Electron

Ammonium nitrate is an inorganic chemical that has numerous applications in different industries. However, various problems are associated with both the production and subsequent storage of ammonium nitrate, including caking, degradation, unwanted phase transition, and recrystallization. Although several methods have been developed to attempt to solve these problems, many of them fail to work in practice. In this study, different compounds including silicic acid and sodium silicate were added to slow the progress of or to prevent the degradation of ammonium nitrate. Multiple instrumental analyses such as ion chromatography and scanning electron microscopy were used to monitor the degradation process.

scholarly journals Effects of Calcium Lignosulfonate and Silicic Acid on Ammonium Nitrate Degradation

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmet Ozan Gezerman ◽  
Burcu Didem Çorbacıoglu
Keyword(s):  
Electron Microscopy ◽  
Environmental Factors ◽  
Ammonium Nitrate ◽  
Silicic Acid ◽  
Ion Chromatography ◽  
Economic Losses ◽  
Screening Analysis ◽  
Nitrate Salts ◽  
Nitrate Degradation

Ammonium nitrate salts are the most commonly used nitrogenous fertilizers in industry. However, storage of ammonium nitrate is problematic, since its initial properties can decline because of environmental factors, leading to large economic losses. In this study, in order to prevent the caking and degradation of ammonium nitrate, an alternative composition with additional calcium lignosulfonate and silicic acid was studied. The resulting fertilizer was analyzed by screening analysis, ion chromatography, and electron microscopy methods.

scholarly journals Effect of Silicate, Carbonate, Calcium Lignosulphonate, and Silicic Acid Additives on Ammonium Nitrate Degradation

2020 ◽  
Vol 69 (3-4) ◽  
pp. 129-136
Author(s):  
Ahmet Ozan Gezerman
Keyword(s):  
Ammonium Nitrate ◽  
Silicic Acid ◽  
Storage Period ◽  
Effective Solution ◽  
Salt Formation ◽  
Phase Conversion ◽  
Nitrate Degradation ◽  
Physical Degradation ◽  
Silicate Carbonate ◽  
Degradation Problem

Ammonium nitrate is the most commonly used nitrogen fertilizer in the agriculture and plays an important role in the development of leaves and stems in plants. The storage and production of ammonium nitrate at the industrial scale can result in degradation and caking. Various solutions have been proposed, however, to date, an effective solution to the degradation problem has not been identified. The addition of silicic acid during the production of ammonium nitrate prevents the double salt formation caused by sulphuric acid additive, which is a process requirement. Silicic acid was combined with calcium carbonate in the dilution stage in order to increase the fracture strength of ammonium nitrate. With the addition of calcium lignosulphonate, the phase conversion of ammonium nitrate granules was completed more rapidly, and thus the problem of degradation was prevented. Thus, chemical and physical degradation of the ammonium nitrate structure were prevented during the 2-year storage period, which was adopted as the standard for the ammonium nitrate production process.

Photocatalytic Degradation of 2-chlorophenol over TiO2 Powder

2014 ◽  
Vol 931-932 ◽  
pp. 291-295
Author(s):  
Pusit Pookmanee ◽  
Songpon Ngamta ◽  
Wiyong Kangwansupamonkon ◽  
Ratchadaporn Puntharod ◽  
Supaporn Sangsrichan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Photocatalytic Degradation ◽  
Ph Value ◽  
Ammonium Hydroxide ◽  
Titanium Isopropoxide ◽  
Chemical Compositions ◽  
Mixed Solution ◽  
Hydrothermal Route ◽  
Scanning Electron

Titanium dioxide (TiO2) powder was prepared by hydrothermal route. Titanium isopropoxide, ammonium hydroxide and nitric acid were used as the starting materials. The final pH value of mixed solution was 1 and treated at 80 and 100 °C for 26h. The phase transition of TiO2powder was studied by Xray diffraction (XRD). Multiphase of anatase and rutile of TiO2powder were obtained at 80 and 100 °C for 26h without calcination steps. The morphology of TiO2powder was investigated by scanning electron microscopy (SEM). The particle was highly agglomerated and irregular in shape with the range of particle size of 0.10.3 μm. The chemical composition of TiO2powder was examined by energy dispersive spectroscopy (EDS). The element chemical compositions show the characteristic Xray energy level as follows: titanium Kα= 4.51 keV and Kβ= 4.93 keV and oxygen Kα= 0.52 keV, respectively. The photocatalytic degradation efficiency of 2chlorophenol (2CP) over TiO2powder was determined by gas chromatography (GC). It was found that TiO2powder prepared by hydrothermal route at 80 °C for 2h was the best efficiency for photocatalytic degradation of 2CP.

Microstructure Analysis of the Weld Metal of Ni-Based Superalloys

2017 ◽  
Vol 371 ◽  
pp. 44-48
Author(s):  
Young Min Kim ◽  
Min Jung Kang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Phase Transition ◽  
Scanning Electron Microscopy ◽  
Weld Metal ◽  
Niobium Carbide ◽  
Metal Analysis ◽  
X Ray ◽  
Analysis Phase ◽  
Scanning Electron

In this study, we analyzed weld cracking in Ni-based superalloys. Alloys with about 64 wt.% Ni and 31 wt.% Ni were used for the weld metal analysis. Phase transition predicted by thermodynamic calculation were compared with experimental results. The weld metal’s microstructure was analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) mapping, and its mechanical properties tested. From EDX mapping, it was established that the alloying elements (Nb and Mo) were segregated around the weld crack as a result of the formation of a niobium carbide (NbC).

scholarly journals Effects of annealing parameters on phase, structure and thermochromic properties of VO2 (M) derived from nanostructured VO2(B)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Different Temperatures ◽  
Thermochromic Properties ◽  
Scanning Electron

Abstract Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (τc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a τc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.

scholarly journals Analysis of the Coulomb-solidification Process in Particle Plasmas

1995 ◽  
Vol 48 (3) ◽  
pp. 469 ◽  
Author(s):  
K Tachibana ◽  
Y Hayashi
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Solid Phase ◽  
Coupling Parameter ◽  
Solidification Process ◽  
Mie Scattering ◽  
Monodisperse Particles ◽  
Carbon Particles ◽  
Solid Phase Transition ◽  
Scanning Electron

The Coulomb-solidification process is analysed using Mie-scattering ellipsometry with the assistance of photography and scanning electron microscopy. Spherical monodisperse carbon particles are observed to grow in a methane plasma. The Coulomb-coupling parameter at the liquid-to-solid phase transition is evaluated to be around 200, which is close to the value predicted by a Monte Carlo simulation. The growth of monodisperse particles of pss: size having the same charge favours the formation of a Coulomb solid.

Phase Transition and Electrical Properties of Ba0.8Sr0.2TiO3: Comparison of Different Preparation Techniques

2017 ◽  
Vol 866 ◽  
pp. 287-290
Author(s):  
Thanawat Kytae ◽  
Krit Sutjarittangtham ◽  
Theerapol Thurakitseree ◽  
Wilaiwan Leenakul
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Electrical Properties ◽  
Molten Salt ◽  
Preparation Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lcr Meter ◽  
Preparation Techniques ◽  
Scanning Electron

This research studied the effect of the different preparation technique on phase transition and electrical properties of Ba0.8Sr0.2TiO3. The samples compared 3 preparation technique, there are conventional mix-oxide, molten-salt and seed-induced method. The samples prepared by molten-salt calcined at 800 °C, the samples prepared by conventional mix-oxide and seed-induced method was calcined at 1200 °C for 3 h. All of samples sintered at 1400 °C for 3 h. The phase formation and morphology of samples were characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The dielectric properties of the samples were measurement by LCR-meter.

scholarly journals Sulfidation of Ceramic-Based Coatings Deposited on Low-Alloyed Steel 16Mo3 Exposed at High Temperature

2021 ◽  
Author(s):  
Ewa Rząd ◽  
Tomasz Dudziak ◽  
Tomasz Polczyk ◽  
Łukasz Boroń ◽  
Paweł Figiel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Kinetic Data ◽  
Degradation Process ◽  
Ceramic Coatings ◽  
Alloyed Steel ◽  
X Ray ◽  
Degree Of Protection ◽  
Low Alloyed Steel ◽  
High Degree ◽  
Scanning Electron

AbstractThis study was carried out to evaluate a series of ceramic coatings in a sulfidation atmosphere containing 99% synthetic air and 1% H2S (vol.%) under a flow rate of 50 mL/min. The study was carried out at 773.15 K for 336 hours (heating rate 278.15 K/min). Chemically resistant glass enamels based on SiO2-B2O3-TiO2-Na2O compounds were deposited on the surface of 16Mo3 (16M) low-alloyed steel. Kinetic data were recorded periodically every 168 hours; macro- and microanalyses using scanning electron microscopy (SEM), phase analyses using x-ray diffractometry (XRD) and chemical composition using energy-dispersive x-ray spectrometry along with EDS x-ray mappings were carried out to observe the degradation process of the sulfidized coatings. The results indicated that some of the ceramic coatings exposed in the harsh atmosphere at 773.15 K for 336 hours showed a high degree of protection.

Preparation of TS-1 Monolithic Catalysts by Dip-Coating

2011 ◽  
Vol 233-235 ◽  
pp. 1730-1733
Author(s):  
Wen Hao Yu ◽  
Li Bin Yang ◽  
Feng Xin ◽  
Jian Jun Yuan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sodium Silicate ◽  
Dip Coating ◽  
Experiment Data ◽  
Monolithic Catalysts ◽  
Silicate Film ◽  
Coating Method ◽  
Dip Coating Method ◽  
Scanning Electron

TS-1 monolithic catalysts were prepared on cordierites honeycomb ceramics supports by dip-coating method in TS-1/H2O suspension. The cordierites honeycomb ceramics supports were treated with different methods, such as coated with a thin layer of sodium silicate, immersed in 0.5N hydrochloric acid. The monolithic catalysts were characterized by Scanning Electron Microscopy. The distribution of TS-1 Catalysts onto supported was observed. The immobilized stability of TS-1 monolithic catalysts was evaluated by ultrasonic cleaning and washing out experiment. TS-1 catalysts were uniformly deposited onto inner smoothed surface of cordierites honeycomb ceramics supports, which ware coated sodium silicate film. And experiment data proved that TS-1 catalysts may be firmly immobilized onto supports coated sodium silicate.

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