Morphology and Chemical Composition of Magnetic Particles Separated from Coal Fly Ash

Iron and other metal compounds are the materials that often appear in coal seams, because they also appear as a component of former organic matter in coal rocks. Although iron is the dominant element in coal rocks, other metals such as titanium, lead, cobalt, nickel, and copper are also present. In this study, the properties of magnetic particles of a size between 1 and 20 µm of globular structure and iron containing, were separated from coal fly ash, and studied using a scanning electron microscopy, energy disperse spectroscopy, and X-ray diffraction spectroscopy. The investigations were comprised of micrographs of the structure of these particles, their elemental composition, and phase analysis.

Characterizing Oligomeric Hydroxyl Silicon Oils by MALDI-TOF MS With the Pyridine-Modified Matrix

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) is a powerful technique for analysis of various polymers, but it is still very difficult to characterize silicone oil due to its poor ionization efficiency. In this work, oligomeric hydroxyl silicone oils were successfully characterized by MALDI-TOF, by using pyridine-modified 2,5-dihydroxylbenzoic acid (DHB) as the matrix. Furthermore, the mixed crystal of DHB and hydroxyl silicone oil was analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), and the analytical results verified that modification with pyridine could remarkably improve the solubility of hydroxyl silicone oil in DHB, leading to the enhancement of its ionization efficiency in MALDI. The analysis of the MS spectra of a series of hydroxyl silicone oils indicated that they tended to be ionized by the attachment with Na+, and the average molecular weight and the degree of polymerization were measured for several oligomeric hydroxyl silicon oils.

Desulfurization of Vulcanized Rubber Particles Using Biological and Couple Microwave-Chemical Methods

Currently, recycling or degradation treatments for tires are an enormous challenge. Despite efforts to dispose of or recycle it, rubber waste is increasing year by year worldwide. To create a rubber-recycling system, several researchers have proposed tire desulfurization. In this study, we compare two methods: one biological, using Acidobacillus ferroxidans in shake 250 ml flask experiments, and one chemical using, for the first time, microwaves and an aqueous solution. The results of these methods were analyzed through sulfate quantification, cross-linking differences, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy disperse spectroscopy (SEM-EDS). We observed that the amount of sulfates generated by the chemical system was 22.40 (mg/L)/g of rubber, which was 22-times higher than the biological system, which generated 1.06 (mg/L)/g of rubber. Similarly, after cross-linking studies, a 36% higher decrease after the chemical treatment was observed. When using FTIR analysis, the disappearance of characteristic bands corresponding to functional groups containing sulfur bonds and metal oxides were observed by treating the sample with both desulfurization methods. Morphological changes on the rubber surface structure was also demonstrated by SEM-EDS analysis with the appearance of holes, cracks and changes in the porosity of the material. This work analyzed two different non-aggressive desulfurization approaches that might be used as methods for rubber recycling processes.

Wear Resistance of TiAlCrSiN Coatings Deposited by Means of the Co-Sputtering Technique

TiAlCrSiN thin films were deposited on K20 WC–Co substrates using the co-sputtering method. The silicon content in the deposited coatings were varied by modifying the number of silicon pieces (1, 2, or 3) on the Cr target. The morphology, semi-quantitative chemical composition, and microstructure were investigated using scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), and X-ray diffraction (XRD), respectively. Modified ASTM B611 abrasive wear and nano-hardness tests were used to evaluate the tribological and mechanical properties of the different coatings, respectively. The results showed that the addition of Si promotes an increased hardness and elastic modulus. Also, mass loss in wear tests decreased as Si increased, due to the growth in hardness related to the microstructural refinement produced by the blocking of sliding bands by the grain boundaries.

Interface Template Synthesis of Zein-Based Amorphous Tio2 Composite Microcapsules with Enhanced Photocatalysis

In order to further enhance the application field of zein-based microcapsule. Zein-based amorphous TiO2 composite microcapsules (ZTCMs) were innovatively prepared from zein, tetra butyl ortho titanate (TBOT) and PEO106PPO70PEO106 (F127) via interface template synthesis. The Effects of TBOT amount on ZTCMs structures and photo-catalytic performances were mainly investigated. Chemical structure and microstructure of the obtained composite microcapsules were characterized mainly by fourier-transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM) and energy disperse spectroscopy (EDS). The results show ZTCMs exhibited evident hollow structure with titanium dioxide (TiO2) wrapped in the outer layer. The average size of ZTCMs300 was approximately 4 µm, which increased as the increase of TBOT dosage. Significantly, ZTCMs showed excellent photo-catalytic ability on dyes, red wine and coffee alike. The degradation rate of Rhodamine B (RB) was more than 80% after irradiation for 5 h under sunlight. This study provides a facile method to fabricate natural-based photo-catalytic material, which will be a good candidate in many fields such as medicine, food packaging, leather and textile.

Enhancing the Solidification Between Mud Cake and Wall Rock for Cementing Applications: Experimental Investigation and Mechanisms

In conventional cementing operations, the mud cake on the well wall cannot be completely removed， which can easily lead to annular channeling. In order to reduce the influence of loose and fragile mud cake on cementing, a kind of mud cake curing agent is used to effectively improve the curing quality of mud cake and rock. In this article, the mud cake compressive strength are tested by compression-testing machine. The samples are analyzed using X-ray diffractometer (XRD), scanning electron microscopy (SEM), and energy disperse spectroscopy (EDS). The results showed that the cementing agent can significantly improve the cementation strength between mud cake and wall rock. A variety of hydration products were resulted such as CaAl2Si2O8 · 4H2O, Ca(SiO4)2(OH)2, and Mg4Al2(OH)14 · 3H2O, as revealed from the XRD analysis. In addition, it was found that the formation of hydration products is the main reason for the increase of cementation strength. The flocculent inclusions filled with solid particles are formed on the solid particles of the mud cake, which makes an integrated cementation at the interface between mud cake and wall rock. A large amount of cations including Ca2+, Mg2+, and Al3+ are collected at the cementation interface, which is the basic condition for various hydration reactions and helps to enhance the cementation strength of the mud cake and rock interface.

Purification and Phase Evolution Mechanism of Titanium Oxycarbide (TiCxOy) Produced by the Thermal Reduction of Ilmenite

The phase evolution mechanism and purification of titanium oxycarbide (TiCxOy) synthesized via the carbothermal reduction of ilmenite are investigated. The reaction process and products of the performed carbothermal reduction are analyzed by means of X-ray diffraction (XRD), scanning electron microscopy-energy disperse spectroscopy (SEM-EDS), X-ray photoelectric spectroscopy (XPS) and enthalpy, entropy and heat capacity (HSC) thermodynamic software. According to the shapes of Ti 2p3/2 and Ti 2p1/2 peaks in XPS spectra, together with the XRD analyses, the reduction products of TiO, TiCxOy or TiC can be judged. The phase evolution mechanism involves FeTi2O5, Ti2O3, Fe, TiO, TiCxOy and TiC under enhancing the content of carbon. The phase evolution law can be written as FeTiO3 → FeTi2O5 → Ti2O3 + Fe → TiO + Fe → TiCxOy + Fe. Due to the incomplete reduction state of TiCxOy, the ΔGθ of TiCxOy is detected between TiC and TiO. TiCxOy could be attained under reduction conditions of Ti:C, 1:3–1:4 in argon atmosphere at 1550 °C after 2 h. Grinding, flotation and magnetic separation processes displayed that C, TiCxOy and Fe are not dissociated until the particle size of −38 μm. TiCxOy and Fe can be separated by an iron-bath in a high temperature. 95.56% TiCxOy can be obtained, and resistance of TiCxOy is less than 0.05 Ω.

Desulfurization of Vulcanized Rubber Particles Using Biological and Chemical Methods

Currently, recycling or degradation treatments for tires are an enormous challenge. Despite efforts to dispose of or recycle it, rubber waste is increasing year by year worldwide. To create a rubber-recycling system, several researchers have proposed tire desulfurization. In this study, we compare two methods: one biological, using Acidobacillus ferroxidans in shake 250 mL flask experiments, and one chemical using, for the first time, microwaves and an aqueous solution. The results of these methods were analyzed through sulfate quantification, cross-linking differences, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy disperse spectroscopy (SEM-EDS). We observed that the amount of sulfates generated by the chemical system was 56 mg / L, which was 10-times higher than the biological system, which generated 5.3 mg / L. Similarly, after cross-linking studies, a 36% higher decrease after the chemical treatment was observed. When using FTIR analysis, the disappearance of characteristic bands corresponding to functional groups containing sulfur bonds was observed by treating the sample with both desulfurization mechanisms. Morphological changes on the rubber surface structure was also demonstrated by SEM-EDS analysis with the appearance of holes, cracks and changes in the porosity of the material. This work analyzed two different non-aggressive desulfurization mechanisms that might be used as sustainable methods for rubber recycling processes.

Effect of high MgO/Al2O3ratio (1.2 to 2.2) on sintering behavior and metallurgical properties

The sintering pot test was used to investigate the effect of MgO/Al2O3ratio in the range of 1.2 to 2.2 on the sintering behavior of iron ore. The main characterization methods of X-ray diffraction (XRD) and scanning electron microscopy-energy disperse spectroscopy (SEM-EDS) were employed. The results showed that the strength, yield,and reducibility of sinter initially increased and then decreased with increasing MgO/Al2O3ratio from 1.2 to 2.2. Theindexwouldreachthe peak valuewiththe strength of70.6% and the yield of83.81%, respectively, when MgO/Al2O3ratio was 1.8. Thereduction indexwouldreachthe peak value of 88.54% with MgO/Al2O3ratio of 1.6. The FeOcontent, solid fuel consumption, and the RDI+3.15of sinter increased dramatically with increasing MgO/Al2O3ratio. When MgO/Al2O3ratio was up to 2.2, the solid fuel consumption and RDI+3.15reached a maximum value of 61.93 kg/t and 96.1%,respectively. The form of SFCA was acicular when MgO/Al2O3ratio was less than 1.6 and then transformed to plate-like which content also reduced. The magnetite increased while hematite decreased with enhancing MgO/Al2O3ratio.

Solid State Phase Equilibria of an Al–Sn–Y Ternary System

A complete understanding of the solid-state phase equilibria of the ternary Al–Sn–Y system is essential for the development of both Al-based structural materials and Sn-based lead-free solders. In this work, the phase relationships in the Al–Sn–Y ternary system at 473 K were investigated mainly by means of X-ray powder diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) with energy disperse spectroscopy (EDS) analysis. The existence of 12 binary compounds, namely Sn3Y, Sn5Y2, Sn2Y, Sn10Y11, Sn4Y5, Sn3Y5, AlY2, Al3Y5, Al2Y3, AlY, Al2Y and α–Al3Y, was confirmed. Controversial phases (Sn5Y2 and Al3Y5) were found in this work. This isothermal section consisted of 15 single-phase regions, 27 two-phase regions and 13 three-phase regions. No ternary compounds were found and none of the other phases in this system revealed a remarkable solid solution at 473 K.