Production of SO2 and Lime from Phosphogypsum Reduced with Lignite in a Nitrogen Atmosphere

2013 ◽  
Vol 803 ◽  
pp. 94-98
Author(s):  
Shao Cong Zheng ◽  
Fei Xiang Cheng ◽  
Zhi Juan Wang

In this study, using lignite as a reducer, the reaction characteristic of the reduction decomposition of phosphogypsum to SO2 and lime was investigated in a nitrogen atmosphere at different conditions. Scanning electron microscopy and XRD-ray diffraction were used to analyze the solid production. The gas production of SO2 was analyzed by the Gas Analyzers. The experiment results showed that the optimal conditions for production of SO2 are founded to be a molar proportion of C:CaSO4=0.8:1 and a decomposition temperature of over 1000°C.Under these conditions the maximum concentration of SO2 reached to 8.23% (vol. %). The CaO content of solid production increased to 62.57%. The desulfurization rate of phosphogypsum reached to 95.16%.

2017 ◽  
Vol 5 (4) ◽  
pp. T487-T501 ◽  
Author(s):  
Tingwei Li ◽  
Zhenxue Jiang ◽  
Chenlu Xu ◽  
Yuan Yuan ◽  
Pengfei Wang ◽  
...  

Research on shale lithofacies is important for shale oil and gas production. This study focused on the lower third member of the Shahejie Formation ([Formula: see text]) in the Luo-69 well in the Zhanhua Sag, Jiyang Depression, Bohai Bay Basin, eastern China. Several methods, including thin section observations, total organic carbon (TOC) analysis, X-ray diffraction analysis, quantitative evaluations of minerals by scanning electron microscopy, major and trace-element analyses, and field emission-scanning electron microscopy, are used to investigate the effect of sedimentary environment on the type and distribution of shale lithofacies. Our research indicates that 36 types of shale lithofacies can be classified based on the TOC content, mineral composition, and sedimentary structure, of which five types are identified in the study area. The [Formula: see text] shale has a high calcareous mineral content (average of 49.64%), low clay and siliceous minerals contents (averages of 19.54% and 19.02%, respectively), a high TOC content (average of 3.00 wt%), and well-developed horizontal bedding. The sedimentary environment during the deposition of the [Formula: see text] shale in the Zhanhua Sag had a warm and moist climate, limited provenance, saline water, and strong reducibility. The sedimentary environment in the early stage had a drier climate, more limited provenance, higher salinity, and stronger reducibility than that in the later stage. Shale lithofacies can reflect a certain sedimentary environment and depositional process; similarly, a depositional environment controls the type and distribution of shale lithofacies. Due to the characteristics of the [Formula: see text] sedimentary environment, organic-rich massive mixed shale, organic-rich bedded mixed-calcareous shale, organic-rich laminated calcareous shale, and organic-fair laminated calcareous shale are developed in the [Formula: see text] formation from top to bottom.


2012 ◽  
Vol 602-604 ◽  
pp. 540-543
Author(s):  
Teng Biao Zheng ◽  
Ping Feng ◽  
Hai Yan Lei

The effect of sintering atmosphere and nitrogen pressure on microstructure of Ti(C, N)–12WC–16Ni–4Mo2C cermet were investigated by scanning electron microscopy (SEM) and optical microscopy (OM), the transverse rupture strength (TRS), porosities, volume fractions of phases and grain sizes were determined. Results show that nitrogen pressure has a significant impact on TRS, appropriate nitrogen pressure could improve TRS. Vacuum sintering promotes the densification of sintered body, however, nitrogen atmosphere sintering could gain maximal TRS. Nitrogen atmosphere sintering facilitates the formation of inner rim phase and reduces the dissolution of TiC and TiN, small grain size is gained.


2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.


2020 ◽  
Vol 83 (11) ◽  
pp. 1983-1988
Author(s):  
XIANQING HUANG ◽  
LIANJUN SONG ◽  
MINGWU QIAO ◽  
PINGAN ZHANG ◽  
QIUYAN ZHAO

ABSTRACT The purpose of this study was to establish a three-variable bactericidal model of temperature, time, and concentration to determine the optimal conditions for Bacillus cereus spore inactivation by surfactin. To obtain the binary regression equation of the inactivated spore model, a total of 17 simulations were performed using response surface methodology. The experimental results showed that the three factors each had a discernible but nonequal impact on the inactivation response value. Multiple regression analysis of experimental results using Design-Expert software yielded the following equation: Y = 1.47 + 0.39ξ1(temperature) + 0.38ξ2(time) + 0.39ξ3(concentration) − 0.20ξ1ξ2 + 0.22ξ1ξ2 − 0.12ξ2ξ3 − 0.23ξ12 − 0.11ξ22 − 0.40ξ32. Optimal inactivation of spores was achieved by treatment with surfactin at a concentration of 4 mg/mL for 40 h at 53°C, with the response value reaching 1.8. The spores were treated with surfactin under these conditions; the microstructural changes of spores were observed by use of scanning electron microscopy. We found that the structures of the outer wall of the spores were damaged, whereas the spores in the control sample showed no visible damage. HIGHLIGHTS


2016 ◽  
Vol 61 (2) ◽  
pp. 493-498 ◽  
Author(s):  
M. Petrova ◽  
M. Georgieva ◽  
V. Chakarova ◽  
E. Dobreva

AbstractThe composite Ni-P coating with diamond particles (D) deposited on the flexible substrates of pressed polyethylene terephthalate material (PET) was obtained, to be used in the development of efficient, flexible grinding and polishing tools. The optimal conditions of the hydrodynamic regime, deposition time and temperature were found. The influence of the concentration and size of the D particles (3/7 ÷ 225/300 μm) on the coating thickness and number of co-deposited particles were studied. By Scanning Electron Microscopy (SEM) images were defined the morphology of dispersion coatings and number of co-deposited particles in them, and Energy Dispersive Spectroscopy (EDS/INCA) was used to determine the elemental chemical composition of the composite coatings.


2018 ◽  
Vol 207 ◽  
pp. 03021
Author(s):  
Guangbo Xie ◽  
Zijun Zhang ◽  
Jingjing Zhang

The new color-tunable luminescent Eu/Tb(BPA)3phen composites have been successfully fabricated by the solvothermal reactions. The characterization of the final products have been investigated by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TG-DSC) and Ultraviolet and visible (UV-Vis) spectrophotometer. It is found that the geometry of the composite particles is regular by scanning electron microscopy image. Thermogravimetric analysis indicates that the initial decomposition temperature of the final products is 334 °C, approximately. The results demonstrate that Eu/Tb(BPA)3phen composites have excellent thermal stability. And the products after decomposition are stable oxides (Eu2O3 and Tb2O3). Furthermore, Eu and Tb ions complexes exhibit strong red and green luminescence, respectively. Emitting color of physically blended Eu(BPA)3phen and Tb(BPA)3phen composites can be tuned in a wide range from red to yellow to green under the excitation of 350 nm single-wavelength ultraviolet light. The CIE coordinates of CTb, C1, C2, C3, C4, C5, C6 and CEu are calculated as (0.24, 0.60), (0.31, 0.56), (0.33, 0.55), (0.38, 0.52), (0.40, 0.51), (0.43, 0.48), (0.54, 0.41) and (0.65, 0.34), respectively. The color-tunable luminescent materials can be widely applications in many fields, such as the optical and electronic devices, fluorescent probe and labels.


2008 ◽  
Vol 55-57 ◽  
pp. 409-412 ◽  
Author(s):  
Ching Wen Lou ◽  
Chao Tsang Lu ◽  
Chao Chiung Huang ◽  
H.Y. Wang ◽  
Jia Horng Lin

In this study, the PLA plied yarn was fabricated by twisting four of PLA yarns together, then PLA plied yarn was used a 16-spindle braid machine to produce the PLA braids. PLA braids were immersed in the suspension of β-tricalcium phosphate (β-TCP), and heat treatment to improve the adhesion of β-TCP particles. PLA/β-TCP composite braids were immersed in simulated body fluid (SBF) to promote bonelike apatite production. The morphology of PLA braids were investigated by scanning electron microscopy (SEM), and the results shown that when twist coefficient was 3 of PLA plied yarn, the concentration of β-TCP suspension was 0.15 wt % and heat treatment at 175 °C for 9 min, we can obtain the optimal conditions of β-TCP particles adhesion.


2007 ◽  
Vol 546-549 ◽  
pp. 2075-2078
Author(s):  
Jian Qing Feng ◽  
Lian Zhou ◽  
Ya Feng Lu ◽  
Ping Xiang Zhang ◽  
Xiao Yan Xu ◽  
...  

The effects of BaF2 on thermal behavior and microstructure of melt-processed YBCO superconductors have been investigated. The differential thermal analysis (DTA) results indicated that the peritectic decomposition temperature of YBCO precursor powder was lowered when BaF2 was added (from 1020 to 976). The peritectic decomposition temperature was lowest at the content of 5 wt.% BaF2, and the variation of melting temperature was not significant above 5 wt.% BaF2. The microstructures of the doped samples have been observed by scanning electron microscopy (SEM). The results showed that the of BaF2 microstructure .


2008 ◽  
Vol 368-372 ◽  
pp. 409-411 ◽  
Author(s):  
Dao Yuan Yang ◽  
Fen Ling Qian ◽  
Kai Zhu ◽  
Zhan Ling Lu ◽  
Rui Zhang

Hexagonal MgAl2O4 spinel fibers were synthesized at 1500oC for 6h in nitrogen atmosphere. The structure and morphology of the fibers were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fibers grew via vapor- liquid- solid mechanism. The twin mechanism was suggested to play a key role in the formation process of the hexagonal fibers.


2014 ◽  
Vol 931-932 ◽  
pp. 1608-1613 ◽  
Author(s):  
Jintara Satarn ◽  
Wimonporn Lamamorphanth ◽  
Khanita Kamwilaisak

The aim of this study is to extract the reducing sugar by acid hydrolysis of corn stover. The corn stover was hydrolyzed by using H2SO4 at different concentrations (0-6%, v/v),reaction times (15-180 min) at temperature 122 C with ratio of 1 g of corn stover to 20 ml of H2SO4 solution. The samples were analyzed the reducing sugar by HPLC. The optimal conditions of acid hydrolysis was at 1% H2SO4 (v/v), 122 C for 60 min, which produced 24.96 g/L of reducing sugar. The hydrolysed sample composed of 12.4 g/L of xylose, 2.9 g/l of glucose and 3.2 g/L of arabinose. Also, the Scanning Electron Microscopy (SEM) was analyzed the morphology of untreated and treated corn stover which showed the breakdown fibril of treated sample.


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