通过LF加石灰,控制LF末期铝含量,RH过程喷80CaO-20CaF_2粉,RH终点喂铝线,RH结束后喂硅钙线等操作生产≤0.003%S的12MnV钢。根据脱硫数据表明,在110 t EAF-LF-RH-CC流程中LF平均脱硫率达88%,RH平均脱硫率不足30%;铝脱氧钢的冶炼过程中,...通过LF加石灰,控制LF末期铝含量,RH过程喷80CaO-20CaF_2粉,RH终点喂铝线,RH结束后喂硅钙线等操作生产≤0.003%S的12MnV钢。根据脱硫数据表明,在110 t EAF-LF-RH-CC流程中LF平均脱硫率达88%,RH平均脱硫率不足30%;铝脱氧钢的冶炼过程中,在不喂铝丝的情况下,随S含量降低,钢中Al含量降低;在RH前钢中应有足够的Al脱除钢中的氧,以利于RH脱硫。展开更多
The high sulfur coal from southwest of China was used to examine the influence of different factors such as irradiation time, particle size of coal, and leachant (Na2CO3, NaOH and CuCl22H2O)on the conversion rate of p...The high sulfur coal from southwest of China was used to examine the influence of different factors such as irradiation time, particle size of coal, and leachant (Na2CO3, NaOH and CuCl22H2O)on the conversion rate of pyrite to pyrrhotite by microwave irradiation. Single factor experiment was performed firstly, then orthogonal test method was used to explore these factors. The result shows that the optimal treating conditions for the conversion are a treatment time of 3 min, a particle size from 0.086 mm to 0.102 mm, and a favorable leachant of sodium hydroxide. Under these conditions the conversion rate of pyrite can reach 45.7 %.展开更多
Fulfill the screen test and float-and-sink analysis for high sulfur coal gangue from a Guizhou coal mine, analyzed the washability of its tail coal. Seen from the results： most of sulfur in sample is pyrite, the sulf...Fulfill the screen test and float-and-sink analysis for high sulfur coal gangue from a Guizhou coal mine, analyzed the washability of its tail coal. Seen from the results： most of sulfur in sample is pyrite, the sulfur content of different particle classification shall be reduced with the decreasing of size and specific gravity, most of sulfur distributed in the coal particles with large-size and high specific gravity. Part of sulfur may be eliminated through special gravity separation, however, most of inorganic sulfur should be removed with the combination of floatation process.展开更多
A systematic and green low-temperature sulfation roasting−water leaching strategy was put forward to achieve a very high fluorine removal rate of 97.82%for spent carbon cathode(SCC),which was believed as a hazardous s...A systematic and green low-temperature sulfation roasting−water leaching strategy was put forward to achieve a very high fluorine removal rate of 97.82%for spent carbon cathode(SCC),which was believed as a hazardous solid waste.And the carbon could be recycled with a purity of 90.29 wt.%in the flaky microstructure.Thermodynamic analysis and the results of SEM,XRD and EDS indicate that most of the fluoride could convert into water-soluble sulfate at low temperature.And the highest fluorine removal rate could be obtained when<0.15 mm SCC particles were mixed with sulfuric acid at a liquid-to-solid ratio of 1:1,and then roasted at 300℃ for 0.5 h.The sulfate was removed to purify the carbon via water-leaching process.Avrami exponents and corresponding activation energy for the roasting and leaching process demonstrated that both processes are controlled by diffusion.展开更多
Thermodynamic diagrams of Na−S−Fe−H_(2)O system were constructed to analyze the behavior of sulfur and iron in the Bayer process.After digestion,iron mainly exists as Fe_(3)O_(4) and Fe_(2)O_(3) in red mud,and partial...Thermodynamic diagrams of Na−S−Fe−H_(2)O system were constructed to analyze the behavior of sulfur and iron in the Bayer process.After digestion,iron mainly exists as Fe_(3)O_(4) and Fe_(2)O_(3) in red mud,and partial iron transfers into solution as Fe(OH)_(3)^(−),HFeO_(2)^(−),Fe(OH)_(4)^(−)and Fe(OH)_(4)^(2−).The dominant species of sulfur is S^(2−),followed by SO_(4)^(2−),and then SO_(3)^(2−)and S_(2)O_(3)^(2−).The thermodynamic analysis is consistent with the iron and sulfur species distribution in the solution obtained by experiments.When the temperature decreases,sulfur and iron can combine and precipitate.Controlling low potential and reducing temperature are beneficial to removing them from the solution.XRD patterns show that NaFeS_(2)·2H_(2)O,FeS and FeS_(2) widely appear in red mud and precipitates of pyrite and high-sulfur bauxite digestion solution.Thermodynamic analysis can be utilized to guide the simultaneous removal of sulfur and iron in the Bayer process.展开更多
Although the FCC process has been used for more than halfa century, new and important developments continue to be made in several areas. Some of these new developments are a direct response to environmental regulation...Although the FCC process has been used for more than halfa century, new and important developments continue to be made in several areas. Some of these new developments are a direct response to environmental regulation. Sulfur oxides （SOx-SO2＋SO3） emitted from fluid catalytic cracking units （FCCU） are one of the most hazardous atmospheric pollutants, which may cause serious environmental problems such as the formation of acid rain and the destruction of the ozone layer. Thus, great attention has been focused on the SOx removal from FCC in last few years. The present papers will focus on the spinel material studies include three samples they were prepared by acidic method, solid solution MgAl2O4, solid solution with cerium10%Ce/MgAl2O4, iron mixed spinel with cerium 10%Ce/MgAl2-xFeO4.MgO and two samples solid solution with cerium introduce by vanadium as second co-catalyst prepared by basic method, 1% V/10%Ce/MgAl2O4.MgO were tested in TGA for oxidation half cycle to study some parameters effect on performance of SOx additives in TGA under condition similar to those of FCC units. Thermogravimetry analysis experiments have been used to demonstrate the pick-up and release of sulfur oxides in the development of additives for SOx control in the FCCU.展开更多
A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and...A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and nitrogen source. The sequence analysis of 16S rDNA illustrated that the similarity of F8 and Desulfovibrio desulfuricans (AF192153) was 99%, and the similarity sequence of dissimilatory sulfite reductase gene (DSR) cloned from the strain and Desulfovibrio desulfuricans (AF273034) was 98%. Their phylogenitic analysis was basically anastomosed, and thus temporarily named as Desulfovibrio desulfuricans F8. The DSR cloned from F8 strain was 2740 bp in length consisting of three ORF, DSRA, DSRB and DSRD as a single operon (DSRABD) regulated by the same operator. DSRA contained typical conservative box of sulfate—sulfite reducing enzyme (SiteⅠand SiteⅡ), which could bind siroheme and [Fe4S4]. DSRB retained a [Fe4S4] binding site, with an uncomplimentary structure for siroheme binding. There was no conservative box in DSRD. Sequence analysis of DSR will provide a theoretical basis for quantitative detection, metabolic pathway modification through gene engineering, and sulfate reducing bacteria (SRB) suppression.展开更多
Desulfurization experiments of CuO, γ-Al2O3 and CuO/γ-Al2O3 were made in simulated flue gas by means of thermogravimetric analysis. It is found that reaction activities of CuO supported on γ-Al2O3 could be highly i...Desulfurization experiments of CuO, γ-Al2O3 and CuO/γ-Al2O3 were made in simulated flue gas by means of thermogravimetric analysis. It is found that reaction activities of CuO supported on γ-Al2O3 could be highly improved. Desulfurization kinetics of CuO/γ-Al2O3 was studied in the temperature range of 250 °C-400 °C and SO2 concentration of 0.1%-0.9%. The experimental data were tested and compared with kinetics models of volume reaction model(VRM), grain size model(GSM), random pore model(RPM) and pore-blocking model(PBM). Correlation analysis shows that VRM and RPM models do not fit experimental data well. GSM contradicts with the changes in the physical and chemical properties of Cu O/γ-Al2O3 as the desulfurization proceeds. It is found that PBM is consistent with the change of pore structure of CuO/γ-Al2O3 sorbent during desulfurization process and predicts the conversion-time curves of the sorbent well. Meanwhile, kinetics parameters are obtained and discussed.展开更多
Coal is one of the important energy sources, but it causes serious environmental problems such as air pollution, acid rain and greenhouse effects. Sulfur in coal is one of the responsibilities of these negative effect...Coal is one of the important energy sources, but it causes serious environmental problems such as air pollution, acid rain and greenhouse effects. Sulfur in coal is one of the responsibilities of these negative effects. Coal includes two types of sulfur： organic and inorganic. While inorganic sulfur can be completely removed with physical desulfurization methods, organic sulfur can be removed only by chemical desulfurization methods. But chemical methods are not only expensive but also difficult processes. Firstly in desulfurization, types of the sulfur content in coal should be well characterized. High sulfur Gediz-Turkey coal has been chosen to this study. This coal basin is located in the centre of the Turkey. In this study, characterization and desulfurization possibilities of high sulfur Gediz coal were investigated. For this purpose, several physical and chemical characterization methods such as proximate and ultimate coal analysis （ash, calorific value, volatile matter, moisture and sulfur analysis）, mineralogical and petrographic analysis, fourier transform infrared spectroscopy, scanning electron microscope were used. Results of these analysis are shown that Gediz coals include 3.15% pyritic sulfur and 2.89% organic sulfur. Removing pyritic sulfur from Gediz-Turkey coal with physical methods such as gravity and sink-float separation is not possible because pyrite particle has 1-2 micron liberation size in coal.展开更多
文摘通过LF加石灰,控制LF末期铝含量,RH过程喷80CaO-20CaF_2粉,RH终点喂铝线,RH结束后喂硅钙线等操作生产≤0.003%S的12MnV钢。根据脱硫数据表明,在110 t EAF-LF-RH-CC流程中LF平均脱硫率达88%,RH平均脱硫率不足30%;铝脱氧钢的冶炼过程中,在不喂铝丝的情况下,随S含量降低,钢中Al含量降低;在RH前钢中应有足够的Al脱除钢中的氧,以利于RH脱硫。
基金Project 2002CB211602 spported by the National Key Besearch and Development
文摘The high sulfur coal from southwest of China was used to examine the influence of different factors such as irradiation time, particle size of coal, and leachant (Na2CO3, NaOH and CuCl22H2O)on the conversion rate of pyrite to pyrrhotite by microwave irradiation. Single factor experiment was performed firstly, then orthogonal test method was used to explore these factors. The result shows that the optimal treating conditions for the conversion are a treatment time of 3 min, a particle size from 0.086 mm to 0.102 mm, and a favorable leachant of sodium hydroxide. Under these conditions the conversion rate of pyrite can reach 45.7 %.
文摘Fulfill the screen test and float-and-sink analysis for high sulfur coal gangue from a Guizhou coal mine, analyzed the washability of its tail coal. Seen from the results： most of sulfur in sample is pyrite, the sulfur content of different particle classification shall be reduced with the decreasing of size and specific gravity, most of sulfur distributed in the coal particles with large-size and high specific gravity. Part of sulfur may be eliminated through special gravity separation, however, most of inorganic sulfur should be removed with the combination of floatation process.
基金the Natural Science Foundation of Hunan Province,China(No.2020JJ1007).
文摘A systematic and green low-temperature sulfation roasting−water leaching strategy was put forward to achieve a very high fluorine removal rate of 97.82%for spent carbon cathode(SCC),which was believed as a hazardous solid waste.And the carbon could be recycled with a purity of 90.29 wt.%in the flaky microstructure.Thermodynamic analysis and the results of SEM,XRD and EDS indicate that most of the fluoride could convert into water-soluble sulfate at low temperature.And the highest fluorine removal rate could be obtained when<0.15 mm SCC particles were mixed with sulfuric acid at a liquid-to-solid ratio of 1:1,and then roasted at 300℃ for 0.5 h.The sulfate was removed to purify the carbon via water-leaching process.Avrami exponents and corresponding activation energy for the roasting and leaching process demonstrated that both processes are controlled by diffusion.
基金the financial supports from the National Natural Science Foundation of China(No.51904052)the Chongqing Research Program of Basic Research and Frontier Technology,China(No.cstc2020jcyjmsxm X0476)+1 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission,China(No.KJQN201901508)the Graduate Science and Technology Innovation Training Program of Chongqing University of Science and Technology,China(No.YKJCX2020201)。
文摘Thermodynamic diagrams of Na−S−Fe−H_(2)O system were constructed to analyze the behavior of sulfur and iron in the Bayer process.After digestion,iron mainly exists as Fe_(3)O_(4) and Fe_(2)O_(3) in red mud,and partial iron transfers into solution as Fe(OH)_(3)^(−),HFeO_(2)^(−),Fe(OH)_(4)^(−)and Fe(OH)_(4)^(2−).The dominant species of sulfur is S^(2−),followed by SO_(4)^(2−),and then SO_(3)^(2−)and S_(2)O_(3)^(2−).The thermodynamic analysis is consistent with the iron and sulfur species distribution in the solution obtained by experiments.When the temperature decreases,sulfur and iron can combine and precipitate.Controlling low potential and reducing temperature are beneficial to removing them from the solution.XRD patterns show that NaFeS_(2)·2H_(2)O,FeS and FeS_(2) widely appear in red mud and precipitates of pyrite and high-sulfur bauxite digestion solution.Thermodynamic analysis can be utilized to guide the simultaneous removal of sulfur and iron in the Bayer process.
文摘Although the FCC process has been used for more than halfa century, new and important developments continue to be made in several areas. Some of these new developments are a direct response to environmental regulation. Sulfur oxides （SOx-SO2＋SO3） emitted from fluid catalytic cracking units （FCCU） are one of the most hazardous atmospheric pollutants, which may cause serious environmental problems such as the formation of acid rain and the destruction of the ozone layer. Thus, great attention has been focused on the SOx removal from FCC in last few years. The present papers will focus on the spinel material studies include three samples they were prepared by acidic method, solid solution MgAl2O4, solid solution with cerium10%Ce/MgAl2O4, iron mixed spinel with cerium 10%Ce/MgAl2-xFeO4.MgO and two samples solid solution with cerium introduce by vanadium as second co-catalyst prepared by basic method, 1% V/10%Ce/MgAl2O4.MgO were tested in TGA for oxidation half cycle to study some parameters effect on performance of SOx additives in TGA under condition similar to those of FCC units. Thermogravimetry analysis experiments have been used to demonstrate the pick-up and release of sulfur oxides in the development of additives for SOx control in the FCCU.
基金Sponsored by the National Basic Research and Development (973) Program of China(Grant No.2004CB418505)
文摘A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and nitrogen source. The sequence analysis of 16S rDNA illustrated that the similarity of F8 and Desulfovibrio desulfuricans (AF192153) was 99%, and the similarity sequence of dissimilatory sulfite reductase gene (DSR) cloned from the strain and Desulfovibrio desulfuricans (AF273034) was 98%. Their phylogenitic analysis was basically anastomosed, and thus temporarily named as Desulfovibrio desulfuricans F8. The DSR cloned from F8 strain was 2740 bp in length consisting of three ORF, DSRA, DSRB and DSRD as a single operon (DSRABD) regulated by the same operator. DSRA contained typical conservative box of sulfate—sulfite reducing enzyme (SiteⅠand SiteⅡ), which could bind siroheme and [Fe4S4]. DSRB retained a [Fe4S4] binding site, with an uncomplimentary structure for siroheme binding. There was no conservative box in DSRD. Sequence analysis of DSR will provide a theoretical basis for quantitative detection, metabolic pathway modification through gene engineering, and sulfate reducing bacteria (SRB) suppression.
基金Projects(51264023,51364020,U1202271)supported by the National Natural Science Foundation of ChinaProject(IRT1250)supported by the Program for Innovative Research Team in University of Ministry of Education of ChinaProject(2014HA003)supported by the Yunnan Province Science and Technology Talents Program,China
文摘Desulfurization experiments of CuO, γ-Al2O3 and CuO/γ-Al2O3 were made in simulated flue gas by means of thermogravimetric analysis. It is found that reaction activities of CuO supported on γ-Al2O3 could be highly improved. Desulfurization kinetics of CuO/γ-Al2O3 was studied in the temperature range of 250 °C-400 °C and SO2 concentration of 0.1%-0.9%. The experimental data were tested and compared with kinetics models of volume reaction model(VRM), grain size model(GSM), random pore model(RPM) and pore-blocking model(PBM). Correlation analysis shows that VRM and RPM models do not fit experimental data well. GSM contradicts with the changes in the physical and chemical properties of Cu O/γ-Al2O3 as the desulfurization proceeds. It is found that PBM is consistent with the change of pore structure of CuO/γ-Al2O3 sorbent during desulfurization process and predicts the conversion-time curves of the sorbent well. Meanwhile, kinetics parameters are obtained and discussed.
文摘Coal is one of the important energy sources, but it causes serious environmental problems such as air pollution, acid rain and greenhouse effects. Sulfur in coal is one of the responsibilities of these negative effects. Coal includes two types of sulfur： organic and inorganic. While inorganic sulfur can be completely removed with physical desulfurization methods, organic sulfur can be removed only by chemical desulfurization methods. But chemical methods are not only expensive but also difficult processes. Firstly in desulfurization, types of the sulfur content in coal should be well characterized. High sulfur Gediz-Turkey coal has been chosen to this study. This coal basin is located in the centre of the Turkey. In this study, characterization and desulfurization possibilities of high sulfur Gediz coal were investigated. For this purpose, several physical and chemical characterization methods such as proximate and ultimate coal analysis （ash, calorific value, volatile matter, moisture and sulfur analysis）, mineralogical and petrographic analysis, fourier transform infrared spectroscopy, scanning electron microscope were used. Results of these analysis are shown that Gediz coals include 3.15% pyritic sulfur and 2.89% organic sulfur. Removing pyritic sulfur from Gediz-Turkey coal with physical methods such as gravity and sink-float separation is not possible because pyrite particle has 1-2 micron liberation size in coal.
