Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which ...Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which relies on lixiviants prepared using volatilized sulfur obtained from roasting,has not been fully elucidated.This study employs the response surface methodology to optimize processing parameters,resulting in an increased gold extraction rate of 96.18%.Analytical factorization and the Tafel curve indicate that CuSO_(4) and NH_(3)·H_(2)O significantly influence the self-leaching process.Furthermore,X-ray photoelectron spectroscopy(XPS)analysis reveals that S^(2−),S_(2)^(2−),polysulfides(S_(n)^(2−)),and thiosulfate(S_(2)O_(3)^(2−))are involved in the gold leaching reaction,with S^(2−),S_(2)^(2−),and S_(n)^(2−) serving as primary ligands for gold complexation.The role of S_(2)O_(3)^(2−) in the early stages of the gold-leaching reaction is also noteworthy.The copper–ammonia complex catalyzes the self-leaching gold reaction;however,an improper addition ratio can lead to copper-sulfur compound precipitates,reducing the extraction rate.展开更多
The effect of the initial(Al+Si)/MnO molar ratio and slag composition on MnO recovery from electroslag by remelting at 1773 K was investigated.High-purity aluminum metal and silicon were employed as the deoxidizers to...The effect of the initial(Al+Si)/MnO molar ratio and slag composition on MnO recovery from electroslag by remelting at 1773 K was investigated.High-purity aluminum metal and silicon were employed as the deoxidizers to effectively promote the recovery of manganese metal(MM).The reduction of MnO in slag,through the interaction between molten MM with a deoxidizer and the Na_(2)O-enriched electroslag melt,was assessed both thermodynamically and kinetically.The sulfur content of high-sulfur rejected electrolytic manganese metal(EMM)scrap decreased to 0.58%with high-temperature pretreatment.The mass ratio between slag and high-sulfur rejected EMM scrap is 2/3.When the Al_(2)O_(3)content in the initial slags decreased and the Na_(2)O content increased,the MnO reduction ratio increased.The residual MnO concentration of the slag reduced with increasing the Al–Si deoxidizer content.When the(Al+Si)/MnO molar ratio reached 0.83,the MnO concentration in the final slag was only 3%.A deoxidizer mainly containing aluminum and a small amount of Si could be added to recover MnO from the slag,resulting in the improvement in the cleanliness of final Mn metal.展开更多
The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper re...The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.展开更多
Segregation and inclusion precipitation are the common behaviours of steel solidification, which are resulted from the redistribution and diffusion of the solute elements at the solid-liquid interface. The effect of t...Segregation and inclusion precipitation are the common behaviours of steel solidification, which are resulted from the redistribution and diffusion of the solute elements at the solid-liquid interface. The effect of the phase transition of high-sulfur free-cutting steel is quantified in the present work for the solute partition coefficient(ki), inclusion precipitation, and microsegregation by establishing a coupling model of microsegregation and inclusion precipitation, wherein the quantified dependencies of ki in terms of temperature, phase and carbon(C) content were applied. Results showed that the solidification temperature range and phase transition of high-sulfur steel that under different solidification paths and C contents were quite different, leading to differences in ki and eventually in microsegregation. kC,kP, and kS were mainly affected by phase composition and kSi was primarily by temperature, while kMn depended on both phase composition and temperature during solidification. Increasing the C content within the interval 0.07-0.48 wt%, the ‘proportion of the δ phase maintained temperature region during solidification’(Pδ), kave Pand kave S(kiave, the average value of the ki across the whole stages of solidification)decreased monotonically, whereas kave Cincreased linearly. The peritectic reaction impacted on the phase composition and ki, leading to the change in microsegregation. Such effect of the peritectic reaction was more significant at the last stage of solidification. When the Pδ was between 75% and 100%(corresponding to 0.07-0.16 wt% C), the solidification path resulted in a greater effect on the microsegregation of solutes C, P, and S because of the peritectic reaction. The microsegregation of solutes Mn and S were comprehensively influenced by kMn, kS and Mn S precipitation as well. The studies would help reveal the solute redistribution at the solid-liquid interface, and improve the segregation of high-sulfur steel by controlling the solidification and precipitation in practice.展开更多
High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic sulfur.Herein,we...High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic sulfur.Herein,we design and construct a highly efective CTAB@HPA composites to be explored for the catalytic oxidative desulfurization of HSPC under mild conditions using hydrogen peroxide as the oxidant and 1-butyl-3-methylimidazole tetrafuoroborate ionic liquid as the extractant.The results demonstrate that the sulfur content of HSPC could be strikingly reduced from 4.46 wt%to 2.48 wt%under 60℃ and atmospheric pressure,and that the organic sulfur in HSPC is mainly oxidized to sulfoxide,sulfone and sulfate,which latter can be directly separated from petroleum coke.Moreover,the efect of reaction conditions on the desulfurization performance of HSPC as well as the catalytic oxidation reaction kinetic of HSPC desulfurization was systematically investigated.Furthermore,a mechanism for the oxidative desulfurization of HSPC over CTAB@HPA catalysts was proposed.Therefore,this work provides new insight into how to construct active catalysts for the desulfurization of HSPC under mild conditions.展开更多
High-sulfur,heavy petroleum is widely occurring in the Tertiary lacustrine Jiyang sub-basin, Bohai Bay Basin.They are differentiated into two families based on the bulk properties and biomarker compositions.Family 1 i...High-sulfur,heavy petroleum is widely occurring in the Tertiary lacustrine Jiyang sub-basin, Bohai Bay Basin.They are differentiated into two families based on the bulk properties and biomarker compositions.Family 1 is characterized by high resins（40%-71%）and sulfur（2%-4%）,and low wax （l%-6%）,with n-alkanes removed by biodegradation,whereas family 2 is characterized by extremely abundant sulfur（3%-10%）,and high asphaltenes（7%-31%）and wax（2%-19%）,with no evidence of microbial attack.The oils of family 1 are distributed in the reservoir,lower than 1500 m throughout the sub-basin.Biomarker assemblages,such as low pristane/phytane ratios（1 Pr/Ph）and a high abundance of carotane,gammacerane,and dinosterane,suggest that they are derived from the calcareous mudstones and shales among the stratified,saline Es_4~u unit,in addition to the in situ biodegradation-concentrated sulfur content.However,the oils of family 2 are identified only in the western Zhanhua and eastern Chezhen depressions,with a depth deeper than 1700 m.Physical properties,together with biomarker ratios,including even-numbered n-alkanes,1 Pr/Ph,trace diasteranes,higher C35 homohopanes,and abundant dibenzothiophene series,with1 dibenzothiophene/phenanthrene,indicate an origin from carbonate source rocks.The X-ray diffraction analysis showed that the carbonate source rock is limited in the Es_4~u unit of the Bonan sag,which is different from most other source rocks in the same horizon.It is suggested that the high-sulfur,heavy oils are generated at the early stage of the oil window.Bacterial sulfate reduction might be responsible for the occurrence of sulfur species in the high-sulfur,heavy oils,while heavy biodegradation will enhance sulfur concentrations.展开更多
The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in soil.Its spatial distribution and environment risk assessment are extremely important for the management and remediatio...The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in soil.Its spatial distribution and environment risk assessment are extremely important for the management and remediation of HMs.Eighty soil samples were collected from the high-sulfur CG site in northern China and analyzed for six HMs.The results showed that the soil was heavily contaminated by Mn,Cr and Ni based on the Nemerow index,and posed seriously ecological risk depended on the geo-accumulation index,potential ecological risk index and risk assessment code.The semi-variogram model and ordinary kriging interpolation accurately portrayed the spatial distribution of HMs.Fe,Mn,and Cr were distributed by band diffusion,Ni was distributed by core,the distribution of Cu had obvious patchiness and Zn was more uniform.The spatial autocorrelation indicated that all HMs had strong spatial heterogeneity.The BCR sequential extraction was employed to qualify the geochemical fractions of HMs.The data indicated that Fe and Cr were dominated by residual fraction;Cu,Ni and Zn were dominated by reducible and oxidizable fractions;Mn was dominated by reducible and acid-extractable(25.38%-44.67%)fractions.Pearson correlation analysis showed that pH was the main control factor affecting the non-residue fractions of HMs.Therefore,acid production from high sulfur CG reduced soil pH by 2-3,which indirectly promoted the activity of HMs.Finally,the conceptual model of HMs contamination at the CG site was proposed,which can be useful for the development of ecological remediation strategies.展开更多
In the leaching solution of high-sulfur bauxite roasted by sulfuric acid,a high concentration of aluminum presented along with titanium and iron.The present work was to remove Ti(IV)from the leach liquor by calcium al...In the leaching solution of high-sulfur bauxite roasted by sulfuric acid,a high concentration of aluminum presented along with titanium and iron.The present work was to remove Ti(IV)from the leach liquor by calcium alginate microsphere sorbent material(CA-P204)based on natural alginate impregnated with di-(2-ethylhexyl)phosphoric acid(D2EHPA)to purify leaching solution.Cation exchange and chelation make major contributions to the adsorption mechanism according to Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis.The results showed that Ti(IV)was successfully removed by the CA-P204 adsorbent from the Ti(IV)-Al(III)-Fe(III)ternary system with a dynamic column experiment.The removal rate of titanium was nearly 95%under optimal conditions and the maximum adsorption capacity was 66.79 mg/g at pH 1.0.Reusability of CA-P204 was evaluated over three consecutive adsorption/desorption cycles.The adsorption process was simple,low-cost,and had no waste discharge,suggesting that the CA-P204 was promising,efficient,and economical for removing Ti(IV)from high-sulfur bauxite leaching solution.展开更多
There exists large space to save energy of high-sulfur natural gas purification process.The multi-objective optimization problem has been investigated to effectively reduce the total comprehensive energy consumption a...There exists large space to save energy of high-sulfur natural gas purification process.The multi-objective optimization problem has been investigated to effectively reduce the total comprehensive energy consumption and further improve the production rate of purified gas.A steady-state simulation model of high-sulfur natural gas purification process has been set up by using ProMax.Seven key operating parameters of the purification process have been determined based on the analysis of comprehensive energy consumption distribution.To solve the problem that the process model does not converge in some conditions,back-propagation(BP)neural network has been applied to substitute the simulation model to predict the relative parameters in the optimization model.The uniform design method and the table U21(107)have been applied to design the experiment points for training and testing BP model.High prediction accuracy can be achieved by using the BP model.Nondominated sorting genetic algorithm-II has been developed to optimize the two objectives,and 100 Pareto optimal solutions have been obtained.Three optimal points have been selected and evaluated further.The results demonstrate that the total comprehensive energy consumption is reduced by 13.4%and the production rate of purified gas is improved by 0.2%under the optimized operating conditions.展开更多
In China,there are a lot of high-sulfur gas reservoirs with total proved reserves of over 1 trillion m3,most of which were discovered in the Sichuan Basin.Most high-sulfur gas reservoirs in China,distributed in marine...In China,there are a lot of high-sulfur gas reservoirs with total proved reserves of over 1 trillion m3,most of which were discovered in the Sichuan Basin.Most high-sulfur gas reservoirs in China,distributed in marine carbonate zones,are characterized by great buried depths,complex geologic conditions,high temperatures,high pressures,high H_(2)S and CO_(2) content,presenting various challenges in gas field development engineering and production safety.Since the development of Sinian high-sulfur gas reservoirs in the Weiyuan area of the Sichuan Basin started in the 1960s,Wolonghe,Zhongba and other medium to small-scale gas reservoirs with medium to low sulfur content have been developed.Ever since 2009,successful production of Longgang and Puguang in the Sichuan Basin,together with some other high-sulfur gas reservoirs highlighted the breakthroughs in development technologies for high-sulfur gas reservoirs in China.This paper reviews the progress made in gas reservoir engineering,drilling and completion engineering,gas production,pipeline transportation,corrosion control,natural gas purification,HSE and other aspects with consideration of specific requirements related to safe,clean and high-efficient development of highsulfur gas reservoirs since the“12th Five-Year Plan”period.Finally,considering the challenges in the development of high-sulfur gas reservoirs in China,we summarized the trend in future technological development with the following goals of reducing risks,minimizing environmental damages,and enhancing the efficiency of high-sulfur gas reservoir development.展开更多
To increase purified gas production and reduce the comprehensive energy consumption of high-sulfur natural gas sweetening unit,a process simulation model was established by using ProMax based on the field operation da...To increase purified gas production and reduce the comprehensive energy consumption of high-sulfur natural gas sweetening unit,a process simulation model was established by using ProMax based on the field operation data in the Sinopec Puguang Natural Gas Purification Plant.Then,sensitivity analysis and optimization study were carried out on the main operating parameters,including circulation rates,the concen-trations and the inlet temperatures of primary and secondary absorption towers of MDEA(methyldiethanolamine)solutions.Furthermore,the effects of reduction of the feed gas load and pressure and increasement of H_(2)S content on the quality and yield rates of purified gas were analyzed under the optimized operating conditions with the actual field situations.And the following research results were obtained.First,the absorption selectivity of MDEA solutions can be improved by decreasing the circulation rates,concentrations and inlet temperatures of MDEA solutions,which is favorable for the increase of the yield rates of purified gas.Specifically,the circulation rate of MDEA solution is the main factor influencing the comprehensive energy consumption of a high-sulfur natural gas sweetening unit.Second,when the flow rate,pressure and H 2S content of feed gas fluctuate,the purification requirements can be satisfied under the optimized operating conditions.Third,energy con-servation under low flow rates of feed gas can be achieved by reducing the flow rates of regenerated steam and adjusting the position of MDEA solutions entering the secondary absorption tower.Fourth,as H_(2)S content is increased by 1%,it is necessary to increase the circulation rate of MDEA solution by about 20×10^(3)kg/h.Fifth,after parameter optimization,the yield rate of purified gas is increased by 0.5%and the comprehensive energy consumption is reduced by 19.1%under the operating condition of full load.展开更多
The centralized processing of high-sulfur and high-acidity crude has contributed to improvement of the overall economic benefits of the oil refining enterprise, but has also resulted in crude emulsification, severe co...The centralized processing of high-sulfur and high-acidity crude has contributed to improvement of the overall economic benefits of the oil refining enterprise, but has also resulted in crude emulsification, severe corrosion of process units and environmental protection issues. The long-cycle, safe and smooth operation of process units were guaranteed after selection of optimal processing routes and adoption of a series of technical measures.展开更多
In order to apply the electric submersible pump(ESP)based drainage gas recovery technology commonly used in conventional gas wells to high-sulfur gas wells,and meet the requirements of casing protection in high-sulfur...In order to apply the electric submersible pump(ESP)based drainage gas recovery technology commonly used in conventional gas wells to high-sulfur gas wells,and meet the requirements of casing protection in high-sulfur gas wells,we conducted a series of technical researches on casing protection,gas interference and vibration of deep-well ESP set in terms of a completion string design and support tools based on the completion modes of high-sulfur gas wells and the technical characteristics of ESP drainage gas recovery technologies.Simultaneously,drainage gas recovery technology was designed for Well L2.The research and application results show:firstly,the completion string system of high-sulfur gas wells composed of a canned ESP system and an anchor intubation packer can realize the normal operation of ESP and meet the requirements of casing protection;secondly,multiphase pump and bleeder line can be used to solve the problem of gas interference,the automatic reverse valve can be used to reduce the effect of ESP complex flow path on the flowing of the gas well,and the anchor intubation packer can be used to reduce the string vibration;thirdly,the canned ESP system designed in this paper is applicable toØ244.5 mm andØ177.8 mm casings,specifically,the ESP corresponding toØ244.5 mm casing has the maximum flow rate of 900 m^(3)/d and the maximum lift height of 4500 m,and that corresponding toØ177.8 mm casing has the maximum flow rate of 300 m^(3)/d and the maximum lift height of 3000 m.It is concluded that this research result provides a technical support for the implementation of ESP based drainage gas recovery technology in high-sulfur gas wells.展开更多
Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5...Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.展开更多
Contents of the rare-earth elements (REE) in two coal seams from North Shanxi Province, China, were determined using the instrumental neutron activation method. Based on the REE distribution patterns, and correlation ...Contents of the rare-earth elements (REE) in two coal seams from North Shanxi Province, China, were determined using the instrumental neutron activation method. Based on the REE distribution patterns, and correlation analysis and cluster analysis, the main conclusions were drawn as follows. The REE contents are controlled mainly by the coal-forming environments, but might be affected by acidic solution leaching after peat sedimentation. The REE distribution patterns should be nearly the same in the sublayers of the same coal seam, and the occurrence of abnormal patterns might indicate the geological effect during post-sedimentation. The REE in coals are present mainly in the inorganic phase, and might be derived mainly from terrigenous detrital minerals. Some harmful elements, such as V, P, Mo, Cr, Cu, Mo, Th and Cd, might have cleaning potential during processing and dressing by washing because they are associated with REE.展开更多
基金supported by the National Natural Science Foundation of China(No.51974016).
文摘Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which relies on lixiviants prepared using volatilized sulfur obtained from roasting,has not been fully elucidated.This study employs the response surface methodology to optimize processing parameters,resulting in an increased gold extraction rate of 96.18%.Analytical factorization and the Tafel curve indicate that CuSO_(4) and NH_(3)·H_(2)O significantly influence the self-leaching process.Furthermore,X-ray photoelectron spectroscopy(XPS)analysis reveals that S^(2−),S_(2)^(2−),polysulfides(S_(n)^(2−)),and thiosulfate(S_(2)O_(3)^(2−))are involved in the gold leaching reaction,with S^(2−),S_(2)^(2−),and S_(n)^(2−) serving as primary ligands for gold complexation.The role of S_(2)O_(3)^(2−) in the early stages of the gold-leaching reaction is also noteworthy.The copper–ammonia complex catalyzes the self-leaching gold reaction;however,an improper addition ratio can lead to copper-sulfur compound precipitates,reducing the extraction rate.
基金the financial support from the Anhui Key Laboratory of Low Carbon Metallurgy and Solid Waste Resource Utilization(Anhui University of Technology)(No.SKF23-01)Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology(No.FMRUlab23-1010)+1 种基金Open Project of State Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS 2022-07)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200).
文摘The effect of the initial(Al+Si)/MnO molar ratio and slag composition on MnO recovery from electroslag by remelting at 1773 K was investigated.High-purity aluminum metal and silicon were employed as the deoxidizers to effectively promote the recovery of manganese metal(MM).The reduction of MnO in slag,through the interaction between molten MM with a deoxidizer and the Na_(2)O-enriched electroslag melt,was assessed both thermodynamically and kinetically.The sulfur content of high-sulfur rejected electrolytic manganese metal(EMM)scrap decreased to 0.58%with high-temperature pretreatment.The mass ratio between slag and high-sulfur rejected EMM scrap is 2/3.When the Al_(2)O_(3)content in the initial slags decreased and the Na_(2)O content increased,the MnO reduction ratio increased.The residual MnO concentration of the slag reduced with increasing the Al–Si deoxidizer content.When the(Al+Si)/MnO molar ratio reached 0.83,the MnO concentration in the final slag was only 3%.A deoxidizer mainly containing aluminum and a small amount of Si could be added to recover MnO from the slag,resulting in the improvement in the cleanliness of final Mn metal.
基金financial support of National Natural Science Foundation of China(U1910201,21878208)Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi(TSTAP)Shanxi Province Science Foundation for Key Program(201901D111001(ZD))。
文摘The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.
基金financially supported by the National Natural Science Foundation of China (Nos. 51504048, 51611130062, 51874059 and 51874060)the Natural Science Foundation of Chongqing (No. cstc2018jcyjAX0647)the Fundamental Research Funds for the Central Universities of China (No. cqu2018CDHB1B05)
文摘Segregation and inclusion precipitation are the common behaviours of steel solidification, which are resulted from the redistribution and diffusion of the solute elements at the solid-liquid interface. The effect of the phase transition of high-sulfur free-cutting steel is quantified in the present work for the solute partition coefficient(ki), inclusion precipitation, and microsegregation by establishing a coupling model of microsegregation and inclusion precipitation, wherein the quantified dependencies of ki in terms of temperature, phase and carbon(C) content were applied. Results showed that the solidification temperature range and phase transition of high-sulfur steel that under different solidification paths and C contents were quite different, leading to differences in ki and eventually in microsegregation. kC,kP, and kS were mainly affected by phase composition and kSi was primarily by temperature, while kMn depended on both phase composition and temperature during solidification. Increasing the C content within the interval 0.07-0.48 wt%, the ‘proportion of the δ phase maintained temperature region during solidification’(Pδ), kave Pand kave S(kiave, the average value of the ki across the whole stages of solidification)decreased monotonically, whereas kave Cincreased linearly. The peritectic reaction impacted on the phase composition and ki, leading to the change in microsegregation. Such effect of the peritectic reaction was more significant at the last stage of solidification. When the Pδ was between 75% and 100%(corresponding to 0.07-0.16 wt% C), the solidification path resulted in a greater effect on the microsegregation of solutes C, P, and S because of the peritectic reaction. The microsegregation of solutes Mn and S were comprehensively influenced by kMn, kS and Mn S precipitation as well. The studies would help reveal the solute redistribution at the solid-liquid interface, and improve the segregation of high-sulfur steel by controlling the solidification and precipitation in practice.
基金This work was financially supported by the National Natural Science Foundation of China(No.21722604)the Postdoctoral Foundation of China(Nos.2019M651743 and 2020M671365)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20190852)the National Youth Natural Science Foundation(No.8111310009).
文摘High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic sulfur.Herein,we design and construct a highly efective CTAB@HPA composites to be explored for the catalytic oxidative desulfurization of HSPC under mild conditions using hydrogen peroxide as the oxidant and 1-butyl-3-methylimidazole tetrafuoroborate ionic liquid as the extractant.The results demonstrate that the sulfur content of HSPC could be strikingly reduced from 4.46 wt%to 2.48 wt%under 60℃ and atmospheric pressure,and that the organic sulfur in HSPC is mainly oxidized to sulfoxide,sulfone and sulfate,which latter can be directly separated from petroleum coke.Moreover,the efect of reaction conditions on the desulfurization performance of HSPC as well as the catalytic oxidation reaction kinetic of HSPC desulfurization was systematically investigated.Furthermore,a mechanism for the oxidative desulfurization of HSPC over CTAB@HPA catalysts was proposed.Therefore,this work provides new insight into how to construct active catalysts for the desulfurization of HSPC under mild conditions.
基金Funds to support this research were provided by the National Science Foundation of China(no. 40703011)
文摘High-sulfur,heavy petroleum is widely occurring in the Tertiary lacustrine Jiyang sub-basin, Bohai Bay Basin.They are differentiated into two families based on the bulk properties and biomarker compositions.Family 1 is characterized by high resins（40%-71%）and sulfur（2%-4%）,and low wax （l%-6%）,with n-alkanes removed by biodegradation,whereas family 2 is characterized by extremely abundant sulfur（3%-10%）,and high asphaltenes（7%-31%）and wax（2%-19%）,with no evidence of microbial attack.The oils of family 1 are distributed in the reservoir,lower than 1500 m throughout the sub-basin.Biomarker assemblages,such as low pristane/phytane ratios（1 Pr/Ph）and a high abundance of carotane,gammacerane,and dinosterane,suggest that they are derived from the calcareous mudstones and shales among the stratified,saline Es_4~u unit,in addition to the in situ biodegradation-concentrated sulfur content.However,the oils of family 2 are identified only in the western Zhanhua and eastern Chezhen depressions,with a depth deeper than 1700 m.Physical properties,together with biomarker ratios,including even-numbered n-alkanes,1 Pr/Ph,trace diasteranes,higher C35 homohopanes,and abundant dibenzothiophene series,with1 dibenzothiophene/phenanthrene,indicate an origin from carbonate source rocks.The X-ray diffraction analysis showed that the carbonate source rock is limited in the Es_4~u unit of the Bonan sag,which is different from most other source rocks in the same horizon.It is suggested that the high-sulfur,heavy oils are generated at the early stage of the oil window.Bacterial sulfate reduction might be responsible for the occurrence of sulfur species in the high-sulfur,heavy oils,while heavy biodegradation will enhance sulfur concentrations.
基金supported by the National Key R&D Program of China (No.2019YFC1805001)Open Foundation of State Key Laboratory of Mineral Processing (No.BGRIMM-KJSKL2022-07)。
文摘The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in soil.Its spatial distribution and environment risk assessment are extremely important for the management and remediation of HMs.Eighty soil samples were collected from the high-sulfur CG site in northern China and analyzed for six HMs.The results showed that the soil was heavily contaminated by Mn,Cr and Ni based on the Nemerow index,and posed seriously ecological risk depended on the geo-accumulation index,potential ecological risk index and risk assessment code.The semi-variogram model and ordinary kriging interpolation accurately portrayed the spatial distribution of HMs.Fe,Mn,and Cr were distributed by band diffusion,Ni was distributed by core,the distribution of Cu had obvious patchiness and Zn was more uniform.The spatial autocorrelation indicated that all HMs had strong spatial heterogeneity.The BCR sequential extraction was employed to qualify the geochemical fractions of HMs.The data indicated that Fe and Cr were dominated by residual fraction;Cu,Ni and Zn were dominated by reducible and oxidizable fractions;Mn was dominated by reducible and acid-extractable(25.38%-44.67%)fractions.Pearson correlation analysis showed that pH was the main control factor affecting the non-residue fractions of HMs.Therefore,acid production from high sulfur CG reduced soil pH by 2-3,which indirectly promoted the activity of HMs.Finally,the conceptual model of HMs contamination at the CG site was proposed,which can be useful for the development of ecological remediation strategies.
基金Project(21201094) supported by the National Natural Science Foundation of China
文摘In the leaching solution of high-sulfur bauxite roasted by sulfuric acid,a high concentration of aluminum presented along with titanium and iron.The present work was to remove Ti(IV)from the leach liquor by calcium alginate microsphere sorbent material(CA-P204)based on natural alginate impregnated with di-(2-ethylhexyl)phosphoric acid(D2EHPA)to purify leaching solution.Cation exchange and chelation make major contributions to the adsorption mechanism according to Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis.The results showed that Ti(IV)was successfully removed by the CA-P204 adsorbent from the Ti(IV)-Al(III)-Fe(III)ternary system with a dynamic column experiment.The removal rate of titanium was nearly 95%under optimal conditions and the maximum adsorption capacity was 66.79 mg/g at pH 1.0.Reusability of CA-P204 was evaluated over three consecutive adsorption/desorption cycles.The adsorption process was simple,low-cost,and had no waste discharge,suggesting that the CA-P204 was promising,efficient,and economical for removing Ti(IV)from high-sulfur bauxite leaching solution.
基金Financial support from National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2016ZX05017-004)
文摘There exists large space to save energy of high-sulfur natural gas purification process.The multi-objective optimization problem has been investigated to effectively reduce the total comprehensive energy consumption and further improve the production rate of purified gas.A steady-state simulation model of high-sulfur natural gas purification process has been set up by using ProMax.Seven key operating parameters of the purification process have been determined based on the analysis of comprehensive energy consumption distribution.To solve the problem that the process model does not converge in some conditions,back-propagation(BP)neural network has been applied to substitute the simulation model to predict the relative parameters in the optimization model.The uniform design method and the table U21(107)have been applied to design the experiment points for training and testing BP model.High prediction accuracy can be achieved by using the BP model.Nondominated sorting genetic algorithm-II has been developed to optimize the two objectives,and 100 Pareto optimal solutions have been obtained.Three optimal points have been selected and evaluated further.The results demonstrate that the total comprehensive energy consumption is reduced by 13.4%and the production rate of purified gas is improved by 0.2%under the optimized operating conditions.
文摘In China,there are a lot of high-sulfur gas reservoirs with total proved reserves of over 1 trillion m3,most of which were discovered in the Sichuan Basin.Most high-sulfur gas reservoirs in China,distributed in marine carbonate zones,are characterized by great buried depths,complex geologic conditions,high temperatures,high pressures,high H_(2)S and CO_(2) content,presenting various challenges in gas field development engineering and production safety.Since the development of Sinian high-sulfur gas reservoirs in the Weiyuan area of the Sichuan Basin started in the 1960s,Wolonghe,Zhongba and other medium to small-scale gas reservoirs with medium to low sulfur content have been developed.Ever since 2009,successful production of Longgang and Puguang in the Sichuan Basin,together with some other high-sulfur gas reservoirs highlighted the breakthroughs in development technologies for high-sulfur gas reservoirs in China.This paper reviews the progress made in gas reservoir engineering,drilling and completion engineering,gas production,pipeline transportation,corrosion control,natural gas purification,HSE and other aspects with consideration of specific requirements related to safe,clean and high-efficient development of highsulfur gas reservoirs since the“12th Five-Year Plan”period.Finally,considering the challenges in the development of high-sulfur gas reservoirs in China,we summarized the trend in future technological development with the following goals of reducing risks,minimizing environmental damages,and enhancing the efficiency of high-sulfur gas reservoir development.
基金Project supported by the National Science and Technology Major Project“Technologies for the Safe and Efficient Operation of Gathering and Purification System in High-Sulfur Gas Fields”(No.2016ZX05017-004).
文摘To increase purified gas production and reduce the comprehensive energy consumption of high-sulfur natural gas sweetening unit,a process simulation model was established by using ProMax based on the field operation data in the Sinopec Puguang Natural Gas Purification Plant.Then,sensitivity analysis and optimization study were carried out on the main operating parameters,including circulation rates,the concen-trations and the inlet temperatures of primary and secondary absorption towers of MDEA(methyldiethanolamine)solutions.Furthermore,the effects of reduction of the feed gas load and pressure and increasement of H_(2)S content on the quality and yield rates of purified gas were analyzed under the optimized operating conditions with the actual field situations.And the following research results were obtained.First,the absorption selectivity of MDEA solutions can be improved by decreasing the circulation rates,concentrations and inlet temperatures of MDEA solutions,which is favorable for the increase of the yield rates of purified gas.Specifically,the circulation rate of MDEA solution is the main factor influencing the comprehensive energy consumption of a high-sulfur natural gas sweetening unit.Second,when the flow rate,pressure and H 2S content of feed gas fluctuate,the purification requirements can be satisfied under the optimized operating conditions.Third,energy con-servation under low flow rates of feed gas can be achieved by reducing the flow rates of regenerated steam and adjusting the position of MDEA solutions entering the secondary absorption tower.Fourth,as H_(2)S content is increased by 1%,it is necessary to increase the circulation rate of MDEA solution by about 20×10^(3)kg/h.Fifth,after parameter optimization,the yield rate of purified gas is increased by 0.5%and the comprehensive energy consumption is reduced by 19.1%under the operating condition of full load.
文摘The centralized processing of high-sulfur and high-acidity crude has contributed to improvement of the overall economic benefits of the oil refining enterprise, but has also resulted in crude emulsification, severe corrosion of process units and environmental protection issues. The long-cycle, safe and smooth operation of process units were guaranteed after selection of optimal processing routes and adoption of a series of technical measures.
基金supported by the National Major Science and Technology Project“Demonstration development project of large carbonate gas field in the Sichuan Basin”(No.2016ZX05052)。
文摘In order to apply the electric submersible pump(ESP)based drainage gas recovery technology commonly used in conventional gas wells to high-sulfur gas wells,and meet the requirements of casing protection in high-sulfur gas wells,we conducted a series of technical researches on casing protection,gas interference and vibration of deep-well ESP set in terms of a completion string design and support tools based on the completion modes of high-sulfur gas wells and the technical characteristics of ESP drainage gas recovery technologies.Simultaneously,drainage gas recovery technology was designed for Well L2.The research and application results show:firstly,the completion string system of high-sulfur gas wells composed of a canned ESP system and an anchor intubation packer can realize the normal operation of ESP and meet the requirements of casing protection;secondly,multiphase pump and bleeder line can be used to solve the problem of gas interference,the automatic reverse valve can be used to reduce the effect of ESP complex flow path on the flowing of the gas well,and the anchor intubation packer can be used to reduce the string vibration;thirdly,the canned ESP system designed in this paper is applicable toØ244.5 mm andØ177.8 mm casings,specifically,the ESP corresponding toØ244.5 mm casing has the maximum flow rate of 900 m^(3)/d and the maximum lift height of 4500 m,and that corresponding toØ177.8 mm casing has the maximum flow rate of 300 m^(3)/d and the maximum lift height of 3000 m.It is concluded that this research result provides a technical support for the implementation of ESP based drainage gas recovery technology in high-sulfur gas wells.
基金the Australian Government and University of Queensland for the research training program scholarship and research facilities used in this study.
文摘Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.
文摘Contents of the rare-earth elements (REE) in two coal seams from North Shanxi Province, China, were determined using the instrumental neutron activation method. Based on the REE distribution patterns, and correlation analysis and cluster analysis, the main conclusions were drawn as follows. The REE contents are controlled mainly by the coal-forming environments, but might be affected by acidic solution leaching after peat sedimentation. The REE distribution patterns should be nearly the same in the sublayers of the same coal seam, and the occurrence of abnormal patterns might indicate the geological effect during post-sedimentation. The REE in coals are present mainly in the inorganic phase, and might be derived mainly from terrigenous detrital minerals. Some harmful elements, such as V, P, Mo, Cr, Cu, Mo, Th and Cd, might have cleaning potential during processing and dressing by washing because they are associated with REE.
