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Separation and enrichment of elemental sulfur and mercury from hydrometallurgical zinc residue using sodium sulfide 被引量:2
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作者 王子阳 蔡晓兰 +3 位作者 张泽彪 张利波 王仕兴 彭金辉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期640-646,共7页
The separation and enrichment of mercury and the recovery of elemental sulfur from flotation sulfur concentrate in zinc pressure leaching process were carried out by sodium sulfide leaching and carbon dioxide precipit... The separation and enrichment of mercury and the recovery of elemental sulfur from flotation sulfur concentrate in zinc pressure leaching process were carried out by sodium sulfide leaching and carbon dioxide precipitating. The results show that the leaching rate of elemental sulfur is more than 98%, and 98.13% of mercury is enriched in the residue, under the optimized conditions of sodium sulfide concentration 1.5 mol/L, liquid/solid ratio 6:1 and leaching time 30 min at room temperature. In addition, the content of mercury is enriched 5.23 times that in the leaching residue. The elemental sulfur is precipitated from leaching solution under conditions of carbon dioxide flow rate 200 mL/min and blowing time 150 min, while solution is stirred adequately. The recovery efficiency of elemental sulfur reaches 97.67%, and the purity of elemental sulfur is 99.75%, meeting the requirements of industrial first-rate product standard according to the national standard of GB/T 2449-2006 (PRC). 展开更多
关键词 flotation sulfur concentrate sodium sulfide leaching carbon dioxide precipitating mercury enrichment elemental sulfurrecovery
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Reaction kinetics of roasting high-titanium slag with concentrated sulfuric acid 被引量:12
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作者 隋丽丽 翟玉春 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第3期848-853,共6页
A novel method of roasting high-titanium slag with concentrated sulfuric acid was proposed to prepare titanium dioxide, and the roasting kinetics of titania was studied On the basis of roasting process. The effects of... A novel method of roasting high-titanium slag with concentrated sulfuric acid was proposed to prepare titanium dioxide, and the roasting kinetics of titania was studied On the basis of roasting process. The effects of roasting temperature, particle size, and acid-to-ore mass ratio on the rate of roasting reaction were investigated. The results showed that the roasting reaction is fitted to a shrinking core model. The results of the kinetic experiment and SEM and EDAX analyses proved that the reaction rate of roasting high-titanium slag with concentrated sulfuric acid is controlled by the internal diffusion on the solid product layer. According to the Arrhenius expression, the apparent activation energy of the roasting reaction is 18.94 kJ/mol. 展开更多
关键词 roasting kinetics high-titanium slag concentrated sulfuric acid TITANIA
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Recovery of scandium from silicate minerals by high-pressure leaching in sulfuric acid
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作者 Peng Yan Xiaoming Chen +1 位作者 Likun Gao Bo Yang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第7期1375-1384,I0007,共11页
This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are ... This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of isomorphism.High-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this samples.The Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 h.The X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole shape.Compared with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption. 展开更多
关键词 Silicate minerals SCANDIUM High-pressure LEACHING Concentrated sulfuric acid Rare earths
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Studies on Material Cycling in Evergreen Broad-LeavedForest Ecosystem in Hangzhon: Ⅲ. S Concentrationand Its Storage in Vegetation
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作者 JIANG QIU-YI HE LI-MING and QIAN XIN-BIAO(Zhejiang Forestey College, Lin’an, 311300 (China)) 《Pedosphere》 SCIE CAS CSCD 1994年第1期47-52,共6页
This paper reveals the variations of S concentration among the leaf surface and other organs of variousplant species, and presents the distribution natures of S storage in the evergreen broad-leaved forest vege-tation... This paper reveals the variations of S concentration among the leaf surface and other organs of variousplant species, and presents the distribution natures of S storage in the evergreen broad-leaved forest vege-tation in Hangzhou on the basis of the tested data concerning plant S contents. The result was that theS concentrations on the tree leaf surfaces varied with the testing time and plant species. The range of Scontents in various organs of a plant was 2.086- 4.245 S g kg ̄(-1), varying with plant species in this forest.The S content in the leaves was the highest, followed by that in the branches, trunks and roots, which showedthat there was an apical dominance of S distribution. The total amount of S storage in the vegetation wasas large as 349.97 S kg ha ̄(-1). The S distribution in this vegetation had two characteristics as follows: 1)for the vegetation layers, arbor layer > renewal layer > herb layer > shrub layer; and 2) for the verticaldistribution per unit height (m), root stratum (0 - 0.20 m of soil depth)> stratum nearby the ground surface(0 - 0.5m) > canopy (4.0- 9.5m) > trunk stratum (2.0- 4.0m). 展开更多
关键词 evergreen broad-leaved forest storage of S sulfur concentration
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A new distance correction method for sulfur analysis in coal using online XRF measurement system 被引量:5
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作者 JIA WenBao ZHANG Yan +3 位作者 GU ChenGuang HEI DaQian LING YongShen SHAN Qing 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第1期39-43,共5页
When X-ray fluorescence (XRF) technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal's uneven surface and the particle size. In order to improve th... When X-ray fluorescence (XRF) technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal's uneven surface and the particle size. In order to improve the accuracy of sulfur concentration measurement, an online measurement system, consisting of a portable X-ray fluorescence instrument and an auxiliary distance correction module, was developed in this paper. By measuring the standard coal samples of known sulfur concentration, we obtained a calibration curve that can be used to analyze the sulfur concentration. We studied the relationship between the X-ray fluorescence intensity (I) and the distance (D) from surfaces to instrument. The results showed that there was a good linear re- lationship between 1 and D when the sulfur content was certain. Based on these knowledge, the distance correction formula of X-ray fluorescence intensity was proposed. By applying the distance correction formula to experimental sulfur concentration measurement, we demonstrated that the measurement accuracy can be significantly increased. 展开更多
关键词 XRF sulfur concentration distance correction COAL
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Recovery of titania from high titanium slag by roasting method using concentrated sulfuric acid 被引量:5
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作者 Li-Li Sui Yu-Chun Zhai Li-Hua Miao 《Rare Metals》 SCIE EI CAS CSCD 2015年第12期895-900,共6页
By means of energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM) analysis, the phase structure characteristics of high titanium slag were analyzed. Through the single factor and the orthog... By means of energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM) analysis, the phase structure characteristics of high titanium slag were analyzed. Through the single factor and the orthogonal experiment methods, the effects of material particle size, mass ratio of acid to ore, roasting temperature, and roasting time on the acidolysis ratio of TiO<sub>2</sub> during the process of roasting high titanium slag with concentrated sulfuric acid were systematically investigated. The results show that the sequence of each factor affecting the acidolysis ratio of TiO<sub>2</sub> is: mass ratio of acid to ore, roasting time, and roasting temperature. The optimum technological conditions are obtained as mass ratio of acid to ore of 2.1, roasting temperature of 310°C, roasting time of 75min, and material particle size of 45–53μm. The acidolysis ratio of TiO<sub>2</sub> is over 96% under the optimum conditions. The roasting process is proved to be significant in the exploitation and utilization of high titanium slag. The advantages of the proposed roasting process are of high efficiency, low power consumption, and minimum pollution. 展开更多
关键词 Concentrated sulfuric acid ROASTING High titanium slag TITANIA
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One-step synthesis of c-caprolactam via the liquid phase catalytic nitrosation of cyclohexane in the presence of concentrated sulfuric acid
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作者 Kuiyi YOU Fangfang ZHAO +3 位作者 Xueyan LONG Pingle LIU Qiuhong AI Hean LUO 《Frontiers of Chemical Science and Engineering》 CAS CSCD 2012年第4期389-394,共6页
A simple and efficient approach for the synthesis of e-caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series ... A simple and efficient approach for the synthesis of e-caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series of novel A1VPO composites were prepared by an impregnation method and the composites were then employed to catalyze the nitrosation reaction of cyclohexane and nitrosyl sulfuric acid. Compared to the reaction using fuming sulfuric acid, the selectivity for the desired product was significantly improved using this one-step catalytic process. This method affords a shortcut to prepare ecaprolactam and its analogs from cyclohexane. 展开更多
关键词 CYCLOHEXANE e-caprolactam A1VPO compo-site catalysts one-step synthesis concentrated sulfuric acid
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Influence of Mechanical Activation on Acid Leaching Dephosphorization of High-phosphorus Iron Ore Concentrates 被引量:1
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作者 De-qing ZHU Hao WANG +1 位作者 Jian PAN Cong-cong YANG 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2016年第7期661-668,共8页
High pressure roll grinding(HPRG)and ball milling were compared to investigate the influence of mechanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was manufa... High pressure roll grinding(HPRG)and ball milling were compared to investigate the influence of mechanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was manufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indicated that when high-phosphorus iron ore concentrates containing 54.92 mass% iron and 0.76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55.74mass%iron and 0.33mass%phosphorus with an iron recovery of 84.64%and dephosphorization of 63.79% were obtained.When high-phosphorus iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing56.03mass%iron and 0.21mass% phosphorus with an iron recovery of 85.65% and dephosphorization of 77.49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58.02mass%iron and 0.10mass% phosphorus were obtained,with the iron recovery reaching 88.42% and the dephosphorization rate reaching 88.99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating aprominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical activation,further strengthening the dephosphorization. 展开更多
关键词 high-phosphorus iron ore concentrate high pressure roll grinding ball milling selective dissociation sulfuric acid leaching dephosphorization iron recovery
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Origin of high particle number concentrations reaching the St. Louis, Midwest Supersite 被引量:2
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作者 Benjamin de Foy James J.Schauer 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第8期219-231,共13页
Ultrafine particles are associated with adverse health effects. Total Particle Number Concentration(TNC) of fine particles were measured during 2002 at the St. Louis — Midwest supersite. The time series showed over... Ultrafine particles are associated with adverse health effects. Total Particle Number Concentration(TNC) of fine particles were measured during 2002 at the St. Louis — Midwest supersite. The time series showed overall low level with frequent large peaks. The time series was analyzed alongside criteria pollutant measurements and meteorological observations. Multiple regression analysis was used to identify further contributing factors and to determine the association of different pollutants with TNC levels. This showed the strong contribution of sulfur dioxide(SO2) and nitrogen oxides(NO x) to high TNC levels. The analysis also suggested that increased dispersion resulting from faster winds and higher mixing heights led to higher TNC levels. Overall, the results show that there were intense particle nucleation events in a SO2 rich plume reaching the site which contributed around 29% of TNC. A further 40% was associated with primary emissions from mobile sources. By separating the remaining TNC by time of day and clear sky conditions,we suggest that most likely 8% of TNC are due to regional nucleation events and 23% are associated with the general urban background. 展开更多
关键词 Atmospheric aerosols Particle number concentrations Fine particles sulfur dioxide plumes Mobile source emissions
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