The feasibility of reducing Cr(VI)from the aqueous solution by sulfuric acid-modified titanium-bearing blast furnace slag(SATBBFS)as a photocatalyst was investigated.The photocatalysts were examined by X-ray diffracti...The feasibility of reducing Cr(VI)from the aqueous solution by sulfuric acid-modified titanium-bearing blast furnace slag(SATBBFS)as a photocatalyst was investigated.The photocatalysts were examined by X-ray diffraction(XRD),UV-vis diffuse reflectance spectra,thermogravimetric analysis(TG)and Fourier transform infrared spectroscopy(FTIR).The photocatalytic activities of the different catalysts were evaluated by the photocatalytic reduction of Cr(VI)under UV-vis light irradiation.The results show that the photocatalytic activities of SATBBFS catalysts are strongly dependent on CaTiO3-to-TiO2 mass ratio,adsorption capacity and surface acidity,and SATBBFS calcined at 400°C shows a higher photocatalytic activity compared with other catalysts.展开更多
In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which i...In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which is comprised of(NH4)2 S04 roasting,acid leaching,ammonium alum crystallization,silicic acid flocculation and Ti hydrolysis.The effects of relevant process parameters were systematically investigated.The re sults showed that under the optimal roasting and leaching conditions about 85%of titanium and 84.6%of aluminum could be extracted while only 30%of silicon entered the leachate.84%of Al^3+was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%.About 85%of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9(AEO-9)to yield a microporous SiO2 material(97.4 wt%)from the crystallized mother liquor.The Al-and Si-depleted solution was then hydrolyzed to generate a titanium dioxide(99.1 wt%)with uniform particle size distribution.It was figured out that approximately 146 kg TiO2 could be produced from 1000 kg of TBBF slag.Therefore,the improved process is a promising method for industrial application.展开更多
Titanium-bearing blast furnace slag(BFS)has valuable compositions and potential environmental hazardousness.Thus,developing efficient and green approaches to utilize BFS is highly desired for resource economization an...Titanium-bearing blast furnace slag(BFS)has valuable compositions and potential environmental hazardousness.Thus,developing efficient and green approaches to utilize BFS is highly desired for resource economization and environmental protection.In the past decades,many attempts have been adopted to reuse BFS efficiently,and significant advances in understanding the fundamental features and the development of efficient approaches have been achieved.This review provides a comprehensive overview of the latest progress on the efficient utilization of BFS and discusses the mechanism and characteristics of various approaches,along with their application prospects.In particular,the extraction and enrichment of titanium-bearing phases from BFS are highlighted because of the high availability of titanium resources.This systemic and comprehensive review may benefit the design of new and green utilization routes with high efficiency and low cost.展开更多
Perovskite-type V-doped titanium-bearing blast furnace slag (VTBBFS) photocatalyst was prepared by high-temperature solid phase method.The influence of calcination temperature on the photocatalytic and antibacterial p...Perovskite-type V-doped titanium-bearing blast furnace slag (VTBBFS) photocatalyst was prepared by high-temperature solid phase method.The influence of calcination temperature on the photocatalytic and antibacterial properties of VTBBFS was studied in details.Its composition and microstructure were evaluated by X-ray diffractometer,ultraviolet-visible absorption spectrometer,Fourier transform infrared spectrometer and scanning electron microscope.The antibacterial properties of VTBBFS to Candida albicans were investigated by flask oscillation method.The results showed that the optical absorption and antibacterial properties of VTBBFS were the best with 10%(ω) doping of vanadium,prepared at 800℃ for 2 h,and its sterilization rate was close to 100% to Candida albicans (ATCC10231).The minimum inhibitory and minimum bactericidal concentrations were 25 and 50 mg/mL.When the concentration was 0.2 μg/mL,the catalyst had the least toxic toxicity.展开更多
An energy-efficient route was adopted to treat titanium-bearing blast furnace slag(TBBFS)in this study.Titanium,aluminum,and magnesium were simultaneously extracted and silicon was separated by low temperature sulfuri...An energy-efficient route was adopted to treat titanium-bearing blast furnace slag(TBBFS)in this study.Titanium,aluminum,and magnesium were simultaneously extracted and silicon was separated by low temperature sulfuric acid curing and low concentration sulfuric acid leaching.The process parameters of sulfuric acid curing TBBFS were systematically studied.Under the optimal conditions,the recovery of titanium,aluminum,and magnesium reached 85.96%,81.17%,and 93.82%,respectively.The rapid leaching model was used to limit the dissolution and polymerization of silicon,and the dissolution of silicon was only 3.18%.The mechanism of sulfuric acid curing-leaching was investigated.During the curing process,the reaction occurred rapidly and released heat massively.Under the attack of hydrogen ions,the structure of TBBFS was destroyed,silicate was depolymerized to form filterable silica,and titanium,magnesium,aluminum,and calcium ions were replaced to form sulfates and enriched on the surface of silica particles.Titanium,aluminum,and magnesium were recovered in the leaching solution,and calcium sulfate and silica were enriched in the residue after leaching.This method could effectively avoid the formation of silica sol during the leaching process and accelerate the solid-liquid separation.展开更多
With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first t...With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first time, which improved the solubility of the slag and converted the nutritional elements into such ones which are prone to be absorbed by plants. The effects of process conditions on dissolution rate of titanium were mainly analyzed through the orthogonal experiment. The results showed that the optimum synthesis process conditions of foliar fertilizer from the slag were 360 ℃ for 35 min, the mass ratio of ammonium sulfate and titanium-bearing blast furnace slag was 8:1. Under these conditions more than 80% of iron, titanium, magnesium and part of silicon in titanium-bearing blast furnace slag converted into water-soluble substances and existing in foliar fertilizer. Foliar fertilizer contained nitrogen, sulfur, potassium, iron, titanium, magnesium and silicon, and pH value of foliar fertilizer was 6. Ca-S-Si compound fertilizer mainly contained calcium silicate and calcium sulfate, which existed in the form of citric acid-soluble substance and slightly soluble substance, respectively.展开更多
Using differential thermal analysis, X-ray phase analysis, electron microscopy, and optical microscopy, the nucleation of crystals in glass obtained by blending metallurgical slag with silicon dioxide has been studied...Using differential thermal analysis, X-ray phase analysis, electron microscopy, and optical microscopy, the nucleation of crystals in glass obtained by blending metallurgical slag with silicon dioxide has been studied. The type of crystallization (homogeneous or heterogeneous, volume or surface) is revealed for each of nine compositions of synthesized glass. It is shown that the first crystalline phase in a volume crystallizing glass is perovskite (CaO·TiO2);in this phase a nucleation of the main phase occurs: melilite (solid solution of gehlenite 2CaO·Al2O3·SiO2 in akermanite 2CaO·MgO·2SiO2). The fundamental characteristics of homogeneous (for a catalizing phase, perovskite) and heterogeneous (for a catalyzed phase, melilite) of crystallization are determined: the steady state nucleation rate Ist, time of unsteady state nucleation τ, crystal growth rate U, and activation energy of frictional flow. The temperature dependences of Ist, τ, and U are obtained. The kinetics of the crystallization of glass is studied and the rates of the surface crystal growth are determined in the glass of nine compositions. The influence of grinding the particles of the original glass on the sequence of deposition of the crystalline phases was studied. Practical recommendations are presented for the use of blast-furnace slag as a raw material for the synthesis of glass and their further utilization.展开更多
The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the en...The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the environmental pressure caused by slag stocking.The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method.Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed.The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.展开更多
Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-pu...Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-purposes of fiber-forming, energy saving, and waste heat recovery, the modifying agents that can improve the acidity coefficient of slag effectively, economically, and environmentally were investigated. Three agents with different acidity coefficients were adopted to modify slag and manufacture wool fibers. The effect of agent and slag proportion on the melting temperature and viscosity of molten slag was studied at a fixed acidity coefficient of 1.8 and 2.0. The results indicate that the sample modified with high acidity coefficient agent and high slag proportion has lower melting temperature and viscosity. The effect of agent and slag temperature on the fiber diameter was also investigated when the acidity coefficient of slag is 2.0. At a fixed slag proportion of 50 wt.%, the mean diameter decreases with increasing temperature and decreasing viscosity coefficient. Besides, the temperature drops caused by the addition of agents and energy consumption of samples for heating the slag were also analyzed.展开更多
基金Project(N090423003)supported by the Basic Scientific Research Costs of Central Colleges of ChinaProject(2007CB613504)supported by the National Basic Research Program of ChinaProject(307009)supported by the Foundation for Key Program of Ministry of Education,China
文摘The feasibility of reducing Cr(VI)from the aqueous solution by sulfuric acid-modified titanium-bearing blast furnace slag(SATBBFS)as a photocatalyst was investigated.The photocatalysts were examined by X-ray diffraction(XRD),UV-vis diffuse reflectance spectra,thermogravimetric analysis(TG)and Fourier transform infrared spectroscopy(FTIR).The photocatalytic activities of the different catalysts were evaluated by the photocatalytic reduction of Cr(VI)under UV-vis light irradiation.The results show that the photocatalytic activities of SATBBFS catalysts are strongly dependent on CaTiO3-to-TiO2 mass ratio,adsorption capacity and surface acidity,and SATBBFS calcined at 400°C shows a higher photocatalytic activity compared with other catalysts.
基金financial support of the National Key Projects for Fundamental Research and Development of China(2016YFB0600904)Sichuan University Postdoctoral Research and Development Fund(2017SCU12017)+1 种基金Project of State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization(18H0083)Sichuan Science and Technology Department Project(2019YJ0111)。
文摘In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which is comprised of(NH4)2 S04 roasting,acid leaching,ammonium alum crystallization,silicic acid flocculation and Ti hydrolysis.The effects of relevant process parameters were systematically investigated.The re sults showed that under the optimal roasting and leaching conditions about 85%of titanium and 84.6%of aluminum could be extracted while only 30%of silicon entered the leachate.84%of Al^3+was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%.About 85%of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9(AEO-9)to yield a microporous SiO2 material(97.4 wt%)from the crystallized mother liquor.The Al-and Si-depleted solution was then hydrolyzed to generate a titanium dioxide(99.1 wt%)with uniform particle size distribution.It was figured out that approximately 146 kg TiO2 could be produced from 1000 kg of TBBF slag.Therefore,the improved process is a promising method for industrial application.
基金This work was financially supported by the National Nat-ural Science Foundation of China(No.51974011)the Key R&D Program of Ningxia Hui Autonomous Region,China(No.2019BFG02032).
文摘Titanium-bearing blast furnace slag(BFS)has valuable compositions and potential environmental hazardousness.Thus,developing efficient and green approaches to utilize BFS is highly desired for resource economization and environmental protection.In the past decades,many attempts have been adopted to reuse BFS efficiently,and significant advances in understanding the fundamental features and the development of efficient approaches have been achieved.This review provides a comprehensive overview of the latest progress on the efficient utilization of BFS and discusses the mechanism and characteristics of various approaches,along with their application prospects.In particular,the extraction and enrichment of titanium-bearing phases from BFS are highlighted because of the high availability of titanium resources.This systemic and comprehensive review may benefit the design of new and green utilization routes with high efficiency and low cost.
基金Supported by the National Natural Science Foundation of China (No. 50874029)Important Project of Education Ministry (No.307009)National Basic Research Program (973) (No.2007CB613504)
文摘Perovskite-type V-doped titanium-bearing blast furnace slag (VTBBFS) photocatalyst was prepared by high-temperature solid phase method.The influence of calcination temperature on the photocatalytic and antibacterial properties of VTBBFS was studied in details.Its composition and microstructure were evaluated by X-ray diffractometer,ultraviolet-visible absorption spectrometer,Fourier transform infrared spectrometer and scanning electron microscope.The antibacterial properties of VTBBFS to Candida albicans were investigated by flask oscillation method.The results showed that the optical absorption and antibacterial properties of VTBBFS were the best with 10%(ω) doping of vanadium,prepared at 800℃ for 2 h,and its sterilization rate was close to 100% to Candida albicans (ATCC10231).The minimum inhibitory and minimum bactericidal concentrations were 25 and 50 mg/mL.When the concentration was 0.2 μg/mL,the catalyst had the least toxic toxicity.
基金financially supported by the National Key Projects for Fundamental Research and Development of China(No.2016YFB0600904)the Sichuan University-Panzhihua city joint strategic cooperation special fund project,China(No.2018CDPZH-7)。
文摘An energy-efficient route was adopted to treat titanium-bearing blast furnace slag(TBBFS)in this study.Titanium,aluminum,and magnesium were simultaneously extracted and silicon was separated by low temperature sulfuric acid curing and low concentration sulfuric acid leaching.The process parameters of sulfuric acid curing TBBFS were systematically studied.Under the optimal conditions,the recovery of titanium,aluminum,and magnesium reached 85.96%,81.17%,and 93.82%,respectively.The rapid leaching model was used to limit the dissolution and polymerization of silicon,and the dissolution of silicon was only 3.18%.The mechanism of sulfuric acid curing-leaching was investigated.During the curing process,the reaction occurred rapidly and released heat massively.Under the attack of hydrogen ions,the structure of TBBFS was destroyed,silicate was depolymerized to form filterable silica,and titanium,magnesium,aluminum,and calcium ions were replaced to form sulfates and enriched on the surface of silica particles.Titanium,aluminum,and magnesium were recovered in the leaching solution,and calcium sulfate and silica were enriched in the residue after leaching.This method could effectively avoid the formation of silica sol during the leaching process and accelerate the solid-liquid separation.
基金This study was supported by the National Natural Science Foundation of China (No. 50874029) and the National Basic Research Program of China (No.2007CB613504). Thanks are due to X.L. Nan and B.Y. Ma for their assistance in language editing.
文摘With titanium-bearing blast furnace slag, ammonium sulfate, citric acid and potassium carbonate as raw materials to produce foliar fertilizer and Ca-S-Si compound fertilizer by means of heating process for the first time, which improved the solubility of the slag and converted the nutritional elements into such ones which are prone to be absorbed by plants. The effects of process conditions on dissolution rate of titanium were mainly analyzed through the orthogonal experiment. The results showed that the optimum synthesis process conditions of foliar fertilizer from the slag were 360 ℃ for 35 min, the mass ratio of ammonium sulfate and titanium-bearing blast furnace slag was 8:1. Under these conditions more than 80% of iron, titanium, magnesium and part of silicon in titanium-bearing blast furnace slag converted into water-soluble substances and existing in foliar fertilizer. Foliar fertilizer contained nitrogen, sulfur, potassium, iron, titanium, magnesium and silicon, and pH value of foliar fertilizer was 6. Ca-S-Si compound fertilizer mainly contained calcium silicate and calcium sulfate, which existed in the form of citric acid-soluble substance and slightly soluble substance, respectively.
文摘Using differential thermal analysis, X-ray phase analysis, electron microscopy, and optical microscopy, the nucleation of crystals in glass obtained by blending metallurgical slag with silicon dioxide has been studied. The type of crystallization (homogeneous or heterogeneous, volume or surface) is revealed for each of nine compositions of synthesized glass. It is shown that the first crystalline phase in a volume crystallizing glass is perovskite (CaO·TiO2);in this phase a nucleation of the main phase occurs: melilite (solid solution of gehlenite 2CaO·Al2O3·SiO2 in akermanite 2CaO·MgO·2SiO2). The fundamental characteristics of homogeneous (for a catalizing phase, perovskite) and heterogeneous (for a catalyzed phase, melilite) of crystallization are determined: the steady state nucleation rate Ist, time of unsteady state nucleation τ, crystal growth rate U, and activation energy of frictional flow. The temperature dependences of Ist, τ, and U are obtained. The kinetics of the crystallization of glass is studied and the rates of the surface crystal growth are determined in the glass of nine compositions. The influence of grinding the particles of the original glass on the sequence of deposition of the crystalline phases was studied. Practical recommendations are presented for the use of blast-furnace slag as a raw material for the synthesis of glass and their further utilization.
基金financially supported by the National Key R&D Program of China (No.2018YFC1900500)the National Natural Science Foundation of China (No.51961020)+1 种基金the Key Technology Research and Industrialization Application Demonstration Project of the Renewable Multi-energy Complementary (No.2018IB020)the Academician Workstation of Kefa Cen (No.2018IC085)。
文摘The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery;it can alleviate the environmental pressure caused by slag stocking.The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method.Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed.The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.
基金the National Natural Science Foundation of China(Grant No.51974054)Scientific and Technological Research Program of Chongqing Municipal Education Commission(No.KJQN202201537)+2 种基金Research Foundation of Chongqing University of Science and Technology(No.ckrc2020017)Natural Science Foundation Project of Chongqing(No.cstc2021jcyj-msxmX0911)Chongqing Science and Technology Commission(No.sl202100000144).
文摘Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-purposes of fiber-forming, energy saving, and waste heat recovery, the modifying agents that can improve the acidity coefficient of slag effectively, economically, and environmentally were investigated. Three agents with different acidity coefficients were adopted to modify slag and manufacture wool fibers. The effect of agent and slag proportion on the melting temperature and viscosity of molten slag was studied at a fixed acidity coefficient of 1.8 and 2.0. The results indicate that the sample modified with high acidity coefficient agent and high slag proportion has lower melting temperature and viscosity. The effect of agent and slag temperature on the fiber diameter was also investigated when the acidity coefficient of slag is 2.0. At a fixed slag proportion of 50 wt.%, the mean diameter decreases with increasing temperature and decreasing viscosity coefficient. Besides, the temperature drops caused by the addition of agents and energy consumption of samples for heating the slag were also analyzed.