In this study,ceramics was prepared by slip casting(no pressure was used during shaping step)and atmospheric pressure sintering with low-melting point glass(LPG)powder as the binding material to facilitate the transfo...In this study,ceramics was prepared by slip casting(no pressure was used during shaping step)and atmospheric pressure sintering with low-melting point glass(LPG)powder as the binding material to facilitate the transformation of spodumene flotation tailings(SFTs)into ceramics at lower temperatures.The influence of sintering temperature and mass ratio of LPG on the mechanical properties(flexural strength and compressive strength)of ceramic materials was studied by orthogonal test.The results showed that when the mass ratio of LPG powder was higher than or equal to 20 wt%and the sintering temperature was higher than or equal to 550℃,mutual adhesion between the sample particles was realised and consequently the ceramic materials could be prepared with good mechanical properties(the maximum flexural strength=19.55 MPa,the maximum compressive strength=42.25 MPa,average porosity=24.52%,average apparent density=1.66 g/cm^(3),and average water absorption=14.79%).The sintered ceramics were characterized by XRF,XRD,optical microscopy analysis,SEM,TGA-DSC and FT-IR.The formation of liquid phase at high temperature may lead to the mutual bonding between particles,which might be the main reason for the improvement of mechanical properties of ceramic materials.Overall,SFTs were successfully sintered at low temperature to prepare ceramic materials with good mechanical properties,which are crucial for energy conservation and environmental preservation.展开更多
Porous ceramics were prepared with spodumene flotation talings(SFT),kaolin and low-melting point glass(LPG)powder,whose pores were formed by the chemical reaction of hydrogen peroxide(H_(2)O_(2)).LPG was used to reduc...Porous ceramics were prepared with spodumene flotation talings(SFT),kaolin and low-melting point glass(LPG)powder,whose pores were formed by the chemical reaction of hydrogen peroxide(H_(2)O_(2)).LPG was used to reduce the sintering temperature of porous ceramics and kaolin was used to realize the adsorption to methylene blue(MB)of porous ceramics.The average flexural strength,compressive strength,apparent porosity,water absorption and maximum MB adsorption capacity were 5.60 MPa,4.66 MPa,52.27%,44.32%and 0.7 mg/g,respectively.Moreover,the results of orthogonal experiments present that the sintering temperature and the dosage of H_(2)O_(2)had great influence on the mechanical properties and apparent porosity of porous ceramics,respectively.The main reason for the improvement of mechanical properties of porous ceramics was that LPG gradually became soft with increasing the sintering temperature,which made the mineral particles adhere to each other closely.Kaolinite was not completely converted into metakaolin at 550℃,which might be the main reason why porous ceramics had adsorption properties.展开更多
The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO_3, NaOH, H_2O and K-feldspar ore, particle size of K-feldspar ore,re...The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO_3, NaOH, H_2O and K-feldspar ore, particle size of K-feldspar ore,reaction temperature and time were investigated, respectively. In addition, the optimum condition for this method was determined by a series of condition experiments. What was more, the K-feldspar ore and the leach residue after reaction based on the above optimum condition were analyzed by XRD, SEM and EDS,separately. The results of which indicated that the mechanism of extraction of potassium for this method was according to the ion exchange reaction between sodium ion and potassium ion, and the extraction ratio of potassium had an obvious improvement than that of traditional methods, which could reach up to 96.25%.Therefore, this method can be a feasible solution to extract potassium from K-feldspar ore for its low energy consumption and high efficiency.展开更多
In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic p...In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic properties and the optical response range of the natase nanocrystalline were analyzed and studied with the hybrid orbital theory. The results show that the band gap of the doped TiO2 was narrow, and the photocatalytic ability could be excited by the visible lighL and the doping of non metallic elements broadens the application range of TiO2, so that it could be excited under the visible light and obtained better use value.展开更多
On the basis of heat transfer and chemical kinetics theory, both connections coal self ignite with oxygen concentration and range of oxidation zone with air leak intensity are analyzed, and calculating method is deduc...On the basis of heat transfer and chemical kinetics theory, both connections coal self ignite with oxygen concentration and range of oxidation zone with air leak intensity are analyzed, and calculating method is deduced to gain the lower limit of oxygen concentration and the range of oxidation zone. The change rule of correlative parameter is quantitatively researched between before nitrogen injection and after nitrogen injection in gob, such as oxygen concentration, oxidation zone width, etc. According to theoretical calculation, the relation position and flow of nitrogen injection with oxidation zone width is conformed, and computational formulas of the best flow and position of nitrogen injection are obtained. It offers a theoretic criterion for preventing and controlling float coal self ignite by nitrogen injection in gob.展开更多
Herein, we for the first time doped Nb^5+into the low-temperature(<100°C) SnO2sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed pero...Herein, we for the first time doped Nb^5+into the low-temperature(<100°C) SnO2sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed perovskites. The results revealed that proper Nb5+doping increased the conductivity of the SnO2 electron transport layer(ETL), and the conduction band(CB) level of the SnO2 ETL was shifted down to approach the CB level of perovskites, which facilitated the electron injection from perovskite to SnO2, accelerated the charge transport, and reduced the non-radiative recombination, leading to improved power conversion efficiency from18.06% to 19.38%. The Nb^5+doping process provided an efficient route for fabricating high-efficiency perovskite solar cells(PSCs) at a temperature lower than 100°C, and promoted the commercialization progress of PSCs.展开更多
Serpentinites have great implications for the oceanic crust, subduction zones, island arc magmatism activity, and the formation of nickel ore deposits. To further determine the mechanism of magnetic property changes o...Serpentinites have great implications for the oceanic crust, subduction zones, island arc magmatism activity, and the formation of nickel ore deposits. To further determine the mechanism of magnetic property changes of serpentinites, samples from ODP Holes 897 D and 1070 A were investigated by integrating both magnetic and non-magnetic methods. Detailed rock magnetic results demonstrate that magnetite prevails in the entire serpentinite section, while maghemite is present in the upper and altered parts. The concentration of Fe in the fresh peridotite is inhomogeneous; nonetheless, the magnetic properties are generally determined by the serpentinization process. The formation and state of the magnetite depend on the fracture conditioning and fluid activities which are controlled by the serpentinization process. By comparing these two holes, we found that the production of magnetite is consistent with the serpentinization process; serpentinization is a multi-stage process which involves early high-temperature serpentinization and later low-temperature oxidation. As the serpentinization continues, the fine magnetic particles become coarser, combined with the formation of new SP particles, and the later low-temperature oxidation leads to the maghemitization of the magnetites. The duration of oxidation also contributes to the differences of remanent magnetization between these two holes. These results greatly improve our understanding of the magnetic enhancement during the serpentinization process, and provide constraints on the interpretation of the paleomagnetic and aeromagnetic anomalies in this area.展开更多
基金Projects(51674207,51922091)supported by the National Natural Science Foundation of ChinaProject(2018QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,ChinaProjects(2019YFS0453,2018JY0148)supported by the Sichuan Science and Technology Program,China。
文摘In this study,ceramics was prepared by slip casting(no pressure was used during shaping step)and atmospheric pressure sintering with low-melting point glass(LPG)powder as the binding material to facilitate the transformation of spodumene flotation tailings(SFTs)into ceramics at lower temperatures.The influence of sintering temperature and mass ratio of LPG on the mechanical properties(flexural strength and compressive strength)of ceramic materials was studied by orthogonal test.The results showed that when the mass ratio of LPG powder was higher than or equal to 20 wt%and the sintering temperature was higher than or equal to 550℃,mutual adhesion between the sample particles was realised and consequently the ceramic materials could be prepared with good mechanical properties(the maximum flexural strength=19.55 MPa,the maximum compressive strength=42.25 MPa,average porosity=24.52%,average apparent density=1.66 g/cm^(3),and average water absorption=14.79%).The sintered ceramics were characterized by XRF,XRD,optical microscopy analysis,SEM,TGA-DSC and FT-IR.The formation of liquid phase at high temperature may lead to the mutual bonding between particles,which might be the main reason for the improvement of mechanical properties of ceramic materials.Overall,SFTs were successfully sintered at low temperature to prepare ceramic materials with good mechanical properties,which are crucial for energy conservation and environmental preservation.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.51674207,51922091)the Young Elite Scientists Sponsorship Program by CAST,China(No.2018QNRC001)the Sichuan Science and Technology Program,China(Nos.2019YFS0453,2018JY0148).
文摘Porous ceramics were prepared with spodumene flotation talings(SFT),kaolin and low-melting point glass(LPG)powder,whose pores were formed by the chemical reaction of hydrogen peroxide(H_(2)O_(2)).LPG was used to reduce the sintering temperature of porous ceramics and kaolin was used to realize the adsorption to methylene blue(MB)of porous ceramics.The average flexural strength,compressive strength,apparent porosity,water absorption and maximum MB adsorption capacity were 5.60 MPa,4.66 MPa,52.27%,44.32%and 0.7 mg/g,respectively.Moreover,the results of orthogonal experiments present that the sintering temperature and the dosage of H_(2)O_(2)had great influence on the mechanical properties and apparent porosity of porous ceramics,respectively.The main reason for the improvement of mechanical properties of porous ceramics was that LPG gradually became soft with increasing the sintering temperature,which made the mineral particles adhere to each other closely.Kaolinite was not completely converted into metakaolin at 550℃,which might be the main reason why porous ceramics had adsorption properties.
基金Supported by the National Natural Science Foundation of China(21373252)Fundamental Research Project of Qing Hai Science&Technology Department(2016-ZJ-749)Qinghai Innovation Fund for Technology Based Firms(2014-GX-Q19)
文摘The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO_3, NaOH, H_2O and K-feldspar ore, particle size of K-feldspar ore,reaction temperature and time were investigated, respectively. In addition, the optimum condition for this method was determined by a series of condition experiments. What was more, the K-feldspar ore and the leach residue after reaction based on the above optimum condition were analyzed by XRD, SEM and EDS,separately. The results of which indicated that the mechanism of extraction of potassium for this method was according to the ion exchange reaction between sodium ion and potassium ion, and the extraction ratio of potassium had an obvious improvement than that of traditional methods, which could reach up to 96.25%.Therefore, this method can be a feasible solution to extract potassium from K-feldspar ore for its low energy consumption and high efficiency.
文摘In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic properties and the optical response range of the natase nanocrystalline were analyzed and studied with the hybrid orbital theory. The results show that the band gap of the doped TiO2 was narrow, and the photocatalytic ability could be excited by the visible lighL and the doping of non metallic elements broadens the application range of TiO2, so that it could be excited under the visible light and obtained better use value.
基金NationalNaturalScienceFoundationofChina! (No .5 99740 2 0 )
文摘On the basis of heat transfer and chemical kinetics theory, both connections coal self ignite with oxygen concentration and range of oxidation zone with air leak intensity are analyzed, and calculating method is deduced to gain the lower limit of oxygen concentration and the range of oxidation zone. The change rule of correlative parameter is quantitatively researched between before nitrogen injection and after nitrogen injection in gob, such as oxygen concentration, oxidation zone width, etc. According to theoretical calculation, the relation position and flow of nitrogen injection with oxidation zone width is conformed, and computational formulas of the best flow and position of nitrogen injection are obtained. It offers a theoretic criterion for preventing and controlling float coal self ignite by nitrogen injection in gob.
基金supported by the National Natural Science Foundation of China (51273104 and 91433205)
文摘Herein, we for the first time doped Nb^5+into the low-temperature(<100°C) SnO2sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed perovskites. The results revealed that proper Nb5+doping increased the conductivity of the SnO2 electron transport layer(ETL), and the conduction band(CB) level of the SnO2 ETL was shifted down to approach the CB level of perovskites, which facilitated the electron injection from perovskite to SnO2, accelerated the charge transport, and reduced the non-radiative recombination, leading to improved power conversion efficiency from18.06% to 19.38%. The Nb^5+doping process provided an efficient route for fabricating high-efficiency perovskite solar cells(PSCs) at a temperature lower than 100°C, and promoted the commercialization progress of PSCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.41430962,41374073)the support from the Chinese Academy of Sciences
文摘Serpentinites have great implications for the oceanic crust, subduction zones, island arc magmatism activity, and the formation of nickel ore deposits. To further determine the mechanism of magnetic property changes of serpentinites, samples from ODP Holes 897 D and 1070 A were investigated by integrating both magnetic and non-magnetic methods. Detailed rock magnetic results demonstrate that magnetite prevails in the entire serpentinite section, while maghemite is present in the upper and altered parts. The concentration of Fe in the fresh peridotite is inhomogeneous; nonetheless, the magnetic properties are generally determined by the serpentinization process. The formation and state of the magnetite depend on the fracture conditioning and fluid activities which are controlled by the serpentinization process. By comparing these two holes, we found that the production of magnetite is consistent with the serpentinization process; serpentinization is a multi-stage process which involves early high-temperature serpentinization and later low-temperature oxidation. As the serpentinization continues, the fine magnetic particles become coarser, combined with the formation of new SP particles, and the later low-temperature oxidation leads to the maghemitization of the magnetites. The duration of oxidation also contributes to the differences of remanent magnetization between these two holes. These results greatly improve our understanding of the magnetic enhancement during the serpentinization process, and provide constraints on the interpretation of the paleomagnetic and aeromagnetic anomalies in this area.
