The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microsc...The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microscope) and XRD (X- ray Diffraction) techniques. Themechanical properties such as bending strength and fracture toughness, as well as their changes withadvancing crystallization were determined. The results show that the changes of the mechanicalproperties are correlated with the microstructures. The sample heated up to 810 deg C and soaked for4 h has smaller crystalline size and less volum fraction of fluorophlogopite, so it has higherbending strength (about 190 MPa), and higher crack toughness (about 2.63 MPa centre dot m^1/2).展开更多
针对高放废液硼硅酸盐玻璃固化体易析出辉石晶相的问题,本文采用P_(2)O_(5)部分替代硼硅酸盐基础玻璃配方中的MgO和CaO,研究了P_(2)O_(5)掺量(质量分数为0~8%)对玻璃固化体析晶和抗浸出性能的影响。结果表明,当P_(2)O_(5)掺量为0~3%时,...针对高放废液硼硅酸盐玻璃固化体易析出辉石晶相的问题,本文采用P_(2)O_(5)部分替代硼硅酸盐基础玻璃配方中的MgO和CaO,研究了P_(2)O_(5)掺量(质量分数为0~8%)对玻璃固化体析晶和抗浸出性能的影响。结果表明,当P_(2)O_(5)掺量为0~3%时,样品为无定形态,在850℃热处理6 h后,P_(2)O_(5)掺量为0~2%的样品主要析出辉石晶相,而P_(2)O_(5)掺量为3%的样品析出了少量硅酸钙晶相,辉石晶相基本消失;当P_(2)O_(5)掺量高于3%时,样品析出球形Na_(3)Ca_(6)(PO_(4))_(5)晶体,且析晶度随P_(2)O_(5)掺量的增加而升高。29 Si MAS NMR和^(11)B MAS NMR分析表明,随着P_(2)O_(5)掺量的增加,玻璃网络结构中Q^(3)、Q^(4)和BO_(3)结构单元含量逐渐增加。静态浸泡法(MCC-1)试验结果表明,样品的抗浸出性能随P_(2)O_(5)掺量的增加而逐渐提高,其中P_(2)O_(5)掺量为3%的样品浸泡28 d后,Si、B、Na和Cs元素的归一化浸出率分别为0.508、0.468、0.533、0.280 g/(m^(2)·d)。展开更多
目的:研究不同含量P_(2)O_(5)替代SiO对生物活性玻璃的力学性能及生物活性的影响。方法:应用高温熔融法烧制各组分基础玻璃,P_(2)O_(5)含量分别为0wt%、1wt%、3wt%、6wt%、9wt%、12wt%。以聚氨酯海绵为模板,有机泡沫浸渍法制作多孔生物...目的:研究不同含量P_(2)O_(5)替代SiO对生物活性玻璃的力学性能及生物活性的影响。方法:应用高温熔融法烧制各组分基础玻璃,P_(2)O_(5)含量分别为0wt%、1wt%、3wt%、6wt%、9wt%、12wt%。以聚氨酯海绵为模板,有机泡沫浸渍法制作多孔生物活性玻璃支架。万能力学试验机单轴压缩和三点弯曲法测试支架的力学性能,标准模拟体液(simulated body fluid,SBF)浸泡计算质量损失百分比及扫描电镜(scanning electron microscope,SEM)观察、X线衍射分析(X-ray diffraction,XRD)观测生物活性。结果:(1)五组多孔支架的抗压强度及抗弯强度测试结果显示,除P_(2)O_(5)含量为0wt%和1wt%两组无显著差异外,随P_(2)O_(5)含量增高材料的力学性能逐渐增强,但当P_(2)O_(5)含量达到12wt%时支架无法烧制成型。(2)五组多孔支架浸泡实验结果表示,高磷含量组材料降解性能强于低磷含量组。且随着浸泡时间延长,除P_(2)O_(5)含量为0wt%和1wt%两组无显著差异外,其余各组之间降解性能有显著差异。(3)在SBF中浸泡后SEM及XRD检测发现,P_(2)O_(5)含量为0wt%和1wt%两组无体外矿化活性,其余各组有矿化活性,且随P_(2)O_(5)含量增高材料体外矿化活性逐渐增强。结论:(1)添加一定量的P_(2)O_(5)可以显著增强生物活性玻璃的力学性能,但含量达到12wt%时支架无法成型;(2)P_(2)O_(5)可以显著增强生物活性玻璃的降解性能及体外矿化活性。展开更多
Dephosphorization slag is one of the bulk solid wastes generated from steelmaking.If P is effectively removed from dephosphorization slag,a phosphate source which can substitute for phosphate rocks is obtained;meanwhi...Dephosphorization slag is one of the bulk solid wastes generated from steelmaking.If P is effectively removed from dephosphorization slag,a phosphate source which can substitute for phosphate rocks is obtained;meanwhile,the tailings can be reutilized as a feedstock in steel plant.To realize the integrated utilization of dephosphorization slag,selective leaching was applied for removing the P-bearing mineral phase from dephosphorization slag.Alkaline oxide was added as the slag modifier and HCl was selected as the acid lixiviant.The P selective leaching from dephosphorization slags modified by Na_(2)O or K_(2)O was studied at different pH values.By modification,the mass fraction of P in the_(2)CaO∙SiO_(2)–3CaO∙P_(2)O_(5)phase increased,indicating that it was in favor of P_(2)O_(5)enrichment.As the Na_(2)O or K_(2)O content increased,the P leaching ratio from slag increased at pH 4,reaching about 80%,and that of Fe was nearly zero.Na_(2)O and K_(2)O modification played a similar role in enhancing the P leaching.The effect of alkaline oxide modification became weak at pH 3,and the slag without modification also realized a good P selective leaching in the HCl solution.To facilitate the P removal,the leaching of Fe from dephosphorization slag needs to be restrained.展开更多
文摘The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microscope) and XRD (X- ray Diffraction) techniques. Themechanical properties such as bending strength and fracture toughness, as well as their changes withadvancing crystallization were determined. The results show that the changes of the mechanicalproperties are correlated with the microstructures. The sample heated up to 810 deg C and soaked for4 h has smaller crystalline size and less volum fraction of fluorophlogopite, so it has higherbending strength (about 190 MPa), and higher crack toughness (about 2.63 MPa centre dot m^1/2).
文摘针对高放废液硼硅酸盐玻璃固化体易析出辉石晶相的问题,本文采用P_(2)O_(5)部分替代硼硅酸盐基础玻璃配方中的MgO和CaO,研究了P_(2)O_(5)掺量(质量分数为0~8%)对玻璃固化体析晶和抗浸出性能的影响。结果表明,当P_(2)O_(5)掺量为0~3%时,样品为无定形态,在850℃热处理6 h后,P_(2)O_(5)掺量为0~2%的样品主要析出辉石晶相,而P_(2)O_(5)掺量为3%的样品析出了少量硅酸钙晶相,辉石晶相基本消失;当P_(2)O_(5)掺量高于3%时,样品析出球形Na_(3)Ca_(6)(PO_(4))_(5)晶体,且析晶度随P_(2)O_(5)掺量的增加而升高。29 Si MAS NMR和^(11)B MAS NMR分析表明,随着P_(2)O_(5)掺量的增加,玻璃网络结构中Q^(3)、Q^(4)和BO_(3)结构单元含量逐渐增加。静态浸泡法(MCC-1)试验结果表明,样品的抗浸出性能随P_(2)O_(5)掺量的增加而逐渐提高,其中P_(2)O_(5)掺量为3%的样品浸泡28 d后,Si、B、Na和Cs元素的归一化浸出率分别为0.508、0.468、0.533、0.280 g/(m^(2)·d)。
文摘目的:研究不同含量P_(2)O_(5)替代SiO对生物活性玻璃的力学性能及生物活性的影响。方法:应用高温熔融法烧制各组分基础玻璃,P_(2)O_(5)含量分别为0wt%、1wt%、3wt%、6wt%、9wt%、12wt%。以聚氨酯海绵为模板,有机泡沫浸渍法制作多孔生物活性玻璃支架。万能力学试验机单轴压缩和三点弯曲法测试支架的力学性能,标准模拟体液(simulated body fluid,SBF)浸泡计算质量损失百分比及扫描电镜(scanning electron microscope,SEM)观察、X线衍射分析(X-ray diffraction,XRD)观测生物活性。结果:(1)五组多孔支架的抗压强度及抗弯强度测试结果显示,除P_(2)O_(5)含量为0wt%和1wt%两组无显著差异外,随P_(2)O_(5)含量增高材料的力学性能逐渐增强,但当P_(2)O_(5)含量达到12wt%时支架无法烧制成型。(2)五组多孔支架浸泡实验结果表示,高磷含量组材料降解性能强于低磷含量组。且随着浸泡时间延长,除P_(2)O_(5)含量为0wt%和1wt%两组无显著差异外,其余各组之间降解性能有显著差异。(3)在SBF中浸泡后SEM及XRD检测发现,P_(2)O_(5)含量为0wt%和1wt%两组无体外矿化活性,其余各组有矿化活性,且随P_(2)O_(5)含量增高材料体外矿化活性逐渐增强。结论:(1)添加一定量的P_(2)O_(5)可以显著增强生物活性玻璃的力学性能,但含量达到12wt%时支架无法成型;(2)P_(2)O_(5)可以显著增强生物活性玻璃的降解性能及体外矿化活性。
基金the National Natural Science Foundation of China(52104326)the Fundamental Research Funds for the Central Universities(N2225016)+1 种基金the Anhui Special Support Plan(T000609)the Distinguished Professor of the Wanjiang Scholars Project.
文摘Dephosphorization slag is one of the bulk solid wastes generated from steelmaking.If P is effectively removed from dephosphorization slag,a phosphate source which can substitute for phosphate rocks is obtained;meanwhile,the tailings can be reutilized as a feedstock in steel plant.To realize the integrated utilization of dephosphorization slag,selective leaching was applied for removing the P-bearing mineral phase from dephosphorization slag.Alkaline oxide was added as the slag modifier and HCl was selected as the acid lixiviant.The P selective leaching from dephosphorization slags modified by Na_(2)O or K_(2)O was studied at different pH values.By modification,the mass fraction of P in the_(2)CaO∙SiO_(2)–3CaO∙P_(2)O_(5)phase increased,indicating that it was in favor of P_(2)O_(5)enrichment.As the Na_(2)O or K_(2)O content increased,the P leaching ratio from slag increased at pH 4,reaching about 80%,and that of Fe was nearly zero.Na_(2)O and K_(2)O modification played a similar role in enhancing the P leaching.The effect of alkaline oxide modification became weak at pH 3,and the slag without modification also realized a good P selective leaching in the HCl solution.To facilitate the P removal,the leaching of Fe from dephosphorization slag needs to be restrained.
