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
Phosphorus (P) and potassium (K) levels in southern Brazilian (Rio Grande do Sul, RS) soils are largely below the critical concentrations more than four decades after implementation of the officially recommended syste...Phosphorus (P) and potassium (K) levels in southern Brazilian (Rio Grande do Sul, RS) soils are largely below the critical concentrations more than four decades after implementation of the officially recommended system. This study aims to evaluate the increase in P and K levels in 0-10 and 0-20 cm deep samples from no-till soils using the Mehlich-1 (M1) and Mehlich-3 (M3) extractants as well as resin methods and to estimate the amount of P2O5 and K2O fertilizers necessary to increase the P and K soil levels by 1 mg·kg-1. The study was conducted in fields cultivated using a no-till system (direct planting) to grow soybeans, wheat, maize, pasture, and cover crops and fertilized with P2O5 and K2O. Soil samples were collected from the 0-10 and 0-20 cm soil layers and analyzed by the M1, M3, and resin methods. The results demonstrated that the P and K levels increased in the 0-10 and 0-20 cm layers. However, the amount of these levels increased depending on the source of phosphate fertilization and on the P and K extraction methods used. The amount of P2O5 fertilization needed to raise the P level by 1 mg·kg-1 was greater in the 0-20 cm layer than in the 0-10 cm layer, and the amount of K2O fertilization needed to raise the K level by 1 mg·kg-1 was higher in the 0-10 cm layer than in the 0-20 cm layer.展开更多
In order to improve the recovery rate of rare earth,the effect of P_(2)O_(5) and cooling rate on the selective precipitation of CaO-SiO_(2)-TiO_(2)-P_(2)O_(5)-Nb_(2)O_(5)-CeO_(2)-CaF_(2) slag system was explored using...In order to improve the recovery rate of rare earth,the effect of P_(2)O_(5) and cooling rate on the selective precipitation of CaO-SiO_(2)-TiO_(2)-P_(2)O_(5)-Nb_(2)O_(5)-CeO_(2)-CaF_(2) slag system was explored using X-ray powder diffraction,a scanning electron microscope,an electron probe micro-analyzer and a confocal laser scanning microscope.The apatite(Ca_(2.02)Ce_(7.98)Si_(6.00)O_(26.00))is tiny and difficult to be separated from the slag without P_(2)O_(5).When the addition of P_(2)O_(5) is 6 wt%-10 wt%,the cerium and phosphorus are found to be enriched in britholite(Ca_(5-x)Ce_(x)[(SiO_(4))_(x)(PO_(4))_(3-x)]F)phase while x is negatively correlated with P_(2)O_(5) content in the slag.The influence of P_(2)O_(5) and cooling rate on the non-isothermal crystallization kinetics was also investigated.For the cooling rate between 5 and 40℃/min,continuous cooling transformation diagram of britholite was constructed when the P205 content is between 6 wt%-10 wt%.The modified Avrami model was applied to determine the crystallization mode of slag with 10 wt%P_(2)O_(5).It is shown that the crystallization mode is diffusion-controlled with constant nucleation rate and one-dimensional growth.In consideration of quantity and volume of crystals,the reasonable cooling rate is between 10and 30℃/min.展开更多
The reduction and recovery of P_(2)O_(5)in dephosphorization slag were examined to establish a new recycling process for dephosphorization slag.The dephosphorization slag is obtained from the dephosphorization furnace...The reduction and recovery of P_(2)O_(5)in dephosphorization slag were examined to establish a new recycling process for dephosphorization slag.The dephosphorization slag is obtained from the dephosphorization furnace in the duplex converter process,and the content of P_(2)O_(5) in the dephosphorization slag can reach 9 wt.%.The dephosphorization slag is considered to be a prospective resource of phosphorus due to its high content of P_(2)O_(5).To explore the effects of temperature and Fe2O3 content in slag on phosphorus recovery from dephosphorization slag,the experimental slag was reduced by carbon powder in a resistance furnace.The results show that the temperature and content of Fe2O3 in slag have a significant effect on the reduction in P_(2)O_(5),and the reduction and recovery ratios of P_(2)O_(5) in slags increase with the increase in the experimental temperature and content of Fe_(2)O_(3),reaching 94.41%and 83.09%,respectively.It has been indicated that phosphorus recovery from dephosphorization slag using carbothermic reduction has significant environmental and economic benefits.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Authors are thankfully to all Universities and agricultural extensions programs from Rio Grande do Sul State that kindly support this work allowing access in their experiments to collect informationto support us with crop yield and crop biomass data.
文摘Phosphorus (P) and potassium (K) levels in southern Brazilian (Rio Grande do Sul, RS) soils are largely below the critical concentrations more than four decades after implementation of the officially recommended system. This study aims to evaluate the increase in P and K levels in 0-10 and 0-20 cm deep samples from no-till soils using the Mehlich-1 (M1) and Mehlich-3 (M3) extractants as well as resin methods and to estimate the amount of P2O5 and K2O fertilizers necessary to increase the P and K soil levels by 1 mg·kg-1. The study was conducted in fields cultivated using a no-till system (direct planting) to grow soybeans, wheat, maize, pasture, and cover crops and fertilized with P2O5 and K2O. Soil samples were collected from the 0-10 and 0-20 cm soil layers and analyzed by the M1, M3, and resin methods. The results demonstrated that the P and K levels increased in the 0-10 and 0-20 cm layers. However, the amount of these levels increased depending on the source of phosphate fertilization and on the P and K extraction methods used. The amount of P2O5 fertilization needed to raise the P level by 1 mg·kg-1 was greater in the 0-20 cm layer than in the 0-10 cm layer, and the amount of K2O fertilization needed to raise the K level by 1 mg·kg-1 was higher in the 0-10 cm layer than in the 0-20 cm layer.
基金Project supported by the Major Projects of Inner Mongolia Natural Science Foundation (2018ZD07)Inner Mongolia Natural Science Foundation (2020BS05016)+2 种基金Open Project for Key Basic Research of the Inner Mongolia Autonomous Region (20140201)Open Project for Major Basic Research of Inner Mongolia (0406091701)Scientific Research Project of Inner Mongolia (ZDZX2018032)。
文摘In order to improve the recovery rate of rare earth,the effect of P_(2)O_(5) and cooling rate on the selective precipitation of CaO-SiO_(2)-TiO_(2)-P_(2)O_(5)-Nb_(2)O_(5)-CeO_(2)-CaF_(2) slag system was explored using X-ray powder diffraction,a scanning electron microscope,an electron probe micro-analyzer and a confocal laser scanning microscope.The apatite(Ca_(2.02)Ce_(7.98)Si_(6.00)O_(26.00))is tiny and difficult to be separated from the slag without P_(2)O_(5).When the addition of P_(2)O_(5) is 6 wt%-10 wt%,the cerium and phosphorus are found to be enriched in britholite(Ca_(5-x)Ce_(x)[(SiO_(4))_(x)(PO_(4))_(3-x)]F)phase while x is negatively correlated with P_(2)O_(5) content in the slag.The influence of P_(2)O_(5) and cooling rate on the non-isothermal crystallization kinetics was also investigated.For the cooling rate between 5 and 40℃/min,continuous cooling transformation diagram of britholite was constructed when the P205 content is between 6 wt%-10 wt%.The modified Avrami model was applied to determine the crystallization mode of slag with 10 wt%P_(2)O_(5).It is shown that the crystallization mode is diffusion-controlled with constant nucleation rate and one-dimensional growth.In consideration of quantity and volume of crystals,the reasonable cooling rate is between 10and 30℃/min.
基金the National Natural Science Foundation of China(Grant Nos.51704080,51874102 and 52074093)the National Key Research and Development Program of China(Grant No.2019YFC1905200).
文摘The reduction and recovery of P_(2)O_(5)in dephosphorization slag were examined to establish a new recycling process for dephosphorization slag.The dephosphorization slag is obtained from the dephosphorization furnace in the duplex converter process,and the content of P_(2)O_(5) in the dephosphorization slag can reach 9 wt.%.The dephosphorization slag is considered to be a prospective resource of phosphorus due to its high content of P_(2)O_(5).To explore the effects of temperature and Fe2O3 content in slag on phosphorus recovery from dephosphorization slag,the experimental slag was reduced by carbon powder in a resistance furnace.The results show that the temperature and content of Fe2O3 in slag have a significant effect on the reduction in P_(2)O_(5),and the reduction and recovery ratios of P_(2)O_(5) in slags increase with the increase in the experimental temperature and content of Fe_(2)O_(3),reaching 94.41%and 83.09%,respectively.It has been indicated that phosphorus recovery from dephosphorization slag using carbothermic reduction has significant environmental and economic benefits.
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.
