Da Qaidam salt lake is known for its both liquid and solid boron resource.Data from previous investigation of the Da Qaidam salt lake provided a comparable framework for this study that focused on investigating the se...Da Qaidam salt lake is known for its both liquid and solid boron resource.Data from previous investigation of the Da Qaidam salt lake provided a comparable framework for this study that focused on investigating the section beneath the bottom of the perennial salt lake,including the timing,展开更多
Boron resources are abundant in the Da Qaidam Salt Lake of the Qaidamu basin in China, which has generated significant attention due to the presence of polyborate species in brine from this lake. In this study, Raman ...Boron resources are abundant in the Da Qaidam Salt Lake of the Qaidamu basin in China, which has generated significant attention due to the presence of polyborate species in brine from this lake. In this study, Raman spectroscopy was used to investigate the existing form of boron in brine during evaporation. MgO·2B2O3 -H2O, MgO·2B2O3 -MgCl2 -H2O, and MgO·2B2O3 -MgSO4 - H2O solutions were also studied to determine the influence of boron concentration, pH, and electrolytes on the borate speciation from brine. The mononborates B(OH)3 and B(OH)4^- were found to be the only forms present in natural salt lake brine. Brine evaporation promoted the formation of the polyborate anions B3O3(OH)4^-,B5O6(OH)4^-, and B6O7(OH)6^2- and also promoted the disappearance of the B(OH)4^- ion from brine at boron concentrations of more than 11 g/L B2O3. The pentaborate ion B5O6(OH)4^- was sensitive to the solution pH and appeared only at pH values less than 8.0. Meanwhile, the hexaborate ion B6O7(OH)6^2- was observed to be more dependent on the electrolyte magnesium chloride due to its special properties, such as promoting boron accumulation, lowering solution pH, and also its strong affinity for water molecules, which were all beneficial for the polymerization of borate ions in brine. Interaction mechanisms between polyborate anions during evaporation are also proposed herein.ake;evaporation;polyborate species;interaction mechanism.展开更多
大柴旦盐湖因蕴藏固体和液体硼矿资源成为柴达木盆地诸多盐湖中最早被关注和开发的盐湖之一。然而,对其常年水体底部沉积剖面的相关研究工作却几乎没有开展。报道了该盐湖中央湖底硼矿层以上连续沉积剖面的加速器质谱计(AMS)14C年代学...大柴旦盐湖因蕴藏固体和液体硼矿资源成为柴达木盆地诸多盐湖中最早被关注和开发的盐湖之一。然而,对其常年水体底部沉积剖面的相关研究工作却几乎没有开展。报道了该盐湖中央湖底硼矿层以上连续沉积剖面的加速器质谱计(AMS)14C年代学和矿物学研究结果,首次揭示湖底硼矿层形成于约3600 a BP之前;剖面的岩性与矿物组成标示了晚全新世以来该盐湖水化学演化的3个主要阶段;受降水量主控的入湖径流量决定了盐湖水位和卤水水化学的阶段性演化特征,以及各阶段中十年级和百年级的水化学变动。研究结果为探讨柴达木盆地北部晚全新世以来水文气候的演变历史提供了代理记录。展开更多
以大柴旦盐湖区及其周边地区为例,选取海韭菜、赖草、毛穗赖草、无脉苔草4种优势盐生植物,对其单根进行单根拉伸试验以及4种植物根–土复合体抗剪强度试验。分别获得4种植物单根抗拉力和单根抗拉强度;通过对4种盐生植物根–土复合体在...以大柴旦盐湖区及其周边地区为例,选取海韭菜、赖草、毛穗赖草、无脉苔草4种优势盐生植物,对其单根进行单根拉伸试验以及4种植物根–土复合体抗剪强度试验。分别获得4种植物单根抗拉力和单根抗拉强度;通过对4种盐生植物根–土复合体在不同含根量梯度下的直接剪切试验,探讨根系对土体抗剪强度增强作用以及根–土复合体的最优含根量。由单根拉伸试验结果表明,4种植物平均单根抗拉力值为4.67~10.97 N,平均单根抗拉强度值为12.32~49.99 MPa,且4种植物平均单根抗拉强度由大至小依次为赖草、毛穗赖草、无脉苔草、海韭菜;4种植物根–土复合体扰动试样黏聚力值为10.44~27.42 k Pa,不含根素土试样黏聚力值为8.10 k Pa,与不含根系素土相比,根–土复合体的黏聚力增长量为2.34~19.32 k Pa,其增幅为28.89%~238.52%;根系增强土体抗剪强度存在最优含根量,根–土复合体试样中的含根量处于最优含根量时,4种植物根–土复合体的抗剪强度为相对最大值,其黏聚力值为17.94~27.42 k Pa,黏聚力由大至小依次为海韭菜、赖草、毛穗赖草、无脉苔草。该研究成果对大柴旦盐湖区以及与该区地质条件相似的其他地区开展利用盐生植物增强土体抗剪强度,且对于开展有效防治土体侵蚀和地表水土流失等地质灾害的发生具有理论价值和实际意义。展开更多
文摘Da Qaidam salt lake is known for its both liquid and solid boron resource.Data from previous investigation of the Da Qaidam salt lake provided a comparable framework for this study that focused on investigating the section beneath the bottom of the perennial salt lake,including the timing,
基金National Natural Science Foundation for the Youth(No.21501187)Qaidam Salt Lake Chemical Scientific Research Joint Foundation of China(No.U1607103)Light of the West Talent Program of the Chinese Academy of Sciences
文摘Boron resources are abundant in the Da Qaidam Salt Lake of the Qaidamu basin in China, which has generated significant attention due to the presence of polyborate species in brine from this lake. In this study, Raman spectroscopy was used to investigate the existing form of boron in brine during evaporation. MgO·2B2O3 -H2O, MgO·2B2O3 -MgCl2 -H2O, and MgO·2B2O3 -MgSO4 - H2O solutions were also studied to determine the influence of boron concentration, pH, and electrolytes on the borate speciation from brine. The mononborates B(OH)3 and B(OH)4^- were found to be the only forms present in natural salt lake brine. Brine evaporation promoted the formation of the polyborate anions B3O3(OH)4^-,B5O6(OH)4^-, and B6O7(OH)6^2- and also promoted the disappearance of the B(OH)4^- ion from brine at boron concentrations of more than 11 g/L B2O3. The pentaborate ion B5O6(OH)4^- was sensitive to the solution pH and appeared only at pH values less than 8.0. Meanwhile, the hexaborate ion B6O7(OH)6^2- was observed to be more dependent on the electrolyte magnesium chloride due to its special properties, such as promoting boron accumulation, lowering solution pH, and also its strong affinity for water molecules, which were all beneficial for the polymerization of borate ions in brine. Interaction mechanisms between polyborate anions during evaporation are also proposed herein.ake;evaporation;polyborate species;interaction mechanism.
文摘大柴旦盐湖因蕴藏固体和液体硼矿资源成为柴达木盆地诸多盐湖中最早被关注和开发的盐湖之一。然而,对其常年水体底部沉积剖面的相关研究工作却几乎没有开展。报道了该盐湖中央湖底硼矿层以上连续沉积剖面的加速器质谱计(AMS)14C年代学和矿物学研究结果,首次揭示湖底硼矿层形成于约3600 a BP之前;剖面的岩性与矿物组成标示了晚全新世以来该盐湖水化学演化的3个主要阶段;受降水量主控的入湖径流量决定了盐湖水位和卤水水化学的阶段性演化特征,以及各阶段中十年级和百年级的水化学变动。研究结果为探讨柴达木盆地北部晚全新世以来水文气候的演变历史提供了代理记录。
文摘以大柴旦盐湖区及其周边地区为例,选取海韭菜、赖草、毛穗赖草、无脉苔草4种优势盐生植物,对其单根进行单根拉伸试验以及4种植物根–土复合体抗剪强度试验。分别获得4种植物单根抗拉力和单根抗拉强度;通过对4种盐生植物根–土复合体在不同含根量梯度下的直接剪切试验,探讨根系对土体抗剪强度增强作用以及根–土复合体的最优含根量。由单根拉伸试验结果表明,4种植物平均单根抗拉力值为4.67~10.97 N,平均单根抗拉强度值为12.32~49.99 MPa,且4种植物平均单根抗拉强度由大至小依次为赖草、毛穗赖草、无脉苔草、海韭菜;4种植物根–土复合体扰动试样黏聚力值为10.44~27.42 k Pa,不含根素土试样黏聚力值为8.10 k Pa,与不含根系素土相比,根–土复合体的黏聚力增长量为2.34~19.32 k Pa,其增幅为28.89%~238.52%;根系增强土体抗剪强度存在最优含根量,根–土复合体试样中的含根量处于最优含根量时,4种植物根–土复合体的抗剪强度为相对最大值,其黏聚力值为17.94~27.42 k Pa,黏聚力由大至小依次为海韭菜、赖草、毛穗赖草、无脉苔草。该研究成果对大柴旦盐湖区以及与该区地质条件相似的其他地区开展利用盐生植物增强土体抗剪强度,且对于开展有效防治土体侵蚀和地表水土流失等地质灾害的发生具有理论价值和实际意义。
