JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
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2022
·Vol. 332
·期 1
·105-117
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IF 1.754
Huang Xin,Shu Xiaoyan,Li Lingshuang,Chen Shuaipeng,Lu Xirui,Liao Bing,Xie Yi,Chen Shunzhang,Dong Faqin
Abstract Natural granite was considered for immobilizing nuclear waste Nd 2 O 3 (Nd 3+ simulated for An 3+ ). The structure and performance of pure granite were compared with Nd 2 O 3 doped granite sintered at 1500 °C. The introduced Nd 3+ distributed mainly in the glass network below the loading capacity (19 wt .%). Beyond that, tetrahedral SiO 4 units existed in a sheet form, while extra Nd 3+ precipitated as Nd 2 Si 2 O 7 . The doped Nd 2 O 3 improved the hardness (6.29–7.07 GPa) and density (2.19–2.71 g/cm 3 ) of matrix. Moreover, the solidified form presented NR Nd below 1.7 × 10 –6 g m −2 d −1 after 28 days. This work disclosed a potential host matrix for nuclear waste. Graphics abstract
研究领域:
材料科学
·
核废料管理
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Yiping Tan,Shuangke Li,Xiaoping Xu,Pan Chen,Zhiyong Gao,Wei Sun,Belinda McFadzean,Jian Cao
Quartz and feldspar are the primary impurities in the mineral processing of pollucite. Due to the highly similar surface properties of these three minerals in terms of physicochemical characteristics, achieving efficient flotation enrichment of pollucite has been a challenging problem. To address this issue, the development of flotation collectors with high selectivity towards pollucite is crucial. In this study, different-sized crown ethers acted as selective collectors for the direct flotation to detach pollucite from feldspar and quartz were investigated, leveraging the selective bonding of crown ethers to alkali metal active site on the surface of pollucite. The properties of 21-crown-7 ether (21C7), benzo-21-crown-7 (B21C7) and dibenzo-21-crown-7 (DB21C7) (with three different cavity sizes) were investigated as collectors for pollucite flotation. The experimental results indicated that DB21C7 exhibited the best collecting performance. The mechanism was studied through various experimental measurements and computational simulations, and the results revealed that the selective adsorption mechanism of crown ethers onto the surface of pollucite was achieved through a combination of chelation interaction involving “spatial effect” and hydrogen bonding interaction. This work has disclosed that crown ether compounds may hold significant potential as collectors for flotation of pollucite.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
·
2024
·Vol. 37
·期 1
·04024444
·
IF 3.1
Xing Gong,Quantao Liu,Yingxue Zou,Xuefei Liu,Huan Wang,Pei Wan,Zhilong Cao,Shaopeng Wu
The poor adhesion of asphalt–granite limits the application of granite. This research aims to enhance the adhesion of asphalt and granite by establishing chemical connections between the hydroxyl groups on granite surface and the incompletely reacted isocyanate groups in polyurethane (PU) modified asphalt. For this purpose, end-capped PU modified asphalt (PUMA) was prepared, the adhesion mechanism between PUMA and granite was analyzed by Raman spectroscopy, the adhesion properties between PUMA and granite at different curing periods were evaluated by boiling and pull-out tests, and the wettability of PUMA on granite and its moisture sensitivity were evaluated using surface free energy (SFE) method. The findings suggested that the incompletely reacted isocyanate groups in PUMA can establish a chemical connection with the hydroxyl groups on the surface of granite. The adhesion between asphalt and granite can be greatly improved by the addition of PU, and this improvement is amplified as the curing time is extended. When the curing time is extended to 3 days, the fracture mode between asphalt and granite changed from adhesive failure to cohesive failure, and after 15 days of curing, the coating ratio of PUMA on granite following the water boiling test can be raised by 28.11% in comparison to the base asphalt. The water damage resistance of PUMA-granite system can be increased by adding PU and the adhesion work and combination ratio of the freshly prepared PUMA were increased by 55.91% and 79.45%, respectively, as compared to base asphalt. This study has great significance for enhancing the adhesion between asphalt and granite and encouraging granite application.
研究领域:
材料科学
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土木工程
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2024
·
IF 9
Maoyan Xu,Xianyu Yang,Zhaokai Dai,Ren Wang,Jianlong Wang,Jingyu Xie,Mengjuan Liu,Yanping Shi,Shuya Chen,Man Xue,Jihua Cai,Guosheng Jiang
Global warming is increasing as CO 2 emissions from the use of conventional fossil fuels continue to rise. The development of geothermal energy is gradually becoming the key to the sustainable development of human society in the future. Enhancing the heat transfer performance of circulating heat transfer fluids is one of the effective means to efficiently exploit deep geothermal resources. In this study, a self-developed circulating heat exchange experimental setup was established. The convection heat transfer characteristics of nanofluids in high-temperature rocks were experimentally investigated. Al 2 O 3 nanofluid and CuO nanofluid were used as the working medium for heat transfer in high temperature granite samples. The effects of the Reynolds number (1000–6000) and parameters such as nanoparticle type (CuO & Al 2 O 3 ), size (20 nm & 40 nm) and mass fraction (0 wt%-2wt%) on the heat transfer intensity were analyzed. The effect of nanoparticle accumulation on the rock surface on the local heat transfer strength was also investigated. The results indicate that the increase of Reynolds number enhances the heat transfer strength of nanofluids in rocks. Nanofluid containing 20 nm Al 2 O 3 nanoparticles has better heat transfer performance in rock than nanofluid containing 20 nm CuO nanoparticles. Meanwhile, the heat transfer performance of nanofluid containing 20 nm Al 2 O 3 nanoparticles in rock is better than that of nanofluid containing 40 nm Al 2 O 3 nanoparticles. The heat transfer intensity increases and then decreases as the nanoparticle mass fraction increases. The heat transfer coefficient at Reynolds number 6000 is 52.2 % higher than that of water. For nanofluids and water, the local heat transfer intensity decreases with increasing distance from the inlet. Meanwhile, accumulation of nanoparticles on rock surfaces during convective heat transfer enhances heat transfer intensity. The results show that nanofluids have the potential to be applied to deep geothermal resource extraction. This paper provides data and technical support for the application of nanomaterials in medium and deep geothermal systems to enhance heat transfer efficiency.
研究领域:
能源工程
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热力学
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地质学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Tian Yunting,Li Yongmei,Tan Kaixuan,Li Chunguang,Li Xiaojie,Liu Wei,Tang Zhipeng,Liu Longcheng
Bentonite colloids and fluid velocity significantly influence the migration behavior of the redox sensitive nuclide Se(IV) in the disposal repository. In this study, the migration behavior of Se(IV) in artificial fracture, which was created by Beishan granite and polyethylene pipe, was studied under reduced condition, with Br − as a tracer. The effects of bentonite colloids and fluid flow rate on the migration of Se(IV) in the fracture were explored. The results show that a part of Se(IV) would adsorb on the surface of granite in reduced condition. The maximum penetration rate of Se(IV) increases with the decrease of water flow rate. In addition, the colloids hindered the migration of nuclide Se(IV) in the fissure to some extent during the process of co-migration.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2022
·
IF 7.693
Kairong Jin,Wanli Bi,Yan Guan,Xiaoyang Chen,Xiangming Zhou,Dezhi Wang
Salt erosion is one of the main factors affecting the durability of cement and concrete. Magnesium oxysulfate (MOS) cement is regarded as a new type of binder with many good features such as lower carbon dioxide emission, excellent fire resistance, etc. However, the salt erosion resistance of MOS cement is rarely studied. This research investigated the performance of MOS cement, with granite powders (GPs) as mineral admixture , soaked in NaCl and Na 2 SO 4 solutions. X-ray diffraction (XRD) and simultaneous comprehensive thermal analyzer (TG-DSC) were used to detect the phase composition and hydration products of MOS cement. Scanning electron microscope (SEM) and mercury porosimeter (MIP) were used to analyze the pore structure and microstructure of MOS cement. The results showed that the value of the salt attack coefficient of MOS cement with 50 % by weight GPs reached 0.58 and 0.57 after immersion in NaCl and Na 2 SO 4 solutions for 230 days, respectively. The compressive strength of MOS cement with 30 % by weight GPs reached the maximum value of 74.1 MPa after standard curing for 28 days by optimizing the pore structure. Both needle-like and plate-like Na 2 SO 4 ·xH 2 O crystals were observed in the hydration products. Gypsum and Na 2 SO 4 ·xH 2 O grew in the pores and matrix, generated expansion stress and destroyed the matrix structure of MOS cement. During the soaking period, the decomposition of the 5·1·7 phase and MgSO 4 ·nH 2 O negatively affected the salt resistance of MOS cement. Physical and chemical erosion leads to a decrease in the value of the salt attack coefficient.
研究领域:
建筑材料学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Guilin Wei,Shuaipeng Chen,Fen Luo,Xiaoyan Shu,Mingfen Wen,Yuexiang Lu,Wenhong Han,Jing Chen,Haijiao Xie,Faqin Dong,Xirui Lu
Nuclear waste immobilization is one of the ways to alleviate the harm of radioactive waste produced in the nuclear field to human beings and the environment. In the current study, granite was utilized as a substrate material for the immobilization of simulated radioactive waste. Based on the obtained results, the relationship between the waste chemical species and the physicochemical properties , such as solid-solubility of waste, infrared, density and leaching data, was systematically studied as well. The findings indicate that the granite substrate used for the immobilization of the simulated waste (Nd 2 O 3 ) exhibits a solid-solubility limit of 27 wt%. When the added content of waste is below 27 wt%, all Nd elements are immobilized into the glassy phase . However, when the waste content exceeds 27 wt%, in addition to being immobilized in the glassy phase, the presence of Nd 2 O 3 reacted with Ca 3 Si 3 O 9 to form Ca 2 Nd 8 (SiO 4 ) 6 O 2 . As the Nd 2 O 3 content increased from 20 wt% to 25 wt%, the microstructures related to Si-, Al-, and Fe-are more involved in the immobilization of waste. However, the appearance of Ca 2 Nd 8 (SiO 4 ) 6 O 2 and Nd 2 O 3 makes the density and Vickers hardness of the matrix not increase further. The maximum density and hardness values are 3.17 g cm −3 and 7.88 GPa, respectively. The leaching results show that the cured body has good anti-leaching performance ( L R Nd = ∼10 −6 g cm −2 d −1 ). Finally, the comparison of vacancy formation energy of Nd in Nd 2 O 3 and Ca 2 Nd 8 (SiO 4 ) 6 O 2 proved that the formation of Ca 2 Nd 8 (SiO 4 ) 6 O 2 is beneficial to the immobilization of simulated waste. This study provides a certain reference for the selection of nuclear waste solidification substrates. This kind of granite material from nature has the potential advantages of low cost and better immobilization effect on waste, and may be more suitable for the treatment of radioactive waste in the future.
研究领域:
材料科学
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环境科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Pan Wang,Zhen Teng,Sifan Zeng,Chen Chen,Wanlin Feng,Xiaosong Zhou
In this study, granite wastes based glass-ceramics containing Eu 2 O 3 as simulated radionuclides is successfully synthesized via solid-state sintering method. The structure, mechanical properties and chemical durability are deeply investigated. The main phase in this glass-ceramics is oxyapatite (Ca 2 Eu 8 (SiO 4 ) 6 O 2 ), which is dispersed homogenously in glass matrix. The density dominates the properties of Vickers hardness and bending strength . The glass-ceramics containing 40 wt % of Eu 2 O 3 has the optimal mechanical properties, with the Vickers hardness , bending strength and density of 5.12 GPa, 79.44 MPa and 98.77 %, respectively. The 28 days leaching experiments show that the glass-ceramics containing 40 wt % of Eu 2 O 3 possess excellent chemical durability. The leaching rate of Al 3+ , Si 4+ , Fe 3+ , Ca 2+ , Eu 3+ are 2.3 × 10 −4 g m −2 d −1 , 6.0 × 10 −4 g m −2 d −1 , 1.2 × 10 −7 g m −2 d −1 , 1.4 × 10 −4 g m −2 d −1 , 3.6 × 10 −8 g m −2 d −1 , respectively. This study indicates that granite wastes based glass-ceramics have excellent chemical stability and mechanical properties, which provides a novel idea for the immobilization of radioactive wastes .
研究领域:
材料科学
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核能工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nuclear Engineering and Technology
·
2024
·
IF 2.6
Xinyu Wang,Xiaojie Li,Yongmei Li,Longcheng Liu,Shuo Meng,Chunguang Li,Zhenzhong Liu,Xiaodong Li,Kaixuan Tan
Deep geologic disposal has been widely accepted as a strategy for long-term disposal of the high-level radioactive waste. It is principal to obtain the migration parameters of radionuclides in natural barrier, such as granite, of a high-level radioactive waste repository for safety assessment of the repository. To quickly determine the diffusion and sorption properties of nuclides in intact granite, two tracers, I − and ReO 4 − , were tested with a modified electromigration device, by imposing a constant voltage over an intact Beishan granitic rock sample. The breakthrough curves of I − and ReO 4 − were obtained under condition of five different voltages. To interpret the electromigration experimental results with more confidence, an advection-dispersion model based on first-order adsorption kinetics was developed in this study. Data analysis of the breakthrough curves by this model suggest that the effective diffusion coefficients of I − and ReO 4 − in intact Beishan granodiorite rock are (6.81 ± 0.53) × 10 −13 m 2 /s and (6.45 ± 0.07) × 10 −13 m 2 /s, respectively. While the distribution coefficient of the two ions are (9.06 ± 1.13) × 10 −7 m 3 /kg and (9.81 ± 0.13) × 10 −7 m 3 /kg, respectively. This indicates that I − and ReO 4 − hardly adsorb in Beishan granodiorite rock.
研究领域:
地质学
·
环境科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Fangfei Cai,Funing Ma,Xiaoying Zhang,Paul Reimus,Linlin Qi,Yu Wang,Di Lu,Hung Vo Thanh,Zhenxue Dai
The disposal of high-level radioactive waste in deep geological repositories is a critical environmental issue . The presence of bentonite colloids generated in the engineering barrier can significantly impact the transport of radionuclides , but their effect on radionuclide sorption in granite remains poorly understood. This study aimed to investigate the sorption characteristics of strontium (Sr) on granite as well as on the coexistence system of granite and colloids under various hydrogeochemical conditions, through batch experiments. Fourier transform infrared spectroscopy was employed to analyze the sorption forms of Sr on granite before and after sorption. Several hydrogeochemical factors were examined, including contact time, pH, ionic strength, coexisting ions, and bentonite and humic acid colloid concentration. Among these factors, the concentration of bentonite colloids exhibited a significant effect on Sr sorption. Within a specific range of colloid concentration, the sorption of Sr on the solid system increased linearly with the bentonite colloid concentration. pH and ionic strength were also found to play crucial roles in the sorption process. At low pH, Sr sorption primarily occurred through the outer sphere's surface complexation and Na + /H + ion exchange. However, at high pH, inner sphere surface complexation dominated the process. As the ionic strength increased, electrostatic repulsion gradually increased, resulting in fewer binding sites for particle aggregation and Sr sorption on bentonite colloids. The results also indicate that with increasing pH, the predominant forms of Sr in the solution transitioned from SrHCO 3 + and SrCl + to SrCO 3 and SrCl + . This was mainly due to the ion exchange of Ca 2+ /Mg 2+ in plagioclase and biotite , forming SrCO 3 precipitation. These findings provide valuable insights into the transport behavior of radionuclides in the subsurface environment of the repository and highlight the importance of considering bentonite colloids and other hydrogeochemical factors when assessing the environmental impact of high-level radioactive waste disposal .
研究领域:
环境科学
·
放射生物学
✓ 已验证
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Jian Zhou,Changyou Liu,Jinshan Lu
The utilization of granite sludge offers significant economic and environmental advantages. This study focuses on preparing porous glass-ceramics from Ca(OH) 2 -modified granite sludge through a two-step sintering process comprising dense sintering and high-temperature foaming, with the addition of 1 % SiC powder as a foaming agent. The impact of foaming temperature and Ca(OH) 2 addition on the structure, compressive strength , specific strength , and thermal conductivity of the porous glass-ceramics is examined. Incorporating the Ca(OH) 2 modifier reduces the glass's viscosity and effectively eliminates micropores on the pore walls. The former promotes foaming and increases porosity, while the latter increases the specific strength of porous glass-ceramics. Increasing both the foaming temperature and the Ca(OH) 2 concentration reduces glass viscosity and promotes mineral dissolution, facilitating the foaming process. However, the specific strength of the porous glass-ceramics initially increases before decreasing due to pore coalescence and excessive mineral dissolution. Theoretical evaluations of compressive strength and thermal conductivity indicate that porous glass-ceramics possess a closed-cell pore structure . Porous glass-ceramic made from granite powder containing 3.5 % Ca(OH) 2 and foamed at 1240 °C exhibits an apparent density and porosity of 0.73 g/cm 3 and 67.1 %, respectively. The compressive strength and thermal conductivity are 14.2 MPa and 0.422 W/(m·K) respectively, with a peak specific strength of 19.4 kN·m/kg. This innovative process enables the scalable recycling of granite sludge into energy-saving building materials.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Geoenergy Science and Engineering
·
2024
·
IF 0
Ou Jiang,Xiuhua Zheng,Qingjie Gong,Haidong Wu,Baozhen Chu
Water-rock interactions induced by working fluids in hot dry rock (HDR) reservoirs lead to reservoir damages through mass transfer. Therefore, investigating the mass transfer mechanisms due to the interactions between working fluids and reservoir rocks contributes to minimizing HDR reservoir damages. Drilling fluid is an important working fluid, yet the interactions between drilling fluids and HDR reservoir rocks lack understandings. Here, interaction experiments were conducted using a high-temperature and high-pressure flow reactor under temperatures of 180 °C and 240 °C, a pressure of 24 MPa, and a flow rate of 0.05 mL/min for 7 days. Pure water and an alkaline NaCl solution, which is referred to a HDR reservoir drilling fluid, were prepared to interact with granite cuttings from the HDR reservoir at Qiabuqia site in Gonghe Basin, Qinghai Province, China. Mineral characteristics, mass and chemical changes in the cuttings, solution element content concentrations, micro-morphology and element contents on the cuttings surface, as well as the size of suspending fines in the solutions were determined to reveal the mass transfer mechanisms. The results indicate that the mass transfer mechanisms include mineral reactions and fines migration, and fines migration is the dominating mechanism. The mineral reactions, including feldspar dissolution, quartz dissolution and feldspar alteration, are strong at the front section, while are weak at the end section. At the middle section, the released element contents by mineral reactions form various precipitates, mainly including aluminosilicate, silicate and silica. Strong mineral reactions at the front section lead to fines migration, while the precipitation of Na-bearing minerals at the middle section inhibits fines migration through a coating effect. Suspending fines are identified in the solutions, with a diameter of 100–300 nm, and settled fines are observed at the end section, with a diameter of hundreds of nanometers to a few microns. Simulations of reaction equilibrium show that the precipitation of quartz and biotite increases with a higher NaCl concentration and a lower temperature, while albite changes from dissolution to precipitation as NaCl concentration rises from 6 wt% to 12 wt%. The formation of halite by simulations supports the coating effect. This study provides theoretical basis to minimize HDR reservoir damage induced by working fluids.
研究领域:
地质学
·
地球化学
✓ 已验证
DOI
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