Spent fuel reprocessing plays a pivotal role in achieving efficient recycling of nuclear fuel.Among thedifferent forms of failure encountered in spent fuel reprocessing,tribocorrosion stands out as a critical concern....Spent fuel reprocessing plays a pivotal role in achieving efficient recycling of nuclear fuel.Among thedifferent forms of failure encountered in spent fuel reprocessing,tribocorrosion stands out as a critical concern.Herein,the tribocorrosion behavior,as well as the corrosion behavior,of 304L stainless steel(SS)in high-temperatureconcentrated nitric acid was investigated.The results indicated that 304L SS formed a thin(1.54 nm)and stable passivefilm on the surface,imparting high resistance to nitric acid corrosion.Meanwhile,it was found that the synergistic effectbetween corrosion and wear accounted for a high total tribocorrosion weight loss of over 85%,implying the dominantrole of the synergistic effect in the tribocorrosion process.Furthermore,the wear of 304L SS in deionized water revealedboth abrasive and adhesive wear characterizations,whereas the tribocorrosion in nitric acid only exhibited abrasive wearfeature.Eventually,the tribocorrosion and corrosion models of 304L SS in hot concentrated nitric acid were proposedbased on the comprehensive experimental findings.展开更多
Nitric humic acid was prepared by catalytic oxidation between nitric acid and Guizhou coal, with added catalysts. We investigated catalytic oxidation processes and the factors that affect the reactions. The effects of...Nitric humic acid was prepared by catalytic oxidation between nitric acid and Guizhou coal, with added catalysts. We investigated catalytic oxidation processes and the factors that affect the reactions. The effects of different catalysts, including NiSO4 support on active carbon （AC-NiS04）, NiS04 support on sil- icon dioxide （SiO2-NiSO4）, composites of SO42-1Fe203, Zr-iron and vanadium-iron composite were stud- ied. As well, we investigated nitric humic acid yields and the chemical structure of products by element analysis, FT-IR and E4/E6 （an absorbance ratio at wavelengths of 465 and 665 nm of humic acid alkaline extraction solutions）. The results show that the catalytic oxidation reaction with added catalysts can increase humic acid yields by 18.7%, 16.36% 12.94%, 5.61% and 8.59%, respectively. The highest yield of humic acid, i.e., 36.0%, was obtained with AC-NiSO4 as the catalyst. The amounts of C and H decreased with the amount of nitrogen. The increase in the E4/E6 ratio in catalytic oxidation of （Guizhou） coal shows that small molecular weights and high yields of nitric humic acid can be obtained by catalytic oxidation reactions.展开更多
Porous Ti3SiC2with high purity was synthesized using TiH2,Si and C powders with mole ratio of Ti to Si to C being3:1.2:2by reactive synthesis method.The corrosion behaviors of porous Ti3SiC2in nitric acid and aqua reg...Porous Ti3SiC2with high purity was synthesized using TiH2,Si and C powders with mole ratio of Ti to Si to C being3:1.2:2by reactive synthesis method.The corrosion behaviors of porous Ti3SiC2in nitric acid and aqua regia were investigated byimmersing test.Scanning electron microscope(SEM),X-ray diffractometer(XRD),energy dispersive spectrometer(EDS)and X-rayphotoelectron spectroscopy(XPS)were used to analyze the morphology,compositions and element contents of the samples beforeand after corrosion to determine the corrosion product and corrosion mechanism.The mass loss values of porous Ti3SiC2are26.9and132.5μg/cm2,respectively after immersing in nitric acid and aqua regia for600h.The results indicate that Ti3SiC2transforms toTi5Si3which has better corrosion resistance in nitric acid and aqua regia with mass loss values of9.34and7.06μg/cm2under thesame immersing time,respectively.The dramatic dissolution of porous Ti3SiC2in the acids is due to its special microstructure.展开更多
The corrosion behavior of a titanium-5% tantalum alloy （Ti-STa） in hot nitric acid condensate was investigated to understand aging behavior ofreprocessing equipments. On the basis of long-term immersion tests, it wa...The corrosion behavior of a titanium-5% tantalum alloy （Ti-STa） in hot nitric acid condensate was investigated to understand aging behavior ofreprocessing equipments. On the basis of long-term immersion tests, it was determined that the corrosion of Ti-STa in nitric acid condensate is accelerated with an increase in the concentration. The corrosion rate was nearly constant during the immersion test and the coupons suffered from uniform corrosion. In addition, it is important to note that the nitric acid concentration in the condensate increased on addition of metal salts to the heated nitric acid solution. The larger valence of metal ions was contributed to the increase in the concentration of nitric acid condensate. Consequently, the metal salt in the heated nitric acid solution accelerates the corrosion of Ti-STa in the condensate. Therefore, the nitric acid condensate condition should be carefully considered for the corrosion environment of titanium and its alloys.展开更多
基金Projects(52101105,52373321)supported by the National Natural Science Foundation of ChinaProject(2023-PY03)supported by the IMR Innovation Fund,ChinaProject(CNNC-LCKY-202274)supported by the LingChuang Research Project of China National Nuclear Corporation。
文摘Spent fuel reprocessing plays a pivotal role in achieving efficient recycling of nuclear fuel.Among thedifferent forms of failure encountered in spent fuel reprocessing,tribocorrosion stands out as a critical concern.Herein,the tribocorrosion behavior,as well as the corrosion behavior,of 304L stainless steel(SS)in high-temperatureconcentrated nitric acid was investigated.The results indicated that 304L SS formed a thin(1.54 nm)and stable passivefilm on the surface,imparting high resistance to nitric acid corrosion.Meanwhile,it was found that the synergistic effectbetween corrosion and wear accounted for a high total tribocorrosion weight loss of over 85%,implying the dominantrole of the synergistic effect in the tribocorrosion process.Furthermore,the wear of 304L SS in deionized water revealedboth abrasive and adhesive wear characterizations,whereas the tribocorrosion in nitric acid only exhibited abrasive wearfeature.Eventually,the tribocorrosion and corrosion models of 304L SS in hot concentrated nitric acid were proposedbased on the comprehensive experimental findings.
基金sponsored by the Shaanxi Key Scientific and Technological Project, China (No. 2010K07-20)the National Science and Technology Major Project (No. 2011ZX05037-003)
文摘Nitric humic acid was prepared by catalytic oxidation between nitric acid and Guizhou coal, with added catalysts. We investigated catalytic oxidation processes and the factors that affect the reactions. The effects of different catalysts, including NiSO4 support on active carbon （AC-NiS04）, NiS04 support on sil- icon dioxide （SiO2-NiSO4）, composites of SO42-1Fe203, Zr-iron and vanadium-iron composite were stud- ied. As well, we investigated nitric humic acid yields and the chemical structure of products by element analysis, FT-IR and E4/E6 （an absorbance ratio at wavelengths of 465 and 665 nm of humic acid alkaline extraction solutions）. The results show that the catalytic oxidation reaction with added catalysts can increase humic acid yields by 18.7%, 16.36% 12.94%, 5.61% and 8.59%, respectively. The highest yield of humic acid, i.e., 36.0%, was obtained with AC-NiSO4 as the catalyst. The amounts of C and H decreased with the amount of nitrogen. The increase in the E4/E6 ratio in catalytic oxidation of （Guizhou） coal shows that small molecular weights and high yields of nitric humic acid can be obtained by catalytic oxidation reactions.
基金Projects(51604305,51504296) supported by the National Natural Science Foundation of ChinaProject(2016M592445) supported by the China Postdoctoral Science FoundationProject(169715) supported by the Postdoctoral Science Foundation of Central South University,China
文摘Porous Ti3SiC2with high purity was synthesized using TiH2,Si and C powders with mole ratio of Ti to Si to C being3:1.2:2by reactive synthesis method.The corrosion behaviors of porous Ti3SiC2in nitric acid and aqua regia were investigated byimmersing test.Scanning electron microscope(SEM),X-ray diffractometer(XRD),energy dispersive spectrometer(EDS)and X-rayphotoelectron spectroscopy(XPS)were used to analyze the morphology,compositions and element contents of the samples beforeand after corrosion to determine the corrosion product and corrosion mechanism.The mass loss values of porous Ti3SiC2are26.9and132.5μg/cm2,respectively after immersing in nitric acid and aqua regia for600h.The results indicate that Ti3SiC2transforms toTi5Si3which has better corrosion resistance in nitric acid and aqua regia with mass loss values of9.34and7.06μg/cm2under thesame immersing time,respectively.The dramatic dissolution of porous Ti3SiC2in the acids is due to its special microstructure.
文摘The corrosion behavior of a titanium-5% tantalum alloy （Ti-STa） in hot nitric acid condensate was investigated to understand aging behavior ofreprocessing equipments. On the basis of long-term immersion tests, it was determined that the corrosion of Ti-STa in nitric acid condensate is accelerated with an increase in the concentration. The corrosion rate was nearly constant during the immersion test and the coupons suffered from uniform corrosion. In addition, it is important to note that the nitric acid concentration in the condensate increased on addition of metal salts to the heated nitric acid solution. The larger valence of metal ions was contributed to the increase in the concentration of nitric acid condensate. Consequently, the metal salt in the heated nitric acid solution accelerates the corrosion of Ti-STa in the condensate. Therefore, the nitric acid condensate condition should be carefully considered for the corrosion environment of titanium and its alloys.
