The formation of a rust layer on iron and steels surfaces accelerates their degradation and eventually causes material failure.In addition to fabricating a protective layer or using a sacrificial anode, repairing or r...The formation of a rust layer on iron and steels surfaces accelerates their degradation and eventually causes material failure.In addition to fabricating a protective layer or using a sacrificial anode, repairing or removing the rust layer is another way to reduce the corrosion rate and extend the lifespans of iron and steels.Herein, an electrochemical healing approach was employed to repair the rust layer in molten Na_(2)CO_(3)-K_(2)CO_(3).The rusty layers on iron rods and screws were electrochemically converted to iron in only several minutes and a metallic luster appeared.Scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS) analyses showed that the structures of the rust layer after healing were slightly porous and the oxygen content reached a very low level.Thus, high-temperature molten-salt electrolysis may be an effective way to metalize iron rust of various shapes and structures in a short time, and could be used in the repair of cultural relics and even preparing a three-dimensional porous structures for other applications.展开更多
The structure, working principles, and main technological parameters of the premajet derusting machine are introduced. Experiments were made to test the relationship among such jet parameters as working pressure, rate...The structure, working principles, and main technological parameters of the premajet derusting machine are introduced. Experiments were made to test the relationship among such jet parameters as working pressure, rate of water flow, abrasive weight consistency and derusting efficiency. Reasonable parameters were decided. Results prove that the derusting machine is characterized by its high derusting efficiency (as high as 20m 2/h), good derusting quality (as good as ISO8501 1 Sa 2.5), and low specific power consumption (about 0.3kW·h/m 2). Therefore it is a new type of high efficiency derusting machine.展开更多
The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentr...The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentrations of citric acid and iron. Because of its iron containment, the Fenton-like reaction automatically took place with the added amount of H2O2. The decomposition rate was found in a sequence of： UV/HEOE/Fe（Ⅲ） 〉 UV/H2O2 〉 Fe（Ⅱ）/H2O2. Two H2O2 injection methods, single and multiple points, were evaluated. The multiple-point H2O2 injection was more efficient to decompose the citric acid. The decomposition of the synthetic citric acid and the real derusting citric acid wastewater was also compared. The 93% COD reduction of the derusting wastewater was achieved using the UV/HEOE/Fe（Ⅲ） treatment.展开更多
基金financially supported by the Fundamental Research Funds for the Central Universities (No.N172505002)the National Natural Science Foundation of China (No.51704060)+1 种基金the National Thousand Youth Talent Program of Chinathe 111 Project (No.B16009)。
文摘The formation of a rust layer on iron and steels surfaces accelerates their degradation and eventually causes material failure.In addition to fabricating a protective layer or using a sacrificial anode, repairing or removing the rust layer is another way to reduce the corrosion rate and extend the lifespans of iron and steels.Herein, an electrochemical healing approach was employed to repair the rust layer in molten Na_(2)CO_(3)-K_(2)CO_(3).The rusty layers on iron rods and screws were electrochemically converted to iron in only several minutes and a metallic luster appeared.Scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS) analyses showed that the structures of the rust layer after healing were slightly porous and the oxygen content reached a very low level.Thus, high-temperature molten-salt electrolysis may be an effective way to metalize iron rust of various shapes and structures in a short time, and could be used in the repair of cultural relics and even preparing a three-dimensional porous structures for other applications.
文摘The structure, working principles, and main technological parameters of the premajet derusting machine are introduced. Experiments were made to test the relationship among such jet parameters as working pressure, rate of water flow, abrasive weight consistency and derusting efficiency. Reasonable parameters were decided. Results prove that the derusting machine is characterized by its high derusting efficiency (as high as 20m 2/h), good derusting quality (as good as ISO8501 1 Sa 2.5), and low specific power consumption (about 0.3kW·h/m 2). Therefore it is a new type of high efficiency derusting machine.
文摘The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentrations of citric acid and iron. Because of its iron containment, the Fenton-like reaction automatically took place with the added amount of H2O2. The decomposition rate was found in a sequence of： UV/HEOE/Fe（Ⅲ） 〉 UV/H2O2 〉 Fe（Ⅱ）/H2O2. Two H2O2 injection methods, single and multiple points, were evaluated. The multiple-point H2O2 injection was more efficient to decompose the citric acid. The decomposition of the synthetic citric acid and the real derusting citric acid wastewater was also compared. The 93% COD reduction of the derusting wastewater was achieved using the UV/HEOE/Fe（Ⅲ） treatment.
