Nanosized TiO2 powder with anatase and rutile structures was synthesized by a sol gel method using TiCl4 ethanol solution as a precursor.The grain size ofTiO2 powder was about 63nm after the precursor was calcined at ...Nanosized TiO2 powder with anatase and rutile structures was synthesized by a sol gel method using TiCl4 ethanol solution as a precursor.The grain size ofTiO2 powder was about 63nm after the precursor was calcined at 600℃for 2 hours .The experimental techniques of XRD,TEM and Particle Distribution were used to characterize the synthesized specimens. Various special effects were investigated for their contribution to crystal structure and the size of TiO2 powder .Theformation of anatase as well as the rutile phase of TiO2 was indicted from the XRD when the reaction temperature was above 30℃and when the sol was irradiated by infrared rays .However, an anatase TiO2 powder formed after the heat treatment of the dried gel in a temperature range from 300℃to 500℃.Under the vacuum drying and with the calcined time below 3hours ,the anatase phase was gained .As well as with the increase of gelatinizing time, the anatase TiO2 powder was obtained.展开更多
以发泡镍为基体,柱状活性炭颗粒和Ti O2粉末均匀混合后作为催化剂涂覆在电极表面。将此复合电极作为双室生物阴极型MFC的电极,研究MFC的产电性能。结果表明:在运行周期内,系统最大输出电压可达到698.1 m V,稳定在500 m V以上的高电压输...以发泡镍为基体,柱状活性炭颗粒和Ti O2粉末均匀混合后作为催化剂涂覆在电极表面。将此复合电极作为双室生物阴极型MFC的电极,研究MFC的产电性能。结果表明:在运行周期内,系统最大输出电压可达到698.1 m V,稳定在500 m V以上的高电压输出时间为18 d;单位质子膜面积上可获得最大功率密度为183.33W/m4,质子膜的使用量明显减少,从而大大降低了MFC的产电成本。同时,阳极室对原生活污水COD去除率可达到74%,而库伦效率也可达到68.9%。试验结果表明,活性炭和Ti O2混合涂覆镍基体电极对双室生物阴极型MFC产电的催化效果良好。展开更多
To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide （w（TiO2）〉98%）, based on the preform reduction process （PRP）, was investigated by me...To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide （w（TiO2）〉98%）, based on the preform reduction process （PRP）, was investigated by means of XRD, SEM and EDS. In this process, the mixture of TiO2 powder and CaC12 was pressed into pieces as feed preform and was reduced by calcium vapor. Titanium powders was recovered after leaching from the reduced preform with hydrochloric acid and deionized water. The results indicate when the mass ratio of CaC12 to TiO2 is about 1：4 and at a constant temperature of 1 273 K for 6 h in vacuum furnace, titanium powders with 99.55% purity by EDS analysis and irregular shape （8-15 μm in particle size） are obtained.展开更多
In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO_(2))in the cold pressed pellets were conducted by metallothermic reduction with an...In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO_(2))in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO_(2) to CaCl_(2)(nTiO_(2)/nCaCl_(2))in the pellets.The results show that metallic Ti was obtained from the reduction of TiO_(2) in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when T_(Redu)=1273 K,t_(Redu)=6 h,and nTiO_(2)/nCaCl_(2)=4;the reasonable nTiO_(2)/nCaCl_(2) value is 3−5 for the pellets with enough strength and high RM.展开更多
文摘Nanosized TiO2 powder with anatase and rutile structures was synthesized by a sol gel method using TiCl4 ethanol solution as a precursor.The grain size ofTiO2 powder was about 63nm after the precursor was calcined at 600℃for 2 hours .The experimental techniques of XRD,TEM and Particle Distribution were used to characterize the synthesized specimens. Various special effects were investigated for their contribution to crystal structure and the size of TiO2 powder .Theformation of anatase as well as the rutile phase of TiO2 was indicted from the XRD when the reaction temperature was above 30℃and when the sol was irradiated by infrared rays .However, an anatase TiO2 powder formed after the heat treatment of the dried gel in a temperature range from 300℃to 500℃.Under the vacuum drying and with the calcined time below 3hours ,the anatase phase was gained .As well as with the increase of gelatinizing time, the anatase TiO2 powder was obtained.
文摘以发泡镍为基体,柱状活性炭颗粒和Ti O2粉末均匀混合后作为催化剂涂覆在电极表面。将此复合电极作为双室生物阴极型MFC的电极,研究MFC的产电性能。结果表明:在运行周期内,系统最大输出电压可达到698.1 m V,稳定在500 m V以上的高电压输出时间为18 d;单位质子膜面积上可获得最大功率密度为183.33W/m4,质子膜的使用量明显减少,从而大大降低了MFC的产电成本。同时,阳极室对原生活污水COD去除率可达到74%,而库伦效率也可达到68.9%。试验结果表明,活性炭和Ti O2混合涂覆镍基体电极对双室生物阴极型MFC产电的催化效果良好。
基金Project(51004058) supported by the National Natural Science Foundation of ChinaProject(2011FB039) supported by the Natural Science Foundation of Yunnan Province,China
文摘To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide （w（TiO2）〉98%）, based on the preform reduction process （PRP）, was investigated by means of XRD, SEM and EDS. In this process, the mixture of TiO2 powder and CaC12 was pressed into pieces as feed preform and was reduced by calcium vapor. Titanium powders was recovered after leaching from the reduced preform with hydrochloric acid and deionized water. The results indicate when the mass ratio of CaC12 to TiO2 is about 1：4 and at a constant temperature of 1 273 K for 6 h in vacuum furnace, titanium powders with 99.55% purity by EDS analysis and irregular shape （8-15 μm in particle size） are obtained.
基金Projects(51774071,50804007,51974073)supported by the National Natural Science Foundation of China。
文摘In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO_(2))in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO_(2) to CaCl_(2)(nTiO_(2)/nCaCl_(2))in the pellets.The results show that metallic Ti was obtained from the reduction of TiO_(2) in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when T_(Redu)=1273 K,t_(Redu)=6 h,and nTiO_(2)/nCaCl_(2)=4;the reasonable nTiO_(2)/nCaCl_(2) value is 3−5 for the pellets with enough strength and high RM.
