In order to evaluate the spontaneous combustion hazard of sulfide concentrates in storage, three different kinds of sulfide concentrates （sulfur-rich sulfide concentrate, iron sulfide concentrate and copper sulfide c...In order to evaluate the spontaneous combustion hazard of sulfide concentrates in storage, three different kinds of sulfide concentrates （sulfur-rich sulfide concentrate, iron sulfide concentrate and copper sulfide concentrate） were obtained from a storage yard in Dongguashan Copper Mine, China. The reaction processes at different heating rates of 5, 10, 15, 20, and 25 ℃/min in air flow from ambient temperature to 1 000 ℃ were studied by TG-DTG-DSC analysis. By the peak temperatures of DTG curves, the whole reaction process for each sample was divided into different stages, and the corresponding apparent activation energies were calculated by the Ozawa-Flynn-Wall method. It is found that the reaction process of each sample is considerably complex; the apparent activation energy values change from 36 to 160 kJ/mol in different temperature ranges; sulfur-rich sulfide and iron sulfide concentrates have lower apparent activation energy than copper sulfide concentrate below 150 ℃; so they are more inclined to cause spontaneous combustion at ambient temperature.展开更多
Sohd-solid reaction under low heat or low temperature is an approach to synthesize various kinds of materials that were widely used in electrochemistry field. In this paper a theoretical treatment has been presented f...Sohd-solid reaction under low heat or low temperature is an approach to synthesize various kinds of materials that were widely used in electrochemistry field. In this paper a theoretical treatment has been presented for analyzing the mechanism of sohd-solid reaction and deriving a series of formulae to describe the variation and rate of reactions. This new model has been used in the manufacturing of spinel Li4Ti5O12. The results show that this new model works very well and will play a useful role for guiding the manufacturing of electrochemical materials.展开更多
Based on the analysis of the properties of Nomex 450 and Nomex 462,the thermal properties of Nomex 462/Lenzing Viscose Flame retardent(FR)blending materials were analyzed.It was discovered through burning test and The...Based on the analysis of the properties of Nomex 450 and Nomex 462,the thermal properties of Nomex 462/Lenzing Viscose Flame retardent(FR)blending materials were analyzed.It was discovered through burning test and Thermal Gravity(TG)analysis that the blended material was superior in thermal behaviors to the material made from either Nomex or Viscose FR filament,when the ratio of Nomex and Lenzing Viscose FR reached 80∶20,and excellent thermal properties were achieved with the value of Limiting Oxygen Index(LOI)up to 36.1%.Blending Nomex and Viscose FR filaments may be recommended for better fire retardant property of related fabric.展开更多
The curing mechanism of furfuryl alcohol and urea-formaldehyde furan resins was investigated using infrared spectroscopy(IR) technique.The curing productions of urea-formaldehyde furan resins modified with different a...The curing mechanism of furfuryl alcohol and urea-formaldehyde furan resins was investigated using infrared spectroscopy(IR) technique.The curing productions of urea-formaldehyde furan resins modified with different agents(i.e.sorbitol,polyester polyol,phenol and acetone) and the productions of incomplete curing were characterized by differential thermal analysis(DTA) and thermal gravity analysis(TG).The results indicate that except for polyester polyol,the other modifiers have little effect on the thermal strength of urea-formaldehyde furan resin.Furthermore,the thermal strength can be improved at a temperature of higher than 550℃.展开更多
The potential combustion-supporting agents for three kinds of coals were selected according to the Thermal Gravity Analysis (TG). The TG analysis shows that the addition of FeCl3 can reduce the ignition point of clara...The potential combustion-supporting agents for three kinds of coals were selected according to the Thermal Gravity Analysis (TG). The TG analysis shows that the addition of FeCl3 can reduce the ignition point of clarain and fusain from Guangxi and also the raw coal from Xinwen. The combustion-supporting effect of FeCl3 on the clarain is quite obvious, with the maximum reduction of ignition point reaching 90 ℃ and that of the burn-out point reaching 95 ℃. What is more, it can make the coal burn more completely. The relationship between the amount of FeCl3 and the ig- nition point was also investigated and the optimum amount of FeCl3 obtained. When FeCl3 is added in doses of 6%, 4%, 2%, and 1%, the reduction of ignition point is proportional to the amount of agent. If 6% of FeCl3 is added, the combus- tion-supporting effect is very significant; while if only 1% of FeCl3 is added, the combustion-supporting effect can be negligible. Therefore the optimum amount of FeCl3 is between 3% and 6% for achieving an obvious combus- tion-supporting effect. In addition, the combustion supporting mechanism of FeCl3 was also studied, which is the com- bined action of chloride and iron in the compound.展开更多
Rare earth elements have been widely used in many areas. Rare earth complex bearing an amino acid was synthesized to study the influence and the long term effect of rare earth elements on environment and human beings...Rare earth elements have been widely used in many areas. Rare earth complex bearing an amino acid was synthesized to study the influence and the long term effect of rare earth elements on environment and human beings, because amino acid is the basic unit of the living things. Previous work on these kinds of complex is focused on synthesis and characterization of them. But their thermodynamic data have seldom been reported. Here we present the thermodynamic study of [Ho(H 2O) 5]Cl 3. The heat capacity of Holmium complex with threonine, [Ho(Thr)(H 2O) 5]Cl 3 , was measured with an automatic adiabatic calorimeter in the temperature range from 79 K to 330 K and no thermal anomaly was found in this range. Thermodynamic functions relative to standard state 298 15 K were derived from the heat capacity data. Thermal decomposition behavior of the complex in nitrogen atmosphere in the range from 300 K to 900 K was studied by thermogravimetric (TG) technique and a possible decomposition mechanism was proposed according to the TG DTG results.展开更多
基金Project (2006BAK04B03) supported by the National Science and Technology Pillar Program during the 11th Five-Year Plan Period of ChinaProject (kjdb200902-7) supported by Doctoral Candidate Innovation Research Support Program of Science & Technology Review, China+1 种基金Project (1960-71131100023) supported by Postgraduate Dissertation Innovation Foundation of Central South University, ChinaProject (ZKJ2009008) supported by Precious Apparatus Opening Center Foundation of Central South University, China
文摘In order to evaluate the spontaneous combustion hazard of sulfide concentrates in storage, three different kinds of sulfide concentrates （sulfur-rich sulfide concentrate, iron sulfide concentrate and copper sulfide concentrate） were obtained from a storage yard in Dongguashan Copper Mine, China. The reaction processes at different heating rates of 5, 10, 15, 20, and 25 ℃/min in air flow from ambient temperature to 1 000 ℃ were studied by TG-DTG-DSC analysis. By the peak temperatures of DTG curves, the whole reaction process for each sample was divided into different stages, and the corresponding apparent activation energies were calculated by the Ozawa-Flynn-Wall method. It is found that the reaction process of each sample is considerably complex; the apparent activation energy values change from 36 to 160 kJ/mol in different temperature ranges; sulfur-rich sulfide and iron sulfide concentrates have lower apparent activation energy than copper sulfide concentrate below 150 ℃; so they are more inclined to cause spontaneous combustion at ambient temperature.
文摘Sohd-solid reaction under low heat or low temperature is an approach to synthesize various kinds of materials that were widely used in electrochemistry field. In this paper a theoretical treatment has been presented for analyzing the mechanism of sohd-solid reaction and deriving a series of formulae to describe the variation and rate of reactions. This new model has been used in the manufacturing of spinel Li4Ti5O12. The results show that this new model works very well and will play a useful role for guiding the manufacturing of electrochemical materials.
文摘Based on the analysis of the properties of Nomex 450 and Nomex 462,the thermal properties of Nomex 462/Lenzing Viscose Flame retardent(FR)blending materials were analyzed.It was discovered through burning test and Thermal Gravity(TG)analysis that the blended material was superior in thermal behaviors to the material made from either Nomex or Viscose FR filament,when the ratio of Nomex and Lenzing Viscose FR reached 80∶20,and excellent thermal properties were achieved with the value of Limiting Oxygen Index(LOI)up to 36.1%.Blending Nomex and Viscose FR filaments may be recommended for better fire retardant property of related fabric.
文摘The curing mechanism of furfuryl alcohol and urea-formaldehyde furan resins was investigated using infrared spectroscopy(IR) technique.The curing productions of urea-formaldehyde furan resins modified with different agents(i.e.sorbitol,polyester polyol,phenol and acetone) and the productions of incomplete curing were characterized by differential thermal analysis(DTA) and thermal gravity analysis(TG).The results indicate that except for polyester polyol,the other modifiers have little effect on the thermal strength of urea-formaldehyde furan resin.Furthermore,the thermal strength can be improved at a temperature of higher than 550℃.
文摘The potential combustion-supporting agents for three kinds of coals were selected according to the Thermal Gravity Analysis (TG). The TG analysis shows that the addition of FeCl3 can reduce the ignition point of clarain and fusain from Guangxi and also the raw coal from Xinwen. The combustion-supporting effect of FeCl3 on the clarain is quite obvious, with the maximum reduction of ignition point reaching 90 ℃ and that of the burn-out point reaching 95 ℃. What is more, it can make the coal burn more completely. The relationship between the amount of FeCl3 and the ig- nition point was also investigated and the optimum amount of FeCl3 obtained. When FeCl3 is added in doses of 6%, 4%, 2%, and 1%, the reduction of ignition point is proportional to the amount of agent. If 6% of FeCl3 is added, the combus- tion-supporting effect is very significant; while if only 1% of FeCl3 is added, the combustion-supporting effect can be negligible. Therefore the optimum amount of FeCl3 is between 3% and 6% for achieving an obvious combus- tion-supporting effect. In addition, the combustion supporting mechanism of FeCl3 was also studied, which is the com- bined action of chloride and iron in the compound.
基金theNationalNaturalScienceFoundationofChina (No .2 0 0 73 0 47)
文摘Rare earth elements have been widely used in many areas. Rare earth complex bearing an amino acid was synthesized to study the influence and the long term effect of rare earth elements on environment and human beings, because amino acid is the basic unit of the living things. Previous work on these kinds of complex is focused on synthesis and characterization of them. But their thermodynamic data have seldom been reported. Here we present the thermodynamic study of [Ho(H 2O) 5]Cl 3. The heat capacity of Holmium complex with threonine, [Ho(Thr)(H 2O) 5]Cl 3 , was measured with an automatic adiabatic calorimeter in the temperature range from 79 K to 330 K and no thermal anomaly was found in this range. Thermodynamic functions relative to standard state 298 15 K were derived from the heat capacity data. Thermal decomposition behavior of the complex in nitrogen atmosphere in the range from 300 K to 900 K was studied by thermogravimetric (TG) technique and a possible decomposition mechanism was proposed according to the TG DTG results.
