The study on the evaporation kinetics of zinc and lead in the pellets made of ZnPbbearing dust mixed with carbon ,in nitrogen atmosphere at the temperature range between 1 100 and 1 300 , shows that the reduction te...The study on the evaporation kinetics of zinc and lead in the pellets made of ZnPbbearing dust mixed with carbon ,in nitrogen atmosphere at the temperature range between 1 100 and 1 300 , shows that the reduction temperature has a significant effect on the evaporation rates of zinc and lead and that both the particle size of coal powder and the extra carbon content have no effect on the evaporation rates . The obtained activation energies for the evaporation of zinc and lead are 7942 kJ/mol and 8874kJ/mol respectively. The evaporation rate of zinc is controlled by the reaction between zinc oxide and CO while that of lead is controlled by lead volatilization and the diffusion of gaseous lead through gas boundary layer covering the surface of liquid lead.展开更多
Direct reduction of pyrite cinder in a rotary hearth furnace (RHF) was studied under the condition of labo ratory simulation. Effects of reduction temperature, reduction time, molar ratio of carbon to oxygen, .and C...Direct reduction of pyrite cinder in a rotary hearth furnace (RHF) was studied under the condition of labo ratory simulation. Effects of reduction temperature, reduction time, molar ratio of carbon to oxygen, .and CaO addition on metallization rate as well as compressive strength of the pellets after reduction were discussed. The results showed that the metallization rate and compressive strength were 93.9% and 2 160 N per pellet respectively under the conditions of the reduction temperature of 1 200 ℃, the reduction time of 16 min, and the molar ratio of carbon to oxygen (xc/xo) of 1. 0; adding 2.5% CaO was beneficial to sulfur enrichment in slag phase of pellet, and metal- lization rate increased slightly while compressive strength decreased.展开更多
To study the combustion characteristics of the polyethylene(PE)particle and coal powder at blast temperature of the blast furnace,the contents of CO and CO2 of off-gas during the combustion of PE particle and coal p...To study the combustion characteristics of the polyethylene(PE)particle and coal powder at blast temperature of the blast furnace,the contents of CO and CO2 of off-gas during the combustion of PE particle and coal powder at the 1 200 ℃ and 1 250 ℃ were measured using carbon monoxide and carbon dioxide infrared analyzer,and then the corresponding combustion ratio was calculated.The results showed that when the temperature is high,the combustion speed of PE and coal powder is high and the corresponding combustion ratio is high.Whereas,the combustion speed and ratio of PE are much higher than those of coal powder.展开更多
A trajectory imaging based method for measuring the velocity and diameter of coal particles was presented.By using an industrial charge-coupled device(CCD)camera and a low power semiconductor laser,the images of coal ...A trajectory imaging based method for measuring the velocity and diameter of coal particles was presented.By using an industrial charge-coupled device(CCD)camera and a low power semiconductor laser,the images of coal particles under relatively long exposure time were recorded and then processed to yield both the velocities and sizes.Fundamental research on this method with special attention to recording parameters,e.g.,magnification factor and exposure time,was carried out.For most of the test cases,the results agree with those obtained by particle image velocimetry(PIV)and shadow imaging method.Measurements with good accuracy can be obtained when the imaging magnification factor and exposure time are set appropriately,making N be larger than 3.5,and R between 5-7,where N and R are the number of pixels occupied by the average width and the ratio of length to width of particle trajectory on the image,respectively.The work indicates the feasibility and potential application of the present measurement method for online measurement of coal powder in pipes in industrial power plants.展开更多
The oxidation behavior of different SiAlON phases(β-SiAlON,X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry(TG) and field-emission ...The oxidation behavior of different SiAlON phases(β-SiAlON,X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry(TG) and field-emission scanning electron microscopy(FE-SEM).The effect of ferric oxide impurities in coal gangue was studied.The results show that ferric oxide contributes to the growth of SiAlON crystalline during the synthesis process.In the oxidation experiment,the existence of ferric oxide decreases the oxidation resistance of SiAlON.The reason is that the impurity causes the formation of a liquid phase at a higher temperature.At 1423-1623 K,the oxidation of SiAlON powders is diffusion controlled and it can be described by Chou's model.A fair agreement is found between theoretical calculations and the experimental data.展开更多
A process of purification of coal-based coke powder as anode for Li-ion batteries was attempted. The process started with the treatment of coke powder with dilute hydrofluoric acid solution, followed by united-acid-le...A process of purification of coal-based coke powder as anode for Li-ion batteries was attempted. The process started with the treatment of coke powder with dilute hydrofluoric acid solution, followed by united-acid-leaching using sulfuric acid and hydrochloric acid. The effects of altering the hydrofluoric acid addition, hydrofluoric acid concentration, contact time, temperature and acid type were investigated. A minimum ash content of 0.35% was obtained when proper conditions were applied. The electrochemical performance of purified coke powder shows greatly improved electrochemical performance. The as-purified coke powder presented an initial reversible capacity of 257.4 mAh/g and a retention rate of 95% after 50 cycles. The proposed purification process paves a way to prepare a promising anode material with good performance with low cost of coke powder for Li-ion batteries.展开更多
The feasibility of preparing flocculant from powdered coal ashes is studied in detail. By means of orthogonal tests, the influence of various factors, such as the activation temperature, the activation time, the ratio...The feasibility of preparing flocculant from powdered coal ashes is studied in detail. By means of orthogonal tests, the influence of various factors, such as the activation temperature, the activation time, the ratio of CaO to Al2O3, the hydrochloric acid concentration, the reaction time and the reaction temperature, on preparation is investigated, and the hest operating condition is determined.展开更多
The Al2O3 -SiC composite powders were prepared in argon atmosphere rising coal gangue and carbonaceous materials ( carbon black, active carbon and antbravite) as starting materials by carbothermal reduction. Effects...The Al2O3 -SiC composite powders were prepared in argon atmosphere rising coal gangue and carbonaceous materials ( carbon black, active carbon and antbravite) as starting materials by carbothermal reduction. Effects of excessive carbon addition, carbon types. temperature, soaking time. shaping pressure, types and amount of additives on phase composition and micro-structure of the Al2O3 - SiC composite powders were investigated. The re.suits indicate that: temperature, soaking time and chloride additi've have significant influence on the synthesized Al2O3 -SiC composite powders. Based on the results, the optimized Al2O3 -SiC composite powders , Al2O3 58 mass% and SiC 42 mass%, with particle size d50 ≤5μm were prepared using coal gangue and carbon black as starting materials after 3 h firing at 1550 ℃. and proper additive addition could reduce the temperattlre by 50 ℃.展开更多
The powdered coal ash (PCA) was classified, then the ash particle (- 45μm) was modified by a surface active agent and obtained modified powder coal ash (MPCA). The character of the MPC was investigated, when it was u...The powdered coal ash (PCA) was classified, then the ash particle (- 45μm) was modified by a surface active agent and obtained modified powder coal ash (MPCA). The character of the MPC was investigated, when it was used as a new type reinforced filler of rubber.The results show that MPCA can replace or party replace carbon black or silica as reinforced fillers of rubbers.展开更多
The prevention and treatment of mercury in coal-fired power plants has always been the focus and difficulty.How to control the pollution of mercury to human body and ecological environment quickly and effectively is a...The prevention and treatment of mercury in coal-fired power plants has always been the focus and difficulty.How to control the pollution of mercury to human body and ecological environment quickly and effectively is a hot research topic nowadays.As a low cost and potential adsorbent,there is a huge space for the development of coal dry powder gasification coarse slag.In this paper,Mercury osmotic tubes are heated by water bath tank as mercury source,and the scavenging effect of adsorbent on Mercury monomer under different influence conditions is explored.The adsorbent plays an important role in adsorption of mercury monomer because of its special active sites on the surface.The reason is that the adsorbent surface is rich in carboxyl group,hydroxyl functional group,combined with mercury to form complexes.This shows that chemical adsorption facilitates the adsorption process.展开更多
文摘The study on the evaporation kinetics of zinc and lead in the pellets made of ZnPbbearing dust mixed with carbon ,in nitrogen atmosphere at the temperature range between 1 100 and 1 300 , shows that the reduction temperature has a significant effect on the evaporation rates of zinc and lead and that both the particle size of coal powder and the extra carbon content have no effect on the evaporation rates . The obtained activation energies for the evaporation of zinc and lead are 7942 kJ/mol and 8874kJ/mol respectively. The evaporation rate of zinc is controlled by the reaction between zinc oxide and CO while that of lead is controlled by lead volatilization and the diffusion of gaseous lead through gas boundary layer covering the surface of liquid lead.
基金Supported by the National Science Foundation for Post Doctoral Scientists of China (20070411124), Scientific and Technological Key Project of Shaanxi Province (2006k07-G19), and Industrialization Project of Shaanxi Provincial Department of Education (06JC 11).
基金Item Sponsored by National Natural Science Foundation of China(51174023)
文摘Direct reduction of pyrite cinder in a rotary hearth furnace (RHF) was studied under the condition of labo ratory simulation. Effects of reduction temperature, reduction time, molar ratio of carbon to oxygen, .and CaO addition on metallization rate as well as compressive strength of the pellets after reduction were discussed. The results showed that the metallization rate and compressive strength were 93.9% and 2 160 N per pellet respectively under the conditions of the reduction temperature of 1 200 ℃, the reduction time of 16 min, and the molar ratio of carbon to oxygen (xc/xo) of 1. 0; adding 2.5% CaO was beneficial to sulfur enrichment in slag phase of pellet, and metal- lization rate increased slightly while compressive strength decreased.
基金Item Sponsored by National Natural Science Foundation of China(50274001)
文摘To study the combustion characteristics of the polyethylene(PE)particle and coal powder at blast temperature of the blast furnace,the contents of CO and CO2 of off-gas during the combustion of PE particle and coal powder at the 1 200 ℃ and 1 250 ℃ were measured using carbon monoxide and carbon dioxide infrared analyzer,and then the corresponding combustion ratio was calculated.The results showed that when the temperature is high,the combustion speed of PE and coal powder is high and the corresponding combustion ratio is high.Whereas,the combustion speed and ratio of PE are much higher than those of coal powder.
基金Project supported by the National Natural Science Foundation of China (Nos. 51176162 and 51276164)the National Basic Research Program (973) of China (No. 2009CB219802)+2 种基金the Zhejiang Provincial Science and Technology Project (No. 2012C21077)the Zhejiang Provincial Natural Science Foundation of China (No. Y1110642)the Program of Introducing Talents of Discipline to University (No. B08026),China
文摘A trajectory imaging based method for measuring the velocity and diameter of coal particles was presented.By using an industrial charge-coupled device(CCD)camera and a low power semiconductor laser,the images of coal particles under relatively long exposure time were recorded and then processed to yield both the velocities and sizes.Fundamental research on this method with special attention to recording parameters,e.g.,magnification factor and exposure time,was carried out.For most of the test cases,the results agree with those obtained by particle image velocimetry(PIV)and shadow imaging method.Measurements with good accuracy can be obtained when the imaging magnification factor and exposure time are set appropriately,making N be larger than 3.5,and R between 5-7,where N and R are the number of pixels occupied by the average width and the ratio of length to width of particle trajectory on the image,respectively.The work indicates the feasibility and potential application of the present measurement method for online measurement of coal powder in pipes in industrial power plants.
基金supported by the National Natural Science Foundation of China(No.50874013)the support from the Key Lab. of the Ministry of Education of China for Ecologic & Recycle Metallurgy,University of Science and Technology Beijing
文摘The oxidation behavior of different SiAlON phases(β-SiAlON,X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry(TG) and field-emission scanning electron microscopy(FE-SEM).The effect of ferric oxide impurities in coal gangue was studied.The results show that ferric oxide contributes to the growth of SiAlON crystalline during the synthesis process.In the oxidation experiment,the existence of ferric oxide decreases the oxidation resistance of SiAlON.The reason is that the impurity causes the formation of a liquid phase at a higher temperature.At 1423-1623 K,the oxidation of SiAlON powders is diffusion controlled and it can be described by Chou's model.A fair agreement is found between theoretical calculations and the experimental data.
基金Projects(51274240,51204209) supported by the National Natural Science Foundation of ChinaProject(2012M521545) supported by the National Postdoctoral Science Foundation of China
文摘A process of purification of coal-based coke powder as anode for Li-ion batteries was attempted. The process started with the treatment of coke powder with dilute hydrofluoric acid solution, followed by united-acid-leaching using sulfuric acid and hydrochloric acid. The effects of altering the hydrofluoric acid addition, hydrofluoric acid concentration, contact time, temperature and acid type were investigated. A minimum ash content of 0.35% was obtained when proper conditions were applied. The electrochemical performance of purified coke powder shows greatly improved electrochemical performance. The as-purified coke powder presented an initial reversible capacity of 257.4 mAh/g and a retention rate of 95% after 50 cycles. The proposed purification process paves a way to prepare a promising anode material with good performance with low cost of coke powder for Li-ion batteries.
文摘The feasibility of preparing flocculant from powdered coal ashes is studied in detail. By means of orthogonal tests, the influence of various factors, such as the activation temperature, the activation time, the ratio of CaO to Al2O3, the hydrochloric acid concentration, the reaction time and the reaction temperature, on preparation is investigated, and the hest operating condition is determined.
文摘The Al2O3 -SiC composite powders were prepared in argon atmosphere rising coal gangue and carbonaceous materials ( carbon black, active carbon and antbravite) as starting materials by carbothermal reduction. Effects of excessive carbon addition, carbon types. temperature, soaking time. shaping pressure, types and amount of additives on phase composition and micro-structure of the Al2O3 - SiC composite powders were investigated. The re.suits indicate that: temperature, soaking time and chloride additi've have significant influence on the synthesized Al2O3 -SiC composite powders. Based on the results, the optimized Al2O3 -SiC composite powders , Al2O3 58 mass% and SiC 42 mass%, with particle size d50 ≤5μm were prepared using coal gangue and carbon black as starting materials after 3 h firing at 1550 ℃. and proper additive addition could reduce the temperattlre by 50 ℃.
文摘The powdered coal ash (PCA) was classified, then the ash particle (- 45μm) was modified by a surface active agent and obtained modified powder coal ash (MPCA). The character of the MPC was investigated, when it was used as a new type reinforced filler of rubber.The results show that MPCA can replace or party replace carbon black or silica as reinforced fillers of rubbers.
文摘The prevention and treatment of mercury in coal-fired power plants has always been the focus and difficulty.How to control the pollution of mercury to human body and ecological environment quickly and effectively is a hot research topic nowadays.As a low cost and potential adsorbent,there is a huge space for the development of coal dry powder gasification coarse slag.In this paper,Mercury osmotic tubes are heated by water bath tank as mercury source,and the scavenging effect of adsorbent on Mercury monomer under different influence conditions is explored.The adsorbent plays an important role in adsorption of mercury monomer because of its special active sites on the surface.The reason is that the adsorbent surface is rich in carboxyl group,hydroxyl functional group,combined with mercury to form complexes.This shows that chemical adsorption facilitates the adsorption process.