The coal washery rejects cause major environmental problems in various parts of the globe.Nearly 1 Mt of coal rejects discarded as waste,is accumulated per annum in India,during washing or cleaning of raw coal.Cleanin...The coal washery rejects cause major environmental problems in various parts of the globe.Nearly 1 Mt of coal rejects discarded as waste,is accumulated per annum in India,during washing or cleaning of raw coal.Cleaning coal,especially washery rejects,has posed a major challenge to the recovery of fine coal.Froth flotation is a better choice for processing coal washery rejects.In this study,flotation studies are attempted on the coal slurry received from Sudamdih coal washery,Jharkhand,India.A statistical design package(Minitab V17)was used to study the effect of process variables like collector and frother dosages on the responses.Regression equations for froth height,froth density,recovery and ash content of clean coal were developed.The coefficient of correlation(R2)values between the experimental and the predicted values of the flotation responses was found to be greater than 0.98 for all the models.Clean coal product was analyzed for recovery,froth height,and ash content by varying pulp densities.Results show that the coal slurry sample could be evaluated with acceptable recovery via flotation.Clean coal with an ash content of 17.2%is obtained with a 70%recovery from 35.5%ash.The cleaned coal can be used in powder coal-consuming industries.展开更多
The effect of removing pyrite and ash ffom fine coal with electrostatic separator is determined by the electric property of coal, the distribution of corona ion and etectrostatic field, and the disperse and even feed....The effect of removing pyrite and ash ffom fine coal with electrostatic separator is determined by the electric property of coal, the distribution of corona ion and etectrostatic field, and the disperse and even feed. The dielectric constant of coal and mineral matter is studied in this paper and the amendment has been made to survey theory. The oscillogram is adopted to study the distribution of corona ion and electrostatic field.The paper details the study of remoing pyrite and ash from fine coal, and the test results demonstrate the high efficiency of removing pyrite and ash with electrostatic separator.展开更多
The statistical random sample technique has been utilized to develop a new Monte-Carlo algorithm MCHET code recently. A large amount of comparative simulation calculation work relating to the neutralized alpha-particl...The statistical random sample technique has been utilized to develop a new Monte-Carlo algorithm MCHET code recently. A large amount of comparative simulation calculation work relating to the neutralized alpha-particle transport has been performed. As a result, we have found the beneficial optimizing plasma density and temperature profiles in the divertor region, with the great resulting improvement of helium ash removal efficiency by the simultaneously externally applied proper RF ponderomotive force potential energy in the vicinity of the divertor plate region. In this work the dominant atomic processes of electron impact ionization and elastic scattering by plasma ions are included. The thermal and streaming motion of the ions along the magnetic field is taken into consideration. Important conclusions are obtained that the probability of neutral helium turning back to the target plate will increase at least by 50% for the optimized combination of the beneficial density, temperature profiles and proper RF perpendicular electric field. For FEB （Fusion Experimental Breeder） reactor design parameters, the RF ponderomotive potential enhancement from 0.5 to 0.9 of ash removal efficiency can be obviously obtained. In the meantime, the tritium inventory may also be reduced to some extent.展开更多
Pre-combustion mercury removal via coal electrolysis was performed and investigated on a bench-scale coal electrolytic cell(CEC)systemically,and factorial design was used to determine the effect of different operating...Pre-combustion mercury removal via coal electrolysis was performed and investigated on a bench-scale coal electrolytic cell(CEC)systemically,and factorial design was used to determine the effect of different operating conditions(coal particle size,operating temperature,operating cell voltage,and flow rate of slurry)on the percentage of mercury removal,percentage of ash removal,and dry heating value change.The results showed that the operating cell voltage,as well as the interaction between operating cell voltage and coal particle size,are significant factors in the percentage of mercury removal.There is no significant factor in the percentage of ash removal and the dry heating value change,but the coal could be purified while keeping the dry heating value almost constant after electrolysis.A co-product of hydrogen could be produced during coal electrolysis with 50%lower energy consumption compared with water electrolysis.Meanwhile,a mechanism for mercury removal in coal was proposed.The facts indicate that coal electrolysis is a promising method for precombustion mercury removal.展开更多
文摘The coal washery rejects cause major environmental problems in various parts of the globe.Nearly 1 Mt of coal rejects discarded as waste,is accumulated per annum in India,during washing or cleaning of raw coal.Cleaning coal,especially washery rejects,has posed a major challenge to the recovery of fine coal.Froth flotation is a better choice for processing coal washery rejects.In this study,flotation studies are attempted on the coal slurry received from Sudamdih coal washery,Jharkhand,India.A statistical design package(Minitab V17)was used to study the effect of process variables like collector and frother dosages on the responses.Regression equations for froth height,froth density,recovery and ash content of clean coal were developed.The coefficient of correlation(R2)values between the experimental and the predicted values of the flotation responses was found to be greater than 0.98 for all the models.Clean coal product was analyzed for recovery,froth height,and ash content by varying pulp densities.Results show that the coal slurry sample could be evaluated with acceptable recovery via flotation.Clean coal with an ash content of 17.2%is obtained with a 70%recovery from 35.5%ash.The cleaned coal can be used in powder coal-consuming industries.
文摘The effect of removing pyrite and ash ffom fine coal with electrostatic separator is determined by the electric property of coal, the distribution of corona ion and etectrostatic field, and the disperse and even feed. The dielectric constant of coal and mineral matter is studied in this paper and the amendment has been made to survey theory. The oscillogram is adopted to study the distribution of corona ion and electrostatic field.The paper details the study of remoing pyrite and ash from fine coal, and the test results demonstrate the high efficiency of removing pyrite and ash with electrostatic separator.
文摘The statistical random sample technique has been utilized to develop a new Monte-Carlo algorithm MCHET code recently. A large amount of comparative simulation calculation work relating to the neutralized alpha-particle transport has been performed. As a result, we have found the beneficial optimizing plasma density and temperature profiles in the divertor region, with the great resulting improvement of helium ash removal efficiency by the simultaneously externally applied proper RF ponderomotive force potential energy in the vicinity of the divertor plate region. In this work the dominant atomic processes of electron impact ionization and elastic scattering by plasma ions are included. The thermal and streaming motion of the ions along the magnetic field is taken into consideration. Important conclusions are obtained that the probability of neutral helium turning back to the target plate will increase at least by 50% for the optimized combination of the beneficial density, temperature profiles and proper RF perpendicular electric field. For FEB （Fusion Experimental Breeder） reactor design parameters, the RF ponderomotive potential enhancement from 0.5 to 0.9 of ash removal efficiency can be obviously obtained. In the meantime, the tritium inventory may also be reduced to some extent.
基金Chemical and Biomolecular Engineering Department in Ohio University。
文摘Pre-combustion mercury removal via coal electrolysis was performed and investigated on a bench-scale coal electrolytic cell(CEC)systemically,and factorial design was used to determine the effect of different operating conditions(coal particle size,operating temperature,operating cell voltage,and flow rate of slurry)on the percentage of mercury removal,percentage of ash removal,and dry heating value change.The results showed that the operating cell voltage,as well as the interaction between operating cell voltage and coal particle size,are significant factors in the percentage of mercury removal.There is no significant factor in the percentage of ash removal and the dry heating value change,but the coal could be purified while keeping the dry heating value almost constant after electrolysis.A co-product of hydrogen could be produced during coal electrolysis with 50%lower energy consumption compared with water electrolysis.Meanwhile,a mechanism for mercury removal in coal was proposed.The facts indicate that coal electrolysis is a promising method for precombustion mercury removal.
