A novel process aimed at the comprehensive utilization of sintering dust was developed by combining wetting grinding with sulfidization flotation. The mineralogical characteristics of the sintering dust and products w...A novel process aimed at the comprehensive utilization of sintering dust was developed by combining wetting grinding with sulfidization flotation. The mineralogical characteristics of the sintering dust and products were studied by powder wettability analysis, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and mineral liberation analyzer（MLA）. It was found that the primary lead species was laurionite and most of the particles were overwrapped with KCl. Wetting grinding was shown to accelerate the dispersion of sintering dust and transform the KCl overlay to a leachate with 20.78 g/L of K＋. A lead and silver concentrate consisting of 40.82% of Pb and 0.96 kg/t of Ag was achieved, while an iron concentrate with 60.89% of Fe was gained as tailings among sulfidization flotation. The recoveries of Pb, Ag and Fe were 89.57%, 87.85% and 88.58%, respectively. The results indicate that this method is a feasible and promising process for the comprehensive utilization of sintering dust.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 basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysi...The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysis of chemical and mineral composition of fly ash in Xinwen power plant. The dielectric constant and charge-mass ratio of carbon and ash of fly ash are tested. Combined with the experimental study on rotary triboelectrostatic separation, the charged characteristic of fly ash particles with different size is gained. The results show that the dielectric constant of fly ash with different grain size decreased with the decrease of particle size, which lead to the poor electrical conductivity, Thus it can be seen that par- ticle size plays a leading role in conductivity, The charge of carbon and ash with each size increased with the decreased of particle size; and the charge-mass ratio between carbon and ash with the same size lar- ger with the decrease of size, which indicated that the finer particle size, the more favorable for triboelec- trification separation. In the same conditions, the best decarburization effect is realized when the particle size ranges from 0.038 to 0.074 ram, whose decarbonization rate and efficiency index reached 38.93% and 120.83% respectively.展开更多
Particulate emission is a major problem in industrial processes, mainly power plants that make use of coal as a primary source of energy. Stringent emissions limits, set by government organisations requires industries...Particulate emission is a major problem in industrial processes, mainly power plants that make use of coal as a primary source of energy. Stringent emissions limits, set by government organisations requires industries to conform to these limits to ensure that air quality is sustained and with minimum pollutant present. Electrostatic precipitators are typically used to filter and collect these particulate emissions. Fly ash resistivity is a primary parameter in the collection of particulate emissions, and there is a resistivity range at which electrostatic precipitator collection is most efficient and anything outside this range limits, their operation. High resistivity ash results in back-corona discharge, whilst low resistivity results in particle re-entrainment into the flue gas stream. The purpose of this paper is to investigate and obtain a fly ash resistivity profile for existing power plants in South Africa. Ash samples obtained from power plants are, tested making use of an ash-resistivity test oven, in accordance with IEEE Standard 548-1984. This paper discusses obtained experimental results, to determine the resistivity profile at which South African power plant electrostatic precipitators operate. The electrical efficiency of the electrostatic precipitator system is evaluated based on the obtained resistivity profiles.展开更多
基金Project(CX2015B053)supported by the Hunan Provincial Innovation Foundation for PostgraduateChinaProject(B14034)supported by National 111 Project of China
文摘A novel process aimed at the comprehensive utilization of sintering dust was developed by combining wetting grinding with sulfidization flotation. The mineralogical characteristics of the sintering dust and products were studied by powder wettability analysis, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and mineral liberation analyzer（MLA）. It was found that the primary lead species was laurionite and most of the particles were overwrapped with KCl. Wetting grinding was shown to accelerate the dispersion of sintering dust and transform the KCl overlay to a leachate with 20.78 g/L of K＋. A lead and silver concentrate consisting of 40.82% of Pb and 0.96 kg/t of Ag was achieved, while an iron concentrate with 60.89% of Fe was gained as tailings among sulfidization flotation. The recoveries of Pb, Ag and Fe were 89.57%, 87.85% and 88.58%, respectively. The results indicate that this method is a feasible and promising process for the comprehensive utilization of sintering dust.
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.
基金supported by the National Natural Science Foundation of China(Nos.51274200 and 51221462)
文摘The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysis of chemical and mineral composition of fly ash in Xinwen power plant. The dielectric constant and charge-mass ratio of carbon and ash of fly ash are tested. Combined with the experimental study on rotary triboelectrostatic separation, the charged characteristic of fly ash particles with different size is gained. The results show that the dielectric constant of fly ash with different grain size decreased with the decrease of particle size, which lead to the poor electrical conductivity, Thus it can be seen that par- ticle size plays a leading role in conductivity, The charge of carbon and ash with each size increased with the decreased of particle size; and the charge-mass ratio between carbon and ash with the same size lar- ger with the decrease of size, which indicated that the finer particle size, the more favorable for triboelec- trification separation. In the same conditions, the best decarburization effect is realized when the particle size ranges from 0.038 to 0.074 ram, whose decarbonization rate and efficiency index reached 38.93% and 120.83% respectively.
文摘Particulate emission is a major problem in industrial processes, mainly power plants that make use of coal as a primary source of energy. Stringent emissions limits, set by government organisations requires industries to conform to these limits to ensure that air quality is sustained and with minimum pollutant present. Electrostatic precipitators are typically used to filter and collect these particulate emissions. Fly ash resistivity is a primary parameter in the collection of particulate emissions, and there is a resistivity range at which electrostatic precipitator collection is most efficient and anything outside this range limits, their operation. High resistivity ash results in back-corona discharge, whilst low resistivity results in particle re-entrainment into the flue gas stream. The purpose of this paper is to investigate and obtain a fly ash resistivity profile for existing power plants in South Africa. Ash samples obtained from power plants are, tested making use of an ash-resistivity test oven, in accordance with IEEE Standard 548-1984. This paper discusses obtained experimental results, to determine the resistivity profile at which South African power plant electrostatic precipitators operate. The electrical efficiency of the electrostatic precipitator system is evaluated based on the obtained resistivity profiles.
