The fundamental question of super-low-ash coal preparation is how to furthest depress high ash component pollution. A jigging process was used to remove high ash refuse and middling, then a high precision heavy medium...The fundamental question of super-low-ash coal preparation is how to furthest depress high ash component pollution. A jigging process was used to remove high ash refuse and middling, then a high precision heavy medium cyclone was used to further separate near gravity light material. A two-stage heavy medium cylindrical cyclone with the same separation density was used to increase the precision of separation. The feed was de-slimed and fine-grind coal was added with media to improve the stability of the suspension. The pump frequency conversion timing and an air spring were used to steady the cyclone inlet pressure. Based on a series of study and pilot tests, a 1.00 Mt/a (output) commercial separation system with Ep value under 0.015 was built up. Super low ash (Ad≤2.00%) Taixi Anthracite has been put into commercial production.展开更多
The poor-reactivity anthracite urgently needs more ways for large-scale and high-quality utilization.Due to the advantage of good fuel adaptability,the circulating fluidized bed(CFB)gasification technology has the pot...The poor-reactivity anthracite urgently needs more ways for large-scale and high-quality utilization.Due to the advantage of good fuel adaptability,the circulating fluidized bed(CFB)gasification technology has the potential of high-quality utilization of anthracite.In this paper,one kind of anthracite from Shanxi province,China,was employed to be gasified in a pilot-scale CFB gasifier.It is found that at the operating temperature of 1049℃and oxygen concentration of 60.75%,the gas with a concentration of combustibles of 66%and a low heating value of 7.93 MJ/m^(3)(at about 25℃and 101.325 kPa)was produced in the CFB gasification process.However,the overall gasification efficiency was not desired because a large amount of gasification fly ash(GFA)escaped and its yield was up to 22%.In this case,the cold gas efficiency was below 48%and the carbon conversion ratio was only 62%.Further analysis reveals that the GFA was featured with a developed pore structure and the specific surface area(S_(BET))reached 277 m^(2)/g.This indicates such GFA has a potential to use as activated carbon(AC)or AC precursor.Basis on this,steam activation experiments of the GFA produced were conducted to investigate the activation characteristics of GFA and thereby to determine its activation potential.Experimental results indicate that increasing temperature sharply accelerated the activation process,while did not impair the maximum activation effect.After activation,the S_(BET)of GFA maximumly increased by 63%,reaching452 m^(2)/g.With the progress of activation,the pore structure of GFA presents a three-stage evolution process:development,dynamic balance,and collapse.Such a process can be divided and quantified according to the carbon loss.In order to achieve an optimal activation of GFA,the carbon loss shall be controlled at~15%.This work provides a new scheme for high-quality utilization of anthracite.展开更多
基金Project 2004300z019 supported by the Ningxia Municipal Torch Science and Technology
文摘The fundamental question of super-low-ash coal preparation is how to furthest depress high ash component pollution. A jigging process was used to remove high ash refuse and middling, then a high precision heavy medium cyclone was used to further separate near gravity light material. A two-stage heavy medium cylindrical cyclone with the same separation density was used to increase the precision of separation. The feed was de-slimed and fine-grind coal was added with media to improve the stability of the suspension. The pump frequency conversion timing and an air spring were used to steady the cyclone inlet pressure. Based on a series of study and pilot tests, a 1.00 Mt/a (output) commercial separation system with Ep value under 0.015 was built up. Super low ash (Ad≤2.00%) Taixi Anthracite has been put into commercial production.
基金financially supported by the Special Research Assistant Project,Chinese Academy of Sciences。
文摘The poor-reactivity anthracite urgently needs more ways for large-scale and high-quality utilization.Due to the advantage of good fuel adaptability,the circulating fluidized bed(CFB)gasification technology has the potential of high-quality utilization of anthracite.In this paper,one kind of anthracite from Shanxi province,China,was employed to be gasified in a pilot-scale CFB gasifier.It is found that at the operating temperature of 1049℃and oxygen concentration of 60.75%,the gas with a concentration of combustibles of 66%and a low heating value of 7.93 MJ/m^(3)(at about 25℃and 101.325 kPa)was produced in the CFB gasification process.However,the overall gasification efficiency was not desired because a large amount of gasification fly ash(GFA)escaped and its yield was up to 22%.In this case,the cold gas efficiency was below 48%and the carbon conversion ratio was only 62%.Further analysis reveals that the GFA was featured with a developed pore structure and the specific surface area(S_(BET))reached 277 m^(2)/g.This indicates such GFA has a potential to use as activated carbon(AC)or AC precursor.Basis on this,steam activation experiments of the GFA produced were conducted to investigate the activation characteristics of GFA and thereby to determine its activation potential.Experimental results indicate that increasing temperature sharply accelerated the activation process,while did not impair the maximum activation effect.After activation,the S_(BET)of GFA maximumly increased by 63%,reaching452 m^(2)/g.With the progress of activation,the pore structure of GFA presents a three-stage evolution process:development,dynamic balance,and collapse.Such a process can be divided and quantified according to the carbon loss.In order to achieve an optimal activation of GFA,the carbon loss shall be controlled at~15%.This work provides a new scheme for high-quality utilization of anthracite.
