Experimental Study on Regeneration of Activated Carbon by Microwave Irradiation
QIE Boyang,1,2,3, LI Pei1,2,3, MIAO Tengfei4, BAI Yang4, TANG Jiayan1,2,3, CAO Zhao,1,2,3
1.School of Mining and Coal, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China
2.Inner Mongolia Key Laboratory of Mining Engineering, Baotou 014010, Inner Mongolia, China
3.Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China
Activated Carbon (AC) is widely used as adsorbent in the process of gold extraction.In the cycle of gold leaching-adsorption-desorption,the AC needs to be activated regularly for reuse,which mainly depends on thermal regeneration,that is,the whole rotary kiln is heated and then AC are heated from outside to inside by heat conduction,where the pollutants are volatilized or decomposed,cleaning the carbon surface and dredging the pores.The thermal regeneration method still has the shortcomings of high energy consumption,large carbon loss and long operation time.The evaporation of pore water takes prolonged time and absorb extensive heat,restricting the improvement of efficiency and effect,which is difficult to be solved.Considering that AC is a good wave-absorbing material,it can be heated directly from the inside to the outside by microwave irradiation,which can greatly improve the energy efficiency.The technique of AC regeneration with 2.45 GHz microwave was studied by experiments where iodine value,specific energy and carbon loss were investigated.The results show that high temperature improves activation efficiency significantly and 650~750 ℃ is recommended;The moisture of AC was optimum at 30%,which might be related to dielectric variation;Execution times could only play a role at high temperature (≥700 ℃).Compared with thermal regeneration,the technique saved 30%~50% energy to achieve equal activation with a lower carbon loss.At 700 ℃ temperature,30% moisture,the regenerated carbon and fresh carbon have approximate iodine value.In the regenerated carbon processed by the technique is feasible to pickling operation that inorganic pollutants (e.g.calcium oxide) are cleaned up effectively.Moreover,BET and SEM detections also supporte the above results at a micro level,i.e.the specific surface area and total pore volume of the carbon is higher than the ones processed by thermal regeneration.
Keywords:activated carbon
;
microwave irradiation
;
activation and regeneration
;
gold processing
;
energy saving
;
microwave discharge
QIE Boyang, LI Pei, MIAO Tengfei, BAI Yang, TANG Jiayan, CAO Zhao. Experimental Study on Regeneration of Activated Carbon by Microwave Irradiation[J]. Gold Science and Technology, 2022, 30(2): 291-301 doi:10.11872/j.issn.1005-2518.2022.02.138
由于活性炭及其孔隙中的水具有良好介电性(炭为超热活性物质)(Shivanshu et al.,2021;檀素霞等,2006),且微波辐照可以不蒸干孔隙水直接加热活性炭本身( Sakemi et al.,2021),因而能量使用效率高、升温速度快。此外,孔隙水在间隙中部分电离并放电,将疏通孔道,增加活性。Bradshaw et al.(1998)研究表明在再生温度为650 ℃的条件下,通入适量水蒸气进行活性炭微波再生,能获得更高的再生活性及强度。浦燕新等(2021)进行微波再生活性炭研究,并开展不同载气条件试验,确定了最佳反应条件,即微波加热温度为500 ℃、加热5 min、氮气载气流量为1 L/min。然而,结合现场设备及安全生产成本,现场很难供给稳定的氮气及水蒸气,所以应探索微波再生在不加注气氛下的再生条件。同时,微波效率与活性炭介电能力有强相关性,活性炭的水份对活性炭的介电能力影响显著,应予以研究。
材料的微波加热主要取决于电场对材料内部束缚电荷的极化能力,而极化不能跟随电场的快速变化。总极化由4个部分组成,即电子极化、原子极化、偶极极化和界面极化(麦克斯韦—瓦格纳效应)(Mingos et al.,1991;Peng et al.,2015)。其中,后两者的时间尺度与微波频率相当,热效应最为显著。
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1998
... 由于活性炭及其孔隙中的水具有良好介电性(炭为超热活性物质)(Shivanshu et al.,2021;檀素霞等,2006),且微波辐照可以不蒸干孔隙水直接加热活性炭本身( Sakemi et al.,2021),因而能量使用效率高、升温速度快.此外,孔隙水在间隙中部分电离并放电,将疏通孔道,增加活性.Bradshaw et al.(1998)研究表明在再生温度为650 ℃的条件下,通入适量水蒸气进行活性炭微波再生,能获得更高的再生活性及强度.浦燕新等(2021)进行微波再生活性炭研究,并开展不同载气条件试验,确定了最佳反应条件,即微波加热温度为500 ℃、加热5 min、氮气载气流量为1 L/min.然而,结合现场设备及安全生产成本,现场很难供给稳定的氮气及水蒸气,所以应探索微波再生在不加注气氛下的再生条件.同时,微波效率与活性炭介电能力有强相关性,活性炭的水份对活性炭的介电能力影响显著,应予以研究. ...
0
2017
The generation of microwave-induced plasma in granular active carbons under fluidised bed conditions
1
2008
... 此外,炭材料如活性炭(Dawson et al.,2008)、碳化硅(Wang et al.,2016)、焦炭、无烟煤和石墨(Menéndez et al.,2011)等受到微波辐照时,会诱导微波能量集中(Hussain et al.,2010),导致材料间隙气体放电.这有助于有机物裂解(徐云鹏等,2002),即有利于微波再生活性炭过程中,活性炭内有机物的去除. ...
Water:A dielectric reference
1
1996
... 水和活性炭均拥有很强的介电能力(Gaglianoa et al.,2021;Ellison et al.,1996,刘彦超等,2019),吸收微波的能力很强.水偶极子在微波场中每秒重新排列数万亿次,并在旋转的分子之间引起摩擦,这一过程导致在材料的整个体积内产生热量(Peng et al.,2015).活性炭的加热原理是碳材料中的π电子,会产生与电磁场同相传播的电流.由于电子不能与电场相位的变化相耦合,能量因麦克斯韦—瓦格纳效应(界面极化或麦克斯韦—瓦格纳极化)以热的形式耗散(Menéndez et al.,2010).这2种效应将微波能转化为热能,即直接对活性炭由内到外迅速升温,如图1所示.活性炭的多孔结构增加了微波的反射与散射,加强了微波能向热能的转化( Negi et al.,2021).污染物受高温被挥发或裂解,而水成为蒸汽也有助于清理并疏通孔隙. ...
Microwave regeneration of granular activated carbon saturated with PFAS
1
2021
... 水和活性炭均拥有很强的介电能力(Gaglianoa et al.,2021;Ellison et al.,1996,刘彦超等,2019),吸收微波的能力很强.水偶极子在微波场中每秒重新排列数万亿次,并在旋转的分子之间引起摩擦,这一过程导致在材料的整个体积内产生热量(Peng et al.,2015).活性炭的加热原理是碳材料中的π电子,会产生与电磁场同相传播的电流.由于电子不能与电场相位的变化相耦合,能量因麦克斯韦—瓦格纳效应(界面极化或麦克斯韦—瓦格纳极化)以热的形式耗散(Menéndez et al.,2010).这2种效应将微波能转化为热能,即直接对活性炭由内到外迅速升温,如图1所示.活性炭的多孔结构增加了微波的反射与散射,加强了微波能向热能的转化( Negi et al.,2021).污染物受高温被挥发或裂解,而水成为蒸汽也有助于清理并疏通孔隙. ...
Comparative study on gold extraction performance of coal activated carbon and coconut shell activated carbon
0
2015
Microwave-metal interaction pyrolysis of polystyrene
1
2010
... 此外,炭材料如活性炭(Dawson et al.,2008)、碳化硅(Wang et al.,2016)、焦炭、无烟煤和石墨(Menéndez et al.,2011)等受到微波辐照时,会诱导微波能量集中(Hussain et al.,2010),导致材料间隙气体放电.这有助于有机物裂解(徐云鹏等,2002),即有利于微波再生活性炭过程中,活性炭内有机物的去除. ...
Research progress of waste activated carbon regeneration technology
0
2020
Analysis on the development status of activated carbon regeneration technology
0
2013
Practices of technological reform in the gold cyanidation plant
0
2012
Microstructures and dielectric properties of activated carbons
0
2019
Study on the harm of waste activated carbon and novel regeneration technology of it
... 水和活性炭均拥有很强的介电能力(Gaglianoa et al.,2021;Ellison et al.,1996,刘彦超等,2019),吸收微波的能力很强.水偶极子在微波场中每秒重新排列数万亿次,并在旋转的分子之间引起摩擦,这一过程导致在材料的整个体积内产生热量(Peng et al.,2015).活性炭的加热原理是碳材料中的π电子,会产生与电磁场同相传播的电流.由于电子不能与电场相位的变化相耦合,能量因麦克斯韦—瓦格纳效应(界面极化或麦克斯韦—瓦格纳极化)以热的形式耗散(Menéndez et al.,2010).这2种效应将微波能转化为热能,即直接对活性炭由内到外迅速升温,如图1所示.活性炭的多孔结构增加了微波的反射与散射,加强了微波能向热能的转化( Negi et al.,2021).污染物受高温被挥发或裂解,而水成为蒸汽也有助于清理并疏通孔隙. ...
Ball lightning plasma and plasma arc formation during the microwave heating of carbons
1
2011
... 此外,炭材料如活性炭(Dawson et al.,2008)、碳化硅(Wang et al.,2016)、焦炭、无烟煤和石墨(Menéndez et al.,2011)等受到微波辐照时,会诱导微波能量集中(Hussain et al.,2010),导致材料间隙气体放电.这有助于有机物裂解(徐云鹏等,2002),即有利于微波再生活性炭过程中,活性炭内有机物的去除. ...
Applications of microwave dielectric heating effects to synthetic problems in chemistry
1
1991
... 材料的微波加热主要取决于电场对材料内部束缚电荷的极化能力,而极化不能跟随电场的快速变化.总极化由4个部分组成,即电子极化、原子极化、偶极极化和界面极化(麦克斯韦—瓦格纳效应)(Mingos et al.,1991;Peng et al.,2015).其中,后两者的时间尺度与微波频率相当,热效应最为显著. ...
Activated carbon derived from mango leaves as an enhanced microwave absorbing material
1
2021
... 水和活性炭均拥有很强的介电能力(Gaglianoa et al.,2021;Ellison et al.,1996,刘彦超等,2019),吸收微波的能力很强.水偶极子在微波场中每秒重新排列数万亿次,并在旋转的分子之间引起摩擦,这一过程导致在材料的整个体积内产生热量(Peng et al.,2015).活性炭的加热原理是碳材料中的π电子,会产生与电磁场同相传播的电流.由于电子不能与电场相位的变化相耦合,能量因麦克斯韦—瓦格纳效应(界面极化或麦克斯韦—瓦格纳极化)以热的形式耗散(Menéndez et al.,2010).这2种效应将微波能转化为热能,即直接对活性炭由内到外迅速升温,如图1所示.活性炭的多孔结构增加了微波的反射与散射,加强了微波能向热能的转化( Negi et al.,2021).污染物受高温被挥发或裂解,而水成为蒸汽也有助于清理并疏通孔隙. ...
Microwave-assisted metallurgy
2
2015
... 材料的微波加热主要取决于电场对材料内部束缚电荷的极化能力,而极化不能跟随电场的快速变化.总极化由4个部分组成,即电子极化、原子极化、偶极极化和界面极化(麦克斯韦—瓦格纳效应)(Mingos et al.,1991;Peng et al.,2015).其中,后两者的时间尺度与微波频率相当,热效应最为显著. ...
... 水和活性炭均拥有很强的介电能力(Gaglianoa et al.,2021;Ellison et al.,1996,刘彦超等,2019),吸收微波的能力很强.水偶极子在微波场中每秒重新排列数万亿次,并在旋转的分子之间引起摩擦,这一过程导致在材料的整个体积内产生热量(Peng et al.,2015).活性炭的加热原理是碳材料中的π电子,会产生与电磁场同相传播的电流.由于电子不能与电场相位的变化相耦合,能量因麦克斯韦—瓦格纳效应(界面极化或麦克斯韦—瓦格纳极化)以热的形式耗散(Menéndez et al.,2010).这2种效应将微波能转化为热能,即直接对活性炭由内到外迅速升温,如图1所示.活性炭的多孔结构增加了微波的反射与散射,加强了微波能向热能的转化( Negi et al.,2021).污染物受高温被挥发或裂解,而水成为蒸汽也有助于清理并疏通孔隙. ...
Experimental study on regeneration of powder activated carbon by microwave radiation
0
2021
Search for the microwave nonthermal effect in microwave chemistry:Synthesis of the heptyl butanoate ester with microwave selective heating of a sulfonated activated carbon catalyst
1
2021
... 由于活性炭及其孔隙中的水具有良好介电性(炭为超热活性物质)(Shivanshu et al.,2021;檀素霞等,2006),且微波辐照可以不蒸干孔隙水直接加热活性炭本身( Sakemi et al.,2021),因而能量使用效率高、升温速度快.此外,孔隙水在间隙中部分电离并放电,将疏通孔道,增加活性.Bradshaw et al.(1998)研究表明在再生温度为650 ℃的条件下,通入适量水蒸气进行活性炭微波再生,能获得更高的再生活性及强度.浦燕新等(2021)进行微波再生活性炭研究,并开展不同载气条件试验,确定了最佳反应条件,即微波加热温度为500 ℃、加热5 min、氮气载气流量为1 L/min.然而,结合现场设备及安全生产成本,现场很难供给稳定的氮气及水蒸气,所以应探索微波再生在不加注气氛下的再生条件.同时,微波效率与活性炭介电能力有强相关性,活性炭的水份对活性炭的介电能力影响显著,应予以研究. ...
Studies on dielectric and magnetic properties of barium hexaferrite and bio-waste derived activated carbon composites for X-band microwave absorption
1
2021
... 由于活性炭及其孔隙中的水具有良好介电性(炭为超热活性物质)(Shivanshu et al.,2021;檀素霞等,2006),且微波辐照可以不蒸干孔隙水直接加热活性炭本身( Sakemi et al.,2021),因而能量使用效率高、升温速度快.此外,孔隙水在间隙中部分电离并放电,将疏通孔道,增加活性.Bradshaw et al.(1998)研究表明在再生温度为650 ℃的条件下,通入适量水蒸气进行活性炭微波再生,能获得更高的再生活性及强度.浦燕新等(2021)进行微波再生活性炭研究,并开展不同载气条件试验,确定了最佳反应条件,即微波加热温度为500 ℃、加热5 min、氮气载气流量为1 L/min.然而,结合现场设备及安全生产成本,现场很难供给稳定的氮气及水蒸气,所以应探索微波再生在不加注气氛下的再生条件.同时,微波效率与活性炭介电能力有强相关性,活性炭的水份对活性炭的介电能力影响显著,应予以研究. ...
Research progress of technologies and equipments for regeneration activated carbon
0
2008
Application of microwave heating in porous carbon treatlng
0
2006
Numerical simulation of hot-spot effects in microwave heating due to the existence of strong microwave-absorbing media
1
2016
... 此外,炭材料如活性炭(Dawson et al.,2008)、碳化硅(Wang et al.,2016)、焦炭、无烟煤和石墨(Menéndez et al.,2011)等受到微波辐照时,会诱导微波能量集中(Hussain et al.,2010),导致材料间隙气体放电.这有助于有机物裂解(徐云鹏等,2002),即有利于微波再生活性炭过程中,活性炭内有机物的去除. ...
Experimental study on gold leaching process of a gold mine in Gansu Province
0
2017
Research on regeneration and new technology of activated carbon
0
2004
Process and practice of CIP disposing the original ore of Hetai gold deposit
0
2009
Conversion of methane to C2 hydrocarbons via active carbon induced continuous microwave discharge under atmospheric pressure
0
2002
A comparison of gold recovery sche-me from cyanide liquid for gold concentrates in Jinping and Weishan
... 水和活性炭均拥有很强的介电能力(Gaglianoa et al.,2021;Ellison et al.,1996,刘彦超等,2019),吸收微波的能力很强.水偶极子在微波场中每秒重新排列数万亿次,并在旋转的分子之间引起摩擦,这一过程导致在材料的整个体积内产生热量(Peng et al.,2015).活性炭的加热原理是碳材料中的π电子,会产生与电磁场同相传播的电流.由于电子不能与电场相位的变化相耦合,能量因麦克斯韦—瓦格纳效应(界面极化或麦克斯韦—瓦格纳极化)以热的形式耗散(Menéndez et al.,2010).这2种效应将微波能转化为热能,即直接对活性炭由内到外迅速升温,如图1所示.活性炭的多孔结构增加了微波的反射与散射,加强了微波能向热能的转化( Negi et al.,2021).污染物受高温被挥发或裂解,而水成为蒸汽也有助于清理并疏通孔隙. ...
... 由于活性炭及其孔隙中的水具有良好介电性(炭为超热活性物质)(Shivanshu et al.,2021;檀素霞等,2006),且微波辐照可以不蒸干孔隙水直接加热活性炭本身( Sakemi et al.,2021),因而能量使用效率高、升温速度快.此外,孔隙水在间隙中部分电离并放电,将疏通孔道,增加活性.Bradshaw et al.(1998)研究表明在再生温度为650 ℃的条件下,通入适量水蒸气进行活性炭微波再生,能获得更高的再生活性及强度.浦燕新等(2021)进行微波再生活性炭研究,并开展不同载气条件试验,确定了最佳反应条件,即微波加热温度为500 ℃、加热5 min、氮气载气流量为1 L/min.然而,结合现场设备及安全生产成本,现场很难供给稳定的氮气及水蒸气,所以应探索微波再生在不加注气氛下的再生条件.同时,微波效率与活性炭介电能力有强相关性,活性炭的水份对活性炭的介电能力影响显著,应予以研究. ...
... 由于活性炭及其孔隙中的水具有良好介电性(炭为超热活性物质)(Shivanshu et al.,2021;檀素霞等,2006),且微波辐照可以不蒸干孔隙水直接加热活性炭本身( Sakemi et al.,2021),因而能量使用效率高、升温速度快.此外,孔隙水在间隙中部分电离并放电,将疏通孔道,增加活性.Bradshaw et al.(1998)研究表明在再生温度为650 ℃的条件下,通入适量水蒸气进行活性炭微波再生,能获得更高的再生活性及强度.浦燕新等(2021)进行微波再生活性炭研究,并开展不同载气条件试验,确定了最佳反应条件,即微波加热温度为500 ℃、加热5 min、氮气载气流量为1 L/min.然而,结合现场设备及安全生产成本,现场很难供给稳定的氮气及水蒸气,所以应探索微波再生在不加注气氛下的再生条件.同时,微波效率与活性炭介电能力有强相关性,活性炭的水份对活性炭的介电能力影响显著,应予以研究. ...
... 此外,炭材料如活性炭(Dawson et al.,2008)、碳化硅(Wang et al.,2016)、焦炭、无烟煤和石墨(Menéndez et al.,2011)等受到微波辐照时,会诱导微波能量集中(Hussain et al.,2010),导致材料间隙气体放电.这有助于有机物裂解(徐云鹏等,2002),即有利于微波再生活性炭过程中,活性炭内有机物的去除. ...