摘要
金属离子在煤炭固液界面的作用机制对促进煤炭清洁高效加工利用、水资源与矿物资源的高效循环利用及"碳减排"具有重要意义。采用耗散石英微晶天平(QCM-D)研究了K^(+)、Mg^(2+)、Al^(3+)、Fe^(3+)四种金属离子在碳表面的吸附脱附行为。结果表明,浓度和价态的升高均有利于提高金属离子的吸附作用,四种金属离子与碳表面的作用强度由高到低排序为:Fe^(3+)>Al^(3+)>Mg^(2+)>K^(+);K^(+)和Mg^(2+)表现为单段吸附,在2 min内达到吸附平衡,随着吸附量增加,吸附层的密实程度无明显变化,用水清洗后可完全脱附;AlCl_(3)溶液只有在100 mmol/L高浓度情况下的吸附是完全可逆的,在10 mmol/L和50 mmol/L的低浓度情况下,AlCl_(3)表现为两段吸附特性,第1段吸附物的量虽少,但比第2段吸附物密实,脱附后仍有少量密实性吸附物残留;FeCl_(3)溶液与其他溶液均有较大区别,在研究的10~100 mmol/L浓度范围内,吸附均不完全可逆,浓度越低,多段吸附和不可逆吸附特性越明显,脱附后的残留量越高,脱附过程中结构较为松散的吸附物优先从表面脱附,结构较为密实的吸附物残留到了碳表面。FeCl_(3)和AlCl_(3)的不可逆吸附行为与其水解反应有关,浓度越低,越容易生成不可脱附的Fe(OH)_(3)和Al(OH)_(3)。
The mechanisms of metal ions at the solid-liquid interface of coal is of great significance to clean processing and utilization of coal,efficient recycling of water and mineral resources and"carbon emission reduction".The adsorption and desorption behaviors of K^(+),Mg^(2+),Al^(3+)and Fe^(3+)on carbon surface were studied by quartz crystal microbalance with dissipation(QCM-D).The results show that the increase of concentration and valence state is conducive to improve the adsorption of metal ions.The interaction between four metal ions and carbon surface is ranked as:Fe^(3+)>Al^(3+)>Mg^(2+)>K^(+);K^(+)and Mg^(2+)show single-stage adsorption and reach adsorption equilibrium within 2 min.With the increase of adsorption amount,the compactness of the adsorption layer has no obvious change,and adsorbent can be completely desorbed after washing with water.The adsorption of AlCl_(3) solution is completely reversible only under the condition of high concentration of 100 mmol/L.In the case of low concentration of 10 mmol/L and 50 mmol/L,AlCl_(3) shows two-stage adsorption characteristics.Although the amount of adsorbent in the first stage is less,it is more compact than that in the second stage.After desorption,there is still a small amount of compact adsorbent residue.FeCl_(3) solution is quite different from other solutions.Within the studied concentration range of 10~100 mmol/L,the adsorption is not completely reversible.The lower the concentration,the more obvious the characteristics of multi-stage adsorption and irreversible adsorption,and the higher the residue amount after desorption.In the desorption process,the adsorbents with loose structure are preferentially desorbed from the surface,and the adsorbents with compact structure remain on the carbon surface.The irreversible adsorption behavior of FeCl_(3) and AlCl_(3) is related to their hydrolysis reaction.The lower the concentration,the easier it is to form non-desorbable Fe(OH)_(3) and Al(OH)_(3).
作者
马晓敏
董宪姝
刘清侠
樊玉萍
陈茹霞
常明
MA Xiaomin;DONG Xianshu;LIU Qingxia;FAN Yuping;CHEN Ruxia;CHANG Ming(College of Mining Engineering,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China;Department of Chemical and Materials Engineering,University of Alberta,Edmonton,AB T6G 1H9,Canada;College of New Materials and New Energies,Shenzhen Technology University,Shenzhen,Guangdong 518118,China)
出处
《矿业研究与开发》
CAS
北大核心
2021年第11期155-161,共7页
Mining Research and Development
基金
国家自然科学基金资助项目(51820105006,52004178,52074189)
山西省留学归国人员择优资助项目(20210036)。
关键词
金属离子
QCM-D
碳表面
吸附脱附
碳减排
Metal ions
QCM-D
Carbon surface
Adsorption and desorption
Carbon emission reduction