Swelling and cation exchange capacity relationship for the samples obtained from a bentonite by acid activations and heat treatments
Swelling and cation exchange capacity relationship for the samples obtained from a bentonite by acid activations and heat treatments
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DOI：
10.1016/j.clay.2006.12.004
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发表时间：
2007-06-01
影响因子：
5.6
通讯作者：
Oenal, Mueserref
中科院分区：
文献类型：
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作者：
Oenal, Mueserref
为了研究加热和酸活化对阳离子交换容量（CEC）和膨胀（SWE）的影响，使用钙膨润土（CaB）。来自Kutahya（土耳其）地区的钙膨润土（CaB）分别含有约65%和30%的钙蒙脱石（CaS）和蛋白石-CT（OCT）。其余为伊利石（1）和其它杂质。将13个样品在100至1300摄氏度之间的不同温度下加热2小时。此外，通过在97 ℃下加热水性悬浮液6小时，用在干燥的蒙脱石-酸混合物中具有0 - 70质量%范围内的各种剂量的H2SO 4活化样品。CEC和总SWE（结晶性和渗透性）分别用标准亚甲蓝（MB）法和定量水凝胶体积法测定。CEC和SWE通过加热而降低，这取决于CaS的2：1层的塌陷。当SWE随着温度的升高而近似线性地减小时，CEC在600 ° C之后减小得更快，并且在900 ° C时达到零。而CEC几乎线性增加与H2SO 4剂量的活化，SWE下降到20%，然后不改变。一般而言，SWE随着CEC而增加。(C)2006 Elsevier B. V.保留所有权利。
To investigate the effect of heating and acid activation on the cation exchange capacity (CEC) and swelling (SWE), a calcium bentonite (CaB) was used. The calcium bentonite (CaB) from the Kutahya (Turkey) region contains approximately 65% and 30% by mass calcium reach smectite (CaS) and opal-CT (OCT), respectively. The rest amount is illite (1) and other impurities. The 13 samples were heated at different temperatures between 100 and 1300 degrees C for 2 h. Furthermore, the sample was activated with H2SO4 having various dosages ranging between 0 and 70% by mass in the dry bentonite-acid mixture, by heating the aqueous suspensions at 97 degrees C for 6 h. The CEC and total SWE (crystalline and osmotic) were measured by the standard methylene blue (MB) method and as gel volume in definite amount water, respectively. The CEC and SWE decrease by the heating depending on the collapse of the 2:1 layers of the CaS. While the SWE decreases approximately linearly by increasing of the temperature, the CEC decreases faster after 600 degrees C and reaches to zero at 900 degrees C. While the CEC increases almost linearly with the H2SO4 dosage by the activation, the SWE decreases up to 20% and then does not change. In general, the SWE increases with CEC. (C) 2006 Elsevier B.V. All rights reserved.