蒙脱石含量对膨润土膨胀行为影响的试验研究

Experimental study on influence of montmorillonite content on expansion behavior of bentonite

高放废物深地质处置中,作为缓冲回填材料的膨润土应具有良好的膨胀性能。为了解蒙脱石含量对膨润土膨胀行为的影响,采用自行设计的试验装置对不同蒙脱石含量膨润土的膨胀行为进行了试验研究。结果表明,在试验条件下,成型膨润土膨胀行为的各项指标(轴向最大膨胀力和径向最大膨胀力)均随着蒙脱石含量的增加而增加,且呈线性关系。蒙脱石含量为70%时,径向、轴向最大膨胀力分别达到2.03 MPa和2.25 MPa,其比值为0.902。结果可为膨润土设计提供参考。

In order to find out the influence of montmorillonite content on swelling behavior of bentonite,the swelling pressure is tested using home - made equipment. Results show that,under experimental conditions,the indexes ( maximum axial swelling pressure and radial swelling pressure ) increase with the increase of montmorillonite content,and there is a linear relationship between the indexes and montmorillonite content. The maximum radial and axial swelling pressure were up to 2. 03 MPa and 2. 25 MPa respectively,and their ratio was 0. 902 for the sample of 70% montmorillonite content. The experimental results can provide reference for design of bentonite in geological disposal.