针对盾构渣土脱水过程中处理时间长、脱水效率较低和药剂环境污染等问题，使用液态二甲醚与三亚磷酸酯复合材料（DME-TTFP），通过相变法对盾构渣土进行脱水，探究不同DMETTFP掺入量和反应时间对盾构渣土脱水效果的影响规律。通过X射线衍射法（XRD）、X射线荧光光谱法（XRF）、扫描电镜（SEM）、比表面积分析（BET）等方法表征盾构渣土脱水前后的物质组成、粒径分布及颗粒形貌，并对盾构渣土在脱水过程中的水分形态变化进行分析。结果表明: 1）DME-TTFP掺入量和处理时间显著影响盾构渣土的脱水效果，盾构渣土的含水率随着液态DME-TTFP投加量和反应时间的增加而降低； 2）将液态DME-TTFP与渣土中水分的质量比控制为8，脱水时间控制为15~20 min，可将渣土的含水率稳定在23%左右，达到最高效的脱水状态； 3）脱水前后渣土粒径分布较为稳定，DME-TTFP不会残留在渣土中，对渣土的成分组成影响较小，具有较强的可重复利用性； 4）在脱水过程中，前期自由水会优先脱离，反应中后期部分结合水会逐渐脱离，结合水脱除率可达35%以上。
The shield muck dehydration has disadvantages such as
long processing time, low efficiency, and environmental pollution caused by
chemicals. Therefore, a novel material composed of liquid dimethyl ether and
triguaiacyl phosphite(DMETTFP) is developed to dehydrate
shield muck using phase change method, and the influence of different DMETTFP amount and reaction time on dehydration effect is examined. The
composition, particle size distribution, and morphology of shield muck before
and after dehydration are characterized by Xray
diffraction, Xray fluorescence spectroscopy, scanning
electron microscopy, and specific surface area analysis, respectively, and the
moisture morphological variations of the shield muck during dehydration process
is analyzed. The results demonstrate the following: (1) The amount of DMETTFP incorporation and treatment time considerably affect the
dehydration of shield muck. The moisture content decreases with increasing
amount of liquid DMETTFP incorporation and treatment
time. (2) The moisture content of the muck can be stabilized at approximately
23% when the mass ratio of liquid DMETTFP to moisture
in the muck is set at 8 with a dehydration time of 1520
min, resulting in an optimal dehydration state. (3) The particle size
distribution of the muck after dehydration is relatively constant, and DMETTFP cannot be found in muck, which exhibits favorable reusability
and weak contribution to the composition of the shield muck. (4) The free water
would preferentially be detached during early stage of dehydration, and almost
completely disengaged in the middle and later stages. Then partial bound water
could be gradually detached, and the removal efficiency of bound water attained
more than 35%.
