黄土颗粒分离方法试验研究

以延安新区I期工程的马兰黄土为研究对象,分别采用筛分法、离心机法和静水沉降法对其进行颗粒分离试验,并利用激光粒度仪对3种分离方法的试验结果进行跟踪对比,以研究最适用于黄土颗粒的分离方法。结果表明:筛分法主要适用于粒径大于0.05mm的黄土颗粒的分离,对粒径小于0.05mm的黄土颗粒分离效果较差,筛分结果的可靠性偏低。离心机法由于自身的局限性且受影响因素较多,试验结果的可靠性较低;静水沉降法主要适用于粒径小于0.05mm的黄土颗粒的分离,颗粒分级效果显著,试验结果的可靠性较高,且试验精度满足要求,但对于粒径小于0.002mm的颗粒分离时间较长。通过3种试验方法的对比可知,在对黄土进行颗粒分离试验时,宜采用筛分—沉降相结合的分离方法,对于大于0.05mm的颗粒宜采用筛分,对于小于0.05mm的颗粒宜采用静水沉降法。

Experimental Study on the Loess Particle Separation Method

In order to find out the most applicable separation method of loess grains,this research adopted three methods such as sieving method,centrifuge method and hydrostatic settlement method to do the particle separation experiment of Malan Loess in the first-stage project of Yan'an District and compared the results of three separation methods with the help of laser particle size analyzer.The results indicate that sieving method is mainly applicable to the separation of ＞0.05 mm loess grains.For ＜0.05 mm loess grains,the separation competence of sieving method is relatively limited and the reliability of separation results is low.On account of its own limitation and many influencing factors,the reliability of centrifuge method's separation results is relatively low.Hydrostatic settlement method is mainly applicable to the separation of ＜0.05 mm loess grains and the reliability of its separation results is relatively high with a remarkable effect of particle sizing.However,for ＜0.002 mm loess grains,the time consumption of hydrostatic settlement method is a bit long.It is concluded that a combination method of sieving method and hydrostatic settlement method is the most applicable separation method to separate the loess particles;sieving method is for ＞0.05 mm coarse particles and hydrostatic settlement method is for ＜0.05 mm fine particles.