超声波作用下尾砂浆浓密沉降及放砂

发布时间：2018-08-21 07:09

【摘要】：为了提高砂仓中尾砂浓密效率,实现高浓度的放砂,引入声场作为研究手段,创新性的利用声场辐射方式传播的特性,将声场非接触性地作用于尾砂浆介质中.通过设计试验,配制质量分数为40%的尾砂砂浆,在尾砂浆分别沉降15,20,25,30,35和40 min后,施加频率20 k Hz,功率50 W的超声波,探究不同沉降时间后施加超声波作用对最终沉降时间和浓度的影响,同时将超声波作用在砂仓放砂阶段,并对超声波作用后不同浓度的砂浆进行流变参数测定.试验结果表明:在沉降20 min后施加超声波,砂浆沉降浓密时间最短为80 min,尾砂浆最终质量分数可达77.5%,与此同时超声波作用下可以实现砂仓稳定高浓度的放砂,放出砂浆质量分数为74.04%.对比超声波处理前后砂浆黏度与屈服应力可知,超声波可有效降低砂浆黏度22.3%,具有良好的降黏效果.超声波的振动作用,空化作用以及声流效应是使得砂浆快速浓密沉降以及放出的原因.
[Abstract]:In order to improve the thickening efficiency of tailings in the silo and realize the high concentration of sand discharge, the sound field is introduced as the research means, and the sound field is acted in the tail-mortar medium by using the characteristics of the radiation mode of the sound field creatively. Through the design test, the tailings mortar with 40% mass fraction was prepared. After the tailings mortar was subsided for 1520 ~ 2530U / 35 and 40 min respectively, the ultrasonic wave was applied at the frequency of 20 kHz and the power of 50 W, respectively. The effect of ultrasonic wave on the final settling time and concentration after different settling time was studied. At the same time, the ultrasonic wave action was applied in the sand release stage, and the rheological parameters of mortar with different concentration after ultrasonic wave action were measured. The experimental results show that when ultrasonic wave is applied after 20 min of settlement, the shortest settling time is 80 minutes, and the final mass fraction of tail mortar can reach 77.5. At the same time, under the action of ultrasonic wave, a stable and high concentration sand discharge can be realized. The mass fraction of the released mortar is 74.04. Compared with the mortar viscosity and yield stress before and after ultrasonic treatment, ultrasonic can effectively reduce the mortar viscosity 22. 3 and has a good viscosity reduction effect. Ultrasonic vibration, cavitation and acoustic flow are the reasons for the rapid and dense settlement and release of mortar.
【作者单位】：北京科技大学土木与资源工程学院;北京联合大学北京市信息服务工程重点试验室;纽约城市大学土木工程系;
【基金】：国家自然科学基金资助项目(51641401)
【分类号】：TD80;TD926.4

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