文献类型：期刊文献

英文题名：Effect of ultrasound on the flocculation-sedimentation and thickening of unclassified tailings

作者：Zhu, Liyi[1];Lyu, Wensheng[1];Yang, Peng[2];Wang, Zhikai[3]

第一作者：Zhu, Liyi

通讯作者：Lyu, WS[1];Yang, P[2]

机构：[1]Univ Sci & Technol Beijing, Sch Civil & Resource Engn, Beijing 100083, Peoples R China;[2]Beijing Union Univ, Beijing Key Lab Informat Serv Engn, Beijing 100101, Peoples R China;[3]China Enfi Engn Corp, Beijing 100038, Peoples R China

第一机构：Univ Sci & Technol Beijing, Sch Civil & Resource Engn, Beijing 100083, Peoples R China

通讯机构：[1]corresponding author), Univ Sci & Technol Beijing, Sch Civil & Resource Engn, Beijing 100083, Peoples R China;[2]corresponding author), Beijing Union Univ, Beijing Key Lab Informat Serv Engn, Beijing 100101, Peoples R China.|[11417103]北京联合大学北京市信息服务工程重点实验室;[11417]北京联合大学;

年份：2020

卷号：66

外文期刊名：ULTRASONICS SONOCHEMISTRY

收录：;EI(收录号：20201408373789);Scopus(收录号：2-s2.0-85082526677);WOS:【SCI-EXPANDED(收录号:WOS:000532046000007)】；

基金：This study was supported by funds from the National Natural Science Foundation of China (grant numbers 51641401 and 51774045), the National Key Research and Development Program of China (grant number 2017YFC0804604), and the National Science and Technology Pillar Program during the 12th "Five-year" Plan Period, China (grant number 2012BAB08B01).

语种：英文

外文关键词：Ultrasound; Flocculant; Unclassified tailings; Sedimentation; Thickening; Microstructure

摘要：In back-fill mining, how to rapidly increase the concentration of tailings is an important problem facing mining engineers. In this paper, the effects of ultrasound frequency (17-25 kHz), power (50-100 W), duration (5-20 min) and start time (3-12 min) on the final underflow concentration (FUC) of unclassified tailings (UTs) were investigated. The flocculation-sedimentation and thickening of tailings were compared with and without ultrasound application. The response surface method was applied to analyze the primary and secondary relationships and interactive relationships between the various ultrasound operating parameters and the FUC, and the optimal conditions were determined. In addition, Environmental Scanning Electron Microscope (E-SEM) was used to analyze the structural changes of underflow aggregates and clearly demonstrated a denser underflow after ultrasound treatment. The results indicated that ultrasound can significantly improve the underflow concentration of the UTs slurry. The frequency and power are the most important influencing factors. The best conditions for ultrasound application are a frequency of 20.4 kHz, power of 90 W, duration of 6.2 min and start time at 15.0 min. The FUC reached 71.75% after several minutes of sonication, which is 4.31% higher than the FUC of free flocculation. The results of E-SEM analysis showed significant differences among the microstructures of settled tailings (STs) after free flocculation and 17 and 20 kHz ultrasound treatment. Ultrasound at a frequency of 20 kHz has a more effective mechanical vibration and cavitation action and can therefore effectively break the polymer flocculant chains into shorter chains and promote the compaction of tailings and the release of water. The size distributions of the flocs before and after sonication also support this conclusion.