Effect of flocculation sedimentation on the yield stress of thickened ultrafine tailings slurry

RUAN Zhu-en; WU Ai-xiang; WANG Yi-ming; WANG Yong; WANG Jian-dong

doi:10.13374/j.issn2095-9389.2020.08.01.002

Volume 43 Issue 10

Oct. 2021

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Article Navigation > Chinese Journal of Engineering > 2021 > 43(10): 1276-1282

RUAN Zhu-en, WU Ai-xiang, WANG Yi-ming, WANG Yong, WANG Jian-dong. Effect of flocculation sedimentation on the yield stress of thickened ultrafine tailings slurry[J]. Chinese Journal of Engineering, 2021, 43(10): 1276-1282. doi: 10.13374/j.issn2095-9389.2020.08.01.002

Citation:

RUAN Zhu-en, WU Ai-xiang, WANG Yi-ming, WANG Yong, WANG Jian-dong. Effect of flocculation sedimentation on the yield stress of thickened ultrafine tailings slurry[J]. Chinese Journal of Engineering, 2021, 43(10): 1276-1282. doi: 10.13374/j.issn2095-9389.2020.08.01.002

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Effect of flocculation sedimentation on the yield stress of thickened ultrafine tailings slurry

doi: 10.13374/j.issn2095-9389.2020.08.01.002

1.
School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
2.
Shunde Graduate School, University of Science and Technology Beijing, Foshan 528399, China

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Corresponding author: E-mail: wuaixiang@126.com
Received Date: 2020-08-01
Available Online: 2020-12-30
Publish Date: 2021-10-01

Abstract

Abstract

With the advantages of efficiency and economy, deep-cone thickener (DCT) has been increasingly applied in tailings management. The rake in the DCT is essential for obtaining high-concentration underflow slurry; thus, more emphasis was placed on the effects of rakes on the underflow concentration. However, high concentration means high yield stress, which may lead to rake blockage. Therefore, this study investigated the effects of flocculation and sedimentation on the yield stress of thickened ultrafine tailings slurry. First, flocculation and sedimentation experiments were conducted under a pH range of 8 to 11 and flocculant dosage of 0 to 45 g·t^?1 to obtain different thickened ultrafine tailings slurries. Then, the yield stress was measured through an in situ test. Finally, the amount of flocculant adsorbed on the tailings particle surface was analyzed by total organic carbon analysis. The amount of flocculant adsorbed on the tailings particles surface increased with the pH and flocculant dosage over the entire experiment range. Then, the yield stress increased with the increase in the amount of adsorbed flocculant, indicating that flocculation sedimentation has a significant influence on the yield stress. Based on the flocculation sedimentation behavior and yield stress, the optimal conditions were a pH of 8 and flocculant dosage of 15 g·t^?1. Under these conditions, the initial settling rate of the solid–liquid interface was 0.4565 mm·s^?1, supernate turbidity was 143 NTU, solid mass fraction of sediment was 51.56%, and yield stress was 243.18 Pa. The relationship between yield stress and the amount of flocculant adsorbed and yield stress was investigated, and an empirical model for yield stress based on flocculant adsorption was established. It was found that the yield stress increased with the amount of flocculant adsorbed, providing a reference for the control of flocculation sedimentation parameters in actual production.
- tailings,
- flocculation sedimentation,
- total organic carbon,
- flocculant adsorption,
- yield stress

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References(33)

References

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