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Xu M, Guo F, Bao X, Gui X, Xing Y, Cao Y. Study on the Strengthening Mechanism of a MIBC-PEG Mixed Surfactant on Foam Stability. ACS OMEGA 2023; 8:27429-27438. [PMID: 37546650 PMCID: PMC10399173 DOI: 10.1021/acsomega.3c02863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/29/2023] [Indexed: 08/08/2023]
Abstract
In the flotation process, the frother, which is typically a surfactant, can be added to the pulp to reduce the surface tension and create stable foam. Currently, the nonionic mixed surfactant is widely employed as the frother for fine coal flotation. In this study, we focused on examining the foam properties of a mixed surfactant comprising short-chain methyl isobutyl carbinol (MIBC) and long-chain polyethylene glycol-1000 (PEG). Analytical techniques such as surface tension measurement, dynamic foam stability measurement, bubble morphology observation, and foam film drainage measurement were used to investigate the foam properties in single and mixed surfactant solution from a macroscopic scale to a microscopic scale. The surface tension results indicated that PEG exhibited higher surface activity than MIBC, and the addition of PEG to MIBC resulted in a significant reduction in solution surface tension. The dynamic foam stability analysis revealed that the incorporation of a small amount of PEG into MIBC solution notably improved foam stability. Furthermore, the addition of PEG to the MIBC solution led to a shift in the bubble size distribution curve from a "double peak" to a "single peak" shape. This shift indicated a substantial reduction in bubble size, indicating an enhanced inhibition of bubble coalescence. Additionally, the liquid film drainage rate was significantly slowed down, and the stability of the liquid film was improved upon the addition of PEG to MIBC. This improvement can be attributed to the synergistic effect of MIBC and PEG molecules adsorbed at the gas-liquid interface. The synergistic effect of mixed MIBC-PEG was due to the additional surface tension gradient created by the difference in surface activity between PEG and MIBC. This surface tension gradient enhances the Marangoni flow of surfactant molecules, thereby improving the self-healing ability of the liquid film and increasing its stability.
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Affiliation(s)
- Mengdi Xu
- Chinese
National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Fangyu Guo
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Xicheng Bao
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Xiahui Gui
- Chinese
National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Yaowen Xing
- Chinese
National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Yijun Cao
- Chinese
National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
- Henan
Province Industrial Technology Research Institute of Resources and
Materials, Zhengzhou University, Zhengzhou 450001, China
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Bao X, Liu J, Wang S, Chen D, Xu W, Zhang D, Li J, Xing Y, Xu M. New Insight into Temperature Effects on Low-Rank Coal Flotation Using Diesel as a Collector. ACS OMEGA 2023; 8:15479-15487. [PMID: 37151510 PMCID: PMC10157877 DOI: 10.1021/acsomega.3c00774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/11/2023] [Indexed: 05/09/2023]
Abstract
Efficient flotation of low-rank coal is of great significance for the development of green and low-carbon cycles. Temperature is a crucial parameter of flotation, but the mechanism of its effect on flotation lacks understanding. In this paper, the mechanism was studied by kinetic flotation, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, low-temperature liquid-nitrogen adsorption (LP-N2A), X-ray photoelectron spectroscopy (XPS), and molecular dynamics simulation. The flotation combustible recovery gradually decreases as temperature rises. Compared with 60 °C, the combustible recovery at 5 °C increases by 18.13%. The desorption energy for oil droplets decreases as the temperature rises. As a result, the oil droplets are easier to desorb at high temperatures. The SEM and LP-N2A results demonstrate that the pores and fractures of the coal sample are well developed. Also, the oil-water interfacial tension and viscosity of oil droplets decrease as the temperature rises, while the diffusion ability increases. These increase the volume of oil droplets that penetrate into the pores, resulting in poor spreadability of oil droplets on the coal surface. The average volume of bubbles gradually increases as temperature rises, which renders the flotation foam unstable and worsens the flotation. Therefore, the flotation performance is better at low temperatures.
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Affiliation(s)
- Xicheng Bao
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
| | - Junling Liu
- Henan
Energy Group Co., Ltd. Zhengzhou, Henan 450046, China
| | - Shasha Wang
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
| | - Dongqin Chen
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
| | - Wenjin Xu
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
| | - Deke Zhang
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
| | - Jihui Li
- School
of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Yaowen Xing
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
| | - Mengdi Xu
- Chinese
National Engineering Research Center of Coal Preparation and Purification, Xuzhou, Jiangsu 221116, China
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