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Role of different types of clay in the floatability of coal: Induction time and bubble-particle attachment kinetics analysis
- Source :
- Powder Technology. 344:814-818
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- The presence of clay minerals presents a great challenge to fine coal and mineral flotation due to the well-known phenomena of mechanical coating and water entrainment. In this paper, we study the effect of two different types of clay, kaolinite and montmorillonite, on the floatability of coal in de-ionized water (without flotation reagents) based on induction time and bubble-particle attachment kinetics. The bubble-particle attachment angle (BPAA) as a function of time was used as the kinetics raw data. We demonstrated how the presence of montmorillonite was detrimental to the floatability of coal in de-ionized water. This was not the case with kaolinite. The induction time and BPAA kinetics of coal particles only changed slightly after conditioning together with kaolinite. In contrast, the induction time increased considerably from 8.73 ms to 83.25 ms when montmorillonite was added. In addition, both the maximum BPAA and BPAA kinetics constant decreased, and hydrophilic montmorillonite coating occurred during the conditioning stage. These hydrophilic sites on the coal surface prevent the thinning-rupture of the water film between bubble and coal particles and thus decrease the floatability and recovery.
- Subjects :
- business.industry
General Chemical Engineering
Bubble
Kinetics
02 engineering and technology
engineering.material
021001 nanoscience & nanotechnology
complex mixtures
chemistry.chemical_compound
Montmorillonite
020401 chemical engineering
chemistry
Coating
Chemical engineering
engineering
Particle
Kaolinite
Coal
0204 chemical engineering
0210 nano-technology
Clay minerals
business
Subjects
Details
- ISSN :
- 00325910
- Volume :
- 344
- Database :
- OpenAIRE
- Journal :
- Powder Technology
- Accession number :
- edsair.doi...........3f6fa6ad675093e79afb16b31793baee