Coal cleaning by froth flotation
A number of experiments were conducted to determine the flotation characteristics of Iowa coals in which various conditions were applied to study the effect of different parameters such as frother dosage, oily collectors, pyrite depressants, and various combinations of these reagents. Flotation tests were also conducted with Appalachian coals for comparison. Bubble-particle attachment was studied from a theoretical view point. This study showed that the mechanism of attachment differs depending on the relative size of bubbles and particles. When small bubbles adhere to a flat or slightly curved surface of a particle, the bubble size was found to be determined by the contact angle between the bubble and the particle. The study indicated that micro-bubbles could separated mineral matter from low rank coal more selectively than macro-bubbles could. A general kinetic model was proposed to represent the rate of flotation of coal. For two Appalachian coals, the model successfully represented the flotation kinetics of uniformly sized coal. The proposed model also represented well the flotation kinetics of coal consisting of two sizes of particles.
- Research Organization:
- Iowa State Univ. of Science and Technology, Ames (USA)
- OSTI ID:
- 5579923
- Country of Publication:
- United States
- Language:
- English
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