Basic principles and mechanisms of selective oil agglomeration. Fossil energy interim report, October 1, 1983--September 30, 1992
Numerous agglomeration tests were conducted with several types of low-ash coal and graphite, high grade mineral pyrite, and other materials. Relatively pure hydrocarbons, including heptane and hexadecane, were used as agglomerants. Access of air to the system was controlled. Particle recovery by agglomeration was observed to depend on a number of system parameters. Among the most important parameters are the hydrophobicity of the particles and the oil dosage, so that the, recovery of solids per unit of oil administered is proportional to the hydrophobicity. The pH and ionic strength of the aqueous suspension affect particle recovery in different ways depending on the surface properties of the particles. On the other hand, the presence of air in the system generally improves particle recovery. The greatest effect of air was observed in a closely related study which showed that air had to be present to produce good agglomerates from a moderately hydrophobic coal in a mixer producing a lower shear rate. The rate of agglomeration was found to be much greater for a strongly hydrophobic coal than for a moderately hydrophobic coal, and the rate was observed to be proportional to the oil dosage. Also the rate was enhanced by the presence of air in the, system. For hydrophobic coals, the rate increased with increasing ionic strength of the aqueous medium, but it was not affected greatly by pH over a wide range. The separation of coal and pyrite particles by selective agglomeration was found to depend on the relative hydrophobicity of the materials, the oil dosage, and the properties of the aqueous medium.
- Research Organization:
- Ames Lab., IA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 10161801
- Report Number(s):
- IS--5105; ON: DE94014237
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oil agglomeration of coal in salt solutions: effects of hydrophobicity and other parameters on coal recovery
Mechanisms for selective coalescence of coals: Fossil energy quarterly report, January 1--March 31, 1988
Mechanisms for selective coalescence of coals: Quarterly report, April 1, 1988--June 30, 1988. [Effects of sodium oleate and salt of humic acid on agglomeration]
Conference
·
Thu Dec 31 23:00:00 EST 1987
· Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States)
·
OSTI ID:5956440
Mechanisms for selective coalescence of coals: Fossil energy quarterly report, January 1--March 31, 1988
Technical Report
·
Sun May 01 00:00:00 EDT 1988
·
OSTI ID:6642259
Mechanisms for selective coalescence of coals: Quarterly report, April 1, 1988--June 30, 1988. [Effects of sodium oleate and salt of humic acid on agglomeration]
Technical Report
·
Mon Aug 01 00:00:00 EDT 1988
·
OSTI ID:6663696