Development of the selective coagulation process
Recent studies have resulted in the development of a novel agglomeration process for upgrading ultrafine coal. This process, which is known as selective hydrophobic coagulation (SHC), is based on the new finding that hydrophobic coal particles can be selectively coagulated in the presence of dispersed mineral matter. The driving force for the coagulation is believed to be due to the structural arrangement of water molecules near the coal surface. In most cases, simple pH control is all that is required to (1) induce the coagulation of the coal particles and (2) effectively disperse the particles of mineral matter. During the past quarter, several important aspects of the SHC process were examined. Direct measurements of the surface forces which control the selective coagulation process were conducted using a Mark 4 surface force apparatus. These preliminary measurements have provided irrefutable evidence for the existence of the hydrophobic force. Key expressions have been presented for a population balance model describing the hydrophobic coagulation process. In order to validate this model, experimental measurements of the size distributions of coal coagulation have been initiated. The liberation characteristics of samples obtained from the Elkhorn No. 3 and Pittsburgh No. 8 coal seams were determined using a SEM-IPS image processing system. Mixing studies were carried out to determine the effects of mixer-impeller configurations on the coagula size distributions. Bench-scale continuous testing has also been initiated during the past quarter using a rotating drum screen and sedimentation tank. 25 figs., 8 tabs.
- Research Organization:
- Virginia Center for Coal and Minerals Processing, Blacksburg, VA (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC22-90PC90174
- OSTI ID:
- 5299161
- Report Number(s):
- DOE/PC/90174-T3; ON: DE91018662
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of the selective hydrophobic coagulation process. Fourth quarterly technical progress report, July 1, 1992--September 30, 1992
Development of the selective coagulation process. Final report
Related Subjects
COAL
AGGLOMERATION
DISPERSIONS
MAGNETITE
PARTICLE SIZE
PH VALUE
PROGRESS REPORT
SEPARATION PROCESSES
SURFACE PROPERTIES
CARBONACEOUS MATERIALS
DOCUMENT TYPES
ENERGY SOURCES
FOSSIL FUELS
FUELS
IRON ORES
MATERIALS
MINERALS
ORES
OXIDE MINERALS
SIZE
010300* - Coal
Lignite
& Peat- Preparation- (1987-)
010600 - Coal
Lignite
& Peat- Properties & Composition