Field and laboratory leaching studies of retorted Kentucky oil shale

Technical Report · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2172/6776453· OSTI ID:6776453

Robl, T L

The purpose of this report is to present the results of a field study on the environmental and reclamation characteristics of retorted eastern oil shale and associated materials. Retorted, raw and raw and retorted mixtures of eastern oil shale from a pilot test using the Dravo Traveling Grate Retort were placed in field lysimeters and sampled weekly or biweekly over a period of 1300 days. Retorting the oil shale induced significant changes in the clay minerals, with the decrystallization of kaolinite and illite being the major effects. The leachates generated in the field lysimeters were highly acidic, with pH's varying from approximately 2.5 to 3.5. The leachates had high concentrations of dissolved elements with sulfate, Mg and Fe present at tens of thousands or thousands of ppM. Acid generation and elemental concentrations in the leachates were highest in the first year. Even after 1300 days, the leachates remained very acidic with pH's in the 2.9 to 3.4 range and sulfate concentrations of 3,000 to 5,000 ppM. Iron, Mg and sulfate were present in the highest concentrations in the leachates from the unretorted oil shale. The clay minerals of the retorted shale were found relatively reactive in comparison to the raw shale as indicated by much higher Al and K concentrations in their leachates compared to that of the raw shale. In general, the chemistry of the leachates was determined by the kinetics of solution reactions and materials transport. Calcium concentration however appeared to be controlled by mineral equilibria with respect to gypsum. Laboratory-based leaching experiments produced leachates with elemental concentrations much lower than the field study. Leachates from column experiments, that closely simulated field conditions, were found to have chemical compositions comparable to that from the field and also produced similar elemental release patterns. 38 refs., 22 figs., 12 tabs.

• Research Organization: Kentucky Univ., Lexington, KY (USA). Center for Applied Energy Research
• Sponsoring Organization: DOE/FE
• DOE Contract Number: FC21-84MC21144
• OSTI ID: 6776453
• Report Number(s): DOE/MC/21144-2821; ON: DE90000482
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
040500 -- Oil Shales & Tar Sands-- Properties & Composition
041000* -- Oil Shales & Tar Sands-- Environmental Aspects
ALKALINE EARTH METALS
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMISTRY
DISPERSIONS
DISSOLUTION
DOCUMENT TYPES
ELEMENTS
ENERGY SOURCES
FEDERAL REGION IV
FIELD TESTS
FOSSIL FUELS
FUELS
IRON
KENTUCKY
LEACHATES
LEACHING
LYSIMETERS
MAGNESIUM
MATERIALS
MEASURING INSTRUMENTS
METALS
MINERALS
MIXTURES
NORTH AMERICA
OIL SHALES
OXYGEN COMPOUNDS
PH VALUE
PROGRESS REPORT
SEPARATION PROCESSES
SOLUTIONS
SPENT SHALES
SULFATES
SULFUR COMPOUNDS
TESTING
TRANSITION ELEMENTS
USA