1999-05-28_PERMIT FILE - M1999002

• Permit No: M1999002
• IBM Index Class Name: Permit File
• Doc Date: 5/28/1999
• Doc Name: Process Solution Analysis
• From: DMG
• To: American Soda LLC
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY DRAFT
Department of Natural Resources
1313 Sherman St., Room 215
Denver,Colorado 80203 D I V I S 1 0 N O F
Phone:[phone] MINERALS
FAX:[phone] &
GEOLOGY
RECLAMATION
MINING-SAFETY
Date: May 28, 1999
Bill Owens
Governor
To: Allen Sorenson Greg E.Watcher
Executive Director
Michael B.Long
From: Harry H. Posey Division Director
Subject: Review: Public Comments Submitted by General Chemical Corporation, May I2,
1999, regarding Yankee Gulch Sodium Minerals Project, American Soda, L.L.P,
M-99-002
GENERAL REVIEW COMMENT
General Chemical has prepared what sounds like a concise and well-supported objection which
states, in part, that nahcolite recovery may damage the oil shale resource. Citing portions of a
letter from the BLM, General Chemical maintains that if nahcolite is to be recovered using water
temperatures in excess of 350 degrees fahrenheit, then the mineral dawsonite [NaAI(OH)2CO31
will dissolve and release CO2, and the oil shale resource will be damaged.
Mr. Bill Hill, BLM-Meeker, was contacted for more information on this question. BLM is
preparing a response which will be delivered with the final review. Meanwhile, it seems that
General Chemical may have misinterpreted the BLM letter cited in their objection. According to
Hill, dawsonite will not dissolve in water even up to temperatures of 425'F, which is the
maximum proposed potential temperature that we have heard in discussions of this project.
Dawsonite can be slaked or retorted, but not below temperatures of about 900' F. Oil shale, on
the other hand, apparently cannot be retorted below temperatures of about 600'F.
There is some uncertainty in the above-cited temperature values. At a minimum, mineral
solubilities and oil shale cracking or retorting temperatures will vary with solution chemistry.
The presence of gases such as CO2 also should affect retorting temperatures. The degree of
uncertainty, however, is not known.
To test whether oil shale destruction will take place at the proposed process solution
temperatures, the BLM and DMG—in consultation with USGS, the County, EPA and the
operator—constructed a set of monitoring requirements which includes, among other parameters,
benzene, toluene, ethylbenzene and xylenes (BTEX) and dissolved organic carbon (DOC).
Baseline studies for DMG are to include reports on the composition of the process solutions,