|D05 Subcommittee Continues Standards Work on Sulfur Determination
The activities of Subcommittee D05.29 on Major Elements in Ash and Trace Elements of Coal include two recent interlaboratory round robin studies that will be discussed during the Oct. 26 to 29 meetings of ASTM Committee D05 on Coal and Coke in Cincinnati, Ohio. The two studies have been under the auspices of task groups on sulfur in solid combustion residues by high temperature combustion followed by infrared detection and on sulfur in solid combustion residues by inductively coupled plasma-atomic emission spectroscopy (ICPAES).
The design of the interlaboratory studies was approved by Subcommittee D05.24 on Statistics and has been constructed so that each task group will be analyzing the same suite of samples. Sulfur is one of the elements contained in the ash from coal combustion processes and can vary widely in concentration depending on the design of the coal combustion facility. Two ruggedness tests preceded the interlaboratory studies and were very helpful in identifying areas of the test procedures that affected both precision and bias. In the case of the high temperature combustion test method, the critical areas included decomposition temperature, decomposition time, and proper use of the accelerator used to help decompose and convert the sulfur species in the test samples to sulfur dioxide. In the case of the ICPAES test procedure, a more rigorous digestion had to be developed to ensure complete conversion of sulfite species that are sometimes found in residues from coal combustion facilities that employ sulfur-scrubbing processes.
The work of the task groups has been aided by the National Institute of standards and Technology, which supplied certified reference materials that will be used to determine method bias, and by LECO, a vendor of sulfur determinators widely used in the coal testing industry, which is supplying a trademarked accelerator to the participants. This work will expand the scope of ASTM D 5016, Standard Test Method for Sulfur in Ash from Coal, Coke, and Residues from Coal Combustion Using High-Temperature Tube Furnace Combustion Method with Infrared Absorption, and ASTM D 6349, Test Method for Determination of Major and Minor Elements in Coal, Coke, and Solid Residues from Combustion of Coal and Coke by Inductively Coupled Plasma-Atomic Emission Spectrometry.
Participants in the sulfur activity are welcome. For technical information about the sulfur in solid combustion residues task group, contact John Bullock, U.S. Geological Survey, Denver, Colo. (phone: 303/236-2496). For information about the task group on determining sulfur by inductively coupled plasma-atomic emission spectroscopy, contact Pete Rosendale, Consol Energy, South Park, Pa. (phone: 412/854-6504). For D05 membership or meeting information, contact Scott Orthey, ASTM International (phone: 610/832-9730). //
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