Devco USA LLC U.S. Administrative Headquarters for the Bay Sulfur, California Sulphur, Devco Australia, Devco Overseas and Devco Services Companies 8801 S. Yale, Suite 250, Tulsa, OK 74137-3535 Phone (918) 496-4400, Fax (918) 496-4422

COMMENTS:

The hot plant was brought up to temperature with a conventional asphalt mix before the SEAM was added.  Once operations were stable, the plant was switched over to the manufacturing of the SEAM-Asphalt mix.  The mix design called for 3.05% AC-30 and 3.05% SEAM on a weight basis.  The aggregate was 3/4" minus.  The initial temperature of asphalt at the discharge was 290 degrees F.  Ultimately, this temperature was reduced down to 280 degrees F.

The plant operated smoothly at a rate of ~290 tons per hour.  The mix was transported to the paver with very few delays. Paving went smooth and was uninterrupted.

A TMX-412 monitor was calibrated to take spot readings of hydrogen sulfide (H2S) and sulfur dioxide (SO2).  Readings were taken at the discharge of the drum feeding the bucket elevator and at the paving unit.  Since the vapors dissipated rapidly, readings were taken within 1 " of the asphalt to see what concentration of H2S and SO2 were released.  Additionally, Personal Breathing-Zone (PBZ) readings were taken at the hot plant and at the paver.

R. G. Bloom
Technical Manager
Devco USA LLC