Abstract |
Since promulgation of new source performance standards (NSPS) for the phosphate fertilizer industry, in 1975, commercial applications of a few new systems that reduce air pollution from phosphate plants have been reported. These include scrubbing system modifications that reduce the size of ponds used to cool process water, and reduce pond fluoride emissions. Also, a proprietary new process produces a stable granular triple superphosphate (GTSP) directly. This process reduces or eliminates the emissions of fluorides and fugitive particulate during the curing, storage period. The new GTSP process also eliminates the scrubbing of certain process gas, thus reducing required cooling pond area and pond fluoride emissions. Wet grinding of phosphate rock, in place of dry grinding, has been introduced, which eliminates dryers and reduces emissions that include particulate with radioactive content. NSPS revision, however, would probably not have significant impact now because the extent of new and modified source construction in this industry is small, and because industry growth projected to 1985 is negligible. The recommendation is, therefore, made not to develop NSPS revisions now, but to assess additional developments in this industry in four years, and then reconsider possible revision. |