Coal ash coating makes AN less explosive

Lexington, Ky.-A University of Kentucky researcher has found that adding coal ash makes ammonium nitrate less explosive and could be used to treat the entire annual production of this type of fertilizer for $10-$15 million. “We found that not only does it appear to be as effective in agriculture as a fertilizer, but it would have a longer shelf life than pure ammonium nitrate,” said Darrell Taulbee, a research scientist and industrial support coordinator at the university’s Center for Applied Energy Research. Taulbee has been researching ammonium nitrate coating on a $125,000 grant from the National Institute for Hometown Security, a DHS contractor, testing a variety of concentrations and using makeshift bombs to gauge how much of the explosive power was suppressed. He determined that a 20 percent ratio of coal ash to 80 percent ammonium nitrate prevented large blasts, even when the samples were crushed. “So far we have only demonstrated its effectiveness in stopping the propagation of the AN explosion,” Taulbee told Green Markets. “We also conducted some scoping lab studies that indicate the bulk density, particle size distribution and nitrogen-release rate are suitable for agricultural applications using existing farm equipment. However, these would need to be confirmed in the field in crop studies by looking at growth rates, trace element uptake, and application properties.” He said the detonation results would also need independent confirmation by experts in the field such as ATF, DHS, and New Mexico Tech., which have indicated an interest. By the time the funding is secured and the tests are conducted, he estimates that it will be a minimum of two years before the process could be available commercially. The material itself wouldn’t represent a high cost, but increased transportation costs would be a different matter. “However, I personally don’t think that farmers should be asked to bear the added cost for something that would benefit society,” Taulbee suggested. “I think subsidizing the coating of our entire annual production of ag-grade AN for $10 million to $15 million would be a drop in the bucket for the Homeland Security budget.”