FIPR-DIPR Pilot Project Update

Currently it looks like Clay Settling Areas (CSAs) take up 113,361 acres, which is an average of 30% of the land that has been mined for phosphate in the Polk, Hillsborough, Hardee and Manatee Bone Valley phosphate region, according to preliminary data the Florida Department of Environmental Protection is collecting to define how many clay settlings areas there are, how big are they and where are they.

Those acres represent 8.4% of the 1.4 million acres of mined and unmined land in Bone Valley, Phil Coram, Chief, Bureau of Mine Reclamation, Florida Department of Environmental Protection (DEP), said when he presented the preliminary figures as part of the “Is Clay Still A Problem” panel discussion at the 2005 Phosphate Conference held in Lakeland, Fl this fall.

Clay settling areas have limited load bearing capacity and usefulness. The clay is only 5% solids. It will harden and form a crust but beneath the surface the clay stays the consistency of pudding for years. The DEP would like to see that change, Coram said, adding that the DEP would like to see the size of clay settling areas decrease and see the acreage put to productive use.

The Florida Institute of Phosphate Research (FIPR) is funding a project to develop a new technique to make this happen.

Phase one pilot testing of the project that is using polymers and fibrous materials such as recycled newspaper to thicken clays and hasten dewatering has been completed. Technical results look promising but the process is still under evaluation. FIPR is anticipating a proposal for next phase of work to get more data, which is critical to be able to evaluate the technical and economic feasibility of the process.

This research is being funded with a special appropriation Florida’s legislature made in 2003 to FIPR to test the possibility of using a process that the Institute developed and patented in 1993 to speed up the time it takes clay to thicken. The process is known as the FIPR-DIPR, an acronym for Dewatering Instantaneously with Pulp Recycle.

FIPR-DIPR worked in a pilot plant but the process was never adopted by the phosphate industry. It was deemed too expensive at the time. While logistics and economics are still the mitigating factors for new technologies, the public and corporate costs attached to phosphatic clay today have renewed the interest in the FIPR-DIPR as a way to thicken the clay.

Dr. Hassan El Shall, Associate professor of Materials Science and Engineering and Associate Director of Research for the Engineering Research Center at the University of Florida, who developed the FIPR-DIPR, is conducting the new research.

February 2006