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Byproducts of Phosphate

One of Mosaic's gypsum stacks in Mulberry, FL. The stacks are the radioactive byproduct of phosphate processing. Mosaic takes what is considered to be a "strategic mineral", processes it, sending it to China and other places and leaves behind the toxic mess in Florida.

In Florida, the phosphate rock is sent to processing plants in which it undergoes "wet process" to convert it into phosphoric acid. In the process, sulfuric acid is added to the phosphate to create phosphoric acid — which is easily absorbed by plants. Phosphogypsum (or “gypsum”), a radioactive material, is a byproduct of this process. Because it cannot be disposed of in the usual way, gypsum is stored in huge piles, called gyp stacks that cover 600 acres and rise to 200 feet. In the flat topography of Florida, they look like small mountains.

At present, there are 20 gyp stacks in Florida and more are being built. Accidents and spills have caused several cases of contamination in Florida, including a natural disaster in 1995 when a 150-foot deep sinkhole opened under an 80-million ton gyp stack, sucking toxic waste into the aquifer that supplies drinking water to millions of residents of the Tampa Bay area.

Another byproduct of phosphate strip-mining is waste clay. The clay is filtered from the slurry mixture during processing. This waste clay contains toxic levels of uranium and radium and cannot be put back into the environment. Instead, the clay is stored in huge settling ponds on the mine site. About 40 percent of a mine site will be clay settling areas. These settling ponds have a negative impact on the surrounding ecosystem, intercepting the rain that otherwise would soak into the soil. As a result, the natural process to replenish both groundwater and the surface water flows to nearby waterbodies are impeded. Occasionally, one of these settling ponds fails, dumping toxic clay into the river and smothering plant life and aquatic populations

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