Processing the Phosphate
Flying over a working Phosphate Strip Mine you see the result of the dragline mining machines. One judge said that strip mining results in the utter destruction of the environment.
In Florida, after the phosphate rock is extracted, the ore is dumped into a pit at the mine site, and high-pressure water guns turn it into slurry. The slurry is pumped to a beneficiation plant.
At the processing plant, the slurry mixture goes through a two-step process to separate the phosphate rock from sand and clay particles. The first stage is a concentrating process that separates the phosphate pebbles from everything else. The average operation can wash and size a maximum of 375 tons of pebbles in an hour.
However, phosphate and sand particles have similar weights, making separation more difficult.
In the second stage of processing the phosphate mixture, the slurry is sent to a flotation plant, where an agent is added to the mix which coats the phosphate particles. Air bubbles are introduced, and the chemically coated phosphate adheres to the bubbles, floating on the surface of the water, while the sand drifts to the bottom of the tanks.
The phosphate particles are then cleaned and washed in a dilute sulfuric bath, followed by a fresh-water rinse. Most of the phosphate processed in Florida is sold for use in the agriculture industry as fertilizer