Phosphate mining


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Phosphate mining

  1. 1. Radiation Phosphate Mining
  2. 2. Phosphate Mining Phosphate is essential to every cell in humans, plants, animals – every living thing It is necessary for many of the biochemical molecules and processes that define life itself Phosphate is a charged group of atoms, or ions It is made up of a phosphorus atom and four oxygen atoms (PO4) and carries three negative charges
  3. 3. Phosphate Mining Phosphate is a natural, non-renewable resource that is not normally artificially produced We get it from the phosphate-containing minerals we mine Examples of phosphate’s role in living matter… • Giving shape to DNA • adenosine triphosphate (ATP) • Found in the lipid bilayer of cell membranes
  4. 4. Phosphate Mining Humans get phosphate from the foods they eat  Milk 93 mg/100 grams  Lean Beef 204  Potatoes 56  Broccoli 72  Wheat Flour 101  Cheddar Cheese 524 Plants get phosphate from the soil along with nitrogen, potassium and a number of other nutrients they need to thrive
  5. 5. Phosphate Mining Fertilizer is added to nutrient-deficient soil to replenish these vital chemicals. Animals get their phosphate from their food About 90% of the phosphate that is mined is used to produce phosphate fertilizers Another 5% is used to make animal feed supplements The remaining 5% goes into making a variety of products from soft drinks to toothpaste to metal coatings
  6. 6. Phosphate Mining How is phosphate mined today?
  7. 7. Phosphate Mining After a mine site is permitted and reclamation plans are in place, the land is prepared for mining  endangered species are relocated  measures are taken to offset any impact to water levels and flow in the surrounding areas  After these measures are taken the land is cleared
  8. 8. Phosphate Mining The dragline bucket holds from 45 to 65 cubic yards of material and is large enough to hold a truck or van It scoops up the top 15 to 30 feet of earth known as overburden and dumps it in spoil piles to the side of the mine pit The dragline then digs out what is known as the matrix The matrix consists of equal parts phosphate rock, clay and sand
  9. 9. Phosphate Mining The matrix is then dumped in a pit where high-pressure water guns create a slurry that can then be pumped to the beneficiation plant At the beneficiation plant the phosphate is separated from the sand and clay After going through beneficiation, the clay is pumped to a settling pond The sand is sent back to the mine site to be used in reclamation and the phosphate is sent to the chemical processing plant
  10. 10. Phosphate Mining Are clay ponds radioactive?
  11. 11. Phosphate Mining Phosphatic clay sediment in the ponds have a higher level of radioactivity than sediment in natural lakes The average Florida soil has about 2 pCi/g of radioactivity from both uranium and radium A clay settling area has up to 40 pCi/g of radioactivity At 40 pCi/g the clay is 20 times higher than average Florida soil Living and eating food grown around these ponds can increase background doses
  12. 12. Phosphate Mining How was Phosphate Deposited in Florida?
  13. 13. Phosphate Mining Florida’s rich phosphate deposits are marine deposits that began to form millions of years ago when the sea covered the state approximately 5-10 million years ago, biological and chemical changes transformed phosphate that existed in the seas into the phosphate sediment that we mine today As time passed, sea levels dropped and the phosphate and limestone layers were exposed as land
  14. 14. Phosphate Mining Where is phosphate located in Florida?
  15. 15. Phosphate Mining A blanket of phosphate deposits covers much of peninsular Florida matrix layer, which consists of approximately equal parts phosphate rock, clay, and sand, averages 12 to 15 feet in thickness The matrix is buried beneath a soil “overburden” that is typically 15-30 feet deep By the end of 1999, approximately 300,000 acres of land, or more than 460 square miles, had been mined in Florida
  16. 16. Phosphate Mining Polk County is the heart of the Bone Valley mining region, but the mineable deposit in this area stretches to Hillsborough, Hardee, Manatee, and DeSoto counties Mining in central Florida has been moving south since the Florida phosphate mining began Phosphate companies are currently seeking permits to open new mine sites in Manatee, DeSoto and Hardee counties However, Sarasota county is the last county with mineable phosphate left in the state of Florida that has not been mined…