1. Radiation
Phosphate Mining

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. 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. 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. 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. Phosphate Mining
How is phosphate mined
today?

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. 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

11. 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

16. Phosphate Mining
Are clay ponds radioactive?

17. 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

18. Phosphate Mining
How was Phosphate
Deposited in Florida?

19. 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

22. Phosphate Mining
Where is phosphate located
in Florida?

23. 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

24. 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…