RadiationPhosphate Mining

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

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

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

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

Phosphate MiningHow is phosphate mined today?

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

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

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

Phosphate MiningAre clay ponds radioactive?

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

Phosphate MiningHow was Phosphate Deposited in Florida?

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

Phosphate MiningWhere is phosphate located in Florida?

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

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…