Phosphogypsum is used in agriculture for soil amendment or as fertilizer, as well as in the brick and cement industry, and in road construction.
Is phosphogypsum toxic?
Phosphogypsum (calcium sulfate) is a toxic byproduct of phosphoric acid created during the production of fertilizers. Not only is it deadly on its own, but phosphogypsum’s high nitrogen content leads to dangerous red algae blooms which threaten seagrass beds and imbalance Florida’s aquatic habitats.
How do you neutralize phosphogypsum?
The phosphogypsum admixtures are also eliminated by using a combined method when phospho- gypsum is washed with a smaller amount of water, and the rest of the acid admixtures are neutralized by adding the following additives: Ca(OH)2, CaCO3, K2CO3, KOH, Portland cement, NH4OH, etc.
How is phosphogypsum treated?
The byproduct phosphogypsum can be purified by treating with 3–4% aqueous citric acid solution and subsequent washing with water. 2. The impurities of phosphates and fluorides are removed as water-soluble phosphoric acid, sodium citrate, hydrofluoric acid, hydrofluorosilicate, hydrofluoroaluminate and ferrate.
What is phosphogypsum waste?
Phosphogypsum, a waste product from manufacturing fertilizer, emits radon, a radioactive gas. It also contains the radioactive elements uranium, thorium and radium.
Where are gypsum stacks in the US?
Florida
In the United States A phosphogypsum stack or “gyp stack”, located near Fort Meade, Florida. These contain the waste byproducts of the phosphate fertilizer industry.
How does phosphogypsum become radioactive?
Phosphogypsum is radioactive due to the presence of naturally occurring uranium and thorium, and their daughter isotopes radium, radon, polonium, etc. Marine-deposited phosphate typically has a higher level of radioactivity than igneous phosphate deposits, because uranium is present in seawater.
What states have phosphogypsum stacks?
Phosphogypsum stacks are located in four counties in Florida including Polk, Hillsborough, Manatee, and Hamilton counties, according to the Florida Department of Environmental Protection.
How much radium is in phosphogypsum?
Radium concentrations at phosphogypsum stacks range from 0.4 – 1.3 Bq/g (11 – 35 pCi/g). Stacks are constructed with little or no soil preparation.
Why is phosphate mining bad?
Synthetic phosphate fertilizer poses a serious threat to our environment. Phosphate rock mining, along with the inorganic fertilizers and animal feed supplements and pesticides for which phosphate is mined, pollute our air, contaminate our water and destroy invaluable wildlife habitat.
What is phosphorus 32 used for?
A radioactive form of the element phosphorus. It is used in the laboratory to label DNA and proteins. It has also been used to treat a blood disorder called polycythemia vera and certain types of leukemia, but it is not commonly used anymore.
What is the half life of phosphogypsum?
1,600-year
Phosphogypsum is the radioactive waste from processing phosphate ore into phosphoric acid, which is predominantly used in fertilizer. Radium-226, found in phosphogypsum, has a 1,600-year radioactive decay half-life.
