Image: J. Henry Fair
Phosphorus mining has a beneficial side and a disturbing side. It gives us ammonium phosphate, a key ingredient in the fertilizer used to grow abundant food. It also produces massive amounts of waste, depicted here.
The phosphorus comes from calcium phosphate rock that is strip-mined across several U.S. states and pulverized. Producers add sulfuric acid to form phosphoric acid, which is later converted to ammonium phosphate. Every ton of phosphoric acid generated creates five tons of a soil-like by-product, phosphogypsum. The white or gray substance emits radon gas and is therefore used in only a few applications, such as peanut farming. Most of the phosphogypsum is bulldozed for permanent storage into giant stacks that can reach 200 feet high and cover 400 acres or more. A gypstack contains one billion to three billion gallons of wastewater that gradually diffuses out, creating small lakes that shimmer blue or green as light bounces off bottom sediment. The water’s pH is between 1 and 2, corrosively acidic. The photograph shows the corner of one such stack in Florida and the lake beside it.
This article was originally published with the title Phosphorus Lake.
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10 Comments
Add CommentWhat is the scale of the photograph?
Reply | Report Abuse | Link to thisThis byproduct gypsum is a low quality material that might be used in road building after some neutralization.But even this use is prevented by concern that the gypsum contains about 100 times more radium than local soils.
Reply | Report Abuse | Link to thisBut francolite, the abundant Florida phosphate mineral that yields the gypsum on reaction with sulfuric acid,contains the same concentration of radium as the gypsum.In addition, francolite contains the uranium that is the source of the radium, elevated concentrations of cadmium,arsenic and other heavy metals, 4% fluorine and 16% of the water pollutant, phosphorus.Yet francolite seems to carry no use restrictions. The presence of 5% of francolite in sands on several Florida public beaches raises no concerns from environmentalists.
A reevaluation of the radium hazard in byproduct gypsum might allow utilization of the unsightly gypsum stacks.
I did not know any of that, is there a link you could share?
Reply | Report Abuse | Link to thisYes, but what is on beaches is mostly material which has been out of ground (by erosion presumably) for a good long time. What is IN the ground is obviously harmless since it stays buried unless maybe some radon seeps into your basement, but what has been liberated by mining and chemical processing is now MOBILIZED into the environment. The result is a big toxic mess because of course all the Cadmium etc you mention is also mobilized (and I will warrant that there is a pretty nasty amount of it in the water seeping out).
Reply | Report Abuse | Link to thisThis is just a general problem with mining. When you crush up and process millions of tons of rock and minerals you will invariably end up with bad stuff.
The only real answer is to stop mining masses of material out of the Earth like this, it is simply unhealthy and no amount of changing regulations or whatever is going to substantially change that.
OK, so you want to stop mining phosphate in FL, potash in Canada, copper & other metals in the west; how do you expect to produce enough food on the ag land left after we build all the housing for our growing population?
Reply | Report Abuse | Link to thisA better answer would be to utilize the problem byproducts by mitigating their hazards and to accept reasonable trade-offs for being able to use the necessary resources. We can't continue to increase our population and standard of living on this planet without having some effect; we do have the technology to avoid many of the serious problems resulting from past abuses.
There is a massive phosphate shortage world-wide, to the point where phosphorus is being reclaimed from sewage and agricultural run-off. Without the Florida phosphate a good segment of the world's population would perish from malnutrition. Now that is in the open, what is your solution, Mr. Green?
Reply | Report Abuse | Link to thisWhoa! The article names not radium or uranium: it names radon gas. Might author Fischetti sort out the confusion?
Reply | Report Abuse | Link to thisRadon gas is a decay product of uranium. Certain places in the country have greater concentrations naturally occurring; such as New England.
Reply | Report Abuse | Link to thisIt's a pity the author didn't elaborate on the famous commercial byproduct of phosphate mining: fluoridation chemicals. In order to prevent (by regulation) fluorine from escaping into the atmosphere during the cooking process, wet scrubbers trap the slurry. Thanks to a loophole in FDA oversight, and a longstanding propaganda campaign promoting the virtues of ingesting fluoride for dental health, the industry avoids the cost of treating the hazardous material. As fluoridefreefairbanks.org makes clear, the practice cannot bear the scrutiny of peer-reviewed science. Research shows that fluoride exposure is connected to brittle bones, kidney disease and IQ loss, among other maladies. Vast areas of Florida has been sacrificed to phosphate mining. Disposing of the mining waste through public water systems extends the toxic footprint from sea to shining sea. There are few examples of corporate welfare that so blindly ignore the effects of a toxic material.
Reply | Report Abuse | Link to thisIn Spain, the phosphoric acid production began in 1968 in an industrial complex located at the estuary formed by the union of the Tinto and Odiel river mouths (Huelva, SW Spain). The phosphogypsum has been stockpiled over an area of 1200 ha containing about 120 million tonnes, less than 1 km away from the city centre.
Reply | Report Abuse | Link to thisThe study about this problema propose a solution to minimize the volum waste.
Our article proposed a solution to this problem, it is to minimize the volume waste and it can use the phosphogypsum to capture CO2.
The reaction is very simple and easy to do in the same place where are the stacks this residue.
The adiction of caustic soda produces sodium sulfate and Portlandite, this portlandite is used to capture CO2 producing calcite. The main impurities (metals such as Cr, As, U, Ni, V, Se, Cd, Pb, Zn and Th) contained in the phosphogypsum are transferred to
the portlandite and, subsequently, to the final calcite after bubbling CO2, with transfer factors close to 100%.
The article was published in "Journal of Hazardous Materials", his title is "Procedure to use phosphogypsum industrial waste for mineral CO2 sequestration".
We hope someone is interested in what is proposed in the article to put research to pilot plant level to be a future solution to phosphogypsum.