Phosphates. Ask ten people on the streets of any major American city what phosphates are used in and nine of those people won’t be able to name one product. Ask them where phosphates come from and most would only be able to answer “the ground” if anything at all. So what, exactly, are phosphates, why are they important, and how are they produced?
Phosphates appear in a broad range of products and are present in trace amounts almost everywhere in the world. The chemical formula for phosphate is P2O5.1 Some common uses for phosphates are for fertilizers, especially in acidic soil, cosmetics, explosives, and other such products. Without phosphates, many of the marginal agricultural lands of the earth could not be farmed. Also, industrial agriculture would not be possible as phosphate is used to recharge the soil faster and without the need to change crops or leave fields fallow.
To get phosphate, one must extract it from rock. Approximately 90% of the world’s reserves of phosphates are contained in sedimentary rock. The other 10% is found in igneous rock.2 Tunisia’s deposits are exclusively sedimentary. Also, Tunisia’s deposits are very rich in the carbonate-fluorapatite form of phosphate, otherwise known as francolite. Francolites with high carbonate for phosphate substitution are the most highly reactive and are the most suitable for direct application as fertilizers. This means that Tunisia’s phosphate reserves are very profitable. In fact, they are some of the best in the world, being in the top 8% of profitable reserves. 3 The extraction process for francolite rich sedimentary rock such as in Tunisia compared to igneous rock found in places such as Canada or South Africa is much easier, less expensive, and cheaper. To turn igneous rock into fertilizer takes much more energy and many more chemicals.4 Tunisia’s rock, after some refining, can be applied directly to the fields of the world.
The extraction process for the phosphate deposits in Tunisia works something like this: Large swaths of overburden, or the top layer of soil, are cleared in strip mine operations to reveal the thick beds of phosphate rich rock beneath. This rock is separated from the earth by various means, most of which involve explosives or large machines that make loud noises, it is then loaded into railway cars and hauled to the refining plants. Tunisia’s primary phosphate reserves are in the Gafsa region in the central Tell. Refining centers are located on the central coast clustered between Gabes and Sfax. Railway cars full of ore roll toward the coast day and night to supply the refining operations around the Gulf of Gabes.5
At the refineries, the rock is washed, dried, tumbled, crushed, run through reactors, and in general poked and prodded, until the phosphates separate out from the other constituents of the ore. Sulfur is extensively used in the processing which leads to very smelly refineries and the need to import large quantities of sulfur into Tunisia. Tunisia has no significant deposits of sulfur. The waste is mainly comprised of phosphogypsum which can either take the form of a solid pile, a liquid solution involving either fresh or salt water, or as dust blown by the wind.6
Tunisia mainly exports raw phosphate to countries such as France, Russia, and Italy. Domestically, phosphates are refined into explosives for the mining industry, some cosmetics, and fertilizer. Homegrown infrastructure to produce cosmetics or fertilizer on an exportable scale hasn’t materialized as of yet. Maybe in another few years, Tunisia will be exporting finished goods produced with its own locally mined phosphates.
Current Issues
By far, the biggest issue facing Tunisia’s phosphate industry today is pollution. The Gulf of Gabes between Sfax, Gabes, and the Kerkennah Islands is one of the most polluted places in all of the Mediterranean Sea. This is a result of several factors including not treating the liquid effluent streams of the refineries, and the massive accumulation of phosphogypsum piles which are unprotected from the elements.7
Recently, the European Union gave Tunisia a series of loans and grants to expedite the cleanup process of the Gulf of Gabes. These loans total more than 45 million Euros in aid to solve the phosphogypsum problem, treat the liquid effluent from the plants, and help clean up the Gulf.8 Were it not for the particular situation of the phosphate plants and the flow of the tides and currents, contamination from the phosphate industry would have spread far beyond the Gulf of Gabes and into the Mediterranean as a whole. Due to the tidal patterns of the Gulf, most of the pollution is kept very close to the shore between Sfax and Gabes. Even so, communities in Europe and other countries which have beach-front property are nervous about the possibility of more general contamination. Unlike in some places, such as America, the Europeans look a little wider when they search for pollution problems.
Phosphogypsum is a rather nasty substance. In the United States, phosphogypsum is specifically covered under the U.S. Environmental Protection Agency: 40 CFR Part 61 National Emission Standards for Hazardous Air Pollutants; National Emission Standard for Radon Emissions From Phosphogypsum Stacks.9 Aside from piling up in significant quantities wherever phosphate is processed, phosphogypsum also effuses radon gas which is radioactive. This means that phosphogypsum is inherently radioactive at some level. Exposure to high enough quantities, such as working for many years in a dust filled environment or through drinking water, could introduce enough radiation into the body to have the same effects as uranium refining tailings. In fact, many groups within America are calling for standards dealing with the treatment of phosphogypsum to be raised to the uranium tailing standards. Specifically,
“Firstly, the uranium tailings standards require a double composite liner with two geomembranes and an underlying layer of 3 feet of compacted soil with minimum hydraulic conductivity of 1×10-7 cm/sec. The gypsum standards require only one geomembrane and 2 feet of compacted gypsum with minimum hydraulic conductivity of 1×10-4 cm/sec (or an underlying 18-inch layer of compacted soil with maximum hydraulic conductivity of 1×10-7 cm/sec, which has not been used in any of the four cases analyzed in Section 4).
Second, the uranium tailings standards require a leachate collection system that is also used as detection system. If the measured volume of liquids recovered exceeds a pre-determined action leakage rate, a response action plan is set in motion to mitigate or stop any leaks. In the gypsum case, leakage through the liner is expected and it is actually calculated in the technical reports presented in the permitting process.”10
In Tunisia, phosphogypsum is currently contained by dumping it in large warehouses. When it rains or when the wind blows, phosphogypsum gets spread around the general vicinity of these warehouses. Long hot and dry summers in Tunisia mean that there are many phosphogypsum particulates floating around in the atmosphere.
Future Possibilities and Problems
To deal with the phosphogypsum, Tunisia has decided to burry it somewhere in the interior of the country where it will have minimal environmental impact. It will be moved by rail from the coast to big pits. A top layer of clay will be used to cap the phosphogypsum, effectively entombing it underground.11 However, the chances for radon leaching from the ground in areas where phosphogypsum has been buried will be quite high. Also, ground water intrusion into phosphogypsum dumps will slowly pollute the surrounding aquifers. This is, however, better than Spain’s approach. Up until the last ten years, all of the phosphogypsum from the plant in Huelva, Spain dumped directly into the salt marsh system. A dam was completed recently to allow for some settling of the phosphogypsum, but a large portion still flows freely into the salt marshes.12
Aside from the pollution problems afflicting Tunisia’s phosphate industry, Tunisia is also in danger of running out of phosphate rich rock. Some sources predict that in the nest 25 to 50 years, Tunisia will have depleted its commercially viable phosphate deposits. Tunisia is estimated to have between 100 000 000 and 600 000 000 tons of phosphate reserves. Tunisia produces 8 000 000 tons of phosphate rock per year. Conservative estimates give Tunisia twelve years before the reserves are exhausted. More liberal estimates, accounting for evolution in phosphate extraction technology, suggest that Tunisia has about 70 years before depletion.13 Of course, as the reserves decline, the easiest phosphate will be gone, leaving harder to mine reserves, which will result in a gradual slowing of production, much like the oil industry in Tunisia is currently experiencing as its primary oil fields are nearing depletion.
Despite all of the challenges and uncertainties facing the Tunisian phosphate industry, it is still a key part of the Tunisian economy, accounting for one third of all exports from the port of Sfax alone.14 Whole regions of the country such as Gafsa rely on the income that phosphate production provides. When the good times run out, Gafsa, Sfax, Gabes, and the railways will be faced with a severe overabundance of labor and deficit money. As Tunisia doesn’t have significant natural resource reserves beyond phosphate, Tunisia will be forced to become more dependant on renewable and sustainable methods for production of employment and revenue. Tunisia already employs tourism and agriculture in this respect but other areas will need to be found.
For the next 75 years, phosphates will continue to play a large roll in Tunisia, but one day, not too far in the future, phosphate production will no longer be a significant part of the Tunisian economy. Even after the mines have closed and the refineries shut, the environmental legacy of phosphate production will be felt for many years to come. Even transitory industries leave a permanent mark on the land.
Notes
1. ____________. World Phosphate Deposits. (11/26/2004)
2. ____________. World Phosphate Deposits. (11/26/2004) 3. Michalski1, Bernedette. THE MINERAL INDUSTRY OF TUNISIA. http://fluoridealert.org/articles/phosphate01/ (11/26/2004)
4. ____________. World Phosphate Deposits. (11/26/2004)
5. ____________. Economy. (11/26/2004)
6. ___________. Management of Phosphate Tailings. (11/26/2004)
7. EIB.Transboundary Cases of Industrial Pollution: European Involvement in Tunisian Phosphogypsum Cleanup. https://www.eib.org/en/press/news/index.htm?press=2830 (11/27/2004)
8. EIB.Transboundary Cases of Industrial Pollution: European Involvement in Tunisian Phosphogypsum Cleanup. https://www.eib.org/en/press/news/index.htm?press=2830 (11/27/2004)
9. ___________. Management of Phosphate Tailings. (11/26/2004)
10. ___________. Management of Phosphate Tailings. (11/26/2004)
11. EIB.Transboundary Cases of Industrial Pollution: European Involvement in Tunisian Phosphogypsum Cleanup. https://www.eib.org/en/press/news/index.htm?press=2830 (11/27/2004)
12. ___________. Management of Phosphate Tailings. (11/26/2004)
13. ____________. World Phosphate Deposits. (11/26/2004)
14. ____________. Tunisia. https://www.polpred.com/en/er/tunisia.htm (11/26/2004)
Bibliography
EIB.Transboundary Cases of Industrial Pollution: European Involvement in Tunisian Phosphogypsum Cleanup. https://www.eib.org/en/press/news/index.htm?press=2830 (11/27/2004)
Michalski1, Bernedette. THE MINERAL INDUSTRY OF TUNISIA. http://fluoridealert.org/articles/phosphate01/ (11/26/2004)
Overview of the mineral industry including recent moves to privatize certain sectors.
____________. Economy. (11/26/2004)
An overview of the Tunisian economy from the German perspective. Sections pertain to the phosphate industry.
___________. Management of Phosphate Tailings. (11/26/2004)
A series of abstracts and excerpts of articles and papers on phosphate tailings. Many multiple authors contained within. If access to this journal was available, these sources would provide a real wealth of information.
____________. Tunisia. https://www.polpred.com/en/er/tunisia.htm (11/26/2004)
An overview of the Tunisian economy as presented from the Russian perspective. Contains sections specifically on the phosphate industry.
____________. World Phosphate Deposits. (11/26/2004)
Gives data on tonnage of phosphate production, phosphate reserves, types of phosphate reserves, methods for extraction, etc.
Additional Resources
CITET. Air Quality. (7/1/2004)
Lists legislation and regulations for air quality in Tunisia. Includes the decree setting up the ACTV (Vehicle Technical Monitoring Unit) which CITET runs to monitor industries in Tunisia.
CITET. Cleaner Industry. (7/1/2004)
Lists legislation in Tunisia covering industrial pollution in Tunisia. Includes legislation on sewage and waste water treatment, legislation on solid waste, and general legislation including a law which regulates environmental impact studies.
CITET. Marine Environment. (7/1/2004)
List of legislation regarding the marine environment passed by Tunisia. Includes laws on fishing, public maritime domain, national land-use and town-planning codes, national emergency intervention plans to deal with marine pollution, monitoring, managing, and disposing of wastes in the sea, etc.
CITET. Water and Waste Water Management. (7/1/2004)
List of Tunisian legislation dealing with water and waste water management. Includes laws and decrees dealing specifically with regulations governing discharges into the environment, into the public sewage system, use of waste water for cropland irrigation, etc.
Hamdy, Karim. Islamic Perspectives on Natural Resources Management and Sustainability. Corvallis: Oregon State University, 2000.
Outlines the Islamic perspective on resource management and sustainability as outlined in religious writings such as the Koran.
Harris, Frances. Global Environmental Issues. Chippenham: Antony Rowe, 2004.
Course textbook covering global environmental issues. Includes case studies of specific environmental challenges.
Plan Bleu. Issues and Concerns: Costal Regions in the Mediterranean. (7/1/2004)
Discusses the costal regions of the countries surrounding the Mediterranean. Highlights dangers of increased population in costal areas to the sea, biodiversity, and historical sites.
Plan Bleu. Issues and Concerns: Free trade and the environment in Euro-Mediterranean context. (7/1/2004)
Reviews issues involved with international free trade and the environment. Lists additional resources and documents on the topic of free trade and the environment.
Plan Bleu. Issues and Concerns: Water in the Mediterranean Region. (7/1/2004)
Outlines water resource issues focusing on the use and overuse of aquifers in the Mediterranean basin including countries such as Libya and Palestine where more than 100% of the renewable water resources are being used.
Tunisia Online. Environment. (7/1/2004)
Gives general background information on Tunisia’s environmental policy. Includes list of agencies, offices, and ministries which are governmental stakeholders in the environmental debate in Tunisia.