Phosphate rock is the only economical source of phosphorus for production of phosphate fertilizers and phosphate chemicals. Most of the world phosphate rock reserves are widely distributed marine phosphorite deposits.
Phosphate ores were first mined in relatively small amounts in the mid-1840s in England, France and Spain and in the 1860s in Norway and Germany. Between 1863 and 1895, phosphate rock was shipped from deposits in Ontario and Quebec to England for processing.
Mining of phosphate in the United States began in 1867 in South Carolina where the ore was first discovered in 1837. Utilization of the vast phosphate rock deposits of Florida found in the 1880s started in 1889. In the Rocky Mountain States, mining of phosphate began in 1906 in Idaho, in Wyoming and Utah in 1907 and in Montana in 1921. The North Carolina deposits were the latest to be exploited and mining started there in the mid-1960s.
Ore in Algeria and Tunisia was discovered in 1873 and mining initiated in 1889. Production
from the large Moroccan deposits, first identified in 1914, began in 1921. The guano phosphate deposits in the Pacific Islands were found in the 1890s and mining commenced in 1900 on Ocean Island, in 1906 on Nauru Island and in 1908 on Makatea Island.
The extensive deposits of igneous apatite of the Kola Peninsula in the Former Soviet Union (FSU) were recognized in about 1930. Many other deposits were found in the period 1960 to 1980 in Mexico; Brazil, Peru and Colombia in South America; Israel, Turkey, Jordan, Iraq and Saudi Arabia in the Near East; Angola, South Africa and Western Sahara in Africa; India and Australia. A large number of these recent finds are now in commercial production.
Currently the leading countries in the mining of phosphate rock are the U.S.A., FSU, Morocco and Algeria, People’s Republic of China, Tunisia, Jordan, Republic of South Africa, Brazil, Togo, Israel, Nauru, Senegal and Syria. Morocco has the greatest reserves, followed by South Africa, U.S.A. and the FSU. China’s reserves are believed to be much more extensive than reported and may rank as high as fourth in the world.
Phosphate rock reserves in the U.S. occur mainly in Florida; North Carolina; the Western states of Idaho, Utah, Wyoming and Montana; and Tennessee. Although the greatest reserves exist in the Western states, Florida leads in mining of phosphate ore. Factors such as the generally high grade of ore, vastness of the resource, ease of recovery and closeness to both requisite sulfur used in processing the phosphate rock and ocean shipping have all contributed to the economic success of the Florida phosphate operations.
Phosphate in the naturally occurring phosphorite ores exists in several variations of the very stable apatite compound. In the manufacture of the common phosphate fertilizers, the strong bonding in the apatites is broken by chemical or thermal processes to render the phosphate more soluble. Treatment with sulfuric acid to produce phosphoric acid is the most widely used method of accomplishing this breakdown.
The first phosphoric acid plant was built in Germany in about 1870. In the U.S., phosphoric acid was first manufactured in 1890.
Animal and human bones were not always effective in improving or sustaining crop yields and the superphosphate industry came into being as a result of attempts to increase the effectiveness of bones and also to find a more plentiful and secure source of phosphate. The brisk demand for bones in England in the early 1800s lead to the importation of bones from the Continent starting in 1815 and reaching a high of 30,000 tons annually. Justus von Liebig criticized the English for collecting bones from old battlefields and burial sites such as the catacombs of Sicily.
As early as 2,000 years ago, Chinese farmers applied calcined or lime-treated bones to their fields. Several individuals, including von Liebig, in Europe during the early 1800s to 1842 acidulated bones, usually with sulfuric acid, to improve the solubility of phosphorus.
In 1842, Lawes of Rothamsted fame was granted a patent for the production of superphosphate and he began manufacturing and selling this fertilizer the same year. His patent was amended in 1848 restricting the sulfuric acid treatment to only apatite and phosphorite.
By 1853, there were 14 superphosphate manufacturing plants in England. Superphosphate production was adopted in the late 1840s and the 1850s by the United States and a number of other countries using bones as the primary source of phosphate. U.S. superphosphate
manufacturing began in South Carolina in 1849 and a thriving industry involving up to 16 companies subsequently evolved with an output of about 140,000 short tons by the mid-1880s.
For more than 100 years superphosphate was the world’s leading phosphate fertilizer. It predominated in the U.S. from 1870 to 1964 and peaked in 1952. Triple or concentrated superphosphate replaced it as the principal phosphate source for a short interval between 1964 and 1967. In 1994, consumption of ordinary or normal superphosphate was a mere 10,500 tons.
Triple (concentrated) superphosphate was initially produced in Germany in 1872. Its manufacture in the U.S. started on a limited scale in 1890 with sustained production not commencing until 1907. This higher analysis phosphate source assumed greater importance after World War II up to about 1970 when its popularity began to decline. By 1994, it represented only approximately 4.8 percent of the 4.5 million tons of plant nutrient phosphorus used in this country.
Ammonium phosphates, which are now the dominant phosphate sources worldwide, were first produced commercially in the U.S. in 1916. The very popular and dependable TVA process for granular diammonium phosphate (DAP) was introduced in 1961 and by 1967 it became the principal phosphate fertilizer in the U.S. Nineteen plants utilizing this technology with a combined capacity of 2 to 3 million tons of product annually were installed in 1962. Two years later there were 31 such plants.
By 1974, DAP became the most widely used phosphate fertilizer worldwide. Mono- and diammonium phosphate accounted for about 60 percent of global fertilizer phosphate production in 1981. Di- and monoammonium phosphates supplied 38.8 and 14.3 percent, respectively of U.S. phosphate usage in 1994.
Efficient Fertilizer Use — A Historical Perspective: by Dr. James Beaton