Phosphoric Acid, Phosphates & Fertilizers Experts


Sodium Nitrate

The world’s first commercial nitrogen fertilizer was sodium nitrate mined from natural deposits in Chile. It was imported into Europe and North America from about 1830 onwards. During the 1920s sodium nitrate imports from Chile were still a very important source of nitrogen in the United States with consumption amounting to about 600,000 tons annually.
Synthetic production of this material in the US began in 1928 and by 1935 it reached 500,000 tons annually. Consumption of the domestic, synthetic and natural Chileanproduct totaled 730,000 tons in 1950 and has since declined steadily to just 84,000 tons in 1980 and 34,700 tons in 1994.

Ammonium Sulfate

Ammonium sulfate was the next commercial source of fertilizer nitrogen. It was originally a by-product of the manufacture of coal gas for use in illumination and later from the coke industry serving the steel industry in Europe and America in the late 1800s. The initial product in England in 1815 was of poor quality but by the 1830s substantial amounts were being used by farmers in that country.
Little of this fertilizer was used in the United States until the late 1800s. For example, total consumption from all sources was estimated to be only 500 tons in 1860 and 2,000 tons in 1870. By 1900, its use had increased modestly to 5,000 tons. It did, however, become a major nitrogen source following the establishment of numerous coke ovens associated mainly with the steel industry of this country.
By-product ammonium sulfate from coke oven gases became the most important nitrogen fertilizer from the 1920s until 1944 when it was overtaken by ammonium nitrate. After attaining a maximum of 981,000 tons in 1955, production from this steel industry related source declined thereafter.
Synthetically manufactured ammonium sulfate began to appear in the 1920s and production rose from 89,000 tons in 1945 to over 1,000,000 tons in 1950. It gained even greater prominence in subsequent years and in 1980 production was 2.1 million tons compared to 398,000 tons of by-product ammonium sulfate. Total usage of ammonium sulfate in 1994 was 950,000 tons.

Calcium Cyanamide

Nitric acid and calcium nitrate were being manufactured in Norway by 1905. Shortly before this time, German chemists discovered how to synthesize calcium cyanamide and its agronomic value was confirmed around 1901.
The first commercial plant for its manufacture was built in Italy in 1905. By 1918, there were 35 plants operating globally in such countries as Germany, Dalmatia, France, Switzerland Norway, Japan and Canada.
It is noteworthy that calcium cyanamide was the first fixed nitrogen fertilizer to be produced on an ongoing basis in North America. Manufacturing of this material started in 1910 at Niagara Falls, Ontario and moderate consumption at levels of about 100,000 tons annually occurred in the 1920s and 1930s. Following maximum usage of 131,000 tons in 1946, it has virtually disappeared from the market place with only 71 tons consumed in 1980.

Anhydrous Ammonia

After Haber and Bosch’s 10 or more years of intensive research and development on the synthesis of ammonia from its elements, the first commercial plant for production of ammonia opened in Germany in 1911. Manufacturing of synthetic ammonia in the United States began in 1921 with water gas as the source of hydrogen. A second U.S. plant, utilizing by-product hydrogen from the electrolytic formation of chlorine came on stream in 1922. By 1932, nine companies were operating 11 ammonia plants in the U.S. with most of them having small capacities of 25 short tons or less per day. However, two of these plants had much larger capacities of 120 and 27 short tons/day and they represented 87 percent of the nation’s capacity.
With the onset of World War II, 10 new ammonia synthesis plants were constructed, the first of which commenced production in 1941. At the end of 1950, 19 plants with an annual capacity of 2.7 million tons of ammonia were operating and at this time 70 percent of the country’s domestic nitrogen consumption was from ammonia synthesis.
As a result of another round of expansions in ammonia capacity ending in 1960, the number of plants increased to 56 with an annual capacity of 5.2 million tons. Now synthetic ammonia represented 95 percent or more of the nitrogen in U.S. fertilizers.
Use of natural gas as an ammonia feedstock became dominant in the 1950s. Of the 53 ammonia plants operating in 1957, 72 percent were using natural gas.
In 1960, about one-half of the ammonia synthesis plants also produced nitrogen fertilizers, either at the plant site or nearby. Eighteen of the 56 plants operating at that time also produced solid ammonium nitrate and 700,000 tons of dry urea fertilizer were made at 13 of these plants. At five of the plants both ammonium nitrate and urea were manufactured. Various nitrogen solutions were also being made at some of the ammonia plants.
A major advance in the technology of ammonia production occurred in the early 1960s when the M.W. Kellogg Company introduced the jumbo-size, single train, centifugal compressor ammonia plants. Ammonia could be produced in these large efficient plants at one-half the cost of smaller plants equipped with the conventional reciprocal compressors. The number of new plants based on this advanced technology grew rapidly from one in 1963 to 10 in 1967, 28 in 1969, 38 in 1971, 39 in 1976, and 43 by 1980. Ammonia production capacity of the new plants in 1980 totaled 14.7 million tons/year or 71 percent of total U.S. ammonia capacity.
As more of the large 1,000 – and 1,500 ton/day plants came into operation, many of the older, smaller obsolete plants were shut down. Although the new plants were more reliable and economical, their operating rates could not be lowered to less than about 70 percent of capacity. Thus, it became much more difficult to maintain an economical supply-demand balance.
Accompanying the rapid acceptance of the new generation of ammonia plant, were major changes and modernization in storage and transportation of the enormous amounts of ammonia being produced. For example, there was a marked shift to refrigerated storage tanks capable of holding liquid ammonia at atmospheric pressure; jumbo rail tank cars of 70 to 80 ton capacities; fully dedicated, refrigerated barges with capacities of 2,000 to 3,000 tons; ocean-going vessels with refrigerated tanks or holds for transporting liquid ammonia, and long-distance pipelines.
The first use of anhydrous am onia on cropland took place in 1932 in California where it was applied in irrigation water. It was first directly injected into soil in 1942, also in California. By the mid-1940s, ammonia became available from large U.S. government plants in the Midwest which facilitated the spread of its use east of the Rocky Mountains.
Due to the adaptability of ammonia to a wide variety of conditions and its price competitiveness, growth in consumption in the U.S. has been rapid, from just a few thousand pounds in 1934, to over 1.1 million tons in 1964 and 5.5 million tons in 1994.
Anhydrous ammonia, excluding aqua ammonia, now accounts for 35.9 percent of the nitrogen applied to U.S. cropland.

Ammonium Nitrate

This nitrogen compound was first employed as a fertilizer in Europe following World War I when large stocks not utilized for explosives were released for agricultural use.
Because of explosions in Germany in 1920 and 1921, it was usually dry-mixed with limestone, gypsum, chalk or ammonium sulfate to avoid such danger and to also serve as conditioning agents.
The first use of ammonium nitrate in the United States occurred in 1926 with product imported from Germany. It was not until 1943 that significant amounts of this nitrogen source were available to American farmers when supplies exceeded the needs for munitions. Additional surplus quantities of this material were released for fertilizer use in 1944 and 1945.
In the 1970’s ammonium nitrate was produced at 29 locations separate from ammonia plant sites. Production of solid and solution ammonium nitrate fertilizer increased continuously from 383,000 tons in 1943 to 7.3 million tons in 1980. Manufacture of solid product was greater than the solution form until 1978, after which it accounted for less than half of the total produced.
Ammonium nitrate accounted for about one-third of all the nitrogen applied directly to U.S. cropland in 1955. By 1980, this use had declined to 10 percent. The tonnage of directly applied nitrogen as ammonium nitrate was exceeded by anhydrous ammonia in 1960, by nitrogen solutions in 1970 and by urea in 1978. Ammonium nitrate supplied 5.3 percent of the total 12.6 million tons of nitrogen consumed nationally in 1994.


The present commercial method of synthesizing urea through the reaction of ammonia and carbon dioxide was first introduced in Germany in 1920. In the U.S., commercial synthesis of urea was first achieved in 1932.
Use of urea, including calcium nitrate-urea as a fertilizer in this country, started in the early 1920s with imported material mainly from Germany. Production of urea in the U.S. for fertilizer purposes increased dramatically from 47,000 tons in 1948 to 549,000 tons in 1960. Expansion in urea capacity slowed between 1960 and 1975, eventually reaching 3 million tons at the end of this period. By 1980, production of fertilizer urea was 7.2 million tons, 60 percent of it in solid form. In 1960, 75 percent of the total primary urea solutions produced at anhydrous ammonia plants was utilized as fertilizer and by 1982 this usage had increased to 92 percent.
Urea consumption in 1994 accounted for 14.7 percent of the 12.6 million tons of nitrogen applied to U.S. croplands.

Natural Organics

Poudrette or human excrement, cottonseed meal, fish scrap and slaughterhouse wastes were major sources of fertilizer nitrogen in the United States from about 1850 to 1900.
In 1910, 90 percent of the fertilizer nitrogen consumed in the U.S. was in the form of natural organic materials including cottonseed meal, dried blood, fish scrap and animal tankage. The significance of these materials subsequently declined rapidly and by 1920 and 1950 they provided only 34 and 3.4 percent, respectively, of fertilizer nitrogen usage. Much of this decrease after 1920 was the result of increasing competition from synthetic nitrogen fertilizers derived from ammonia plus diversion of the higher quality organics to more profitable livestock feed supplements. Two new natural organics, activated sewage sludge and digested sewage sludge were introduced in the 1950s.

Efficient Fertilizer Use — A Historical Perspective: by Dr. James Beaton