The production of mineral fertilizers is highly dependent today on just three materials, ammonia, phosphoric acid and mined potash. In turn ammonia production is highly dependent on the supply of natural gas, and phosphate fertilizers on the supply of by-product (non-discretionary) and mined sulphur.  

NITROGEN

The Nitrogen Fertilizer Industry

Up to the 1960s, the development of the nitrogen industry took place in the developed countries of West Europe, North America and Japan. However, In the 1970's and early 1980's, the construction of new plants shifted to the gas-rich countries of the Caribbean and Middle East and also to some large consuming countries such as China, India, Indonesia and Pakistan. At the same time, many plant closures occurred in West Europe and Japan. West Europe's share fell from 20% in 1980/81 to 11% in 1997/98. In 1980/81 the developing countries accounted for 31% of nitrogen fertilizer production. By 1997/98 their share had increased to 55%.

In 1980/81 the developing countries accounted for 31% of nitrogen fertilizer production. Today their share had increased to more than 55%. Over a third of the world's production is in just two countries, China and India, but ammonia is produced in about 80 countries and urea in about 60.

Ammonia

Anhydrous ammonia is produced in about 80 countries. Approximately 85% is used for nitrogen fertilizer production, including about 6% that is directly applied to the fields.

In 1974 the developing countries accounted for 27% of ammonia capacity. Today their share is 52%.

Some 88% of world ammonia production is processed or used in the countries where it is produced. The remaining 12% of world ammonia production enters international trade directly for all end-users.

World ammonia capacity grew from 119 Mt in 1980 to a peak of 141 Mt product in 1989. Virtually all the growth in capacity occurred in the FSU and Asia. Between 1989 and 1995 capacity remained relatively flat, with increases in Asia being offset by closures in Europe and the FSU.  Today ammonia and urea capacities are increasing most rapidly in the Middle East region.

Since 1973 the share of urea in the total world nitrogen fertilizer market has increased from 20% to 50%. Urea is by far the dominant nitrogen fertilizer used in developing countries and is continuously increasing its share in these markets. As with ammonia, most of the increase in capacities is in the Middle East region.

PHOSPHATE

Phosphate Rock

The main producers of phosphate rock and phosphate fertilizers are the USA, the former USSR, China, Africa (the Maghreb countries, Egypt, Senegal, Togo and South Africa), and the Middle East. Several of these countries are developing countries and the phosphate industry makes an important contribution to their economies. More than 75% of the world's commercially exploited phosphate rock is surface mined. The mining techniques take many forms, from manual methods to the employment of highly mechanized technologies, with the remainder recovered by underground mining.

Overall, mineral fertilizers account for approximately 80% of phosphate use, with the balance divided between detergents (12%), animal feeds (5%) and specialty applications (3%), e.g. food grade, metal treatment etc.

The production of phosphate rock peaked in 1988 at a level of 166 million tonnes product, falling to 125 million tonnes today. Production in the FSU has fallen from 39 million tonnes in 1988 to 11 million tonnes. Over 30 countries are currently producing phosphate rock for use in domestic markets and/or international trade. However, the worlds top 12 producing countries account for nearly 95% of the worlds total phosphate production. The main producers are the USA, China and Morocco.

Phosphate Rock Quality

The nutrient content in currently mined rocks can range from over 40% to below 5% P₂0₅. The mined rock is further processed to remove the bulk of the contained impurities and thus upgrade the rock. The beneficiation process usually allows a concentration of around 1.5 times but higher ratios are needed with some rocks. After beneficiation, phosphate rock (concentrate) generally ranges from 26% to about 34% P205 and up to as much as 42% P₂0₅. Higher phosphate contents equate to lower impurity contents, higher yields per tonne of material shipped, handled and processes, increased reaction efficiencies, fewer processing problems and less waste.

Phosphoric acid

Over the past two decades there has been a distinct trend towards the processing of phosphate rock in countries with substantial natural resources of this material, especially in North Africa and the U.S.A., but also in the Middle East and South and West Africa and China. Most plants in West Europe have been closed for economic and environmental reasons.

Some 85% of world phosphate fertilizers are manufactured by reacting phosphate rock either directly with sulphuric acid or indirectly with phosphoric acid produced using sulphuric acid. The purpose is to increase the nutrient concentration in the final product and improve the availability of the phosphate to the plants.

The main environmental problem associated with phosphoric acid production is the disposal of phosphogypsum; some 4 to 5 tonnes of which are produced per tonne of phosphoric acid (expressed as 100% P205) manufactured.

The concentration of phosphoric acid production in just a few countries is likely to continue. Integrated phosphate mining and processing offer significant technical and economic advantages.

POTASH

The world potash industry consists of over 55 mines and refineries, with a current total capacity of 36.3 Mt K₂0 annually.

Potash is produced in the few countries where the economic ore reserves are located. A large proportion of mined potash enters international trade. Twelve countries, plus two of the republics of the FSU, account for all of the world mined production. Canada and the FSU alone account for 55-60%. About 70% of world deliveries are exported as such, and a further 10-12% is exported in multi-nutrient fertilizers. Canada and the FSU account for two thirds of world exports.

In Europe a large reduction in German capacity took place following reunification, from 6.2 to 3.7 Mt K20 per year. Potash mines in France will be closed by the year 2004, when the deposits will be exhausted.

SULPHUR

World sulphur production currently amounts to about 60 million tonnes S. The quantity currently used in the production of phosphoric acid is estimated at 27 million tonnes of S.  The remainder is used in other industrial processes.

Elemental sulphur (brimstone) accounts for over two thirds of the total.  Some 8% of total sulphur production is obtained from pyrites and the remainder from sulphur in other forms, principally smelter sulphuric acid.  China accounts for three quarters of the world production of pyrites, mostly for the production of single superphosphate.  China’s production of pyrites is tending to fall.

Almost all the elemental sulphur today is sulphur recovered from the desulphurization of oil products and natural gas.  Some 5% is mined, mostly in Poland and Mexico.