Ammonium Nitrate-urea Solution

Synonym Ammonia Water Amfbnioformaldehyde Ammonium Acetate Ammonium Acid Fluoride Ammonium Amidosulfonate Ammonium Amidosulphate Ammonium Benzoate Ammonium Bicarbonate Ammonium Bichromate Ammonium Bifluoride Ammonium Carbonate Ammonium Chloride Ammonium Citrate Ammonium Citrate, Dibasic Ammonium Decaborate Octahydrate Ammonium Dichromate Ammonium Disulfate-Nickelate (II) Ammonium Ferric Citrate Ammonium Ferric Oxalate Trihydrate Ammonium Ferrous Sulfate Ammonium Fluoride Ammonium Fluosilicate Ammonium Formate Ammonium Gluconate Ammonium Hydrogen Carbonate Ammonium Hydrogen Fluoride Ammonium Hydrogen Sulfide Solution Ammonium Hydroxide Ammonium Hypo Ammonium Hyposulfite Ammonium Iodide Ammonium Iron Sulfate Ammonium Lactate Ammonium Lactate Syrup Ammonium Lauryl Sulfate Ammonium Molybdate Ammonium Muriate Ammonium Nickel Sulfate Ammonium Nitrate Ammonium Nitrate-Urea Solution Ammonium Oleate... 

Ammonium nitrate, urea solution (containing ammonia) 190 Ammonyx Cetac 30 735... 

Ammonium Nitrate Ammonium Nitrate-Urea Solution... 

Ammonium Nitrate Ammonium Nitrate-Urea Solution Ammonium Oleate Ammonium Oxalate Ammonium Oxalate Ammonium Pentaborate Ammonium Pentaborate... 

AMMONIUM NITRATE-UREA SOLUTION Solar Nitrogen Solutions, Nhrex Nitrogen Solutions NL 0 2 0 ... 

Ammonium Nitrate-Urea Solution — Fire Hazards ... 

Steel Ammonium nitrate/urea solutions 0.05-0.1 0% ammonia, 0.1 % ammonium thiocyanate... 

Mixed with additives, urea is used in soHd fertilizers of various formulations, eg, urea—ammonium phosphate (UAP), urea—ammonium sulfate (UAS), and urea—phosphate (urea + phosphoric acid). Concentrated solutions of urea and ammonium nitrate (UAN) solutions (80—85 wt%) have a high nitrogen content but low crystallization point, suitable for easy transportation, pipeline distribution, and direct spray appHcation. 

Table 4. Properties of Urea Ammonium Nitrate Nonpressure Solutions...

Table 21.2 lists all important direct application materials and their percentage of direct application fertilizers. Direct application use is increasing mainly because of anhydrous ammonia gas becoming popular. It can be pumped in 3-6 in. beneath the soil during plowing and is absorbed by the soil rapidly. Nitrogen solutions can also be applied in this manner (mixture of free ammonia, ammonium nitrate, urea, and water). 

Ammonia Ammonia, Anhydrous Ammonium Hydroxide (28 % or less) Ammonium Nitrate, Urea, Water Solutions (containing Ammonia)... 

The demand for nitrogen in a chemically fixed form (as opposed to elemental nitrogen gas) drives a huge international industry that encompasses the production of seven key chemical nitrogen products ammonia, urea, nitric acid, ammonium nitrate, nitrogen solutions, ammonium sulfate and ammonium phosphates. Such nitrogen products had a total worldwide annual commercial value of about US 50 billion in 1996. The cornerstone of this industry is ammonia. Virtually all ammonia is produced in anhydrous form via the Haber process (as described in Chapter 2). Anhydrous ammonia is the basic raw material in a host of applications and in the manufacture of fertilizers, livestock feeds, commercial and military explosives, polymer intermediates, and miscellaneous chemicals35. 

Production of fertilizer grade AN is concentrated mainly in Europe and North America. Apparent demand in the United States was 18% below the 1998 level of 10 billion tons. This was mainly due to weakness in the fertilizer sector. US production of urea-ammonium nitrate (UAN) solutions also dropped significantly (from 3.8 million tons in 1998 to 2.9 million tons in 2001) from 1999 to 2001. In 2001 US ammonium nitrate capacity remains well in excess of domestic requirements as the industry operated at less than 70% of nameplate US capacity. Table 10.1 summarizes US supply and demand240. 

Ammonia is also used commercially in the manufacture of fertilizers, mainly ammonium nitrate, urea, and ammonium sulfate. It is used to a smaller extent in the refrigeration industry. Liquid ammonia is an excellent solvent for certain substances, which ionize in the solutions to give ionic reactions similar to those occurring in aqueous solutions. Ammonia is marketed... 

In Malaysia, this term includes anhydrous ammonia, ammoniating solutions, liquid mixed fertilizer solutions, suspensions, and slurries. The principal materials used in making liquid fertilizer are ammonia, ammonium nitrate, urea, phosphoric add, and potassium chlorideT... 

Ammonia is also used in the production of nitrogen fertilizer solutions that consist of ammonia, ammonium nitrate, urea, and water in various combinations. Some are pressure solutions and others are not. Nonpressure and low-pressure solutions are widely used for direct application to the soil. Pressure solutions containing free ammonia are used in the manufacture of high-analysis mixed fertilizers. 

Ammonium Nitrate. Urea, Water Solutions (containing Ammonia)... 

The urea produced is normally either prilled or granulated. In some countries there is a market for Hquid urea—ammonium nitrate solutions (32% N). In this case, a partial-recycle stripping process is the best and cheapest system. The unconverted NH coming from the stripped urea solution and the reactor off-gas is neutralized with nitric acid. The ammonium nitrate solution formed and the urea solution from the stripper bottom are mixed, resulting in a 32—35 wt % solution. This system drastically reduces investment costs as evaporation, finishing (priQ or granulation), and wastewater treatment are not required. 

Urea processes provide an aqueous solution containing 70—87% urea. This solution can be used directiy for nitrogen-fertilizer suspensions or solutions such as urea—ammonium nitrate solution, which has grown ia popularity recentiy (18). Urea solution can be concentrated by evaporation or crystallization for the preparation of granular compound fertilizers and other products. Concentrated urea is sohdified ia essentially pure form as prills, granules, flakes, or crystals. SoHd urea can be shipped, stored, distributed, and used mote economically than ia solution. Furthermore, ia the soHd form, urea is more stable and biuret formation less likely. 

Several zinc and copper micronuttient compounds are soluble in a variety of nitrogen solutions. Ammonia—ammonium nitrate solutions containing 2.5% Zn and 1% Cu can be prepared (100). Micronutrients are not very soluble in urea—ammonium nitrate solution unless the pH is raised to 7 or 8 by adding ammonia, whereupon zinc and copper become much more soluble. 

When this reaction was first discovered, a considerably higher (ca 1300°C) temperature was required than that used in the 1990s. Thus, until Haber discovered the appropriate catalyst, this process was not commercially attractive. As of this writing (ca 1995), the process suffers from the requirement for significant quantities of nonrenewable fossil fuels. Although ammonia itself is commonly used as a fertilizer in the United States, elsewhere the ammonia is often converted into soHd or Hquid fertilizers, such as urea (qv), ammonium nitrate or sulfate, and various solutions (see Ammonium COMPOUNDS). 

Markets. Industrial use of ammonia varies according to region. Eor example, industrial usage represents 20% of the ammonia production in the United States and Western Europe, 10% in the USSR, 1—10% in Asia, and 5% in Latin America and North Africa (79). Fertiliser ammonia consumed domestically in most countries is converted to straight or compound fertilisers such as urea, ammonium nitrate, diammonium phosphate, and various grades of mixed fertilisers. However, almost 29% of ammonia nitrogen in the United States is consumed as direct appHcation material. The use of nitrogen solution such as urea and ammonium nitrate (UAN) has also become popular in the United States and the USSR. 

Nitrogen solutions consist of fertilizer product combinations, eg, ammonium nitrate —ammonia, urea—ammonium nitrate—ammonia, urea—ammonium nitrate, and urea—ammonia solutions. Mixed fertilizers cover a broad range and can be loosely defined as fertilizers which contain chemically mixed nitrogen, phosphoms, and potassium (N—P—K). Examples are ammonium phosphate—potash mixtures and ammonium phosphate nitrates. 

Manufacture. Historically, ammonium nitrate was manufactured by a double decomposition method using sodium nitrate and either ammonium sulfate or ammonium chloride. Modem commercial processes, however, rely almost exclusively on the neutralization of nitric acid (qv), produced from ammonia through catalyzed oxidation, with ammonia. Manufacturers commonly use onsite ammonia although some ammonium nitrate is made from purchased ammonia. SoHd product used as fertilizer has been the predominant form produced. However, sale of ammonium nitrate as a component in urea—ammonium nitrate Hquid fertilizer has grown to where about half the ammonium nitrate produced is actually marketed as a solution. 

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