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Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
Ammonium nitrate, NH4NO3, is a strong inorganic oxidizer that can be an explosive all by itself under certain conditions. It is primarily used as an agricultural fertilizer for its nitrogen content. Ammonium nitrate is the primary component of ANFO, a commercially available explosive as well. Response personnel should deal with ammonium nitrate incidents with a great deal of caution. Ammonium nitrate is a colorless or white-to-gray crystal that is soluble in water. It decomposes at 210°C (392°F), releasing nitrous oxide gas and ammonia. Ammonium nitrate itself does not burn, but as an oxidizer supports and enhances combustion. When in contact with other combustible materials, the fire hazard is increased.
Chronicles of Incidents and Response
Published in Robert A. Burke, Chronicles of Incidents and Response, 2020
Ammonium nitrate that was loaded on the two ships at the Port of Texas City had been coated with paraffin (a hydrocarbon product) and other chemicals to prevent caking of the material. By adding paraffin to the ammonium nitrate oxidizer, it is like combining fuel and oxygen fulfilling two requirements of the fire triangle. You now have two of the three materials necessary for a fire to occur. All that is missing is heat. Because ammonium nitrate is also an oxidizer under certain conditions it can become explosive.
Common Sense Emergency Response
Published in Robert A. Burke, Common Sense Emergency Response, 2020
Ammonium nitrate, NH4NO3, is a strong inorganic oxidizer that can be an explosive all by itself under certain conditions. It is primarily used as an agricultural fertilizer for its nitrogen content. Ammonium nitrate is the primary component of ANFO, a commercially available explosive. Response personnel should deal with ammonium nitrate incidents with a great deal of caution. Ammonium nitrate is a colorless or white-to-gray crystal that is soluble in water. It decomposes at 210°C (392°), releasing nitrous oxide gas and ammonia. Ammonium nitrate itself does not burn but as an oxidizer supports and enhances combustion. When in contact with other combustible materials the fire hazard is increased. A fire involving ammonium nitrate in an enclosed space can lead to an explosion. Because it is an oxidizer, a fire involving ammonium nitrate can occur in the absence of atmospheric oxygen. Ammonium nitrate may explode when exposed to strong shock or high temperatures under confinement. Contaminants may increase the explosion hazard of ammonium nitrate. Organic materials, such as chlorides, and some metals, such as chromium, copper, cobalt, and nickel, can make explosions involving ammonium nitrate more severe. National Fire Protection Association (NFPA) 704 hazards for ammonium nitrate are Health 1, Fire 0, Reactivity 3, and special information OX for oxidizer. The 4-digit identification number is 1942 with an organic coating, and 2067 as the fertilizer grade. There are a number of other ammonium nitrate mixtures that have four-digit numbers; they can be found in the Department of Transportation’s (DOT) Hazardous Materials Tables and in DOT Emergency Response Guidebook (ERG).
Contribution of tailpipe and non-tailpipe traffic sources to quasi-ultrafine, fine and coarse particulate matter in southern California
Published in Journal of the Air & Waste Management Association, 2021
Rima Habre, Mariam Girguis, Robert Urman, Scott Fruin, Fred Lurmann, Martin Shafer, Patrick Gorski, Meredith Franklin, Rob McConnell, Ed Avol, Frank Gilliland
As for secondary inorganic aerosols, ammonium sulfate was resolved in all size fractions with high loadings of La in PM0.2 and PM2.5, suggesting emissions from petroleum refineries are contributing to secondary PM (Du and Turner 2015; Kulkarni, Chellam, and Fraser 2007). Ammonium sulfate is formed as a result of a series of reactions between sulfur dioxide and ammonia (ammonium) under warmer temperature conditions, which also favor photochemical ozone formation (Christoforou et al. 2000; Hasheminassab et al. 2014b; Schiferl, Heald, and Nowak et al. 2014). Ammonium nitrates were resolved in PM2.5 (with ammonium chloride) and PM2.5–10. Ammonium nitrate forms as a result of ammonia and nitric acid reactions under cool temperatures which shift the equilibrium into the particle phase. Ammonia is emitted from upwind agricultural and dairy production in Mira Loma, while nitric acid is formed as a result of the oxidation of nitric oxides emitted from primary fuel combustion sources (Wang et al. 2015; Ying and Kleeman 2006; Ying, Lu, and Kleeman 2009). Coarse nonvolatile sodium nitrate is also formed by heterogeneous replacement of chloride by nitrate in coarse sea-salt particles (Gard, Kleeman, and Gross et al. 1998) which may explain the large percentage of secondary aerosol in PM2.5–10. Ammonium chloride can also form under similar conditions as a result of hydrochloric acid reactions with ammonia (Hayes, Ortega, and Cubison et al. 2013; Kelly et al. 2013; Schiferl, Heald, and Nowak et al. 2014; Wang et al. 2015).
Recycling nutrients contained in human excreta to agriculture: Pathways, processes, and products
Published in Critical Reviews in Environmental Science and Technology, 2019
Robin Harder, Rosanne Wielemaker, Tove A. Larsen, Grietje Zeeman, Gunilla Öberg
Solutions rich in ammonia-N have been obtained, starting from hydrolyzed urine, through membrane separation, notably nanofiltration (e.g. Pronk, Palmquist, et al., 2006; Lazarova & Spendlingwimmer, 2008). A more widely researched approach to obtaining a solution rich in ammonia-N is the release of ammonia from liquid streams (e.g. through air stripping from urine or treated effluent) (e.g. Desloover et al., 2012; Luther et al., 2015) or organics (e.g. during thermal drying of sewage sludge) (e.g. Horttanainen et al., 2017) followed by absorption in an acid trap. Depending on the acid trap used, the respective product is ammonium sulfate ((NH4)2SO4) (e.g. Desloover et al., 2012), ammonium borate ((NH4)3BO3) (e.g. Kuntke et al., 2014), ammonium chloride (NH4Cl) (e.g. Wu & Modin, 2013), ammonium nitrate (NH4NO3) (e.g. Horttanainen et al., 2017), or diammonium phosphate ((NH4)2HPO4) (e.g. Licon Bernal et al., 2016). These products are generally free of pathogens, organic pollutants, and heavy metals. Yet other studies have used sorption followed by desorption to render ammonia water, starting from urine (e.g. Tarpeh et al., 2017) or treated effluent (e.g. Sancho et al., 2017; You et al., 2017). The fate of contaminants is less reported. Ammonium nitrate and ammonium sulfate are common fertilizer products applied for instance in combination with CULTAN (controlled uptake long-term ammonia nutrition) fertilization (Deppe et al., 2016). Ammonium nitrate is also a common ingredient in the production of synthetic fertilizers.
Alternative solutions for the physicochemical evaluation and improvement of the caking properties of calcium ammonium nitrate fertilizer as a quality problem under atmospheric conditions
Published in Journal of the Chinese Institute of Engineers, 2023
It is known that the phase contacts are very closely related to the ambient temperature, especially for ammonium nitrate fertilizers. Ammonium nitrate is a polymorphic compound and exists in five different stable crystalline forms in the solid phase. During the crystal phase transitions of ammonium nitrate, a sudden increase or decrease in volume is experienced. Ammonium nitrate, which is in the IV phase at room conditions, changes phase over 32.2°C and experiences volume expansion. This creates structural degradation that can cause caking (Gezerman 2020; Amonovich and Nozimovna 2021). When ammonium nitrate is completely moisture-free, it remains stable in the same phase for a long time in this process, this situation is called meta-stabilization. Some stabilizers can generally be used in CAN fertilizer to increase the temperature of IV-III phase transition. Magnesium nitrate, silicic acid, calcium lignosulfonate and sodium silicate can be counted as additives that provide stabilization of ammonium nitrate by lowering the crystal transition temperature in the two-stage vacuum ammonium nitrate production process (Gezerman 2020; Gezerman and Corbacioglu 2011). As mentioned in the related study, the silicate and sulfonate content ensures that the molecules are directed to silica and other inorganic molecules rather than nitrogen content according to their chemical potential during moisture diffusion in the fertilizer particle. The chemical potential of a molecule, similar to its electronegative behavior, can be expressed as the orientation of the molecules to the silicate content instead of nitrogen molecules in a humid environment where this molecule interacts, while there is silica and nitrogen content in a molecule. The meta-stabilization state represents the thermal stability desired to be achieved in the prevention of caking. With different stabilizers and an effective drying system, the phase transition temperature of 32°C, which is an easy temperature to reach in natural weather conditions, can be increased to 40–45°C in general (Hignett 2013). Fertilizers containing ammonium nitrate undergo a phase change over 32.2°C under normal conditions. However, this limit value is increased to approximately 45°C by using additives called stabilizers in fertilizers produced in the sector. Therefore, the transition, which will take place at 32.2°C in its natural conditions, takes place around 45°C. This is one of the reasons why nitrogen fertilizers such as CAN begin to deteriorate after 45°C. However, phase transition reactions begin to be observed above 45°C, and it may be the reason why granules caking above 45°C as seen in Table 1.