Ammonium Nitrate.docx

THESIS AMMONIUM NITRATE

PREPARED BY:PDD DEPARTMENT

BEEZAASAN EXPLOTECH PRIVATE LIMITED

ABSTRACT A thesis is presented on brief history of ammonium nitrate. The primary goals of this work are to advance the understanding of the root causes associated with AN explosions and find out ways to make AN storage inherently safer by studying its thermal stability. This research focuses on conditiondependent AN decomposition, including the effect of additives, confinement, heating rate, temperature, thermal history, and sample size. Pseudo-adiabatic and adiabatic calorimeters are used to study the characteristics of AN decomposition. Thermodynamic and kinetic parameters are evaluated; models are proposed to predict the temperature rise of AN mixtures with additives; decomposition pathways are analyzed; safer AN storage conditions are identified; and AN explosion phenomenology are reported. In addition, this work discusses the role of water as a chemical, interfering physically and chemically with AN related fire scenarios possibly leading to explosions. Thermal stability analysis showed that AN is stable up to approximately 200 °C. Sodium sulfate is a good inhibitor for AN in that its presence can mitigate AN decomposition, while potassium chloride is a promoter because it intensifies the runaway reaction. AN should be separately stored from promoters, even when inhibitors are also present. Furthermore, exposure of AN to heat and storage in confined spaces should be avoided, and the size of AN piles should be limited. While water remains the choice for tackling ANrelated fires, care should be taken in doing so. It must be understood that a significantly sufficient quantity of water should be used. Actually, evidence shows that insufficient quantities of water may exacerbate the fires and consequences. This work demonstrates the complexity and the multiple studies required for making AN safer as a explosive, providing suggestions to the explosive industry. It can also serve as a model for studies on various reactive chemicals.

TABLE OF CONTENTS 1. Introduction……………………………………………………….8 1.1 Overview………………………………………………………9 1.2 Structure…………………………….……………………….9 2. Production of Ammonium nitrate .……………………................10 2.1 Neutralization……………………………………………....10 2.2 Major hazards………………………………………………14 2.3 Grades of ammonium nitrate…………………………...….15 3. Reactions…………………………………………………………15 4. Properties…………………………………………………….…..16 5. Explosive data……………………………………………………17 6. Hazards…………………………………………………………..17 7. NFPA 704………………………………………………………..18 8. Uses……………………………………………………………....20 9. Ammonium nitrate Market segment……………………….…….21 10. Storage of Ammonium Nitrate…………………………….23 11. Transportation of Ammonium Nitrate……………………..24 12. Conclusions………………………………………………...25 13. Future Works……………………………………………....25

LIST OF FIGURES 1.1 1.2 1.3 1.4 1.5 1.6 1.7

Structural formula……………………………………………….9 Crystal structure………………………………………………...10 Process diagram of AN Production……………………………..11 Process Flow diagram for ammonium nitrate manufacturing…..12 World consumption of ammonium nitrate………………………20 Ammonium nitrate in market size in year 2012-2025…………..22 Ammonium nitrate in market use………………………………..22

INTRODUCTION Ammonium nitrate is commercially available both as a colorless crystalline solid and processed into prills for specific applications. Soluble in water. Does not readily burn but will do so if contaminated with combustible material. Accelerates the burning of combustible material. Produces toxic oxides of nitrogen during combustion. Used to make fertilizers and explosives, and as a nutrient in producing antibiotics and yeast. AN is one such material that has been extensively used as a fertilizer since it is an excellent source of nitrogen. At the same time, it has also been widely used as an explosive material for detonation in mines. According to literature, AN is not considered as a dangerous material at atmospheric conditions, but it is a strong oxidizing agent that can result in incidents. A number of incidents have occurred due to the detonability of AN, which has caused extensive loss of property and life. Ammonium nitrate is a chemical compound, the nitrate salt of the ammonium cation. It has the chemical formula NH4NO3, simplified to N2H4O3. It is a white crystal solid and is highly soluble in water. It is predominantly used in agriculture as a high-nitrogen fertilizer. Its other major use is as a component of explosive mixtures used in mining, quarrying, and civil construction. Despite considerable research performed on understanding the details of AN. This research investigated the mechanisms that cause AN to run away. The effects of different contaminants and environmental conditions, such as temperatures, confinement, and heating rate, were studied using different types of calorimeters to understand their role in its detonability. In addition, predictive models were developed to understand its interaction with these contaminants and environmental conditions at a fundamental level. Furthermore, the complexities of fighting AN-related fires with water were discussed. Specifically, this work aims to reduce the explosion risk associated with AN while maintaining its agricultural benefit.

1.1 AN Overview Ammonium nitrate is a white crystalline substance first made artificially in 1659 by the german chemist Johann Rudolf glauber (1604-1670). Ammonium nitrate is found as a natural mineral in the driest regions of the Atacama Desert in Chile, often as a crust on the ground and/or in conjunction with other nitrate, iodate, and halide minerals. Ammonium nitrate was mined there in the past, but virtually 100% of the chemical now used is synthetic.  Blasting agent:- Any material or mixture consisting of a fuel and oxidizer intended for blasting, not otherwise classified as an explosive and in which none of the ingredients is classified as an explosive (provided that the material or mixture cannot be detonated by a No. 8 test blasting cap under the conditions specified for the cap sensitivity test).

 Nitro-Carbon-Nitrate :- A blasting agent that has been classified as a nitro-carbon-nitrate under the Interstate Commerce Commission regulations and that is packaged and shipped in compliance with the regulations of the Interstate Commerce Commission.

1.2 Structure The industrial production of ammonium nitrate entails the acid-base reaction of ammonia with nitric acid : HNO3 + NH3 → NH4NO3

Figure 1.1:- Structural formula

Figure 1.2:- Crystal Structure Ammonia is used in its anhydrous form (i.e., gas form) and the nitric acid is concentrated. This reaction is violent owing to its highly exothermic nature. After the solution is formed, typically at about 83% concentration, the excess water is evaporated to an ammonium nitrate (AN) content of 95% to 99.9% concentration (AN melt), depending on grade. The AN melt is then made into "prills" or small beads in a spray tower, or into granules by spraying and tumbling in a rotating drum. The prills or granules may be further dried, cooled, and then coated to prevent caking. These prills or granules are the typical AN products in commerce. Ammonium nitrate occurs naturally as a mineral in certain desert regions of the world. However, it is not abundant and is found as a mixture with many other minerals.

2. Production of Ammonium Nitrate The production process comprises three main unit operations: neutralization, evaporation, solidification (prilling and granulation). Individual plants vary widely in process detail.

2.1 Neutralization : Anhydrous liquid ammonia is evaporated in an evaporator using cooling water. The stoichiometic quantities of nitric acid (55% concentration wt/ wt) and gaseous ammonia are introduced by an automatic ratio controller to a neutralizer. The reaction between Ammonia and nitric acid produces

ammonium nitrate solution according to the following exothermic reaction. NH3 + HNO3 NH4 NO3 Neutralization can be performed in a single stage or in two stages. The neutralizer can be carried out at atmospheric (either normal or low emission neutralizers where the C and pH will be 6 and 3 respectively) or at elevatedtemperature does not exceed 105 pressure of almost 4 atmospheres. The normal neutralizers are usually followed by flash evaporation in order to increase the out let A.N concentration to 70%. In case of pressure C and the steam generated fromneutralizers the temperature will be in the range of 178 the heat of reaction will be utilized in the subsequent step namely concentration of A.N solution. During evaporation some ammonia is lost from the solution. The steam which is boiled off is contaminated. The control of the neutralizer is important. The pH and the temperature must both be strictly controlled to limit the losses from the neutralizer. All installations must include pH and temperature controls. At the operating temperature of the neutralizer, impurity control is of great importance because a safety incident will also be a significant environmental incident. The ammonium nitrate solution from neutralizer may be fed to storage without further processing but, if it is used in the manufacture of solid ammonium nitrate, it is concentrated by evaporation.

Figure 1.3:- Process diagram of AN production

1. Evaporation to Concentrate the A.N The outlet from the neutralizer is received in an intermediate tank. The solution should be made alkaline before being pumped (no need for pumps in case of pressure neutralizers since the pressure will maintain the flow) to the evaporation section (multieffect) running under vacuum. The solution will be steam heated in the multi effect evaporation section. The solution will be concentrated up to 97.5-99.5% (normally over 99 %) depending on whether ammonium nitrate will be granulated or prilled.

2. Mixing the Filling Material In order to reduce the nitrogen content of A.N from 35% to 33.5%, the proper filling material is added (about 4% by weight of powdered limestone or dolomite or even kaolin)

3. Prilling or Granulation The hot concentrated melt is either granulated (fluidize bed granulation, drum granulation. etc) or prilled. Ammonium nitrate is formed into droplets which then fall down a fall tower (prill tower) where they cool and solidify. Granulation requires more complicated plant than prilling and variety of equipment. The main advantage of granulation with respect of environment is that the quantity of air to be treated is much smaller and abatement equipment is cheaper.

4. Drying, Screening The ammonium nitrate (prills or granules) is dried (usually in drums) using hot air (steam heated), then screened to separate the correct product size. The oversize and undersize will be recycled either in the mixing tank (in case of prilling) or to the granulator.

5. Final Cooling The hot proper size granules, are then cooled (against cooled and humid free air) down to C and treated with anti-caking (usually amines) and then coated with an inert material40 (usually, kaolin, limestone or dolomite) and then conveyed to the storage. Following figure indicate process flow diagram for ammonium nitrate manufacturing

Figure 1.4:- Process Flow Diagram for Ammonium Nitrate Manufacturing Inputs

Liquid ammonia

Nitric Acid

Operations

Evaporation

Reaction Neutralization

Flash Evaporation Ammonia injection steam

Steam

Dolomite, Kaolin or Limestone

Steam heated air

Secondary Evaporation

Mixing

Prilling

Drying

Screening

Cold dry air

Polyethylene bags Clay or diatomaceous earth

Ammonia emissions Steam condensate (NH3, ammonium nitrate Vapours to ammonium nitrate separator

Storage

Granulation

Air

Outputs

Cooling

Coating & Bagging

Vapours to ammonia separator Condensate (NH3, ammonium nitrate Particulates of dolomite, kaolin or lime stone

Particulates Particulates (ammonium nitrate) and NH3 Heat stress water vapour Particulates Noise Particulates

Particulates (ammonium nitrates)

2.2 Major hazards The main chemical hazards associated with ammonium nitrate are:1. Fire 2. Decomposition 3. Explosion Burns caused by hot AN solution should also be considered from a safety point of view.

1) Fire Ammonium nitrate itself does not burn. Being an oxidizing agent, it can facilitate the initiation of a fire and intensify fires in combustible materials. Hot AN solution can initiate a fire in rags, wooden articles etc., on coming into contact with them. Similarly, fertilizer products or dust contaminated with oil or other combustible materials can also start fires when left on hot surfaces. Fires involving AN cannot be extinguished by the prevention of air ingress (e.g. smothering with steam) because of the in situ provision of oxygen from the AN. 2) Decomposition Pure solid AN melts at 169°C. On further heating it decomposes by way of a complex set of reactions. Up to about 250°C it decomposes primarily into N2O and H2O. Above 300°C reactions producing N2, NO, NO2 etc., become significant. These reactions are exothermic and irreversible. They are accompanied by the vapour pressure dependent endothermic dissociation into HNO3 and NH3 vapours which can provide a temperature limiting mechanism, provided the gases can escape freely. If they cannot, the endothermic dissociation is suppressed and a runaway decomposition can develop, leading to explosive behaviour. A number of materials have a strong catalytic effect on the thermal decomposition of AN. These include acids, chlorides, organic materials, chromates, dichromates, salts of manganese, copper and nickel and certain metals such as zinc, copper and lead. The decomposition of AN is suppressed or prevented by an alkaline condition. Thus the addition of ammonia offers a major safeguard against the decomposition hazard. The release of toxic fumes is one of the main hazards associated with the decomposition of AN. 3) Explosion AN is especially difficult to detonate and neither flame, spark nor friction is known to cause detonation. Shocks derived from detonating gas mixtures (hydrogen/oxygen or acetylene/oxygen) have been found to be incapable of producing detonation in AN. AN fertilizer dust, being non-combustible in nature, does not give rise to a dust explosion such as those commonly associated with grain and organic dusts. Shock initiation in solid prilled AN needs a fairly substantial stimulus. Heating under confinement and shock initiation of hot or contaminated AN by projectile impact appear to be more credible mechanisms in the context of industrial operations.

Strongly acidic conditions and the presence of contaminants should be avoided to counter the explosion hazard in AN solutions. Explosions can occur when ammonium nitrate is heated under confinement in pumps. Reasons for pump explosions include:– No (or insufficient) flow through the pump – Incorrect design (Design may incorporate low flow and/or high temperature trips) – Poor maintenance practices – Contamination Burns Caused by Hot AN Solutions These solutions are dangerous because of their high temperatures (commonly in the range 120180°C) and because they attack the skin on account of their oxidising properties.

2.3 Grades of Ammonium Nitrate The many grades of ammonium nitrate being sold for field mixing into blasting agent compositions have led to much uncertainty and confusion. There are prilled, flaked, and grained ammonium nitrates, which may be uncoated or coated with clay, diatomaceous earth, or proprietary inorganic or organic antisetting agents. A clay coating may comprise from 0.1 to 4 percent of the total weight. The bulk density may range from less than 0.8 gram per cubic centimeter (g/cm3 ) to over 1 g/cm3 • Particle sizes may range from 4- to 7- mesh to 90 percent through 100-mesh (grained or crushed prills). Additionally, it should be noted that ammonium nitrate prills, both raw and sensitized, tend to disintegrate physically, producing fines, when their temperature passes 90° F, a solid-phase transition point . Temperature fluctuations past 90° F could readily occur twice daily under some conditions of storage. When mixed with oil, in proportions that may range from 2 to 10 percent (though more commonly from 4 to 6 percent), these different kinds of ammonium nitrate form compositions of widely varying sensitivity. Investigations have shown it possible to produce cap-sensitive compositions (l) while other compositions have failed to propagate in large diameters even though large gelatin-dynamite boosters were used.

3. Reactions Ammonium nitrate reacts with metal hydroxides, releasing ammonia and forming alkali metal nitrate: NH4NO3 + MOH → NH3 + H2O + MNO3 (M = Na, K) Ammonium nitrate leaves no residue when heated: NH4NO3 → N2O + 2H2O When rapidly heated or exploded the predominant reaction is: 2NH4NO3 → 2N2 + O2 + 4H2O

Ammonium nitrate is also formed in the atmosphere from emissions of NO, and NH3, and is a secondary component of some PM10particulates.

SO2,

4. Properties Physical Properties and Chemical Properties Chemical formula – NH4NO3 Crystal structure - trigonal Molar Mass – 80.043 g/mol Appearance – white/grey solid Density- 1.725 g/cm3(20℃) Melting Point -169.6℃ (337.3℉, 442.8 k) Boiling Point - approx 210 ℃ (410℉, 483 k) decomposes Solubility in water – Endothermic 118g/100 ml (0℃) 150g/100 ml (0℃) 297g/100 ml (0℃) 410g/100 ml (0℃) 576g/100 ml (0℃) 1024g/100 ml (0℃) 9. Magnetic Susceptibility (x) – 33.610-6 cm3/mol 10.Critical relative humidity - 78% (0 °C) 65% (20 °C) 58.5% (30 °C) 52.5% (40 °C) 46.5% (50 °C) 41% (60 °C) 11.Nitrogen content – 34.5%N 1. 2. 3. 4. 5. 6. 7. 8.

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Chemical Properties – Ammonium nitrate is readily water soluble. It is also highly hygroscopic, meaning that it readily absorbs water from the atmosphere and clumps up. It is not particularly reactive and is fairly stable. It decomposes at high temperatures (over 200°C) to form nitrous oxide and water vapor.

5. Explosive data 1. Shock sensitivity – very low 2. Friction sensitivity – very low 3. Detonation velocity – 2500 m/s

6. Hazards 1. Main hazards – Explosive, Oxidizer 2. GHS Pictograms :-

3. GHS signal word:- warning 4. GHS Hazard Statements – H272:- May intensify fire; oxidizer. H303:- May be harmful if swallowed. H315:- Causes skin irritation. H319:- Causes serious eye irritation. H335:- May cause respiratory irritation.

5. GHS Precautionary StatementsP220:- Keep/Store away from clothing/ combustible materials. P261:- Avoid breathing dust/ fume/ gas/ mist/ vapours/ spray. P305 + P351 + P338 IF IN EYES:- Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

6. NFPA 704:-

7. Other cations :- Sodium nitrate Potassium nitrate Hydroxylammonium nitrate 8. Related Compounds :- Ammonium Perchlorate

9. Reactivity alerts – 1. Explosive

10.

2. Strong oxidizing agent Reactivity Problem – The hazards of Ammonium Nitrate have been well studied because of several extremely severe explosions. Mixtures with alkyl esters may explode, owing to the formation of alkyl nitrates. Mixtures with phosphorus, tin (II) chloride or other reducing agents may react explosively. A mixture with aluminum powder can be used as an explosive. A number of explosions in which ammonium nitrate and aluminum were mixed with carbon or hydrocarbons, with or without oxidizing agents have occurred. A mixture with acetic acid ignites when warmed, especially if concentrated. Causes the decomposition of sodium hypochlorite within a few seconds.

11. Air & water ReactionsWater soluble. Hot aqueous solutions of the Nitrate above 50% conc., Under confinement may decompose explosively. This process is aided catalytically with such substances as nitric acid and chloride ion,

12. Fire hazard – These substances will accelerate burning when involved in a fire. Some may decompose explosively when heated or involved in a fire. May explode from heat or contamination. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing etc). Containers may explode when heated. Runoff may create fire or explosion hazard.

 Fighting Fires in Ammonium Nitrate In the absence of nearby stores of sensitizing agents such as fuel oils, unconfined, limited-area fires in even large quantities of ammonium nitrate can be fought with copious amounts of water. However, massive fires may present a substantial hazard, and firefighting efforts on these should be abandoned unless water can be applied by remote control. Water acts solely as a cooling agent. Ammonium nitrate, an oxidizing material, does not need atmospheric oxygen for combustion. Consequently, ammonium nitrate fires cannot be smothered, and chemical extinguishing agents are essentially ineffective.

 Fighting Fires Involving Explosives If high explosives are present in a fire involving either or both ammonium nitrate and fuel-sensitized ammonium nitrate, they should be removed from the danger area if this can be done promptly and safely. However, if this is impossible or the explosives are already aflame, the entire area

should be evacuated in anticipation of detonation, and the fire should be allowed to burn.

13.

Health hazardInhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or death. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution. While several toxic, ammonium nitrate can cause health issues if ingested or inhaled in high concentrations. Ingesting large amounts of ammonium nitrate can cause headache, dizziness, abdominal pain, vomiting, weakness, irregular heartbeat and conclusions, while inhalation of this powder may cause breathing problems, coughing, sore throat, even suffocation at high concentrations.

7. NFPA 704 Diamond

Hazard Health

Value Description Exposure could cause irritation 1

Flammability 0 Instability 3

Special

ox

but only minor residual injury even if no treatment is given. Materials that will not burn.

Capable of detonation or explosive reaction, but requires a strong initiating source or must be heated under confinement before initiation, or reacts explosively with water This denotes an oxidizer, a chemical which can greatly increase the rate of combustion/fire.

8. Uses – Ammonium nitrate is most commonly used in fertilizers (as an excellent and inexpensive nitrogen source) and in instant cold packs. It is also used to manufacturing explosives as it acts as a strong oxidizing agent. In particular, ammonium nitrate is used to prepare an industrial explosive called ANFO (ammonium nitrate fuel oil), which is composed of 94% ammonium nitrate and 6% fuel oil. In addition to its usefulness as a fertilizer ammonium nitrate is also employed in certain industrial and construction setting. The chemical compound

is explosive and useful in mining, demolition activities and quarry work. The granules are very porous and can absorb large amounts of fuel. Exposure to fire will cause a long, sustained and large explosion. In most cases, the compound is very stable and can only become explosive in certain conditions. Food preservation is another area that is using ammonium nitrate. The compound makes an excellent cold pack when one bag of water and one bag of the compound are united. In fireworks, where it provides the oxygen needed to ignite other chemicals. In rocket engines where it provides oxygen needed to burn the rocket fuel; In the manufacture of nitrous oxide (N2O) commonly known as laughing gas.

 Explosive use Ammonium nitrate is used in manufacturing explosives. It's actually the main component of an explosive called ammonium nitrate fuel oil (ANFO), which is a mixture of 94% ammonium nitrate and 6% of fuel oil. In this mixture, the ammonium nitrate serves as an oxidizing agent for fuel. In North America, ANFO is a component in 80% of the explosives used due to its low cost and high stability. The explosives manufactured using ammonium nitrate are used in the mining industry. Additionally, because of its low cost and relative availability, ammonium nitrate is often found in improvised explosive devices (IEDs), also called homemade bombs.

Figure 1.5:- world consumption of ammonium nitrate

9. Ammonium Nitrate Market Segment The global ammonium nitrate market will be primarily driven by the increasing product application in various end-user industries like agriculture, mining & quarrying, civil construction. Ammonium nitrate is majorly used in fertilizer and explosive manufacturing. Increasing food safety concerns around the globe has led to concerted efforts by governments, farmers and institutions to increase the yield per unit area of cultivated land. The agriculture industry is a key end-user for the product market where it is used as a nitrogen fertilizer. In India and the US, arable land per person was 0.18 & 0.74 hector per person respectively in 1990 which was reduced to 0.11 & 0.47 hector per person in 2016. At a global level, arable land per person was 0.23 hector per person which was reduced to 0.19 hector per person in 2016. Increasing global population has increased the demand of the food to a great extent. Thus, the yield has to be increased in proportion with the increasing population in order to maintain the balance between the demand & supply and to do so; high-quality fertilizers are required. The rising agriculture industry across the globe has triggered the demand of fertilizers which are essential for the growth of the crops. Nitrogen fertilizers have lesser nitrogen content (33%) as compared to urea-based fertilizers (46%). Plants consume nitrogen in a nitrate form which is readily available in ammonium nitrate. The conversion of nitrogen component in urea into anitrate results in high nitrogen loss. In addition to that, ammonium nitrate-based fertilizers release nitrogen in the atmosphere at a much slower rate which improves the longevity. Thus, ammonium nitrate-based fertilizers are extensively used in the agriculture industry. The significant increase in the demand for high-quality crop has increased the fertilizer consumption. China, one of the leading fertilizer manufacturers in the world, was the largest consumer of the nitrogen fertilizer in the world. This has led to the remodeling and expansion of the older manufacturing plants along with building the new ammonium nitrate production facilities to meet the escalating demand. In 2016, Yara International opened the world’s first modular plant to produce ammonium nitrate with the annual production capacity of 330,000 tonnes.

Figure 1.6:- Ammonium nitrate in market size in year 2012-2025

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Industry background of ammonium nitrate

Figure 1.7:- Ammonium nitrate in market use. In 1659, ammonium nitrate was first produced artificially in Germany. It is a white, crystalline solid, highly soluble in water, stable at lower temperatures but it decomposes explosively at the temperatures above 390°F (200°C). It is primarily used in fertilizers and explosives. The growing demand for fertilizers, rising mining activities, increasing food demand in the world will drive the growth of the ammonium nitrate market. However, stringent government regulations to prevent the misuse of the product coupled with the availability of the substitutes in end-user segments will hamper the growth of the market.

10. Storage of Ammonium Nitrate 1. Ammonium nitrate should be stored in accordance with guidelines of peso 2. If ammonium nitrate is stored in the same building with a blasting agent, the combined quantities of both materials should be considered as blasting agent, and the building should be isolated from inhabited buildings, passenger railroads, and public highways in accordance with the guidelines of PESO 3. If ammonium nitrate is stored with explosives, only a properly constructed explosives magazine should be used. The aggregate weight of all stored materials should be the determining factor in establishing the location of the magazine in accordance with the guidelines of peso. 4. Storage buildings should preferably be constructed of noncombustible or fire-resistant materials. It is desirable for such a building to be equipped for fire protection with an adequate-capacity, automatic water deluge system. Only a limited degree of fire protection is provided by a conventional sprinkler system. 5. The storage building should be dry and well ventilated. 6. The storage-building floor should be of noncombustible material and its design should be such as to eliminate open, piped drains into which molten ammonium nitrate could flow and be confined in case of a fire. 7. The following factors should be considered in judging the adequacy of a site for a storage building: Maximum amount of intended storage, congestion of the area, fire fighting facilities, local regulations, toxic-fume hazards in event of fire, etc. 8. Smoking and open flames should not be permitted in the storage building. 9. Under no circumstances should caked ammonium nitrate in bags or bulk be loosened by blasting with explosives. 10. Ammonium nitrate from broken bags should be cleaned up promptly and removed from the premises.

11. Transportation of ammonium nitrate 1. The regulations of the Interstate Commerce Commission governing the transportation of blasting agents over public highways should be considered as minimum requirements. 2. Vehicles used for transporting blast ing agents should be in a safe operating condition and should be driven by competent drivers who have a State driver's license valid for the type of vehicle driven. Drivers should also be familiar with applicable Federal, State, and local regulations and codes. 3. The construction of any truck or van used for transporting blasting agents should include a means for low-pressure venting in case the truck and its contents are involved in a fire. 4. Mobile processing equipment should not be used for mixing blasting agents while on public highways and other public thoroughfares. 5. No person should smoke or carry matches or any other flame-producing device or firearms while in or near a motor vehicle transporting blasting agents. 6. Any tarpaulin used to cover the load of blasting agents should be fire resistant. 7. Acids or other corrosive liquids should not be transported in any vehicle containing blasting agents. 8. Blasting agents should not be transported in any public vehicle carrying passengers for hire. 9. If an auger is used to deliver the blasting agent from the truck, the shell of the auger should be selected so as to minimize buildup of pressure internally. 10. All trucks transporting blasting agents should carry two 5-pound or larger carbon dioxide fire extinguishers or two 4-pound or larger dry chemical extinguishers. The extinguishers should be of an approved type and properly maintained. These extinguishers are effective against ordinary truck fires but not against fires involving the blasting agent. 11. Fires involving blasting agents should only be fought in the incipient stage. If all efforts in attempting to control the fire appear futile, then the area should be evacuated.

12. Conclusions In this thesis we have presented about the ammonium nitrate. From a safety perspective, AN is not considered a flammable or combustible material at ambient temperatures; however, it is a strong oxidizing agent that can detonate under certain conditions. AN is associated with several types of hazards including fire and explosion, which have occurred time and again in the past century. This research advanced the understanding of the root causes associated with AN explosions, and identified ways to make the AN storage inherently safer. This work focused on the condition-dependent AN decomposition, including the effect of additives, confinement, heating rate, thermal history, heating temperature, and sample size. Further, the safe condition for AN storage, handling and transportation was determined.

13. Future Work This section summarizes the opportunities to study about AN. It also provides recommendation for future work, based on the challenges faced during this study such as:I. Thermal stability studies of ammonium nitrate II. Condition dependent thermal decomposition of ammonium nitrate. III. The complexities of using water to fight ammonium nitrate related fires. IV. Molecular simulation V. Effect of additives VI. Effect of humidity and surrounding gas atmosphere VII. Design of experiments VIII. Scale up design.