[en] Highlights: • Root causes and contributing factors from ammonium nitrate incidents are categorized into 10 lessons. • The lessons learned from the past 100 years of ammonium nitrate incidents can be used to improve design, operation, and maintenance procedures. • Improving organizational memory to help improve safety performance. • Combating and changing organizational cultures. - Abstract: Process safety, as well as the safe storage and transportation of hazardous or reactive chemicals, has been a topic of increasing interest in the last few decades. The increased interest in improving the safety of operations has been driven largely by a series of recent catastrophes that have occurred in the United States and the rest of the world. A continuous review of past incidents and disasters to look for common causes and lessons is an essential component to any process safety and loss prevention program. While analyzing the causes of an accident cannot prevent that accident from occurring, learning from it can help to prevent future incidents. The objective of this article is to review a selection of major incidents involving ammonium nitrate in the last century to identify common causes and lessons that can be gleaned from these incidents in the hopes of preventing future disasters. Ammonium nitrate has been involved in dozens of major incidents in the last century, so a subset of major incidents were chosen for discussion for the sake of brevity. Twelve incidents are reviewed and ten lessons from these incidents are discussed

[en] Emission of BVOC (Biogenic Volatile Organic Compounds) from plant leaves in response to ozone exposure (O₃) and nitrogen (N) fertilization is poorly understood. For the first time, BVOC emissions were explored in a forest tree species (silver birch, Betula pendula) exposed for two years to realistic levels of O₃ (35, 48 and 69 ppb as daylight average) and N (10, 30 and 70 kg ha⁻¹ yr⁻¹, applied weekly to the soil as ammonium nitrate). The main BVOCs emitted were: α-pinene, β-pinene, limonene, ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexanal. Ozone exposure increased BVOC emission and reduced total leaf area. The effect on emission was stronger when a short-term O₃ metric (concentrations at the time of sampling) rather than a long-term one (AOT40) was used. The effect of O₃ on total leaf area was not able to compensate for the stimulation of emission, so that responses to O₃ at leaf and whole-plant level were similar. Nitrogen fertilization increased total leaf area, decreased α-pinene and β-pinene emission, and increased ocimene, hexanal and DMNT emission. The increase of leaf area changed the significance of the emission response to N fertilization for most compounds. Nitrogen fertilization mitigated the effects of O₃ exposure on total leaf area, while the combined effects of O₃ exposure and N fertilization on BVOC emission were additive and not synergistic. In conclusion, O₃ exposure and N fertilization have the potential to affect global BVOC via direct effects on plant emission rates and changes in leaf area. - Highlights: • Ozone exposure stimulated BVOC emission. • Responses to an episodic O₃ metric were stronger than to a seasonal one. • N fertilization showed compound-specific effects (from inhibition to stimulation). • N-driven changes in total leaf area affected the magnitude of these effects. • O₃ and N impacted BVOC emission individually, with no significant interactions. - Ozone exposure increased BVOC emission and reduced total leaf area, while N fertilization increased total leaf area and showed compound-specific effects (from inhibition to stimulation) on BVOC emission.

[en] The Savannah River Site's (SRS) H-Canyon facility uses ceric ammonium nitrate (CAN) to separate impure neptunium (Np) from a nitric acid feed stream containing 0.5-1.0 M concentrations of iron, sodium and sulfate impurities. The material is processed using a two-pass solvent extraction purification which relies on CAN to oxidize Np to Np(VI) during the first pass prior to extraction. Spectrophotometric oxidation-state analyses normally used to validate successful oxidation to Np(VI) prior to extraction were compromised by this feed stream matrix. Therefore, a rapid chromatographic method to validate successful Np oxidation was developed using Eichrom Industries' TRU and TEVA^R resins. The method was validated and subsequently transferred to existing operations in the process analytical laboratories. (author)

[en] The reduction of ceric ammonium nitrate by anhydrous ammonia has been studied. The reaction yields cerous ammonium nitrate complex. This is an easy method to prepare an anhydrous Ce (III) salt, suitable for synthesis of organo cerium (III) derivatives

[en] Lanthanum ammonium nitrate of purity 97%, containing 34.1 kg RE₂O₃, was crystallized fractionally and yielded 32.5 kg oxide of purity better than 99.9% (the larger part was 99.99% pure). Out of mixtures with 66% Pr there resulted praseodymium ammonium nitrate containing 13.45 kg oxide of purity better than 99.5%. The effective separation factors are discussed, showing a better efficiency of the ammonium than of the magnesium double nitrates for the separation ofpraseodymium and lanthanum. (author)

[en] With the increase in uranium loading in the organic, there was an increase in % stripping of uranium for ammonium nitrate whereas for distilled water it became reversed. With the increase of pH of the aqueous ammonium nitrate solution, it was found that stripping increased up to a pH of 8.5 and after that precipitation starts. Increase in temperature of the biphasic system shows an enhancing effect of uranium stripping. Evaluation of thermodynamic data like ΔH and ΔS indicated that the process is endothermic. Equilibrium isotherms at various operating conditions were generated for both water and ammonium nitrate. Based on the optimized conditions, Mc-Cabe Thiele diagrams were constructed using ammonium nitrate (50 g/L) of pH 7.5 at room temperature. Result showed that at an O/A ratio of 2/5, at least 7 theoretical countercurrent stages are needed at room temperature with an initial uranium loading of 115.4 g/L to get 40 g/L of uranyl nitrate pure solution in the rich end leaving only 3 g/L uranium in the lean solvent whereas for water to strip all the uranium (from 100 g/L) requires only 4 numbers of countercurrent stages at an O/A ratio of 2/3 at room temperature

[en] Full text: The samples with high content of chlorides form deposits of salts on the reflector used for the analysis TXRF, affecting the quality of the thin film required for the analysis, producing an increase of the bed (bottom) and consequently an increase of the detection limit. Joined this, the levels of chlorine present in this type of samples, imply the presence of a peak K alpha of high-intensity, and as a consequence, the spectral interference with the neighboring peaks (lines of potassium K alpha, calcium and L of cadmium and silver, for example). By means of this work it is intended the use of chemical modifiers added in situ, on the sample, in the reflector, which allow the the elimination of chlorides and other salts formed on the reflector. For that reason three modifiers were proved: Ammonium nitrate, ammonium oxalate and oxalic acid in solutions of 10000 ppm. These compounds are added in excess, in a proportion of 50 microliters on an 10 microliters deposit of a pattern sample, with 1% of sodium chloride. The decrease of the the intensity of the pick K alpha of Cl with each one of the modifiers in function of the method of addition of modifier on the sample holders, heating mode and drying of the sample, temperature and drying time. For each case the limits of detection of the elements Ca, K, Se, Cd and Ni were determined. It was found that the more effective modifier is the ammonium nitrate more effective

[en] Oxophilicity of cerium(IV) ammonium nitrate (CAN) can be controlled by addition of hydrogen peroxide and such a control has been utilized to prepare 3-aroyl-2-aryl-4H-1-benzopyran-4-ones 2a-d from 3-arylidene-2-aryl-2,3-dihydro-4H-1-benzopyran-4-ones 1a-d in good yields

[en] Thermal decomposition behavior of a completely incenerable ionic liquid namely methyltrioctylammonium nitrate ((N₁₈₈₈)(NO3)) was investigated in the presence and absence of nitric acid using adiabatic calorimeter in closed air ambience. The decomposition stages and the corresponding rise in the temperature and pressure were computed from exothermic excursions. The thermokinetic parameters of decomposition reaction were derived from the temperature curves. (author)

[en] The double resonance cross-relaxation rates between H¹ and N¹⁵ in powders of solid NH₄NO₃ were measured as a function of the rotating field magnitude H₁. The cross-relaxation rate, obtained in a low dipolar temperature state, exhibits an exponential dependence on H₁. This result shows that the previous assumptions of a Lorentzian correlation function for the dipolar fluctuations introduced by McArthur et al., is a correct approximation in this case, too. An attempt was made to include the molecular motion effects on the cross-relaxation rate. (author)