硝酸铵热危险性综合研究

发布时间：2018-03-06 05:19

  本文选题：硝酸铵　切入点：固体　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：硝酸铵(Ammonium nitrate)是我们非常熟悉的一种化合物,其用途非常广泛。它不仅是优质农用化肥,同时它还是许多化学工业的原料。在工业生产中,不只使用固态硝酸铵还常使用硝酸铵高温水溶液,因此有必要对硝酸铵进行固液两相全方位的安全性研究,同时研究杂质对其热危险性的影响对硝酸铵的安全生产使用具有很重要的现实意义。本文以硝酸铵热危险性为研究主线,从固液两相分别进行研究。对固态硝酸铵,首先,通过同步热分析技术对硝酸铵的升温分解过程进行分析;其次,利用粉尘层着火温度装置、固体自燃点试验仪探讨了堆积状态硝酸铵热危险性,接着利用粉尘云着火温度装置研究粉尘云状硝酸铵热危险性;同时利用固体氧化性试验仪对硝酸铵的氧化性危险进行研究。对硝酸铵溶液,首先,使用C600微量热仪对硝酸铵溶液进行热分析;其次,使用小容量绝热试验仪对硝酸铵溶液的临界爆炸温度进行测试研究。具体研究内容和结论如下:(1)硝酸铵在空气开放环境中发生吸热分解,分解产物主要有H2O、NH3、N2O、NO。硝酸铵中掺杂木粉杂质时,发生放热分解,起始分解温度降低,木粉质量分数增大时,热分解温度向高温方向偏移,放热量增大。(2)堆积状态硝酸铵在高温热表面加热下,在熔点之前没发生发火燃烧;当混入木粉后,在220℃左右发生剧烈燃烧,随着木粉含量的增加,着火温度呈下降趋势。(3)堆积状态硝酸铵在高温环境下,在熔融之前没有发生自燃,混入木粉,在150℃左右发生自燃,且自燃温度随木粉质量分数增大而降低。(4)粉尘云状硝酸铵在炉壁温度410℃时发火燃烧,加入木粉,着火温度降至330℃左右,且随着木粉含量增大,着火温度降低。(5)硝酸铵氧化性为第2类。硝酸铵标签符号为“火焰在圆环上”,被标记为“危险”,危险说明为“可能加剧燃烧;氧化剂”。(6)通过C600微量热仪测试,硝酸铵固体在密闭环境下在271.6℃发生放热分解,加入水形成溶液后,起始分解温度在浓度80%时低于纯硝酸铵,浓度90%放热量大于纯硝酸铵放热量。混入Cl-后,硝酸铵水溶液的热分解温度显著减小,随着Cl-含量增大又呈现逐渐升高的趋势。(7)硝酸铵溶液临界爆炸温度在浓度70%、80%、90%时,80%浓度临界爆炸温度最低,加入氯离子临界爆炸温度降低,同时随着Cl-含量增大临界爆炸温度又呈现升高趋势。
[Abstract]:Ammonium nitrateis a very familiar compound that has a wide range of applications. It is not only a high-quality agricultural fertilizer, but also a raw material for many chemical industries. Ammonium nitrate is often used not only in solid ammonium nitrate, but also in high temperature aqueous solution. Therefore, it is necessary to study the safety of ammonium nitrate in both solid and liquid phases. At the same time, it is very important to study the influence of impurity on the thermal hazard of ammonium nitrate. In this paper, the thermal hazard of ammonium nitrate is taken as the main line of study, and the solid ammonium nitrate is studied separately from solid-liquid two phases. The thermal decomposition process of ammonium nitrate was analyzed by simultaneous thermal analysis. Secondly, the thermal hazard of ammonium nitrate in stacking state was discussed by using the dust layer ignition temperature device and the solid spontaneous combustion point tester. Then using the dust cloud ignition temperature device to study the thermal hazard of dust cloud ammonium nitrate; at the same time, using the solid oxidation test instrument to study the oxidation hazard of ammonium nitrate. For the ammonium nitrate solution, first of all, Thermal analysis of ammonium nitrate solution using C600 microcalorimeter. Secondly, The critical explosion temperature of ammonium nitrate solution was measured by using a small capacity adiabatic tester. The specific contents and conclusions are as follows: 1) ammonium nitrate decomposes endothermically in the open air environment. The decomposition products are mainly H _ 2O _ 3 NH _ 3N _ 2O _ 2 no. When the wood powder impurity is doped in ammonium nitrate, the exothermic decomposition occurs, the initial decomposition temperature decreases, and the wood flour mass fraction increases, the thermal decomposition temperature shifts to the high temperature. The accumulated state of ammonium nitrate does not ignite before melting point when heated at high temperature; when mixed with wood flour, it burns violently at about 220 鈩，

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