Application Of Modified Ammonium Nitrate In Field Mixed Loading

In recent years,due to the imbalance of regional resources,the cross regional transportation of porous granular ammonium nitrate brings about the increase of transportation cost,and the strong hygroscopicity of porous granular ammonium nitrate will also be affected in the long-term transportation process,resulting in the failure to achieve the expected goal in engineering blasting.Therefore,the modification of ordinary granular ammonium nitrate can be used in engineering practice instead of porous granular ammonium nitrateIn the production process,on the one hand,ammonium nitrate is modified and expanded.On the other hand,modified ammonium nitrate is obtained by spray drying and recrystallization.At the same time,the physical and chemical properties of the two process samples were tested.The results showed that in the process of modification of expanded ammonium nitrate,the change of expansion time would affect the adsorption degree of surfactant on ammonium nitrate.When the expansion time was about 15 minutes,the more obvious the expansion effect was,the greater the performance of ammonium nitrate was.The modified ammonium nitrate prepared by spray drying and recrystallization and the addition order of composite surfactants have great influence on the modification of common industrial ammonium nitrate.According to the experimental results,octadecylamine acetate(OCTA·AC)was added preferentially to modify ammonium nitrate,and the electrostatic force of OCTA·AC on ammonium nitrate was stronger than that of SDBS.In order to improve the performance of expanded ammonium nitrate,the effects of SDBS and OCTA·AC ionic surfactants and their combination with other surfactants on the performance of ordinary granular ammonium nitrate were studied.The hygroscopicity,oil absorption,water solubility,anti caking,microstructure and crystalline characteristics of the modified ammonium nitrate were tested.The experimental results show that the two kinds of ionic surfactants can improve the performance of ammonium nitrate,especially when SDBS and OCTA·AC are used as the main surfactants and compounded according to the ratio of 1:2,the effect is the most obvious.The test results of ammonium nitrate modified by composite surfactant showed that the moisture absorption rate was 5.3%in the environment of 15? and 90%humidity for 24 hours,which was 2.5%lower than that of 7.8%before modification,the oil absorption rate was 16.73%,which was 10.63%higher than that of 6.10%before modification,and the stress on anti caking property was 4.33MPa,which was 1.9MPa lower than that of 6.23MPa before modification.SEM photos show that the inner surface of the modified ammonium nitrate microstructure is smoother than that before modification,indicating that the ionic surfactant adsorbs on the inner surface of expanded ammonium nitrate,forming a single or sub single molecular layer,reducing the surface free energy.The results of C80 microcalorimetry showed that the ionic surfactant had an inhibitory effect on the transformation of ?-to ?-orthorhombic crystal of ammonium nitrate.In this paper,the effects of different process and different ratio of composite surfactants on the modification of ammonium nitrate were studied.The results show that the modified effect of ammonium nitrate can be improved by adding OCTA·AC preferentially,and the properties of composite surfactant mainly composed of OCTA·AC and SDBS are better than those of unmodified granular ammonium nitrate.Figure[41]table[36]reference[69]...