Influence of an emulsifier on the pressure desensitization of emulsion explosives

The desensitization degree of emulsion explosives （EE） was calculated with the peak pressure of explosion shock waves tested in water. To an explosive, the less the desensitization degree, the better the compression resistance, so the compression resistance of an explosive can be compared and analyzed quantificationally with the desensitization degree. The influence of an emulsifier on the pressure desensitization of EE was studied, including the content and category of emulsifiers. Three kinds of emulsifiers （Span-80, compound emulsifier, and T-152） were used in the tests. The experimental results show that both the content and category of emulsifiers make a great effect on the pressure desensitization of EE. The desensitization degree of EE reduces with the emulsifier content being increased, but there is an optimal content of an emulsifier for the compression resistance of EE. While the content of Span-80 reaches 4wt%, the desensitization degree of EE becomes a minimal value, and augments somewhat if the emulsifier content is increased more. That is to say, the compression resistance of EE becomes the highest while the content of Span-80 is 4wt%, and the compression resistance will decline if the content of Span-80 is increased more. The compression resistance of the explosive emulsified by compound emulsifier is the highest among all the explosives, when the content of the whole components and manufacturing engineering are kept invariable.

3D direct writing and micro detonation of CL-20 based explosive ink containing O/W emulsion binder

The booming development of DIW technology present an unprecedented prospect in energetic materials field and has attracted great interest due to its relative simplicity and high flexibility of manufacturing.Herein,a novel CL-20 based explosive ink formulation have been developed successfully for MEMS initiation systems via DIW technology.We designed PVA/GAP into an oil-in-water(O/W)emulsion,in the way that the aqueous solution of PVA as water phase,the ethyl acetate solution of GAP as oil phase,the combination of Tween 80 and SDS as emulsifier,BPS as a curing agent of GAP.The ideal formulation with good shear-thinning rheology properties and clear gel point was prepared using only 10 wt%emulsion.The dual-cured network formed during the curing process made the printed sample have good mechanical properties.The printed samples had satisfactory molding effect without cracks or fractures,the crystal form of CL-20 not changed and the thermal stability have improved.Deposition of explosive inks via DIW in micro-scale grooves had excellent detonation performances,which critical detonation size was 1×0.045 mm,detonation velocity was 7129 m/s and when the corner reaching 150°can still detonated stably.This study may open new avenues for developing binder systems in explosive ink formulations.

Explosion temperature mapping of emulsion explosives containing TiH_(2)powders with the two-color pyrometer technique

In the study,the two-color pyrometer technique was used to measure the transient temperature field of emulsion explosives with different contents of TiH_(2)powders.The experimental results showed that the introduction of TiH_(2)powders could significantly increase the explosion temperature and fireball duration of emulsion explosive.When emulsion explosives were ignited,the average explosion temperature of pure emulsion explosive continuously decreased while emulsion explosives added with TiH_(2)powders increased at first and then decreased.When the content of TiH_(2)powders was 6 mass%,the explosion average temperature reached its maximum value of 3095 K,increasing by 43.7%as compared with that of pure emulsion explosive.In addition,the results of air blast experiment and explosion heat test showed that the variation trends of shock wave parameters,explosion heat and theoretical explosion temperature of emulsion explosives with different contents of TiH_(2)powders were basically consistent with that of explosion temperature measured by the two-color pyrometer technique.In conclusion,the two-color pyrometer technique would be conducive to the formula design of emulsion explosive by understanding the explosion temperature characteristics.

Effect of hydrogen-storage pressure on the detonation characteristics of emulsion explosives sensitized by glass microballoons

In this study,hydrogen-storage glass microballoons were introduced into emulsion explosives to improve the detonation performance of the explosives.The effect of hydrogen-storage pressure on the detonation characteristics of emulsion explosives was systematically investigated.Detonation velocity experiments shows that the change of sensitizing gas and the increase of hydrogen pressure have different effects on the detonation velocity.The experimental parameters of underwater explosion increase first and then decreases with the increase of hydrogen pressure.The decrease of these parameters indicates that the strength of glass microballoons is the limiting factor to improve the detonation performance of hydrogen-storage emulsion explosives.Compared with the traditional emulsion explosives,the maximum peak pressure of shock wave of hydrogen-storage emulsion explosives increases by 10.6%at 1.0 m and 10.2%at 1.2 m,the maximum values of shock impulse increase by 5.7%at 1.0 m and 19.4%at 1.2 m.The stored hydrogen has dual effects of sensitizers and energetic additives,which can improve the energy output of emulsion explosives.

Rheology of typical emulsifiers and effects on stability of emulsion explosives

Structure of emulsifiers or functionality and molecular weight determines its rheology, emulsification and stability of emulsion explosives. Rheology of typical emulsifiers was studied by automatic rheometer. Relations between rheology and structural properties of typical emulsifiers were analyzed. Experimental results show that viscosity of emulsifiers didn＇ t change with shear rate at room temperature and appeared properties of Newtonian fluid. Viscosity of different component emulsifiers declines with temperature in different modes. The change of strain doesn＇ t affect modu- lus of emulsifiers. Loss modulus increases linearly with the increase of frequency in oscillation and storage modulus does non-linearly. The higher the temperature is, the lower change amplitude of loss modulus with frequency will be. The emulsifiers with imide and amide functionality for emulsion explosives have better shear properties at high temperature and better shapingness and stability at room temperature than other emulsifiers with ester and Sorbin Monoleate （SMO） functionality.

An optimizing selection model in preparation of powdery emulsion explosives

In order to get cheap and excellent PEE (Powdery Emulsion Explosives), themodel of optimizing selection on preparation of PEE was established by the Neural Net Theory (NNT).On the basis of some data in the study of PEE, the training, prediction and optimizing selection ofthe Neural Net (NN) model were finished by compiling procedures. The results indicate that the modelis helpful to the preparation of PEE and worthy to extend and apply broadly.

Experimental research on influence of emulsifier on crystallization quantity of emulsion explosives under dynamic pressure

Dynamic pressure was applied on emulsion explosive by using an underwater explosion measuring apparatus, and the crystallization quantity was measured by dissolution method after emulsion explosive was pressed; the influence of emulsi- fier content and type was analyzed. The experimental results show that emulsifier content and type have an important effect on crystallization quantity of emulsion explosive. The crystallization quantity will reduce with Span-g0 content from 2% to 4%, so the demulsification and crystallization will decrease if the emulsifier content improves appropriately and the dynamic pressure resistance will increase. For emulsion explosive emulsified by T-152 and Span-g0, the crystallization quantity with T-152 is less than that of Span-g0 under the same dynamic pressure. This shows that the emulsifying effect ofT-152 is better than Soan-80.

LOGARITHMIC GAUSS NORMAL DISTRIBUTION OF MICROLATEX PARTICLE OF EMULSION EXPLOSIVES

Microlatex particles of emulsion explosives determined by microphotography were studied with the law of logarithmic Gauss normal distribution, and results obtained showed that the microlatex particle just possessed the law of logarithmic Gauss normal distribution. The particle diameter in statistical average value, such as DNL, DNS, DLS, DSV and DVM was calculated through the diagram of logarithmic Gauss normal distribution of microlatex particles of emulsion explosives, so was SW.

Major hazard sources analysis and prevention measures of packaging emulsion explosive production line

Emulsion explosive with favorable water-resistance performance,storage performance and detonation stability has been widely used in all over the world.The development actuality and production technique characteristics of emulsion explosive in China were introduced firstly.Taken the technique characteristics of packaging emulsion explosive into account,major hazard sources of emulsion explosive production line were analyzed.Finally,prevention measures based on inherent safety of emulsion explosive production were put forward.

COMPATIBILITY OF EMULSIFIERS IN EMULSION EXPLOSIVES

Compatibility of polyisobutylene succinimide emulsifier with Span-80 emulsifier and with paraffine oil as continuous phase in emulsion explosives was studied by fluid viscosity with thermodynamic methods. The Obtained results showed that the compatibility was excellent, and that the coemulsifier from polyisobutylene succinimide and Span-80 could be formed emulsion co efficient effect at the interface between the continuous oil phase and discontinuous water phase.

Prediction of concentration of toxic gases produced by detonation of commercial explosives by thermochemical equilibrium calculations

An adverse effect resulting from explosive mine blasts is the production of toxic nitrogen oxides(NO and NO_(2)) and carbon monoxide(CO).The empirical measurements of the concentration of toxic gases showed that it depends not only on the composition of an explosive and properties of its ingredients but also on several other parameters,such as volume of blasting chamber,explosive charge mass and design,confinement characteristics,surrounding atmosphere,etc.That explains why measured concentrations of toxic gases reported in literature significantly differ.In this paper,we discuss the possibility of theoretical prediction of the concentration of toxic gases by thermochemical equilibrium calculation applying two models:ideal detonation model and deflagration model.It can be demonstrated that thermochemical calculations can provide a good estimation of the measured concentrations and reproduce experimentally obtained effects of additives on the production of toxic gases.It was also found that the ideal detonation model applies to heavily confined explosive charges,while the deflagration model is more suitable for low detonation velocity explosives with light confinement.

负压条件对T2/Q235爆炸焊接复合板界面的影响

为了探究负压条件对T2/Q235爆炸焊接复合板界面的影响,选用硅藻土敏化的低爆速粉状乳化炸药作为焊接专用药,T2为覆板,Q235为基板分别在100、60、20kPa环境压力下进行爆炸焊接试验;采用金相分析等方法研究了复合界面的形貌特征和元素组分,采用数值模拟进一步揭示了负压爆炸焊接机理。结果表明,负压条件会增大粉状乳化炸药的装药密度,但爆速变化不大,20kPa条件下猛度比常压条件下提高8.4%;随着环境压力的降低,复合板界面波高和波长逐渐增大,20kPa条件下波高比常压下增加了49%,波长增加了23%;负压条件下T2/Q235结合面氧元素含量低于常压环境;数值模拟结果表明,T2/Q235界面波随着炸药的装药密度变大而增大,与实验结果一致。在爆炸焊接时密度为0.8g/cm^(3)(20kPa)比0.711g/cm^(3)(常压)炸药碰撞速度提高了16.3%,碰撞压力提高了66.3%。研究表明,负压相比于常压条件提高了爆炸焊接的炸药能量利用率。

内相粒径对现场混装乳化基质老化过程的影响

为研究内相粒径对现场混装乳化基质老化过程的影响,利用可程式高低温箱对乳化基质进行周期性储存来加速基质老化,使用激光粒度仪、光学显微镜、水溶法和数字黏度计测试乳化基质老化过程中的内相粒径、微观结构、硝酸铵析晶量及黏度的变化。测试结果表明:内相粒径为9.47μm的现场混装乳化基质在储存1个周期后就已严重析晶,在储存3个周期后硝酸铵析晶量为储存前的3.32倍,黏度增大45.72%。内相粒径为3.76μm的现场混装乳化炸药在储存2个周期后平均内相粒径增大为10.06μm,硝酸铵析晶量为储存前的1.43倍,黏度增大10.18%,储存3个周期后的硝酸铵析晶量为储存前的1.71倍,黏度增大14.48%,内相粒径越小,现场混装乳化基质的储存稳定性越好。在实际生产中,应根据混装车设备性能的实际情况,考虑基质泵送及其安全性,尽可能制备内相粒径约小于5μm、黏度合理的乳化基质,用以生产现场混装乳化炸药。

添加复合稀释剂的低爆速乳化炸药的制备及性能

以玻璃微球和滑石粉共同作为稀释剂制备一种低爆速乳化炸药。观察不同质量分数的玻璃微球和滑石粉对乳化炸药形貌的影响,并对乳化炸药的爆速、猛度、空中爆炸冲击波压力及储存稳定性进行测试。实验结果表明,随着滑石粉质量分数的增加,乳化炸药的形貌由乳胶状逐渐向颗粒状转化,爆速呈线性下降,对玻璃微球质量分数为5%、10%、15%的乳化炸药,测得最低爆速分别为3440、2740、2188 m/s。而随着滑石粉质量分数的增加,猛度、空中爆炸冲击波峰值超压均呈非线性下降,当滑石粉控制在一定量时,冲击波正压作用时间变化不大,乳化炸药储存稳定性较好。这种低爆速乳化炸药成本低廉、爆轰性能可调、储存稳定性好,具有较好的实用性。

低温环境对乳化炸药爆炸性能的影响

在低温条件下乳化炸药爆炸性能的下降会严重影响爆破效果,研究药体温度改变后乳化炸药爆炸性能的变化规律具有一定的工程应用价值。为此,设计了一系列乳化炸药药体温度精确控制装置,对药体温度为25、0、-5、-10、-15℃的乳化炸药的爆速、猛度、做功能力及空中爆炸冲击波超压进行测量,并观察乳化炸药的微观结构。实验结果表明:当药体温度由25℃降至-15℃时,炸药的爆速由4227 m/s降至3291 m/s,猛度由13.0 mm降至5.2 mm,做功能力由323 mL降至208 mL,爆炸冲击波超压由284.9 kPa降至115.8 kPa。随着药体温度的降低,硝酸铵析晶量增加,乳胶粒子的局部结构被破坏,致使乳化炸药的微观结构发生变化,爆炸性能降低。低温环境对乳化炸药猛度的影响最大,对爆速的影响最小;随着温度的降低,爆炸性能的降幅增大。在工程应用中,需综合考虑爆炸性能的降幅进行爆破参数设计。

以废弃煤矸石为惰性剂的低爆速乳化炸药性能研究

为了研制低成本、低爆速乳化炸药,并将大量废弃的煤矸石进行废物利用以减小环境污染,将3种不同粒径的煤矸石粉末作为惰性剂,添加入乳化炸药中进行了爆速测试、空中爆炸冲击波超压试验和TG-DSC同步热分析。试验表明,随煤矸石粉末质量分数由0%升至40%,爆速呈降低趋势,其中含较小粒径粉末的炸药爆速要较低,当3#煤矸的质量分数达40%时爆速降至2 755 m/s,空中爆炸冲击波超压峰值由48.53 kPa降至22.23 kPa,正压时间从343.15μs升至426.10μs,压力上升速率由2.210 9 kPa/μs降至0.369 1 kPa/μs,正相冲量减少25.44%。可见煤矸石可有效降低乳化炸药的爆速和爆轰冲击载荷。热分析结果表明,煤矸石粉末未显著改变乳化炸药热分解结果,仅使热分解温度下降29~34℃,仍处于乳化炸药合理的热分解温度范围。

含双子表面活性剂的新型油相材料制备与性能研究

为了增强乳化炸药的稳定性和爆炸性能,在传统基于失水山梨醇单油酸酯(Span80)和聚异丁烯丁二酰亚胺(T154)的复合油相材料中加入阳离子双子表面活性剂18-2-18,设计了一种新型复合油相材料,并以此制备了乳化炸药,测试了复合油相材料主要性能参数,考察了18-2-18含量对乳化炸药的乳胶基质粘度、内相粒径及爆炸性能的影响。结果表明:加入18-2-18的新型复合油相材料的酸值、水分、粘度、滴熔点等指标均达到工业生产标准;与传统复合油相材料相比,新型复合油相材料中的18-2-18含量为0.7%时,其乳化剂含量从38.0%降低至23.7%,降低了复合油相材料的生产成本;乳胶基质内相粒径由4.00μm减小到1.22μm,提高了乳胶炸药的稳定性;乳化炸药爆速达到5042 m·s^(-1),且20次高低温循环后仍然能够稳定爆轰,爆速为4512 m·s^(-1)。

模拟高原环境下敏化方式对乳化炸药爆轰性能的影响研究

为研究高原环境对不同敏化方式乳化炸药的影响程度,选取3种典型的敏化材料制备乳化炸药样品,模拟并对比分析了高原环境(-20℃、约0.05 MPa)储存后乳化炸药的微观结构和爆轰性能变化。结果表明:低温低压下的高原环境主要从加剧破坏乳化体系稳定性与热点分布两方面影响炸药的性能,在该环境下化学敏化炸药相较于物理敏化炸药的析晶程度较低,但热点变化较大,导致爆轰性能下降;物理敏化中,膨胀珍珠岩炸药晶体的生长方式更加复杂,因此更易破乳析晶,储存稳定性与爆轰性能均有明显降低;相对而言,树脂微球炸药在低温低压下的析晶程度与爆轰性能均较稳定。综合上述结果,树脂微球乳化炸药具有更好的高原适应性。

含硫化铁杂质的乳化炸药意外爆炸现象研究

为了解硫化铁杂质对乳化炸药热稳定性和自燃的影响,本文借助SEM、TG-DSC以及高温热台等设备对含硫化铁乳化炸药的热稳定性和点火燃烧过程进行分析。实验结果表明:乳化炸药自身具有较强的热稳定性,但是当其掺杂硫化铁杂质时,乳化炸药在较低温度下就可以发生分解反应,其热稳定性得到大幅度降低;硫化铁杂质可以明显降低乳化炸药燃烧的火焰持续时间,同时可以提升乳化炸药燃烧的火焰高度、亮度、面积和燃烧强度。

露天煤矿富水深孔爆破间隔器研发与应用

为解决露天矿开采中,遇到的富水炮孔无法安装空气间隔器进行间隔装药爆破的问题,在分析空气间隔器适用性和结构的基础上,研发了一种水孔专用间隔器,用于减少乳化炸药使用量。通过地面实验与现场检验的方式研究了水孔间隔器的膨胀效果、对乳化炸药的支撑作用,以及对爆破效果的影响。结果表明:该水孔间隔器应用于富水深孔爆破中,爆破后爆堆情况、大块率和铲装后根底均与周边非间隔装药爆破情况相当,实现了降本增效。