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.

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.

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.

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.

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.

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.

Reliability investigation of demolition initiation network for urban viaduct

This paper presented the delay characteristics of relay point detonator used in multiple parallel initiation networks and proposed the simple formula to calculate expectations of relay point initiation time.Corresponding reliability standards were established based on the different scale of non-electric initiation network.A multiple parallel initiation network were created,which could not only avoid the occurrence of the viaduct rollover during dumping process,but also improve the reliability standard and realize the unlimited segmentation.Results could provide a good reference for the design of viaduct blasting initiation network.