Emulsion Explosives Research Articles

Theft-Safe Explosive Mixtures Based on Hydrogen Peroxide: Study of Properties and Built-In Self-Deactivation Kinetics.

The current focus on both environmental and general safety is an important issue in the field of explosives. As such, environmentally-friendly explosives, based on hydrogen peroxide (HTP) as an oxidising agent, are of significant interest. These explosives can be designed to undergo self-deactivation, denying access to them by any unlawful third parties that may attempt scavenging blasting sites for any residual energetic materials. Such deactivation also improves blasting safety, as, after a set time, misfired charges no longer pose any explosive threat. In this work, we have designed HTP-based explosive formulations that undergo deactivation after approximately 12 h. To this effect, Al powders were used both as fuels and HTP decomposition promoters. The shock wave parameters and ability to perform mechanical work of the proposed explosive formulations are comparable to those of dynamites and bulk emulsion explosives, and the details of the changes of these parameters over time are also reported.

Обоснование технологий и средств для проведения горизонтальных горных выработок с использованием эмульсионных взрывчатых веществ

Обоснование технологий и средств для проведения горизонтальных горных выработок с использованием эмульсионных взрывчатых веществ

Liquid CO2 Phase Change Fracturing and Vibration Monitoring in Roadbed Slope Excavation

In order to analyze the vibration impact of carbon dioxide fracturing tube blasting red sandstone, combined with the engineering conditions and surrounding environment of Anqing High-tech Zone, the rock-breaking blasting plan is carefully designed. The fracturing tube is arranged in two rows, the first row has 23 holes with a spacing of 1.5m, and the second batch of holes has 22 holes, which are arranged in a quincunx pattern with a distance of ‘1.3m between the front and rear rows. And design the corresponding vibration signal monitoring test to study the crack propagation caused by blasting, the attenuation law of vibration and its frequency spectrum distribution. The results show that after blasting, there is a relatively smooth crack in the plane area of the fracture zone 7m away from the critical surface. The width of the crack is between 20-40cm. The vibration velocity of the measuring point decays rapidly with the increase of the vibration source distance, and the vibration velocity decay curves in the X and Y directions are basically the same. Spectrum analysis shows that the main frequency band of each sub-velocity is generally below 100Hz, and the main vibration frequencies in the X and Y directions are concentrated in 30∼60Hz. The main vibration frequency band of the rock-breaking blasting vibration signal has little correlation with the direction and propagation distance of the vibration signal. And compared with the analysis of emulsion explosives, it is found that the particle vibration speed caused by the emulsion explosive rock-breaking blasting is much greater than that of the liquid CO2 fracturing tube rock-breaking blasting, indicating that the use of liquid carbon dioxide to break the rock can effectively reduce the vibration generated by blasting.

Assessment of the Parameters of a Shock Wave on the Wall of an Explosion Cavity with the Refraction of a Detonation Wave of Emulsion Explosives

At present, studying the parameters of shock waves at pressures up to 20 GPa entails a number of practical difficulties. In order to describe the propagation of shock waves, their initial parameters on the wall of the explosion cavity need to be known. With the determination of initial parameters, pressures in the near zone of the explosion can be calculated, and the choice of explosives can be substantiated. Therefore, developing a method for estimating shock wave parameters on an explosion cavity wall during the refraction of a detonation wave is an important problem in blast mining. This article proposes a method based on the theory of breakdown of an arbitrary discontinuity (the Riemann problem) to determine the shock wave parameters on the wall of the explosion cavity. Two possible variants of detonation wave refraction on the explosion cavity wall are described. This manuscript compares the parameters on the explosion cavity wall when using emulsion explosives with those obtained using cheap granular ANFO explosives. The detonative decomposition of emulsion explosives is also considered, and an equation of state for gaseous explosion products is proposed, which enables the estimation of detonation parameters while accounting for the incompressible volume of molecules (covolume) at the Chapman–Jouguet point.

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.

Full-scale tests and application of NPGM emulsion explosive at ALROSA

ALROSA performs blasting operations mainly using explosives manufactured on the spot. Considering modern trends of using local manufacture explosives, Company’s experience of application of emulsion explosives, as well as prompt introduction of technological innovations, novel process solutions are utilized in manufacture and use of emulsion explosives. To this effect, Udachny Mining and Processing Plant constructed and commissioned a plant to manufacture non-explosive components for emulsion explosives within the Plant’s infrastructure area. Emulsion explosives enable blasting in open pit and underground mines which are assumed hazardous in terms of oil and gas shows. Within the framework of technical upgrading at MMLT-500-PR Plant, the investment project on construction and commissioning of a modular production line to manufacture packaged emulsion explosives has been implemented. The field trials of NPGM grade emulsion explosive has proved the economic and production efficiency of blasting using this explosive in open pit and underground mining. This article presents the results of testing and application of NPGM emulsion explosive during blasting in open pit and underground mines of ALROSA. The outcomes of pilot explosions using this type explosive as the main borehole and chain charges, as well as intermediate detonators in full-scale conditions of an underground mine and in an open pit are described. The proposed technology features higher operational efficiency and is applicable in various geotechnical conditions of mineral mining.

Effects of Micro‐Encapsulation Treatment on the Thermal Safety of High Energy Emulsion Explosives with Boron Powders

AbstractThe effects of micro‐encapsulation technology on the thermal safety of boron‐containing emulsion explosives were experimentally studied. Micro‐structures of additives, demulsification states and thermal characteristics of boron‐containing emulsion explosives were characterized by the laser particle size analyzer, scanning electron microscope and thermal analysis equipment, respectively. The storage experiments showed that emulsion explosives with boron powders would be demulsified in a short time, while those with micro‐encapsulated boron powders were not demulsified and had good surface morphologies and structures. The results of TG‐DSC experiments showed that the thermal stability of emulsion explosive with polymethyl methacrylate (PMMA) micro‐encapsulated boron powders was higher than that of other samples with boron powders, and the order of thermal stability was as follows: PMMA/Boron sensitized emulsion explosive > Paraffin/Boron‐Glass microspheres (GMs) sensitized emulsion explosive > Boron‐GMs sensitized emulsion explosive. The experimental data of accelerating rate calorimeter (ARC) tests showed that the addition of boron powders would significantly increase the risk of thermal explosion of emulsion explosives under the adiabatic condition, and PMMA micro‐encapsulation for boron powders could largely reduce the thermal explosion risk of boron‐containing emulsion explosives compared with paraffin coating. The coating effect of micro‐encapsulation technology was much better than that of traditional paraffin coating method, and the compatibility and thermal safety of boron‐containing emulsion explosives were also improved.

Substantiation of parameters of mine working drivage with blasting technique and cleaning charges in advance cutting holes

Drilling and blasting operations (D&B) are the most difficult and laborious operations in the process of mineral extraction, requiring permanent development and upgrading of methods and equipment. The aim of the study is to substantiate the parameters of drilling and blasting drivage of horizontal and inclined (up to 12o) mine workings on the basis of high-performance self-propelled equipment and new designs of box cuts with cleaning explosive charges (0.2 kg of 6ZhV ammonite), placed in advance holes of 65 to 105 mm in diameter. The paper presents the results of the analysis of practical experience and scientific achievements in the field of drilling-andblasting rupture of solid media and continuum mechanics. The need for new designs of box cuts, reliability of which in the formation of high-quality (clean) cut cavity reaches 0.95-1.00, was substantiated. New design options of box cuts have been developed, the peculiarity of which consists in provision of sufficient compensation (peripheral) volume with the use of blast hole cut charges for blasting rupture of trapezoidal partitions, with the compensation volume factor of 2.50 to 1.34. Promising areas of research were shown using the example of complicated structure ore deposits and large faults in the Kirovograd ore district and crystalline rocks of the Ukrainian shield at the following mines of Ukraine: PJSC KZhRK, CJSC Sukhaya Balka (Kryvyi Rih), Vostok-Ruda LLC, SE VostGOK (Zheltye Vody), CJSC ZZhRK, etc. Promising areas of research were proposed using the example of complicated structure ore deposits typically formed at the junction of large faults; besides, the use of environmentally friendly emulsion explosives and self-propelled emulsion explosive chargers was recommended.

Control of density and velocity of emulsion explosives detonation for ore breaking

Purpose.Development of a new procedure for calculating the density of emulsion explosives (EE), that will allow determining the detonation velocity along the charging length, depending on the inclination of boreholes during ore breaking. Methodology.A calculation method for the redistribution of EE density and mass in boreholes at different angles of inclination has been developed by using the well-known laws of hydrostatics. Measurement of the detonation velocity of the EE Ukrainit-PP-2B was conducted by using the method of polygon experimental tests. The numerical simulation of changes in the detonation velocity of explosives in boreholes was conducted by using the proposed method and established regularities. Findings.Methods of calculation of EE density changing along the charging column length under the action of hydrostatic pressure at different angles of inclination of both ascending and descending boreholes have been developed. Based on experimental data, regularities of detonation rate changing from density and charge diameter for EE Ukrainit-PP-2B, varying according to exponential law have been established. The rational initial density of EE Ukrainit-PP-2B has been established for ores breaking by boreholes, which is equal to 8001000 kg/m3, at which the detonation rate along the length of the charge column at different angles of inclination of the boreholes is maintained. The obtained results will allow controlling density and detonation velocity during ore breaking. Originality.The density of EE increases in the formed charging column under the action of hydrostatic pressure: in ascending boreholes from the face, while in descending boreholes from the brow. Practical value.Application of the calculation results of EE density at different inclination angles of boreholes makes it possible to determine in the charge column sections with its critical values more than 1410 kg/m3, at which a sharp attenuation of the detonation rate begins. Consideration of this phenomenon makes it possible to prevent the occurrence of failures at the explosion of charges in boreholes during ore breaking.

Novel Jet Cutter Cartridge for Eliminating Deepwater Stuck Pipe Hazards

Pipe sticking is one of technical challenges in the drilling industry that has a major impact on the drilling efficiency and well costs. In order to eliminate deep water stuck pipe hazards, a new type of the jet cutter cartridge is designed. The main structure of the cartridge is a linear shaped charge including hydrogen-based emulsion explosives and copper tubes. During the detonation process of emulsion explosives, the copper tubes form several linear jet cutters along the ring direction to penetrate the stuck drill pipe. Experimental results indicate that the properties of hydrogen-based emulsion explosive meet the requirement to the explosive for the environment of the stuck point. This annular jet cutter cartridge is successfully applied in a copper mine to solve a stuck pipe incident.

Research and substantiation of rational parameters of drilling and blasting operations when using emulsional explosives in underground mining

Purpose. To determine and substantiate the rational parameters of drilling and blasting operations using emulsion explosives such as Ukrainit PP-2B and to develop a methodology for their determination for the effective development of mineral deposits underground mining method. Methodology. To achieve this goal, a set of modern research methods was used, including an analysis of literature sources, design documentation and the practice of mining iron ore deposits at great depths, theoretical generalization of laboratory and industrial experiments, methods and techniques of technical and economic, graphic-analytical, correlation analysis. Results. The regularities of the change in the value of least resistance line from the ultimate strength of the ore to uniaxial compression and the diameter of blast holes were established. The obtained regularities made it possible to develop a methodology for calculating the rational parameters of drilling and blasting operations using an emulsion explosive of the Ukrainit PP–2B type in the deep horizons of the Kryvbas mines. Dependences of the technical and economic indicators of the use of the emulsion explosive of the Ukrainit PP–2B type in ore breaking on mining-geological and mining-technical factors were established. On the basis of the established rational parameters of drilling and blasting operations, a variant of the technological scheme for breaking iron ores by using an emulsion explosive of the Ukrainit PP–2B type with loading of ascending fans of deep wells using a self-propelled charging module RTCh–23 was proposed and economically justified. Originality. Power-law dependences of the least resistance line on the ultimate strength of the ore for uniaxial compression and the diameter of blast holes were established when using an emulsion explosive of the Ukrainit PP-2B type. Practical value. The method is developed for calculating the parameters of drilling and blasting operations with using an emulsion explosive of the Ukrainit PP-2B type in the deep horizons of the Kryvbas mines. The economically justified version of the technological scheme for breaking off iron ores with using an emulsion explosive of the Ukrainit PP-2B type, which will make it possible to achieve an annual economic effect in the amount of UAH 11.9 million. Conclusions. It is established that the use of an emulsion explosive of the Ukrainit PP-2B type is a non-alternative direction in the further development of minerals at great depths, which will make it possible to reduce the cost of the technological process of breaking by 21% and reduce the harmful environmental impact on the world by 2,6–3,9 times.

Specific Features of a Mini-Plant to Prepare Non-Explosive Components of Emulsion Explosives

Specific Features of a Mini-Plant to Prepare Non-Explosive Components of Emulsion Explosives

Experimentation of a new type of permissible explosive under the specific conditions of the Jiu Valley mines

At the underground mining works performed in coal, rock and mixed coal & rocks, the process applied almost exclusively is by drilling & blasting. Given that the mines in the Jiu Valley are classified as methane mines, this involves the use of explosives and means of initiation that are safe from methane gas and coal dust. To date, permissible powdered explosives have been widely used. The drilling & blasting patterns were established according to the physical - mechanical and geological characteristics of the rocks in the massif, the type and section of the mining works as well as the restrictions imposed by the methane regime of the mines. In recent years, the widespread use of emulsion explosives has led to the development of permissible types of emulsion explosives. In order to use the permissible emulsion in the coal mines in the Jiu Valley, it was necessary to test in the INSEMEX landfill the safety and functioning parameters as well as to perform underground blasts, in the specific conditions of the methane coal mines. The paper describes the underground experimental blasting works performed, as well as technical and safety recommendations for the use of this type of explosive - permissible emulsion.

Review of the use of advanced technologies in drilling and blasting

The mining industry is the main blasting process, the quality of performance which depend on all subsequent processes of extraction and processing of minerals. In recent decades, conducting blasting technology has been rapid development. New technologies in drilling and blasting, and include the introduction of high-performance drilling rigs, and the use of safer emulsion explosives, and the use of new means of priming. It is noted that the reduction in cost BSB is mainly achieved through the introduction of electronic blasting initiation system that provides reliable synchronization alternately triggered wells. This technology helps to maximize the use of the control system for the release of explosive energy, and each works well guaranteed in a certain sequence that allows you to avoid the adverse effect of "overlay", ie simultaneous operation of several wells. In addition, significantly reduced the negative influence of seismic and acoustic mass explosions in the environment, reduces the emission of harmful combustion products and dust in the atmosphere. The main result has improved the results of blasting operations, reducing the percentage of oversize and exit screenings, and they thus reduce the cost of excavation, transportation and processing of blasted mass. Currently in production blasting in the world there are different systems of priming. The article discusses the principle of operation and parameters of one of the most advanced in the world - the electronic charge initiation system I-KON™. It is shown that due to the high accuracy of electronic detonators and a wide range of possible delays, it is possible to choose a blasting scheme that exactly matches the conditions for drilling and blasting. The I-KON™ system under consideration contributes to seismic safety and makes it possible to achieve an optimal distribution of the explosion energy in the array. At the same time, BVR optimization is possible by selecting appropriate schemes for mounting the explosive network. The result is a more efficient crushing of the rock mass, which can help reduce drilling and blasting costs.

Influence of Aluminum Additive on the Detonation Velocity and Propulsive Capability of an Emulsion Explosive

Influence of Aluminum Additive on the Detonation Velocity and Propulsive Capability of an Emulsion Explosive

Safety assessment of buried gas pipeline subject to surface explosion: A case study in Wuhan, China

To ensure the safety of the underground gas pipeline in urban ground explosion construction and terrorist attack, a study of the safety of buried gas pipelines under surface explosions is inevitable. In this paper, an operating gas pipeline in Wuhan Economic Development Zone is taken as an example, and the surface explosion full-scale experiment is carried out in the open site. In the field experiment, small charge of No. 2 rock emulsion explosives were used to simulate ground construction blasting, the blasting vibration velocity tester (TC-4850) and dynamic strain measurement system (DH5956) are used to monitor data, the analysis of field data shows that the experimental data meet the general rules, which proves the reliability of the field experiment. Secondly, the numerical model of pipeline response characteristics under surface explosion is established, and the reliability of the model is verified by field monitoring data. In the numerical analysis, the operating pressure of 0.2 MPa is given to the pipeline following the actual working condition, and the response characteristics of the pipeline under the condition of large explosive charge blasting on the surface are discussed. Based on the simulation results, the dangerous section and dangerous point of the pipeline under the action of ground explosion are analyzed, and the functional relationship between the peak effective stress (PES) of pipeline dangerous point and the explosive charge on the surface is deduced. Finally, according to the pipeline control value of PES determined in relevant specifications, the controlled explosive charge of surface construction blasting is obtained. Further, the equivalent conversion analysis of No. 2 rock emulsion explosive and TNT explosive is carried out, and the TNT controlled explosive charge of ground terrorist attack is obtained.

Estimation of factual energetics of emulsion explosives by experimental detonation velocity test data

Estimation of factual energetics of emulsion explosives by experimental detonation velocity test data

Influence of Different Gases on the Performance of Gas‐Storage Glass Microballoons in Emulsion Explosives

AbstractA new type of emulsion explosive sensitized by hydrogen‐storage has been invented previously. To better understand the role of hydrogen in emulsion explosives, the detonation experiments with different gas storage were conducted. Several gases, such as helium, oxygen, and nitrogen, were taken into account. Brisance tests, detonation velocity tests, and underwater detonation experiments showed that the high‐pressure hydrogen can improve the power and energy of emulsion explosive. The adiabatic compression of different gases was calculated. The pressure and temperature of the gas in GMs were obtained. Hydrogen has better compression performance than the other gases. Combining experiments and theoretical calculations can obtain that, hydrogen plays an important role in hot spots formation rate and emulsion explosive energy, and nitrogen and oxygen have little contribution to the energy of emulsion explosive, while helium is difficult to store in GMs and has a negative influence on the performance of emulsion explosive.

Investigation of PE-4 Equivalence of Spherical Emulsion Explosive at Different Point of Initiataion

Investigation of PE-4 Equivalence of Spherical Emulsion Explosive at Different Point of Initiataion

Effects of content and particle size of cenospheres on the detonation characteristics of emulsion explosive

ABSTARCT Cenospheres are the main component of industrial waste of fly ash and taking full advantage of them has good economic and environmental values. In this paper, cenospheres sensitized emulsion explosive was prepared by adding cenospheres into the emulsion matrix as the sensitizers. The effects of content and particle size of cenospheres on detonation performance of emulsion explosives were studied, and the optimum formula was determined by comparing its detonation performance with glass microspheres (GMs) sensitized emulsion explosive. The optimum content and particle size of cenospheres were 12 mass% and 83 μm, and the brisance and detonation velocity were 18.34 mm and 4970 m/s, respectively, which were close to the maximum values of the traditional GMs sensitized emulsion explosive. Air blast experiments indicated that the influence of particle size of cenospheres on the work capability of emulsion explosive was consistent with its explosion power. Shelf-life test and optical microscope results showed that cenospheres sensitized emulsion explosives had good storage stability. Therefore, cenospheres could be a promising physical sensitizer for emulsion explosives.