Blasting Systems Research Articles

Residual Compressive Stress to Increase Strength of Welded Constructions Using Mobile Processing Methods

Abstract Can residual compressive stress, which is etablished using mobile processing methods without the use of specially designed equipment (mobile blasting systems or special hammering equipment), i. e., without noteworthy machine investment, significantly increase the fatigue strength of welded structural steel structures? To answer this question, samples were welded, ground and/or brushed, residual stress states were determined and fatigue tests were carried out. The results obtained show why welded constructions often are characterized by a very different service life. Currently, however, the last operation is not yet used in a standardized, targeted and prescribed manner to ensure a defined and repeatable residual stress state on the surface and thus guarantee a superior fatigue strength of welded assemblies.

Enhancements of Slow-propagation Tungsten-‎Based Delay Compositions for Blasting and ‎Propulsion Systems

Enhancements of Slow-propagation Tungsten-‎Based Delay Compositions for Blasting and ‎Propulsion Systems

Knowledge mapping of research progress in blast-induced ground vibration from 1990 to 2022 using CiteSpace-based scientometric analysis.

Blasting constitutes an essential component of the mining and construction industries. However, the associated nuisances, particularly blast vibration, have emerged as significant concerns that pose threats to operational stability and the safety of the surrounding areas. Given the increasing emphasis on sustainability, ecological responsibility, safety, and geo-environmental practices, the impact of blast vibration has garnered heightened attention and scrutiny. Nevertheless, the field still lacks comprehensive phase analysis studies. Therefore, it is imperative to elucidate the research progress on blast vibration and discern its current frontiers of investigation. To address this need, this study employs bibliometric methods and the CiteSpace 6.1.R2 software to analyze 3093 papers from the Web of Science database. Through this comprehensive analysis, the study aims to chronicle the developmental trajectory, assess the present research status, and identify future trends in the field of blast vibration. The findings of this study reveal that research on "blasting vibration" is advancing rapidly, with the number of citations exhibiting a J-shaped growth curve over time. China emerges as the leading contributor to this research, followed by India, and the foremost institution in this field is Central South University in China. Cluster analysis identifies the effects of ground vibration, numerical simulation, blast load, blasting vibration and rockburst hazard as the most prominent research areas presently. The primary research directions in this domain revolve around therock fragmentation, compressive strength, particle swarm optimization, and ann. The emergence of these keywords underscores a dynamic shift towards a more holistic and multidisciplinary approach in the field of blasting-induced ground vibration. Furthermore, this study provides a concise overview of blast vibration, discusses prediction techniques, and proposes measures for its control. Additionally, the discussion delves into the social significance of intelligent blasting systems within the context of artificial intelligence, aiming to address the hazards associated with blast-induced ground vibrations.

Обоснование эффективности взрывных работ с использованием электронных систем в сравнении с неэлектрическими средствами инициирования

Carrying out large-scale blasting using non-electric primers in surface mining is concerned with a number of deficiencies, one of which being the error in borehole and surface delay times. As a consequence, the design blasting system is compromised, the face blasting rates are affected, and the rock mass fragmentation quality goes down. Due to their advantage in the triggering accuracy, the electronic blasting systems ensure absolute control over the execution of large-scale blasting, reduce the negative impact of blasting operations on residential areas near the surface mine and improve the quality of rock mass fragmentation. Electronic blasting systems enable the development of new ways to execute blasting, for example, though selecting the face blasting rates, which in turn increases the rock mass fragmentation quality and reduces dilution. The paper presents comparative indicators of bias in the nominal delay times of various non-electric primers and electronic blasting systems, discusses the components and designs of electronic detonators, and provides a number of advantages of the electronic systems in conditioning of the the preparation of blasted rock. A conclusion is made that blasting with electronic detonators and the use of their advantages will help to reduce the specific consumption of explosives and the scope of drilling operations due to larger blasthole patterns.

Оценка качества капсюлей-детонаторов (с пиротехническим замедлением) неэлектрических систем инициирования по времени их срабатывания

Blasting operations in surface and underground mining are characterized by the need to protect the environment from harmful effects of the detonation products of explosives, the fly rock zone, the seismic manifestations of the blast, as well as airborne shock waves. Non-electric blasting systems by various manufacturers are used in Russia, but all of them have certain advantages and disadvantages. It can be stated that the blasting caps of the applied blasting system do not always correctly execute the firing times specified by their manufacturer. Mismatches of the actual firing times from the rated ones might be so great that the applied blasting systems sometimes produce disturbances in the order of charge firing, which, in turn, may cause detonation failure in the boreholes. Studies have shown that in order to reduce the risk of detonation failures, regardless of their causes, it is recommended to initiate the borehole at two points with placing the second primer in the upper part of the borehole, or using extended priming charges.

Positive Phase Pressure Function and Pressure Attenuation Characteristic of a Liquid Carbon Dioxide Blasting System

As environmental requirements become more stringent, the liquid carbon dioxide blasting system is one of the non-explosive blasting technologies that, with low tensile stress energy, will replace the chemical explosive blasting technology, and the impact pressure characteristic of high-pressure fluid is a crucial factor in the process of rock breaking. To further investigate the impact and pressure attenuation characteristics of high-pressure fluid during the phase transition of liquid carbon dioxide blasting system, the pressure curves of high-pressure fluid in liquid carbon dioxide blasting systems at different distances were measured in the laboratory. Based on the mechanism analysis of phase transition kinetics, the initial jet velocity of the four experiments was calculated, and the rationality of results was verified by the Bernoulli equation. The general expression of the positive phase pressure–time function was proposed, and the idealized impact pressure curve can be divided into five stages. The impact pressure field of the liquid carbon dioxide blasting system can be divided into three areas at different distances: the explosive jet impact zone, the jet edge zone and the shock wave action zone, and the pressure–contrast distance fitting equation of the liquid carbon dioxide blasting system were obtained.

Thermodynamic properties and explosion energy analysis of carbon dioxide blasting systems

ABSTRACTA carbon dioxide (CO2) blasting system is a reusable non-explosive blasting product that can be used in many engineering applications. To investigate the influences of thermodynamic properties of liquid CO2 and its explosion energy during the phase transition, the pressure within the blasting tube was measured in a laboratory for a liquid CO2 blasting system. Based on the measured pressure curve, the CO2 blasting process can be divided into three stages: pressure rising stage, pressure release stage and pressure recovery stage. The evolutions of temperature, pressure, phase transition and explosion energy of the CO2 blasting system were analysed in detail in this work. The results show that the variation rate of temperature increases as the initial density of CO2 decreases. The effect of initial CO2 density on its isochoric heat capacity is also significant as the lower the initial density, the higher the peak specific heat capacity at the critical temperature. Based on the Span and Wagner CO2 equation of state and the thermodynamics of explosions, a method is proposed to calculate the explosion energy of CO2 blasting systems. This method produces more accurate and realistic results.

Controlled Blasting in a Limestone Mine using Electronic Detonators: A Case Study

ABSTRACT Except for very deep-seated deposits, open cast mining method has been recognized as the safest and most productive mode for mining minerals. Ever growing demand in minerals and coal has compelled the mine operators to increase the size of mine, which has resulted in an increasing trend towards large capacity open cast projects. Explosives and blasting techniques play a significant role in efficient opencast mining operations. There have been constant technological developments towards safer, faster, economical and more efficient blasting systems. Further, globally increased competitiveness has necessitated to carryout blasts in such a way that the desired degree of fragmentation is achieved in the primary blast, with minimum undesired side effects such as ground vibration, air blast/noise, flyrock, generation of oversize boulders, formation of toe, and over break or back break. Hence, the ultimate objective of the blasting engineer is to ensure that the blasts are carried out in an eco-friendly manner. This paper presents a case study of limestone mine where a controlled blasting was conducted near a green structure of wagon tippler (at 2 m) being constructed for foundation work of belt conveyor as the mine management wants to double the existing production. This paper deals with controlled blast design and its implementation using electronic detonators with signature hole technique.

Numerical investigation of multiphase supersonic swirl flow inside convergent-divergent nozzle

Numerical study of multiphase swirl flow induced by helical insert inside the supersonic nozzle is investigated as applied in sandblasting systems. The finding of this research is crucial in improving the performance of abrasive blasting systems by reducing operation time and saving energy. Simulations are performed with Reynolds Stress Model turbulence modelling to capture anisotropy inside the flow. To simulate particles inside the nozzle, discrete phase model has been applied. The multiphase Eulerian method did not provide accurate results on modelling particles with small volume fraction ( <10%), and also it was not capable of modelling particles interaction. The analyses are performed at three inlet pressures (2, 3 and 4 atm) with constant mass flow rate for particles. The results show that swirl effect increases the mixing feature of the flow, and therefore increases the cleaning area on a working surface. Furthermore, with swirl there was less reduction in maximum velocity compare with single phase simulations, hence particles will have greater speed at the exit of the nozzle.

Road safety audit on a major freeway: implementing safety improvements

The paper presents (i) the method followed in a road safety audit of Attica Freeway (“Attiki Odos”), (ii) the findings and recommendations which arose from the RSA, (iii) the improvements made by the freeway operator to improve safety, and (iv) the pilot safety treatments which were proposed with a view to broader implementation in order to mitigate similar problems at other locations. The Road Safety Audit team conducted the RSA with the goal of identifying potentially dangerous roadway or traffic features of the freeway operating environment, as well as potentially misleading or missing information by the applying the safety principles of positive guidance and self-explaining roads. The RSA findings were recorded in the RSA report together with recommendations for implementation. On the basis of the RSA findings, the freeway operator decided on the prompt implementation of several countermeasures, and in cooperation with the RSA team submitted to the Ministry of Infrastructure a proposal for pilot implementation of safety improvements included in the RSA report. An important factor determining the effectiveness of the RSA was that the RSA recommendations were implemented shortly after the RSA was completed. Preliminary results from a before-and-after analysis of data regarding skid resistance characteristics, speeds and crashes at locations where RSA recommendations had been implemented showed improvements in skid resistance characteristics and a reduction in the number of crashes and incidents. The RSA of Attica Freeway promoted the implementation of innovative road safety measures such as shot blasting and motorcyclist-friendly restraint systems.

The Latest Generation of the Electronic System Enhanced Safety and Productivity

Digital blasting systems represent a new, enabling step forward in mining process optimization, providing the mining industry with different ways to improve operational efficiency or even to develop new extraction methods. The new features of the systems also reinforce both the security and the safety of the blasting process. At this point in time; the second decade of the commercial use of electronic detonators, we introduce the fourth generation system; DTSP. As the need for efficiency increases in the mining and construction industry operations, Davey Bickford has adapted its technology to meet this demand. As the use of the system is taken up by many companies, the achievable benefits are more extensively monitored and accepted in many blasting operations. Two principal points are explained in this paper. Firstly; new system features such as RFID, GPS, multiblasting, synchroblasting, remote blasting through wireless networks, etc. are explained. Secondly a number of case studies are used to demonstrate the value added by these technologies, for the mining operations. These case studies include a large open cast mine in North America as well as a number of surface quarries where electronic initiation has been adopted for specific reasons, including safety, environmental compliance, productivity, and economic concerns. The current initiation techniques are described, as are the Key Performance Indicators used in the quantification of benefits and justification process. While emphasis is placed on the opportunities that the technology offers, constant consideration is always given to the practical aspects of the blasting process, which will ultimately drive the success or failure of this program.

A Study on Cost Optimization of Steel Shot Blasting Systems

This paper introduces a new study on cost optimization of steel shot blasting systems. In the study, the influences of blasting process parameters such as air pressure, nozzle diameter, cost components as well as the effect of the nozzle wear on the cleaning cost were investigated. For calculation of the optimum exchanged nozzle diameter (called optimum diameter) a regression model was proposed. By using this model, both cleaning cost and cleaning time can be reduced considerably.

The application of airless wheel blasting systems

Summary Airless wheel blasting is a highly productive and efficient process if applied properly. Remember to thoroughly consider the information obtained from the questions presented above regarding part, production, and machine design factors. Selecting the correct system will depend on the ability to evaluate and understand the factors that relate to an airless wheel blast system and applying that knowledge to meet specific surface preparation needs.

A Study on Multi-Objective Optimization of Abrasive Blasting Systems

This paper introduces a study on a multi-objective optimization problem of abrasive blasting systems. The aim of the study is to find the optimum exchanged diameter of boron carbide nozzles. In the study, the effects of several parameters such as the maximum nozzle diameter, the nozzle wear and the cost components on the optimum initial nozzle diameter were taken into account. From the study, a regression model for determination of the optimum initial diameter of boron carbide nozzles was introduced.

Seismic vibrations in bulk blasting with high-precise electronic and nonelectric blasting systems at quarries

The authors report measurement data on seismic waves in bulk blasting at quarries by using new high-precise electronic and pyrotechnic blasting systems. It is proved that both systems are efficient, intensity of seismic waves is much lower in large-scale bulk blasting. The authors implemented numerical modeling of seismic wave propagation under a short-delay bulk blast at a quarry. Influence of the blast delay parameters and their precision on the maximum level of seismic vibrations has been studied, and their optimal ranges have been established.

Profit Optimization of Abrasive Blasting Systems

This paper presents a new study on profit optimization of abrasive blasting systems. In the study, the effects of many parameters such as the air pressure, the initial nozzle diameter, the cost components and the nozzle wear on the profit rate were investigated. Based on the results of the optimization problem, regression models for determination of the optimal exchanged nozzle diameter in order to get the maximal profit rate were proposed. With “optimal diameter”, both the profit rate and the cleaning time can be reduced significantly.

Cost Optimization of Abrasive Blasting Systems: A New and Effective Way for Using Blasting Nozzles

This paper introduces a new and comprehensive study on cost optimization of abrasive blasting systems. In the study, the effects of many parameters such as nozzle diameter, air pressure, efficiency, cost components as well as the effect of the nozzle wear on the cleaning cost were investigated. A new model for calculation of the optimal exchanged nozzle diameter (called “optimal diameter”) was proposed. With “optimal diameter” a new and effective way of using and making blasting nozzles was proposed and both the cleaning cost and the cleaning time can be reduced significantly.

Further Field Applications of Electronic Detonator Technology

The increasing use of the Daveytronic digital programmable detonators is continuing to yield data reinforcing earlier studies concluding that accurate timing will provide substantial performance and economic benefits. This study quantifies performance increases as they relate to fragmentation, excavation, vibration control and productivity in a limestone aggregate mining operation. High levels of field controls were adhered to during the drilling and blasting process as they related to blast design, bench preparation, pattern layout, drilling and blasthole loading. Following each blast, the fragmentation composite of the post-blast muckpile was quantified. The excavation and crushing procedures were then studied to quantify any down stream advantages due to improvements in fragmentation. This study will help provide the industry with more information as to the advantages of high accuracy electronic blasting systems over conventional pyrotechnic systems.

Abrasive blasting systems

Abrasive blasting systems

Abrasive blasting systems

Abrasive blasting is the process of propelling abrasive particles from a blast machine using the power of compressed air. Three fundamental components constitute a blast equipment setup: air compressor, blast machine, andabrasive. The compressor must produce sufficient air pressure and volume to convey abrasive from the blast machine to the surface being blasted. Cleaning takes place as a direct result of how efficiently air moves from the compressor to the surface. A restriction in just one part reduces the entire system's production rate. A blast machine's role is to smoothly meter abrasive into the passing air stream. Sometimes, contractors install restrictive air fittings or hoses that actually cut the airflow in half. Avoid these self-imposed problems by selecting a blast machine with large-diameter piping and by connecting it to large-diameter air and blast hoses. The third major component in the blasting system is the abrasive. It produces the finish on the surface. Match the abrasive material and size to the surface being blasted to ensure the best possible finish, cleaning speed, and cost efficiency. Count on your abrasive supplier to recommend the best abrasive for the job. With these three components in place, a trained, skilled blast operator has the tools to produce a flawlessly finished surface.