Wyniki wyszukiwania - BazTech

1

Economic and environmental aspects of using mining equipment and emulsion explosives for ore mining

Kononenko Maxim, Khomenko Oleh, Myronova Inna, Kovalenko Ihor

Mining Machines

|

2022

|

vol. 40, iss. 2

88--97

EN

The calculation of economic efficiency during the preparatory mine operations using various mining equipment and types of explosives was performed. The general exponential regularity of determining the cost of carrying out 1 m3 of working depending on the strength of rocks to compression when using different types of explosives and tunneling equipment was established. An environmental assessment of the use of emulsion explosives in an iron ore mine showed a decrease in concentrations of environmentally hazardous substances and a decrease in environmental hazard coefficients, which resulted in a decrease in the pollution of the atmospheric air.

2

The Effect of the Energetic Additive Coated MgH2 on the Power of Emulsion Explosives Sensitized by Glass Microballoons

Cheng Y., Wang Q., Liu F., Ma H., Shen Z., Guo Z., Liu R.

Central European Journal of Energetic Materials

|

2016

|

Vol. 13, no. 3

705--713

EN

Traditional emulsion explosives, in spite of excellent water resistance, safe handling and good storage performance, have low power problems which seriously hinders their use. In order to improve the power of emulsion explosives, a hydrogen based emulsion explosive was devised. Scanning electron microscope pictures and experimental storage results show that the coating effect and stability of coated magnesium hydride (MgH2) are very good. The power of an emulsion explosive sensitized by glass microballoons was significantly increased (24.30 mm compression of lead block) after adding coated MgH2, compared to only 16.10 mm compression when not added. Thus emulsion explosives with coated MgH2 as an energetic additive have many potential applications.

3

Influence of the Shape of an Explosive Charge: Quantification of the Modification of the Pressure Field

Simoens B., Lefebvre M.

Central European Journal of Energetic Materials

|

2015

|

Vol. 12, no. 2

195--213

EN

Many scientific articles dealing with the detonation of explosive charges and their effects suppose that the charge is spherical and centrally initiated. Yet, when discussing the blast wave effect, the charge shape and the location of initiation could be as important as the composition or the mass of the considered explosive. Specifically, close to the charge, the shape may cause significant modifications of the pressure field compared to the predictions developed for spherical charges. Experiments have been carried out, using an emulsion explosive, TNT and C4, in order to quantify the shape effect. Unconfined, centrally initiated spherical and cylindrical charges with different length-to-diameter (L/D) ratios have been fired. The pressure in the median plane was recorded for different reduced distances. Results for spherical charges showed excellent agreement with well-known references. The expected change of the pressure field in the median plane of a cylindrical charge was observed, directly linked to the L/D ratio. Peak overpressure magnifications of up to almost 3 have been measured. The dimensions of the zone within which an increase of the blast wave effect is observed, have also been determined. A similar behaviour for TNT and C4 has been demonstrated; but a different behaviour has been observed for the emulsion explosive.

4

On Possibility of Detonation Products Temperature Measurements of Emulsion Explosives

Silvestrov V. V., Bordzilovskii S. A., Karakhanov S. M., Plastinin A. V.

Archives of Metallurgy and Materials

|

2014

|

Vol. 59, iss. 3

1151--1154

EN

The new view on the structure of the radiance signal recorded by optical pyrometer and the preliminary results of brightness detonation temperature of the emulsion explosive are presented. The structure of an optical signal observed is typical for the heterogeneous explosives. First, there is the short temperature spike to 2500 ÷ 3300 K connecting with a formation of “hot spots” assembly that fire the matrix capable of exothermal reaction. Then the relaxation of radiance to equilibrium level is observed that corresponds to brightness temperature 1840 ÷ 2260 K of explosion products at detonation pressure 1 ÷ 11 GPa. Experimental results are compared with the calculations of other authors. The detonation temperature of the investigated explosive is measured for the first time.

PL

Przedstawiono nowy sposób analizy struktury promieniowania rejestrowanego przy użyciu pirometru optycznego oraz wstępne wyniki pomiaru temperatury promieniowania w procesie detonacji emulsyjnego materiału wybuchowego. zaobserwowano, że struktura rejestrowanego sygnału optycznego jest typowa dla niejednorodnych materiałów wybuchowych. Początkowo obserwuje się krótkotrwały pik temperaturowy o wartości 2500 ÷ 3300 K, związany z formowaniem się “gorących punktów”, które zapalają matrycę zdolną do reakcji egzotermicznej. Następnie, obserwuje się relaksację promieniowania do poziomu równowagi, które odpowiada temperaturze produktów eksplozji o wartości 1840 ÷ 2260 K, przy ciśnieniu detonacji 1 ÷ 11 GPa. Wyniki pomiarów uzyskane w niniejszej pracy (po raz pierwszy prezentowane w literaturze) porównano z wynikami obliczeń innych autorów.

5

Enhancement of Explosive Welding Possibilities by the Use of Emulsion Explosive

Zlobin B., Silvestrov V. V., Shtertser A., Plastinin A., Kiselev V.

Archives of Metallurgy and Materials

|

2014

|

Vol. 59, iss. 4

1587--1592

EN

Explosive welding is an effective method of joining of various metals and alloys. However, when the materials with very different strength and thermo-physical properties are welded or thin-layer cladding is performed, the difficulties occur which call for extra investigations. In the present paper, with the couples of steel / carbide composite and copper / hardened steel used as examples, under study were the peculiarities of bonding formation by the explosive welding of metals with highly differing properties. The experiments were carried out with emulsion explosive containing hollow micro-spheres and detonating in thin layers with the low (2 - 3 km/s) detonation velocity. Obtained results show that the emulsion explosives enable to extend the explosion welding potentiality.

PL

Połączenie wybuchowe jest wydajną metodą łączenia silnie zróżnicowanych metali i stopów. Jednakże, pojawiają się realne trudności w łączeniu, gdy jeden z materiałów posiada bardzo odmienne właściwości wytrzymałościowe lub termo-fizyczne bądź też wytwarzane jest połączenie bardzo cienkich folii. W niniejszej pracy, badano przykładowe: stal/węglik oraz miedź/stal hartowana, jako układy materiałów o silnie zróżnicowanych własnościach spajanych z wykorzystaniem metod wybuchowych. Badania eksperymentalne wykonano z użyciem emulsji wybuchowych zawierających wydrążone mikrosfery oraz układy złożone z cienkich warstw. Proces łączenia wykonywano z wykorzystaniem małych prędkości detonacji (2-3 km/s). Otrzymane rezultaty pokazują, że zastosowanie emulsji wybuchowych znacznie poszerza potencjalny zakres możliwości wykorzystania techniki spajania wybuchowego.

6

Infuence of Different Parameters on the TNT-Equivalent of an Explosion

Simoens B., Lefebvre M. H., Minami F.

Central European Journal of Energetic Materials

|

2011

|

Vol. 8, nr 1

53-67

EN

Emulsion explosives are used in a wide range of applications, amongst which some in closed vessels, where the properties at short range need to be known. A series of tests with spherical charges has been carried out to determine the TNT-equivalent at short range of an explosive emulsion based on both peak overpressure and impulse. Generally, the value is found to be constant over the considered range, with a value of 1 for overpressure and of 0.7 for impulse. In most common applications, explosive charges are not spherical. Experiments with cylindrical charges have been performed to study the infuence of (1) the shape of the charge (length-to-diameter ratio) and (2) the location of initiation (central or at one end). At the considered range, increasing L/D increases the peak overpressure and the impulse perpendicular to the axis, but decreases these effects on the axis. The central initiation causes the largest effects on the centreline. The initiation at one end causes a shift in the location of the peak overpressure, but the highest impulse remains on the centreline.