Tests for mining explosives

Any explosive which is intended for use in mines has to satisfy certain requirements and to ensure overall safety. All mining explosives, both for coal and rock must be subjected to the tests before being licensed for use. The tests vary from one country to another. Those described below are based mainly on methods applied in Poland. 

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W) C. Belgrano, "Gli Esplosivi , U. Hoepli, Milano (1952), pp 15 to 53 (Physical tests for mining explosives. Included are density, stability, Trauzl test, detonation velocity, Hess test, crusher test, sympathetic detonation test, sensitiveness to initiation, sensitiveness to impact, steel plate test and explosion temperature determination) pp 73 to 75 (Analysis of NG) 76 to 84... 

Inert ingredients increasing safety Inert neutralizing agents Tests for mining explosives Transmission of detonation Sensitiveness to detonation Power of explosives Safety tests with methane and coal-dust Experimental gallery in Poland Experimental gallery in U.5.S.R. 

Table 7.1 Galleries for Testing Coal Mining Explosives...

Crawshaw-fones Apparatus for Testing Coal Mine Explosives for Permissibility. See Vol 3, p C555-R... 

Note A.J.Clear gives in PATR 3278 (1965) detailed descriptions of Impact Test with Picacinny Arsenal Apparatus (pp 2-4 with Fig 4 on p 35) and "Impact Test with US Bureau of Mines Apparatus (pp 4-7 with Fig 7 on p 38). He also describes on p 7 "Modified Impact Tests for Liquid Explosives", made with US Bureau Mines and PicArsn Apparatuses... 

H.Muraour, "poudre et Explosifs, Paris( 1947),80-1 5)Belgrano(l952),28 30 6)TM 9-1910(1955), 76-8 Crawshow-Jones Apparatus for testing coal mine explosives for permissibility will be discussed in Vol II, under C. Ref US BurMinesBull 346, (1931),95... 

Non-Permissible (Amer) or Non-Permitted Brit) Explosives. See under Commercial or Industrial Explosives in Vol 3, C435-R to C437-R, and Coal Mining Explosives, Testing for Permissibility in Vol 3, C368-R ff... 

The requirement to use both P4 and P5 explosives in a single mine working leads not only to inconvenience in supply but also to a potential hazard should either explosive be used for the wrong purpose. This has led to the development of P4/5 explosives which pass the tests for both P4 and P5 types and which can therefore be used either for ripping or for firing off the solid with delays. 

In Britain in 1912 and 1913, a rash of mine explosions lead to a formal court inquiry. It was found that at this time the practice of signaling was accomplished by the rubbing together of two bare wires connected to a battery to form a circuit. As a result of the court findings, testing became required for signaling equipment in British mines. 

Pa are described under ".Coal Mining Explosives, Testing for Permissibility , Vol 3, pp C370-R to C377-L. Gallery used in Dortmund, Germany during WWII is briefly described as "Versuchstrecke, Dortmund-Derne in PATR 2510(1958), p Ger 215-R... 

Prussian Govt established at Neunkirchen the first testing station for investigating mining explosives, which included a testing gallery. 

Si completed Mark 29 Explosive Streamliners, ranging in diameter from 1 to inches, were assembldd at Yorktown. Mine Depot and tested for propagation and damage by counts nil iniiig. Propagation trials were entirely satisfactory, but countermining trials reveaLed damage to the outer 2A inch hose of two streamers... 

See Vol 3, p C376-R, under Coal Mining Explosives, Testing for Permissibility... 

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