Water-stability

WATER-STABILITY of the explosive substances (EN: water resistance of explosives, stability in water of explosives; DE: Wasserbestandigkeit der Sprengstoffe; FR: resistance à l'eau des explosifs; ES: estabilidad de los explosivos en el agua; RU: водоустойчивость) is the ability of the explosive substances to withstand the penetration of the water into these substances, or to preserve the explosive properties in case of the filling with the water.

The water, which is penetrating into the charge, can wash the soluble components away from this charge (for example, the ammonium nitrate), and to phlegmatize the explosive substances, thus decreasing the detonation ability of this charge, or causing the complete loss of this ability. They impart the water-stability to the powdered explosive substances, using the addition of some hydrophobic substance (for example, of the finely dispersed calcium stearate), sometimes in combination with the polymer, which swells during the contact with the water. They impart the water-stability to the granulated explosive substances of the ammonium nitrate type, either using the total capsulation of the pellets of these substances with the melted TNT, or using the introduction of the liquid paraffin or mineral oil before the granulation. Within the water-containing explosive substances, they thicken their liquid phase using the water-soluble polymer (polyacrylamide, sodium salt of the carboxymethyl cellulose), and they add the salts of the metals for the transverse "crosslinking" of the micelles, which have been formed. For the water-insoluble explosive substances (for example, for the granulotol), the water-stability is achieved using the selection of the sizes for the granules of these substances, in case of which the phlegmatizing action of the water is little noticeable.

They consider the explosive substances as unlimitedly water-stable (alumotol, granulotol, and so on), if these substances are able to detonate within the water at any depth during the indefinitely long time, and as the limitedly highly water-stable (granitols, and so on), if these substances do not lose the detonation abilities during several days of the staying within the watered boreholes, or during several hours of the staying within the watered blastholes.

The degree of the water-stability is acceptable to evaluate using the following methods: for the explosive substances of the powdered type, which have not been cartridged, using the method for the determination of the hydrostatic pressure of the water column, which is necessary for the pressing of the water through the layer of the explosive substances with the determined thickness; for the explosive substances, which have been cartridged, according to the maximal distance (in terms of the centimetres) for the transmission of the detonation between the cartridges, which have been stored within the water at the determined depth during the specified time; for the granulated and water-containing explosive substances of the ammonium nitrate type, according to the quantity of the ammonium nitrate, which has transitioned from these substances into the solution, in case of the storage within the water during the determined time.