Method for the “on-site” manufacture of water-resistant low-density water-gel explosives

A method for the continuous “on-site” manufacture of a water-resistant low-density water-gel explosive, which comprises:

• a) transporting to the manufacturing site:
• (i) a non-explosive or low-sensitivity matrix product comprising an aqueous solution or suspension of at least one oxidizing salt, and at least one cross-linkable water-soluble polymer;
• (ii) a gas bubble-generating agent;
• and
• (iii) a cross-linking agent capable of cross-linking said cross-linkable water-soluble polymer contained in said matrix;
• b) mixing said products (i), (ii) and (iii) in at least one device with mixing capability to obtain a mixture which is conveyed by means of a pump and/or an auger;
• c) loading the mixture resulting from b) directly in the blast hole by means of a pump or an auger;
• and
• d) generating gas bubbles by means of said gas bubble-generating agent and cross-linking said polymer by means of said cross-linking agent within the mixture already introduced in the blast hole, under conditions in which the chemical cross-linking process and the chemical bubble-generating process occur primarily once the mixture is inside the blast hole, the chemical cross-linking process forms a fixed three dimensional network solid that is unable to expand after the chemical bubble-generating process is complete, and wherein the final density of the explosive mixture is regulated with the concentration of the gas bubble-generating agent and the final physical consistency of the explosive is regulated with the cross-linking agent.