Stimulation of water resistance of ammonium nitrate-based emulsions

The article discusses aspect of environmental and industrial safety of industrial emulsion explosives based on ammonium nitrate. Because of their metastable nature, high energyintensive emulsions tend to divide into immiscible phases right after formation, which explains their limited water resistance during their service life. For this reason, when used in moist conditions, in long contact between the emulsion and water, ions migrate from the charge column to adjacent wellbore and ground water. The content of contaminating agents in natural water sources and bodies nearby mining sites can greatly exceed the allowable sanitary concentration of nitrite, nitrate and ammonium nitrogen. The factors of influence on the rate of wash-out of water-soluble components from an explosive charge are discussed. The contact of an uncaged industrial emulsion explosive preproduct — emulsion matrix with distilled water is model with the subsequent measurement of nitrate ion concentrations in water samples decanted from the surface of emulsion. The measurement used two concurrent methods: potentiometry using ion-selective electrodes; conductometry with an ion-exchange-high-performance liquid chromatography recorder. The nitrate ion concentrations are experimentally determined as functions of the charge–water contact area, charge–water contact time, as well as the type and content of an emulsifier. It is proposed to reduce the rate of migration of nitrate by selecting the type and content of an emulsifier used to stabilize a high energy-intensive emulsion. The research findings of the methods proposed agree well with the data of the standard titrimetric determination of emulsion water resistance. In future, the presented analysis can be a tool to assess physical and chemical stability of emulsion explosives.