Strategy for Reducing Ammonium Nitrate Loss to Mine Discharge Water
CIM MEMO 2010
Daniel J. Corkery, Nicolas Lauzon, David L. Sprott,
Mines in Canada and the United States are subject to regulations limiting nitrate, nitrite and ammonia levels in mine effluents. The primary source of these water quality constituents is the explosive used in blasting operations, and ammonium nitrate (AN) remains a significant component of most explosives used in the mining industry. The amount of AN entering a local system is related to the site conditions, explosives used, explosive handling and blast efficiency.
Most mining operations understand the relationship between explosives and AN loss to mine water. However, they may not be aware of the mechanisms by which ammonia, nitrite and nitrate are entering the system or the relative contribution of specific mechanisms. Identification of these mechanisms, through systematic investigations, allows a mining operation to focus its efforts on reducing AN loss related to target mechanisms.
This paper outlines a strategy for investigating the mechanisms through which AN enters the mine discharge water and methods to mitigate this loss. This includes collection and analysis of data to identify and quantify the AN loss mechanisms, design and implementation of tests to mitigate this loss, and assessment of the results. Such investigations are not intended to be a separate one-time project, but part of a long-term process of continual feedback and optimization that is related to the collection and reporting of AN levels for regulatory purposes. The implementation of the strategy must be tailored to each mine requirements and existing conditions.
Water quality, Environment, ANFO, Emulsion, Mining, Explosives