Britannica
Sources used in this answer
Why do coal-mine explosives use cooling agents such as sodium chloride?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
explosive
A coal miner loading a drill hole with a water gel explosive called Tovex.
In underground coal-mining, explosives must be carefully formulated to ensure safety in environments that may contain flammable gases or dust.
Coal-mine explosives, often referred to as "permissibles," primarily use ammonium nitrate because it produces a relatively low explosion temperature. To further enhance safety, these mixtures incorporate cooling agents such as sodium chloride (common salt) or ammonium chloride.1
The primary purpose of these cooling agents is to lower the heat generated during the explosion. By reducing the temperature of the blast, these agents prevent the ignition of underground gases, such as methane, or the ignition of coal dust, which could otherwise trigger a fire or a disastrous secondary explosion.1