Abschnitt 1.3 - 1.3 Sludge
Magnesium sludge consists of magnesium dusts or particles bound with water or hydrous wetting agents.
Sludge which is generated during machining with water-miscible metalworking fluids (e. g. during grinding), tend to self-ignite due to the low particle size. On reaction with water, gaseous hydrogen is generated in addition and an explosive mixture may develop. The same applies to watery sludge which is generated during wet separation, e. g. during blasting work.
Fine magnesium particles particularly tend to self-heat on reaction with water/humidity. This exothermic reaction releases heat which can finally lead to self-ignition. In practice, violent reactions including fires and oxyhydrogen explosions mainly occur during storage of large sludge quantities in barrels and tippers.
Even fine magnesium particles which have been separated, e. g. through filter fleece, can provoke self-ignition in conjunction with humidity/water.