"fire started, the furnace was loaded with 3,300 pounds of magnesium"

The Aluminium Plant Safety Blog has posted numerous incidents about magnesium fires. One common concern in using magnesium ingots is the variability and quality. We have reported many incidents where magnesium ingots have cavities filled with moisture in them. Resulting in explosions when inserted directly into a furnace with molten metal. To prevent this many plants preheat their magnesium ingots (as well as aluminium ingots, sows, t-bar, etc) prior to placing into a furnace. Here is a recent incident involving the preheating of the magnesium ingots:

                 

Officials are still investigating the cause of a magnesium fire that broke out early one morning at a factory in the USA during the week of September 9, 2018 . Local firefighters responded to the aluminium manufacturing company at 4:56 a.m. and found a fire contained to a large furnace used to heat magnesium billets, local fire chief said in an email. By the time the fire department arrived, the building had been evacuated and no injuries were reported. 

When the fire started, the furnace was loaded with approximately 3,300 pounds of magnesium, local fire chief said. Firefighters had to use “special extinguishing agents” to battle the blaze, because neither water nor any substance containing moisture can extinguish a magnesium fire, local fire chief said. 

The fire remained contained to the furnace, and firefighters focused on protecting the hydraulic oil reservoir tank, which contained about 1,100 gallons of oil, and which is located next to the furnace, local fire department chief said. 

The fire was out at 8:32 a.m., and units cleared the scene at 9:03 a.m., local fire chief said. He said the cost of the damage is not yet known. 

We are glad no one was injured in this incident. We are glad that the local fire department knew how to extinguish this fire. We would like to congratulate the fire department on extinguishing a large fire in such a short period of time. All too often on our plant visits we tour plants and see that they do not have enough fire extinguish agents on hand. Why? Do the plants expect the local fire department to store 2,000 pounds of class D extinguishing agent? We have no idea. Regardless, we always talk to plant management about the importance of having enough fire fighting supplies on hand for the local fire departments to use.

Please comment.