"defect in the furnace, hot aluminum flowed onto the floor..."

 

Containers such as furnaces, crucible, and troughs that hold molten metal will eventually fail. Typically, this occurs at the end of their life cycle, or due to misuse. Regardless, if the lining of the containers is not replaced prior to failing, molten metal will escape. When this occurs the hazard of molten metal becomes a reality and a potential nightmare. Molten aluminium has a similar viscosity to water. Just as water, molten aluminium will flow to the lowest point allowed. The lowest point in factories is typically horizontal or vertical casting pits, maintenance pits adjacent to the casting pits, maintenance pits under furnaces, conduit trenches, etc. If those areas contain equipment, piping, etc. the molten metal can cause damage, if not a fire. Worst case scenario would be if molten metal flowed to an area where the substrate was bare concrete, steel or stainless steel and an explosion was generated. Here is a recent incident from last year that emphasizes the hazard of molten metal escaping it’s intended destination.

The fire alarm system of a company in the industrial area triggered an alarm during the last week of December 2020 in Germany. Due to a defect in the furnace, hot aluminum flowed onto the floor of a factory hall and into a duct. This caused a lot of smoke, which triggered the company's fire alarm system. However, there was no open fire, so that the fire brigade on-site did not have to intervene. There was material damage to the stove, floor and cables amounting to approx. 25,000 euros.

We are ecstatic no one was injured in this incident. An explosion or fire could have easily occurred. For new plants this is one hazard that they ignore. We understand that it is difficult for a new company to acknowledge a hazard that might not happen for years. But, it is best to prepare for this hazard now when the plant is brand new prior to the furnaces being run then to clean up the aftermath. Let alone if an explosion occurs. That is why we have always recommended that all bare surfaces (e.g., concrete, steel, and stainless steel) that can be exposed to molten aluminium be coated with WiseChem. That is why it is important to coat all maintenance pits under furnaces. The Aluminium Insight publication had an article on this topic.

 Please comment.