Molten metal hazards have resulted in more injuries and deaths than any other hazard in our industry. Yet still some workplaces fail to acknowledge the seriousness of this hazard. Here is a recent incident emphasizing the seriousness of a molten metal explosions.
Six workers (other media accounts list 8 workers burned) were hit and
injured in the explosion at the factory in (town name omitted) and transported
to hospital, including 4 in serious condition, urgently transferred to
specialized clinics, one also in (another country). Affected by the explosion
during the casting and cooling phase of molten aluminum in a mold.
The explosion in the
aluminium factory in (town name omitted) in which six workers were injured,
including 4 very seriously, occurred during the pouring phase of the molten
material. This was explained by the (town name omitted) Public Prosecutor's
Office, which has opened an investigation into the serious accident at work,
ordering the seizure of the place where the incident took place, inside the company
(name omitted). Six workers were hit and injured in the explosion and I was
transported to the hospital, including 4 hospitalized in serious condition.
Accident site seized for
technical investigations
In fact, now the ball
passes to technical experts who will be in charge of carrying out the necessary
investigations. "There are, at present, no hypotheses about the causes of
the explosion. They will have to be verified through technical checks that will
be carried out in an adversarial manner, subject to the appointment of
experts," the investigators explain. The explosion also caused a fire to
break out, which was then extinguished by the firefighters who intervened
promptly together with the medical staff. The Labour Inspectorate of the
Autonomous Province of (town name omitted) was also on site to determine
whether the safety measures were adequate.
TO BE READ
Explosion in (town name
omitted) in an aluminum factory: six workers injured, four are in serious
condition
"At present there are still no suspects, as the investigating bodies have to reconstruct the guarantee positions within the plant on the basis of the company documentation that was acquired as a result of the first interventions," explained the Prosecutor's Office.
The company: "Full cooperation"
The Aluminium company, for
its part, expresses in a note "maximum closeness to the workers" and
their families and assures "complete collaboration to clarify what
happened". "The employees represent the true wealth of this company
and the protection of their health has always been a primary objective of our
company. It is in the company's primary interest that the causes of the
accident are quickly ascertained in order to be able to prevent similar
situations in the future, in the interest of the safety of workers," reads
the press release, which adds that "a process of maximum collaboration and
sharing of the information in its possession with all the investigating
authorities engaged in ascertaining what happened was immediately
initiated."
How are the six injured
workers doing?
In the same way, the
ownership and management of the factory let it be known that they are
"deeply saddened and express the utmost closeness to the workers who were
involved in the serious accident that took place last night, as well as to
their families to whom they express their solidarity by putting themselves at
their complete disposal to support them in every possible way at this time and
in the future". As a result of the severe burns sustained, all six injured
people involved were initially transported to a nearby hospital. Subsequently,
four workers were urgently transferred to specialised clinics: one in (a city
175 kilometers), two in (in a city 200 kilometers) and one in (over 200
kilometers away in another country).
There is a difference in the number of workers injured, 8 or 6. Regardless, many workers were burned and injured from this incident. We assume that 8 were burned, and 6 were sent to hospitals. While the remaining two had injuries that either did not require hospitalization or were minor and treated by ambulances on site.
We offer our sincere prayers that the injured workers recover fully from their burns. We pray for the families of the injured workers. We acknowledge that the families of the workers are under an additional stress because their loved ones are hundreds of kilometers away. But, we hope they understand that if the injured workers were not airlifted to the specialized burn centers several if not all could have died.
We commend the local hospital for taking the initiative to send the injured workers to specialized burn centers.
Please note that the earliest news media articles mentioned an explosion and a fire. The question we always ask, “what caused the explosion?” Subsequent news media and social media posts clarified that a molten metal explosion occurred. Some if not all of the injured workers had molten metal thrown onto them.
What caused the explosion? In the simplest explanation moisture and molten aluminium interacted. That interaction can result in either a physical reaction and/or chemical reaction with the molten aluminium and water (H2O).
A physical reaction is a change in texture, shape, temperature, and state, without a change in the composition. Common examples melting, boiling, and mixing substances. With a molten metal explosion that involves a physical reaction the molten aluminium mass does not change. That information will be important later in this discussion. So, if there are 1000 kg of aluminium in a physical reaction molten metal explosion. There will be 1000 pounds of solidified metal spread around afterwards.
Molten metal covers the moisture (either visible or invisible). The moisture expands due to the heat of the metal. That expansion is equivalent to a marble turning instantaneously into a beach ball. That rapid expansion results in the molten metal being propelled or thrown. The issue becomes where does the molten metal land. On a worker? On a combustible (e.g., cardboard boxes, wood pallets, etc.). Numerous media reports state that some if not all injured workers were contacted by molten metal. Subsequently, the molten metal came into contact and ignited combustibles.
The other type of explosion that can occur is a chemical reaction. When chemical reactions occur,
the atoms are rearranged, and the reaction is accompanied by an energy
change as new products are generated. Examples: rusting of iron, cooking
an egg, a bomb going off..
In a chemical reaction explosion water (H2O) breaks apart. O (oxygen) bonds with Al(aluminium) forming aluminium oxide. The remaining H(hydrogen) is released as energy. Think of a bomb. Scientists determined that the energy giving off in a chemical reaction of 1 kg of aluminium is equivalent to a force of 3 kg of TnT exploding. These explosions commonly result in a white mushroom cloud billowing above the workplace. The white cloud is not a byproduct of combustion, but aluminium oxide generating from the explosion.
The earlier example of 1000 kg of molten aluminium now in a chemical
reaction would result in a force generated to 3000 kg of TnT exploding. There
is no solidified aluminium. Instead, there is powered aluminium oxide.
Commonly, after a chemical reaction explosion the workplace will look like it
has been snowed upon. But instead of snow it is aluminium oxide.
Those are how explosions can occur. The question the aluminium company and the investigators are looking at is how moisture entered into the process of casting. One only must look back upon past incidents for a list of potential sources. Moisture can come from leaks, contaminated molten metal tools, contaminated drain pans.
Lastly, we pray that our comments above are respectful to both the company and to the workers. We do not blame workers nor the company after incidents. All we care about is to bring awareness to incidents to hopefully prevent recurrence.
We did want to comment that the news media videos of the aftermath show workers at the aluminium plant wearing cotton fabric. Cotton fabric should never be worn in an aluminium plant. Why? Because cotton fabric will ignite if it meets a flame source. Decades ago, the reason why so many workers died because of molten metal explosions was primarily because their clothes ignited. When workers clothes ignite the severe burns can result in a worker dying.
That is why we recommend only fire-resistant clothing in an aluminium plant. Whether or not the plant processes molten metal. On our plant visits we are properly dressed in fire resistant clothing.
Lastly, we have posted nearly 1000 incidents here on this blog over the past 14 years. We do not mention the company name nor the location. Why? Because with all due respect in our opinion there are three groups of individuals who care about the company name. They are widows, orphans, and lawyers. We do not care. All we care about is preventing a recurrence.
Finally, our hope is that someone will read this post and will become aware and learn about molten metal explosions. If your workplace processes molten metal you should be aware of the following document. As I heard one industry contact say “it simply is our industry best practices toward safety.” Which is very true. This document is the foundation of countless aluminium companies molten metal safety program.
Link for this publication, search "casting" is here.
We will update this story as further information is brought forth.
Update
It is with utter sadness that we report one of the injured workers succumbed to their injuries three days after the explosion. We offer our sincere condolences to the deceased worker's family, friends, and coworkers. We are at a loss of words to express our sorrow for a worker who we did not know. Regardless, we acknowledge that every worker has a family and life story. We are heartbroken that the worker's life story ended in a workplace incident.
We pray that someone will read this post and look upon their workplace and ask "can we have an explosion here?" The answer should be "yes". The next step is to list how an explosion can occur and either install engineering controls or revise worker training to mitigate the hazards.
We will continue to update this story. We pray that all the remaining workers recover fully from their injuries.
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