There are somehow no limits to the creativity of the detractors and repressors - but you also have to understand them somehow...
You only have to master the game with the so-called "dangerous half-knowledge", or also: I'm making up the world for myself
We can almost assume that some people have already heard something about the so-called "chromium (VI) dilemma".
Thanks to LinkedIn and some premium functions, we can also see which target group is being addressed and a few thousand views per LinkedIn article suggest that one or the other is already oriented or is trying to deal with the topic.
Although we try to present the "problem" as simply as possible, people tend to absorb only fragments of a topic, probably because the media overstimulation is much too high nowadays, just take the topic "Corona" as an example.
We are grateful that those who are really interested in the topic always provide us with the latest statements of those who think they absolutely have to contribute something to the topic and so we always receive statements from manufacturers and users for whom we as an editorial team have been on the so-called blacklist for a long time, at this point many thanks to those who do not look away and have an interest in a solution and tell us these things.
The certainly funniest hint from the area of high temperature insulations came from a manufacturer of insulation systems, who probably really did not understand anything, we quote (example I):
"..Calcium oxide (CaO) consists of calcium (Ca) and oxygen (O), not chromium (Cr).
Chromium VI does not consist to any part of calcium, the oxygen necessary for the bonding
(O) is present in the ambient air.
The formation of chromium VI is therefore independent of the presence of calcium oxide.
This could also be proven by test series, chromium VI occurred both in the presence and absence of calcium oxide.
An accumulation was seen in the area of welds on exhaust systems.
The chromium necessary for the formation of chromium VI is found in stainless steels as part of the alloy to prevent rust.
part of the alloy to achieve an anti-rust effect.
During the formation of chromium VI, the chromium dissolves from the stainless steel and escapes from the
surface. At this point it is then absorbed by the products that are placed there.
that are applied there. ... If the stainless steel is uninsulated, the chromium VI trickles down and collects as a yellow powder on the floor below.
It can therefore be summarized that insulation is not responsible for the formation of chromium VI as long as it does not contain chromium..."
Interesting also another explanation attempt of another manufacturer of insulation materials, we cite (example II):
"..According to our current knowledge, the formation of Cr(VI) compounds involves the chemical reaction of the Cr(III) passivation layer (Cr2O3) of the stainless steel surface to Cr(VI), which takes place at high temperatures and oxygen partial pressures.
This reaction process is accelerated by the presence of water vapor, which is present, for example, as a result of the combustion process in gas turbines and may escape when turbines are started up and shut down, and also takes place already
at temperatures well below 1000° C. In this process, the volatile Cr(VI) compound CrO2(OH)2 is formed, which can escape from the stainless steel surface due to its presence in the gas phase.
Possible reactions of this Cr(VI) compound with reactive alkali or alkaline earth compounds, e.g. possibly from anti-seize agents, can result in optically very conspicuously colored compounds (e.g. calcium chromate), making the Cr(VI) emissions from the stainless steel surface visible.
Dear "Example I" author, chromium VI is usually not yellow dust, chromium VI is rather reddish brown, has the chemical formula CrO3 and does not trickle down when stainless steel is uninsulated and heated.
Chromium VI really has nothing to do with calcium oxide and what are we talking about now, chromium VI, or a chromium VI compound?
So reddish brown chromium VI trickles down in yellow form as a powder when stainless steel is uninsulated, but not when stainless steel is insulated because it is absorbed? So from the insulation? But chromium VI has a melting point of 197°C. German industry may just be starting to insulate at these temperatures.
So no matter how we twist and turn this explanation attempt, in chemistry class this would be a flat "insufficient", "deficient" would already be an insult... A close miss is also a close miss.
The "Example II" author has made an effort, he has read up a lot on the so-called "high temperature corrosion". Here, especially turbine builders have investigated how much pressure and temperature they can drive to still increase the efficiency of a steam or gas turbine.
The process described actually takes place, but unfortunately it does not help as an explanation.
Let's look at the sentence "..This reaction process is accelerated by the presence of water vapor, which is present, for example, as a result of the combustion process in gas turbines and may escape when turbines start up and shut down, and also takes place even at temperatures well below 1000° C. In this process, the volatile Cr(VI) compound CrO2(OH)2 is formed, which can escape from the stainless steel surface due to its presence in the gas phase..." take a closer look, do you, dear reader, notice anything?
That's right!
It says "IN" gas turbines here and where is the SURFACE of a gas turbine that we are talking about here?
Correct, dear readers, the SURFACE IN a gas turbine is therefore INSIDE the turbine and from the point of view of the insulator, from the point of view of the studies, the OUTSIDE of the turbine is insulated and by the way: no insulation would withstand these pressures that we are talking about inside a turbine, all insulation would be literally pulverized and the insulator would probably be pulverized at the same time.
This may be the reason why turbines are insulated on the outside until today, inside it simply would not be so good...
Furthermore, the author of the "Example II" explanation seems to understand little about materials science. Or how should the so-called "volatile chromium (VI) compound" pass through the material wall of the turbine onto the evil anti-seize agent?
Anti-seize agents are located IN the turbine?
Wouldn't the water vapor attack them? And at these pressures?
Questions about questions...
Glass is not inert! Neither is the glass core of a commercially available insulating material!
And please, no - do not now also claim that glass is inert just because lemonade bottled in a former beer bottle does not taste like beer.
Glass is not inert! It is not magic, if e.g. calcium oxide (CaO) is found on the so-called "gel layer" of glasses, from which one THOUGHT, that they are inert and so one makes today already thoughts about what one can do, so that nuclear garbage, which one has "glazed in" as a precaution, because glass is inert or one should better say: seemed to be inert, can be further safely stored.
Please google "glass corrosion" or "glass rust" or look at the windows of the local indoor swimming pools, or why does a glass mirror actually become "milky"?
We are not talking about chromium (VI) (CrO3), we are talking all the time about calcium chromate (CaCrO4), a CHROMIUM (VI) COMPOUND!
If you have justified concerns about the insulation you use, please ask properly, then you will save yourself the nonsense quoted above!
We will soon provide you with a list of questions to download here. In advance, here are the key questions you should ask your supplier as an insulator, insulation company or operator of plants that have high-temperature insulation:
Yes, I know that your insulations or insulation systems do NOT contain and probably do NOT release CHROMIUM (VI); please answer us only the following questions
Do the insulation materials or insulation systems you offer contain calcium or calcium oxide and if so, what is the percentage of calcium (Ca or CaO)?
Do the insulation materials or insulation systems you offer contain sodium or sodium oxide (Na or NaO) or potassium (K) or magnesium (Mg) or their oxides (KOH or MgO) and if so, what is the proportion of these substances in the insulation materials and systems you offer?
Are the alkali- or alkaline earth-containing materials you offer already reinforced with chromium-containing materials (wire mesh/wire reinforcement) in the as-delivered condition?
Enclosed is an exemplary scientific study on the formation of chromates (calcium chromate, sodium chromate), in which insulation materials or insulation systems are examined, which also exemplify or depict the insulation materials or insulation systems sold by you. What is your opinion regarding these investigations, of which there are several, which we would be pleased to make available to you in addition?
If you claim that the so-called "glass core", which forms the main component of the insulation in your insulation materials/insulation systems, is considered "inert", where do you get this certainty from, although there is sufficient scientific knowledge that the so-called "gel layer" of a glass surface contains calcium oxide?
If you, as a manufacturer of insulation materials or as a supplier of insulation systems, refer to the fact that, among other things, calcium-containing anti-seize pastes can be responsible for the formation of calcium chromates, what then leads you to argue that your calcium-containing insulation material or your calcium-containing insulation cannot also be responsible for the formation of calcium chromate when it comes into contact with surfaces containing chromium at higher temperatures? How do you justify your statement that calcium-containing materials can certainly promote the formation of calcium chromate on the one hand, but on the other hand your product, which also contains calcium, although it has a much higher mass fraction in terms of area, cannot of all things?
Do you have scientifically reliable documents that prove the non-formation of calcium chromate when using your products (insulation material/insulation system)?
Please spare us scientific elaborations on the subject of "high temperature corrosion" at high temperatures and steam pressures IN turbines and boilers and the possible formation of "volatile" (gaseous) CHROMIUM (VI). On the one hand, these processes take place inside a closed unit and rather at temperatures above 600°C, on the other hand, the "TOP surfaces" mentioned in all scientific studies are located INSIDE the investigated systems and have nothing in common with the insulated surface.
All our questions refer to the possible formation of calcium chromate, sodium chromate and potassium chromate, i.e. chromium (VI) compounds (chromates) when using your insulation materials/insulation systems on surfaces containing chromium, NOT to the formation of the pure substance CHROMIUM (VI)!
Provided that you submit these questions to your supplier of insulation materials/insulation systems and receive answers, we would be pleased if you send us the received answers, gladly anonymized.
Thank you!