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BenkeiDNA

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Posts posted by BenkeiDNA


  1. I read "Charged lead-acid batteries have one plate with PbO2 and the other one Pb. Discharged batteries have both plates PbSO4. So neither one is pure lead. The electrolyte is sulfuric acid, more concentrated when the battery is charged." Does this mean that there is no metallic lead at all in USP system batteries when there is a failure in a fire and that only the powder PbSO4. would leak out in the fire, so there would not be any metallic lead at all on the floor in a violent fire if the fire melted the USP systems with the batteris so they discharged?. Could i write in my paper that in a fire, only the powder PbSO4. would pour out on the floor and no metallic lead would pour out at all?.

    I also read "About 60% of the weight of an automotive-type lead–acid battery rated around 60 A·h is lead or internal parts made of lead; the balance is electrolyte, separators, and the case. For example, there are approximately 8.7 kg (19 lb) of lead in a typical 14.5-kg (32 lb) battery.".." and ..."The grid structure of the lead acid battery is made from a lead alloy. Pure lead is too soft and would not support itself, so small quantities of other metals are added to get the mechanical strength and improve electrical properties. The most common additives are antimony, calcium, tin and selenium. These batteries are often known as “lead-antimony” and “lead­calcium.”"...


  2. Hi, i am doing research for a paper about fires and metals and reactions and stuff and would like to ask you guys about lead from USP batterys.

    If you had a USP system room with many lead batteries like in this picture, would the total amount of lead still be considered quite small quantities if it leaked out?, and i think it would be very unlikely that most of this lead could get mixed together in a violent fire, so it would create a large steam of molten lead. I was told by a metal exper that he thinks this is true, that it probably would be hard for all the lead to get into a large molten steam that flowed away. He also said this "Also, lead isn’t just present as metal in batteries – it is also a dissolved salt. Therefore, even less metallic lead is present than the total amount of lead in the battery."

    Assuming the batteries are charged, there would be lead metal in them. The electrochemical process of lead acid batteries does convert lead sulfate into lead metal at the anode when it is charged. When fully discharged it is lead sulfate and not lead metal – although there probably still is some lead metal under the sulfate layers on the anode. So I suppose it’s possible in a really large fire that the batteries spark/short circuit, the plastic casings melt open, and the metals + acid leak out. Whether or not they all melt/fuse together into a large molten stream of lead is the question, it seems improbable, even with this many batteries in one place. So there should be less metallic lead present assuming these batteries are getting discharged.

    So in the fire when the batteries are destroyed and gets discharged, could you estimate from a picture like this with that many batteries in a room what would be a reasonable total amount of metallic lead that would leak out, if it is hard to figure out how much lead sulfate there would be, maybe it is more easy to estimate how much metallic lead there should be?, i am most interested in how much metallic lead there would be.

    That being said, lead sulfate is a white powder, but depending upon how sulfuric acid and lead metal interact with one another in a fire, could we maybe see other sulfur compounds being formed which yield yellowish materials forming with other metals involved in the fire?, would any sulfur compounds if they got mixed with the metallic lead make the silver color of the lead change to a more yellow color, and would there be any reactions between lead sulfate, other sulfur compunds, metallic lead and other metals like aluminium and mercury?, i am mostly interested in reactions that could change the silver color of the molten lead and other metals that got mixed.

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  3. On 2/3/2020 at 2:52 PM, Bufofrog said:

    Do you have a source for this or is this something you heard somewhere?  

    it is difficult to answer questions about how the wind would effect burning steel in an office fire when a piece of steel doesn't burn.

    You need to formulate a better question.

    In extreme cases, for example in the case of a well-ventilated fire with a chimney effect (or the 35 mph wind effect i said before), the fire temperature, which is normally 800-1000 degrees, may rise to a few hundred degrees more i was thinking, if the fire is directly on the steel, it might make some molten iron i was thinking?, but if the fire only last lets say 20 min, it might be much more unlikely?.

    And If there were strong winds of 35 mph at high altitude, and a molten material and its sparks fell out of a window down through the air, then should not these 35 mph winds make this material and its sparks travel sharply to the left or right so that it was not possible for the material to fall straight down a straight line?.


  4. 5 minutes ago, Strange said:

    Why are you writing a report you know nothing about? Why not employ an expert?

    It is not me writing the report, its an educated engineer, but i am doing some research and asking around to get some better ideas of how i want things explained in the report.

    When you say that water vapour in the air is already vapourised, i am told that the heat from the metal can have some effect on the water so there could be a quick speck of light rather than a continuous light emission. You'd need high speed camera zoned in to high res to see it.


  5. 22 minutes ago, Bufofrog said:

    I would not expect there to be large amounts of molten metal in an office fire, certainly not enough to pour out of a window.  Again the whole office fire thing is not important, I assume.  What is your question?  Is it something about how a stream of molten metal (a specific metal?) will react with the air or water or what exactly

    I have the 5 detailed questions as above. But yes i wonder if it is very unlikely that molten metals will give off flashes as a result of the water effect in the air that i mentioned, with normal levels of water vapor in the air, 68% RH. And i want to know the effect of 10 mph winds compared to 35 mph on burning steel, if there would be any chance at all for the steel to become molten in a office fire with destroyed windows or a hole in the wall if the wind of 10 mph came into the burning office. These two questions of water vapor and winds are important for me.  


  6. 13 minutes ago, Bufofrog said:

    I have ignited a strip of magnesium foil and it didn't have any flashes as it burnt.  I looked at couple of you tube videos and I didn't see any flashes.  Powders will flash, which is probably due to the uneven amounts of powder the fire front encounters.

    You talk about office fires, is this related to specific event of scenario?  If not it would be best to leave out the office part as it only confuses the situation IMO.

    It was a foundry guy that told me this about that when magnesium burns with oxygen and extremely high temperatures, maybe its different somehow in their foundry due to the extreme heat, i don't know. He was talking about a magnesium wire.  

    The scenario i am thinking about, and thats why i mention a fire in a office, is when the molten metal escapes the room and falls in the air through a open window. How would it react in those conditions, when falling in the air molten, and then after we think about the color and what is possible or not regarding flashes from the metal itself, we can add the rapid vaporization  effect of water in the air, but under normal conditions/leves like i said, i wonder if it still would be possible with any flashes then from the water. 


  7. 2 minutes ago, Bufofrog said:

    I am not sure what you mean by flashes, could you expound on this?

    Yes, for example there is metallic flash powders, and nano poweders of aluminium that can flash in exotic reactions, but when we think of only metals that are burning or melting it is less likely that there are any flashes, and im trying to figure this all out, what would and would not flash, i am told that there is white flashes when magnesium burns with oxygen due to the extremely high temperature of the flame, making it look white. The burning specks of magnesium with oxygen flash white while they burn, leaving a white MgO-powder when all of the magnesium has reacted with oxygen. But i dont think regular magnesium alloys that are burning in like a office fire would make flashes or make a very bright white flame. As i said in the post above also "I am told that metallic magnesium can be difficult to ignite depending on it thickness. That a magnesium rod, about 1 cm in diameter, will not ignite in a Bunsen burner flame, even with prolonged heating. Magnesium burns to produce magnesium oxide. That product is quite inert by normal conditions. It does not flash nor will it burn, i am told.". 


  8. I work for municipality with urban management and i have a interest for the environment, and have become fascinated with metals. Together with a engineer i will be making a report about metal reactions etc. So i would like to get you guys take on these questions that i have in mind for my report.

    1. When you have flashes from metals that are burning, like from magnesium, aluminium or iron, how often should you see the flashes, and what will the duration of the flashes be?, can any of these 3 metals when molten flash 6 times in lets say 8 seconds?, with the longest duration of one flash beeing 0.87s?. And is it possible for any molten material falling in the air to give off these flashes because of rapid vaporization of the water in the air when the water vapor in the air is at normal levels of 68% RH and not 100% RH or is this extremely unlikely?.

    2. If within minutes the oxygen in a fire zone is depleted, and you have some molten iron pouring, could metallic alloy magnesium get mixed somehow with the molten iron in a fire, and while the molten iron was pouring and flowing in the air with a orange color, could the alloy magnesium then from the falling and flowing molten iron in the air make a couple, lets say 6 flashes, in short time of 8 seconds, white flashes from inside of the molten iron?, like the burning specks of burning magnesium in a foundry with oxygen that flash white while they burn?, or is this not how alloy magnesium behave?. I am told that a magnesium rod, about 1 cm in diameter, will not ignite in a Bunsen burner flame, even with prolonged heating. Magnesium burns to produce magnesium oxide. That product is quite inert by normal conditions. It does not flash nor will it burn, i am told.

    3. And my next question about magnesium is not about any flash effect, but about a flame effect. If you have an unusual flame visible within a office fire, a very bright white flame, as opposed to the typical yellow or orange surrounding regular flames, this would suggest that some type of metal is burning, i know aluminum will burn, but in normal fires it usually melts instead because the metal surface is protected by an oxide layer that must be breeched before ignition can take place. Aluminium oxide melts at 2072C that typical office fires will not reach. But do you think that the burning of alloy magnesium in a regular office fire could explain a very bright white flame?. I am told that metallic magnesium can be difficult to ignite depending on it thickness. That a magnesium rod, about 1 cm in diameter, will not ignite in a Bunsen burner flame, even with prolonged heating. Magnesium burns to produce magnesium oxide. That product is quite inert by normal conditions. It does not flash nor will it burn, i am told. So maybe it would haft to be some form of hot reaction that made the white flame, and not alloy magnesium by itself?.

    4. If within minutes the oxygen in the fire zone depleted, and the pace of burning was regulated by the area available for venting the hot exhaust gases, and the area available for the entry of fresh air. And forces of impact and explosion could have broken some of the aluminum in the building into small granules and powder. Chemical reactions with hydrocarbon or water vapors might have occurred on the surfaces of freshly granulated hot aluminum. And lets add in this hypothetical scenario that there was strong 35 mph winds that through a large hole turned the building into a large blast furnace. Since iron can be made molten in a small furnace only 12 feet high, one that was several stories high with plenty of fuel and air would maybe have some effect on the fire so that some amounts of molten iron could be produced?, but i am not sure?, how powerful would the winds haft to be to have any effect on the fire on the steel in a scenario like this?, would 35 mph be enough?, and if the winds where much lower, maybe 10 mph, they would have zero effect on the fire?, please speak a little about this possible wind effect on a fire.

    5. I also wonder what happens when aluminium is molten and flowing and falling down in the air, if the molten aluminium will have a orange or silver color as it falls down in the air and if it will remain orange during its whole descent or if it will have a silvery color the whole time. I once saw aluminium being heated in a container to 980c or 1800 F and you could see that it cools rapidly to a silvery colour, it didnt have any orange color. I also saw when they added organic materials to the molten aluminium and it floats on the liguid aluminium and burns up (oxidizes), it didnt change the silvery color of the aluminium. Rapid cooling of aluminum does produce a silvery looking "precipitate" for lack of a better word right now. As i understand it they would only stay molten for as long as they're above the melting temperature and flowing, once it stops flowing it begins to cool even faster than it already is. But while it's falling, could it have the molten orange color or not is the question, i know iron will have orange color when molten and falling in the air, but now i want to find out if the same is true for aluminium. I heard that aluminium only rapid cools when it's standing, because it's flowing, the silver is an oxidized layer, it can't form that layer if the surface it's constantly being broken up. I guess this also could depend on flow rate. Personally aluminum sparks which are small particles of aluminum burning i have only seen burn silver or white, no orange color. Even if we look at the scenario in question number 3, and some explosion impact had broken some of the aluminum in the building into small granules and powder and chemical reactions with hydrocarbon or water vapors might have occurred, this would still not change the silver color of any molten aluminum into a orange color while it was falling in the air, and would not make it flash either?, like the effect i described in my first question with 6 flashes in 8 seconds from a orange melted material falling in the air?.

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