Question - Question regarding flooding and air quality

[Mintyjimbob]

Hi everyone, occasional poster and long time lurker here.

I have a question.

My 'local' mine is currently completely submerged at the minute with seasonal rains. It should dry up in late spring early summer. My question is, as the water level lowers will this in effect pull air in from outside as it does so? I'm assuming so as otherwise it would leave a void?

On that basis does the air quality generally get better then after flooding as new air is forced into it? I've got a detector so I'm not silly enough to go in unequiped but would like to venture further in if the air conditions allow.

Many thanks, and keep posting the great stuff!

 

[Lord Oort]

it would help if we knew what sort of mine it was. Generally air pressure is the most important factor.

 

[Mintyjimbob]

Sorry, it's an Iron mine

 

[Lord Oort]

Quite a few of the iron mines near me flood on a regular basis and it makes no difference at all. We do know the mines are well ventilated tho. On that basis I cant suggest that you go and have a look for obvious reasons but if you are confident underground and know how to use a meter etc. etc. then theres no reason really stopping you.

HTH

 

[pirate]

That’s an interesting question.

I do wonder........what happens to all the noxious gas when mine is filled with water.........do the gasses combine with the water or do they get forced out as water level rises.

I would say for the water to draw in air when it drops........the water would have to drop extremely rapidly and the mine would only have a single air entry point which may create a vacuum type effect

 

[westernsultan]

Gases dissolve in a liquid, like water, just in the same way that solids do. They touch the surface and, if their polarity is similar to the liquid in question, they can slip in between the molecules of liquid. If there is a high concentration in the gas above the liquid, then more have the possibility of going into the liquid. Some gases may react with the liquid as in the case where ammonia dissolves in water actually reacting with the water to form ammonium hydroxide. Others are completely non reactive and the amount of gas dissolving in the liquid is very (very) small as Neon dissolving in water.
Equally, when the atom, or molecule, of gas comes to the surface it can take on off and the more gas dissolved the better chance it has to leave. So there is an equilibrium between a gas dissolving and the gas evaporating.
Some pure gases dissolve in water at significant amounts, so we can consider them as water-soluble gases.
Examples of water-soluble gases are: Carbon dioxide, ammonia, chlorine, sulphur dioxide, and hydrogen sulphide.
But, some pure gases only dissolve in water at traces amounts, we can consider these gases as water-insoluble.
Examples of water-insoluble gases: Hydrogen, nitrogen, helium, and methane.
The solubility values of pure gases in water dramatically depend on the temperature (and pressure). For instance, the solubility values of carbon dioxide in water at 5 (refrigerator temperature) and 23 (room temperature) deg C are 3 and 1.5 g CO2/kg water, respectively. That is why when we move a bottle of soda drink out of fridge, lots of bubbles are formed and gas escapes out of bottle, because the solubility of CO2 in water drops to about half as a result of changing the conditions from refrigerator to ambient temperature.

So depends on which gases are present, their concentration, pressure and temperature - sorry for chemistry lesson - delete this if you wish

Source: https://www.quora.com/How-do-gases-dissolve-in-water

 

[Down and beyond]

So we do not really no as we cannot tell what gasses where present before it filled up as such very good information to the question

 

[pirate]

We can tell the possible gasses by the type of mine

Ironstone mines will generally suffer from low oxygen levels as the iron in the rock oxidises to form iron oxide, leaving any non circulating air in the mine depleted in oxygen.

This is a pretty good read https://digital.library.unt.edu/ark:/67531/metadc12517/m2/1/high_res_d/Bulletin0347.pdf

 

[westernsultan]

So we do not really no as we cannot tell what gasses where present before it filled up as such very good information to the question

well here are just a few of the more common ones

• Carbon monoxide
• Carbon dioxide
• Nitrogen oxides (nitric oxide and nitrogen dioxide)
• Sulphur dioxide
• Volatile organic compounds (VOC) including benzene
• Oxygen defficiency
• methane
• radon

 

[Lord Oort]

And are any of those gases prevalent to iron mines?

 

[westernsultan]

And are any of those gases prevalent to iron mines?

Top of my list would be carbon dioxide and oxygen deficiency in old iron mines, but can depend if near coal mines and therefore migration of methane. In depth report at https://hal-ineris.archives-ouvertes.fr/ineris-00972431/document may interest you

 

[Lord Oort]

Thats French iron mines and doesnt really have any bearing here other than overcomplicating the issue. FYI C02 and low oxygen is the only thing you need to worry about in Iron mines.

 

[Kidney]

In addition to the above. Unless the mine is air tight then pressure will want to balance out to 1 atmosphere. It's all about ventilation and whether it's enough to facilitate air exchanges.

 

[Down and beyond]

I have been in around 7 iron mines in my area some flooded in waders some not ,i am not the most experienced on this site by far , but this is well over complicated now lol I always thought if the 4x beeps get out , if any one shows signs of head ace illness you all get out as it affects everybody different

 

[pirate]

Well that all depends on what you have your 4gas set at........
I’ve seen YouTube goons read 14%02 like it’s an everyday occurrence then just carry on without a care in the world.........I’d be well out of there at that point but hey they survived.

the other gasses are far more deadly and yer any beeping would be gtfo time