# SO2 AND ICE WATER



## Gold Lady (Sep 12, 2010)

HOW MUCH SO2 GAS CAN YOU BUBBLE THROUGH 1 GALLON OF ICE WATER?
How long will it stay stable and how fast can you bubble it?
Thank You,
Gold Lady


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## Irons (Sep 12, 2010)

Gold Lady said:


> HOW MUCH SO2 GAS CAN YOU BUBBLE THROUGH 1 GALLON OF ICE WATER?
> How long will it stay stable and how fast can you bubble it?
> Thank You,
> Gold Lady



Solubility of Sulfur Dioxide in Water vs Temperature:

22.97 g/100 mL (0 °C)
11.58 g/100 mL (20 °C)
9.4 g/100 mL (25 °C) 

Smaller bubbles will go into solution faster, so if you are attempting to dissolve Sulfur Dioxide in Ice water, a glass frit bubbler would be advantageous.


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## Harold_V (Sep 13, 2010)

From years of experience, using SO2 to precipitate gold:
A great deal depends on the depth of your container, and where you introduce the SO2. My solutions were always iced, so it's safe to say I introduced the gas @ 32° F, or nearly so. I did not use a regulator, instead using just a valve, to control flow. That, by the way, was more than adequate. I wouldn't recommend the use of a regulator, for it serves no real purpose. 

If you introduce the SO2 at a gentle rate, you can watch the bubbles rise to the surface, but they never get there, assuming your solution depth is around 10", and you introduce the gas at the bottom, as I did. using a 3/8" OD glass tube. The gas is absorbed by the solution at an alarmingly fast rate (to your benefit). As the solution warms, the result of precipitating the gold, the absorption rate decreases to the point where the bubbles burst on the surface. You can regulate how much is lost by slowing down delivery, however. 

Hope this helps.

Harold

edit: replaced improper term with proper term. Sorry, folks. I scewed up! (Thanks, Lou!)


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## Lou (Sep 13, 2010)

Absorption rate ought to decrease as it heats up. The reaction is quicker, but a warmer solution will hold less gas.


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## dtectr (Sep 14, 2010)

Great info, folks.

This has aroused my curiosity, hot vs. cold solutions here seems like the designated hitter ruling & night games(obscure baseball reference).
What I mean is, everyone seems to have strong feelings for or against either of the above.

It sounds to me, then, that if using SMB as precipitant, which introduces SO2, (is that right?), 
a colder solution would hold *more* gas, thus displacing *more* gold from solution, 
requiring the use of *less* SMB, to drop the same amount of gold.

I am currently using HCl/Cl to dissolve Au. Do I have this correct? Or does the above only hold true when using straight SO2 gas as precipitant?


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## goldenchild (Sep 14, 2010)

dtectr said:


> It sounds to me, then, that if using SMB as precipitant, which introduces SO2, (is that right?),
> a colder solution would hold *more* gas, thus displacing *more* gold from solution,
> requiring the use of *less* SMB, to drop the same amount of gold.



I think you are correct in saying this. You're also correct in how divided we are about hot vs cold solutions. I think the main thing it comes down to is how much gold you are precipitating out of solution. 

The heavy weights such as Lou, Harold, GSP, 4metals, fournines and so on that are used to precipitating ounces upon ounces out of solution get an advantage out of chilling their solutions. This is because the chemical reaction is so great that the solution heats up and gas is wasted if not chilled. 

For most of us however I dont think it will ever be a problem. Especially if you are only precipitating a few grams of Au per drop. There simply wont be enough heat generated for any gas to be wasted. The most I ever precipitated out at one time was I think 7 ounces. Its the "chameleon eyes" in the gallery. The vessel got pretty hot. Even then, I only added about 5 grams SMB more than the estimated yeild and it worked just fine. Putting a lid on the vessel (not completly sealed) along with adding in increments was sufficient to get all the gold out. As far as how fast the gold settles when the solution is hot vs cold is still up for debate for me.


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## goldsilverpro (Sep 14, 2010)

A long time ago, I mentioned that a guy I knew made "SO2 water" by bubbling SO2 into ice water until it was saturated. He then put this into jugs and used it to drop gold. This may be what Gold Lady was referring to. I saw no advantage of doing this. If you have SO2 gas, why not just use it directly instead of going through the extra step?


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## 4metals (Sep 14, 2010)

> The heavy weights such as Lou, Harold, GSP, 4metals, fournines and so on that are used to precipitating ounces upon ounces out of solution get an advantage out of chilling their solutions



There are multiple benefits to chilling solutions, chilling before filtration causes more of the silver to come out of solution as a chloride and it is retained with the insolubles. The solubility of silver chloride in cold water is considerably less than in warm water. Catching it in the filter keeps it away from your precipitated gold and yields finer gold. 

Chilling the solution for dropping the gold does drop the gold faster due to the increased solubility of the SO2 in the cool solution. Unless you continually cool the reaction it will warm up when gassing so the effect is temporary. 

I like to filter the acid cold and start gassing while it remains cold to get the benefit of cold acid on both ends, but the reasons for the acid being cold are different. Cold before filtering is to decrease the solubility of silver chloride, cold before gassing is to increase the solubility of the precipitant in solution.


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## Irons (Sep 14, 2010)

goldsilverpro said:


> A long time ago, I mentioned that a guy I knew made "SO2 water" by bubbling SO2 into ice water until it was saturated. He then put this into jugs and used it to drop gold. This may be what Gold Lady was referring to. I saw no advantage of doing this. If you have SO2 gas, why not just use it directly instead of going through the extra step?



Isn't there heat generated when the SO2 is dissolved in Water? By dissolving the SO2, chilling the SO2/Water solution prior to adding it to the GoldIII Chloride solution, the resulting reaction will warm less than adding the SO2 gas directly?


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## goldenchild (Sep 14, 2010)

Irons said:


> Isn't there heat generated when the SO2 is dissolved in Water? By dissolving the SO2, chilling the SO2/Water solution prior to adding it to the GoldIII Chloride solution, the resulting reaction will warm less than adding the SO2 gas directly?



I've never felt heat generated when dissolving SMB in water. Anymore I add SMB dry but will dissolve SMB in water every once in a while. Its whatever I feel like at the time because variety is the spice of life  

The 7 ounces I mentioned previously was precipitated with dissolved SMB in water. It heated up very quickly after adding it to the Au chloride. The SMB/water will only stay cool as long as the chloride/chemical reaction allows it. This was in my case. 

If you added a cup of SMB/water to say a half cup of diluted Au chloride it wouldnt heat up much if at all. This again goes back to how much gold is in the solution and how great the chemical reaction is.


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## goldenchild (Sep 17, 2010)

Ok here is a little vid I put together showing a prcipitation in a room temp solution. The material is from RAM gold fingers which pictures can be seen in "Hindsight is 20/20, or... How NOT to do it " Enjoy

[youtube]http://www.youtube.com/watch?v=Nwc4LTTuZB4[/youtube]


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## goldsilverpro (Sep 17, 2010)

Good video! Good music! Moonlight Sonata?


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## goldenchild (Sep 17, 2010)

goldsilverpro said:


> Good video! Good music! Moonlight Sonata?



Yes sir. Thanks


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## Harold_V (Sep 18, 2010)

goldenchild said:


> Ok here is a little vid I put together showing a prcipitation in a room temp solution.



Very well done! (In all ways, I might add)

Harold


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## HAuCl4 (Sep 18, 2010)

4metals said:


> > The heavy weights such as Lou, Harold, GSP, 4metals, fournines and so on that are used to precipitating ounces upon ounces out of solution get an advantage out of chilling their solutions
> 
> 
> 
> ...



How do you promptly chill 100-200 gallons of pregnant solution?. Do you dilute it at all with ice before filtering?.


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## 4metals (Sep 18, 2010)

Most dilute their acid with cold water before gassing, I skip the water and use buckets of crushed ice. The benefit of dropping the silver chloride before filtering is larger than gassing a cold solution. But if you do one right after the other, it stays cold when you start gassing.


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## philddreamer (Sep 29, 2010)

Bravo Mario! I enjoyed your video. 8)


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