# Acid Chlorox reaction



## bswartzwelder (Aug 31, 2013)

I have been wondering for quite some time about the acid/Chlorox method. I used the AP method to recover the gold from some finger contacts, then put the gold into a beaker with HCl and added Chlorox. It fizzed, and slowly, the foils dissolved. Am I correct to assume the gasses which are given off when Chlorox is added to HCl are not responsible for dissolving the gold and are a by-product? I believed this to be the case since the gold dissolved after the gasses had dissipated.


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## chlaurite (Aug 31, 2013)

bswartzwelder said:


> I have been wondering for quite some time about the acid/Chlorox method. I used the AP method to recover the gold from some finger contacts, then put the gold into a beaker with HCl and added Chlorox. It fizzed, and slowly, the foils dissolved. Am I correct to assume the gasses which are given off when Chlorox is added to HCl are not responsible for dissolving the gold and are a by-product? I believed this to be the case since the gold dissolved after the gasses had dissipated.


If you mix them in equal molar amounts, you get NaClO + 2 HCl -> Cl2 + H2O + NaCl. Free Cl2 acts as a strong enough oxidizing agent to oxidize gold - Except, free Cl2 doesn't tend to stick around very long.

So really, as the only effect of HCl + NaClO, you get free Cl2 both evolved and placed into solution. The evolved gas effectively goes to waste, but we do this with such an excess that we still saturate the solution; the lag between evolving gas and the gold dissolving just comes from the time it takes for the Cl2 in solution to fully dissolve the gold.

As an experiment (which I haven't done, but you've inspired me to try it in the near future next time I have some foils to dissolve), use a pipette of chlorox to release it in very small doses well below the surface of your acid while stirring vigorously (careful, re-reading that on preview looks like a recipe for some serious burns if you screw up!). Theoretically, if you can get most of your Cl2 to go into solution, you should only need a very small amount of it to dissolve any realistic (ie, small) amount of metallic gold. We only add so much normally as consequence of just dumping it in on top of the acid, so most of the Cl2 goes to waste.


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## bswartzwelder (Sep 1, 2013)

WOW! you just blew my old mind. I have looked for pipettes for some time and just haven't been able to find them in larger sizes. Probably a good deal, as they would most likely get dropped or roll off a bench and break anyhow. I never liked the idea of using my mouth to provide the motive force for transferring liquids into a pipette, that's why I always used a piece of tubing of some sort between the pipette and me. I did like how easily you could control the flow when you were releasing the liquid out of the pipette.

It's true, anytime I added Chlorox to HCl, it fizzed up immediately and seemed to finish reacting almost at once. However, I do have a bunch of old syringes around from the days when I refilled ink jet cartridges. Add a piece of airline tubing to the end of the syringe and I could suck up the Chlorox. Then, place the tubing all the way to the bottom of the vessel containing the HCl and slowly "pump" in the Chlorox. It would go to the bottom of the vessel giving the most time for the Chlorine to react before it finally off gasses. It would also put space between the chemicals and my beautiful face. Don't want to take any chances. I've been told I have a face that only a mother could love. Seeing how many mothers there are out there, I take that as a supreme compliment.

As a side note, ink jet cartridges usually have gold plated contacts on them. They are tiny, but instead of just tossing them, I try to recover the gold from them by adding them to me other e-scrap. If, where you purchase ink jet cartridges, they offer either a discount or a rebate for returning used cartridges, you will certainly get the most bang for your buck by trading them in. If they just accept them and offer no incentive, process them.


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## Traveller11 (Sep 9, 2013)

bswartzwelder said:


> WOW! you just blew my old mind. I have looked for pipettes for some time and just haven't been able to find them in larger sizes. Probably a good deal, as they would most likely get dropped or roll off a bench and break anyhow. I never liked the idea of using my mouth to provide the motive force for transferring liquids into a pipette, that's why I always used a piece of tubing of some sort between the pipette and me. I did like how easily you could control the flow when you were releasing the liquid out of the pipette.
> 
> It's true, anytime I added Chlorox to HCl, it fizzed up immediately and seemed to finish reacting almost at once. However, I do have a bunch of old syringes around from the days when I refilled ink jet cartridges. Add a piece of airline tubing to the end of the syringe and I could suck up the Chlorox. Then, place the tubing all the way to the bottom of the vessel containing the HCl and slowly "pump" in the Chlorox. It would go to the bottom of the vessel giving the most time for the Chlorine to react before it finally off gasses. It would also put space between the chemicals and my beautiful face. Don't want to take any chances. I've been told I have a face that only a mother could love. Seeing how many mothers there are out there, I take that as a supreme compliment.
> 
> As a side note, ink jet cartridges usually have gold plated contacts on them. They are tiny, but instead of just tossing them, I try to recover the gold from them by adding them to me other e-scrap. If, where you purchase ink jet cartridges, they offer either a discount or a rebate for returning used cartridges, you will certainly get the most bang for your buck by trading them in. If they just accept them and offer no incentive, process them.




Chlorine gas dissolved in water becomes hypochlorous acid (HOCl) and hydrochloric acid (HCl). It is not necessary to have an extremely low pH, as in the "Acid/Clorox" method. HOCl is the oxidizer and the chloride ion is provided by the HCl, or "hydrogen chloride", as it is also known. In the Acid/Clorox process, the chloride ions are also supplied by the NaCl created when an acid and a base meet each other and cancel each other out.

As I have stated before, it is not necessary to use HCl to dissolve gold with chlorine, nor is it necessary to make chlorine gas. It actually disturbs me to see people with little or no experience in chemistry being advised to mix HCl and NaClO together, and next to no safety instructions on how to avoid a violent acid/base reaction, or inhaling chlorine gas.

To achieve EXACTLY the same process for dissolving gold into a soluble chloride, with the process at a neutral pH and NO chlorine gas is quite a simple thing. First, take a volume of bleach (stronger the better) whose pH will be slightly over 12 and, using a pH tester, slowly add acetic acid (vinegar) until the pH is between 7 and 8. To this, add un-iodized salt to 10% of the volume of the water. This mixture will put gold into solution.

What we have done by lowering the pH of the bleach (NaClO) is converted a good portion of the sodium hypochlorite (NaClO) into hypochlorous acid (HOCl), EXACTLY the same as if we were to bubble chlorine gas through water. There are other steps necessary to make this process work but, they are mechanical and quite easy to understand. 

As I have stated many times on this forum, this process for dissolving gold with chlorine at an almost neutral pH is not theory, it was the primary method employed for recovering gold from hard rock mines right up until the introduction of cyanide leaching in the early 1900's. Cyanide had the advantage of not only being far simpler to use, it was also much cheaper; and chlorine leaching was abandoned almost overnight. However, as cyanide is both difficult for the small operator to obtain, and somewhat dangerous to use, a chlorine leach made from common household products definitely has a place for the modern small operator. Especially one that produces no chlorine gas, and does not employ highly corrosive acids.


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## Harold_V (Sep 10, 2013)

Traveller11 said:


> As I have stated many times on this forum, this process for dissolving gold with chlorine at an almost neutral pH is not theory, it was the primary method employed for recovering gold from hard rock mines right up until the introduction of cyanide leaching in the early 1900's. Cyanide had the advantage of not only being far simpler to use, it was also much cheaper; and chlorine leaching was abandoned almost overnight. However, as cyanide is both difficult for the small operator to obtain, and somewhat dangerous to use, a chlorine leach made from common household products definitely has a place for the modern small operator. Especially one that produces no chlorine gas, and does not employ highly corrosive acids.


The one serious negative aspect of using chlorine is that silver is not recovered, unlike with cyanide.

Harold


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## Traveller11 (Sep 10, 2013)

Harold_V said:


> Traveller11 said:
> 
> 
> > As I have stated many times on this forum, this process for dissolving gold with chlorine at an almost neutral pH is not theory, it was the primary method employed for recovering gold from hard rock mines right up until the introduction of cyanide leaching in the early 1900's. Cyanide had the advantage of not only being far simpler to use, it was also much cheaper; and chlorine leaching was abandoned almost overnight. However, as cyanide is both difficult for the small operator to obtain, and somewhat dangerous to use, a chlorine leach made from common household products definitely has a place for the modern small operator. Especially one that produces no chlorine gas, and does not employ highly corrosive acids.
> ...



Harold

At $23.62/ounce, I don't really lose any sleep over it.


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## FrugalRefiner (Sep 10, 2013)

Poor silver... The Rodney Dangerfield of precious metals - it just doesn't get any respect.

When I was a kid, gold sold for around $35.00 an ounce. I wish someone had invested a bucket full of cash in it then. Now I see silver in the $30.00 an ounce range (yes, I know it's lower right now...), and I think what might this silver be worth someday to my grandchildren? They might just think old Gramps wasn't such an old feeb after all. :lol: 

Dave


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## Traveller11 (Sep 10, 2013)

By the way, the soluble gold product created with this leach is not the usual gold (III) chloride or auric chloride (formula AuCl3 or Au2Cl6) that is made with the Acid/Clorox process. This leach will produce something called sodium tetrachloroaurate or sodium gold chloride for short, with a chemical formula of NaAuCl4. From what I can gather, the precipitants used to recover metallic gold from auric chloride will work on this, as well.


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## modtheworld44 (Sep 10, 2013)

Traveller11 said:


> By the way, the soluble gold product created with this leach is not the usual gold (III) chloride or auric chloride (formula AuCl3 or Au2Cl6) that is made with the Acid/Clorox process. This leach will produce something called sodium tetrachloroaurate or sodium gold chloride for short, with a chemical formula of NaAuCl4. From what I can gather, the precipitants used to recover metallic gold from auric chloride will work on this, as well.



Traveller11

Does this leach base metals as well or does it work similar to the way cyanide leaches gold?



modtheworld44


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## Traveller11 (Sep 10, 2013)

modtheworld44 said:


> Traveller11 said:
> 
> 
> > By the way, the soluble gold product created with this leach is not the usual gold (III) chloride or auric chloride (formula AuCl3 or Au2Cl6) that is made with the Acid/Clorox process. This leach will produce something called sodium tetrachloroaurate or sodium gold chloride for short, with a chemical formula of NaAuCl4. From what I can gather, the precipitants used to recover metallic gold from auric chloride will work on this, as well.
> ...



Unfortunately, it will leach base metals, as well, as chlorine is very reactive. However, because it is not an acidic leach, but rather is close to neutral in pH, it cannot break the bonds of metal oxides (ie. haematite and magnetite). This is why, in the 1890's, ground ore was roasted, in the presence of oxygen, prior to leaching with this method. Roasting broke up the pyrites, turning the sulphur into sulphur dioxide and the iron into an oxide of iron. Any free iron in the ore was also turned into oxides. Large amounts of copper are also poison on this leach, unless oxidized as well.

Another drawback to this leach is that the process must take place inside an airtight revolving container, with either ALL of the air excluded by completely filling the container with ore and liquid, or by pumping air into the container and maintaining a pressure of 60 psi. In the 1890's, this pressure was created by mixing two chemicals together inside the sealed container to create chlorine gas, which then dissolved in the water in the container. Chlorine gas which did not dissolve built up pressure inside the container, achieving the same purpose as pumping in 60 psi air. This container must be either plastic or, if made from steel or other metals, plastic or lead lined to prevent the chlorine from reacting with the metal. Even stainless steel will react with chlorine and, outside of lead, the only other suitable metal is titanium.

The reason for excluding air, or for raising the pressure, is that hypochlorous acid (HOCl), the lower pH alter ego of sodium hypochlorite (NaClO) bleach, is, unlike sodium hypochlorite, a very powerful oxidizer and, for that reason, is very unstable. It wants nothing more than to lose that lone oxygen atom to the atmosphere and go from HOCl to HCl which is, of course, hydrochloric acid or hydrogen chloride. In the water system I operate, this can easily be proven. I add sodium hypochlorite bleach to drinking water, as a disinfectant, by means of a metering pump and injection nozzle. As the pH of our water is typically 7.5, this hypochlorite gets converted to a roughly 50/50 mixture of sodium hypochlorite and hypochlorous acid. I measure this mixture out in the system on a regular basis as "free chlorine" by means of a reagent. Once all the reactions with bacteria, organics and metals such as iron and manganese have occurred, the remaining free chlorine will stay in the water for as long as two weeks, temperature dependent, before the free chlorine is depleted. This is because the water pressure in our pipelines is a static 94 psi. However, once this water is poured from the tap into a glass and left to stand at atmospheric pressure, the oxygen atom is quickly lost from the HOCl and, within half an hour, most of the free chlorine is gone from the water. The same will happen with this leach. If attempted in open air, the oxygen will take the path of least resistance, and instead of oxidizing gold, will be lost to the atmosphere. The resulting HCl will also begin lowering the overall pH of the solution, and, once under pH 5, chlorine gas will be released. At a lower pH, the increased acidity is also enough to break the bonds of the metal oxides, putting base metals into solution and not gold.

Strangely enough, I thought the sole purpose of revolving the container was to keep the leach and ore mixed and in contact with each other. From reading an old mining paper, I learned the other purpose was to keep the gold particles in motion in order to abrade the silver chloride precipitating on the gold particles. It seems that silver chloride will form an impenetrable coating on the gold particles and impair the leach process. Constant tumbling knocks the silver chloride off, as, from what I have read, it does not have a strong bond to the surface of the gold particle.


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## Traveller11 (Sep 10, 2013)

I should also add that adding acetic acid (vinegar) to bleach is not the only way of lowering the pH of bleach to 7-8. You can accomplish the same thing with HCl and use far less of it than you would vinegar. However, adding HCl to bleach can give one a rather violent reaction, whereas vinegar barely sizzles when added to bleach.

This is another thing that has always concerned me about the Acid/Clorox process. Typically, the material is first covered in HCl, then bleach is added to that. As everyone knows, one of the first rules of chemistry is to always add acid to water, and NEVER add water to acid. If bleach is typically made up of over 90% water, would this not mean this process violates that rule?


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## solar_plasma (Sep 11, 2013)

> acid to water, and NEVER add water to acid. If bleach is typically made up of over 90% water, would this not mean this process violates that rule?



Dilluting strong bases or acids generates heat. Some generate more heat, some less - *you don't want to put water into conc. sulfuric acid.* Following this rule means avoiding violent reactions and splashing. When you use HCl/chlorox you will have a more or less violent reaction generating heat and chlorine, yes, but you are prepared and if done cautious, it will normally not splash. Nevertheless, you are prepared, it could splash.

The more concentrated the acid or base is,the more likely it would splash. Conc. sulfuric is an example for an acid that definately WILL splash.


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## bswartzwelder (Sep 11, 2013)

Traveller11,
Thank you for your well thought out and informative posts. I read the first one with great interest. I was planning to research this process in more depth before attempting the acid/Chlorox method again. It is obvious to me that others on the forum have had the same experiences as I have based on some of their comments. I was trying to formulate a couple of questions, but also wanted to know more before asking those questions. Now, after having read your second post on the process, that has (for me) become a moot point. 

I will be the first to admit I am not a chemist. I have had high school chemistry and while attending Penn State had some college level chemistry as well. I have always tried to be as safe as possible when dealing with chemicals. Always adding acid to water and not vice versa and always making additions slowly. Also, anytime I use a chemical with chlorine in its makeup, I make sure there is a breeze (either natural or forced) before I start out. Ever since I was a very small lad, I had heard stories of how my grandfather had been gassed in World War One and had one lung removed and part of the other one as well. It was the fact that according to the way you described the procedure there was little chlorine off gassing that really piqued my interest.

As far as my own acid/Chlorox experiences, the first time I tried it, I was dissolving foils from circuit boards with little or no base metals. They had first been processed with AP. After that worked so well, I decided to try it with some very small placer nuggets. That was the experience whereby it didn't work as expected. 

I can see several drawbacks (at least for me) in your version. First, copper will "poison" the leach. That means it should only be used on foils which have already been stripped by the AP method and are free of base metals. It's a shame that it would not be effective on circuit boards (even those with the components removed) if there was still copper underneath or solder present. 

Another drawback is the necessity of an airtight revolving container under a pressure of at least 60 PSI. The revolving container is not much of a problem, but a plastic, titanium, or lead lined container able to withstand 60 PSI would certainly pose some issues (at least for me). If it would work at close to ambient pressure, there are many plastic containers, easily obtainable (and cheap) which could suffice.

Your explanation of the chlorine coming out of solution at room temperature and pressure reminded my of one of the experiments/training sessions of my Nuclear Engineering classes. At the State College campus of Penn State, there is "swimming pool" nuclear reactor named the Brazealle (not sure of the spelling after all these years) nuclear reactor. You can stand around the gallery and look down into the reactor as it is being operated. As the power level increases, the blue glow from the core gets brighter. It has a 1 megawatt thermal rating for continuous operation, but can be pulsed to a thousand megawatts for a few thousandths of a second demonstrating an effect called "going prompt critical". During that instant, the light produced looks almost like looking at a huge flashbulb. Anyhow, as the reactor is in operation, it produces a byproduct which has a very short life span (on the order of a few seconds). This byproduct would rise with the heated water and as it broke the surface, it would set off radiation monitors in the area. The depth from the top of the core to the surface of the water was something like 9 to 12 feet. A few more feet of water meant the product would never get to the surface in a concentration that would set off the monitors as the radiation would decay to an acceptable level by then. The solution was to place a nozzle above the reactor core and blow water across the top of it. The radioactive byproduct now had to travel a longer distance by going at some angle other than the 90 degrees straight up. That was all it took to cause the byproduct to decay to safe levels before reaching the top of the surface.

Thank you, again for your explanation of the process. It was very informative and I do remember reading about it, but not lately. Do you have any pictures of your setup that you would care to share?


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## Traveller11 (Sep 11, 2013)

bswartzwelder said:


> Traveller11,
> Thank you for your well thought out and informative posts. I read the first one with great interest. I was planning to research this process in more depth before attempting the acid/Chlorox method again. It is obvious to me that others on the forum have had the same experiences as I have based on some of their comments. I was trying to formulate a couple of questions, but also wanted to know more before asking those questions. Now, after having read your second post on the process, that has (for me) become a moot point.
> 
> I will be the first to admit I am not a chemist. I have had high school chemistry and while attending Penn State had some college level chemistry as well. I have always tried to be as safe as possible when dealing with chemicals. Always adding acid to water and not vice versa and always making additions slowly. Also, anytime I use a chemical with chlorine in its makeup, I make sure there is a breeze (either natural or forced) before I start out. Ever since I was a very small lad, I had heard stories of how my grandfather had been gassed in World War One and had one lung removed and part of the other one as well. It was the fact that according to the way you described the procedure there was little chlorine off gassing that really piqued my interest.
> ...



Sorry about that. I don't think I explained everything quite adequately for you. The method of pressurizing the revolving leaching container to 60 psi with air was only one way out of several that was employed in the late 1800's. Another method pumped a chlorine solution (hypochlorite/hypochlorous acid) into the bottom of the revolving container, which also had a valve at the top of it. As the solution filled the ore filled container, it eventually overflowed the top valve and, by design of the container, all of the air in the container was displaced by solution at this point. The flow of chlorine solution to the bottom of the container was cut off at this point, and the top valve was closed. This left a solution filled container with no air in it; or, if there was air, such a miniscule amount that the first bit of oxygen lost from the HOCl would very quickly build to a pressure that would not allow any more oxygen to be lost from the HOCl.

Another method employed was to have a mixture of ground ore and water in the revolving cylinder and, to this mixture, adding chloride of lime (calcium hypochlorite) and sulphuric acid, and then quickly sealing the container. This mixture, of course, produced chlorine gas. A goodly portion of the chlorine gas dissolved in the water, making hypochlorous acid (HOCl) and hydrochloric acid (HCl or hydrogen chloride), while the excess chlorine gas built up pressure inside the container; achieving the same end as pressurizing with air to 60 psi.

You see, there is more than one way to skin a cat; it all depends on how much you enjoy breathing chlorine gas.

It is unfortunate that copper has the effect it does on this leach. I have read several patents that recommended oxidizing copper to an oxide but, they were dealing with finely ground ore, and I do not know if this would be economical to do with printed circuits. As I stated in the last post, finely ground ores, in the late 1800's, were roasted in the presence of air to convert base metals and sulphides into oxides, which were impervious to chlorine at a pH close to neutral.

Here is a link to a good article from 1898:

http://geology.com/publications/getting-gold/secondary-gold-extraction.shtml

One minor correction; it is not the chlorine that is lost to the atmosphere when a solution of hypochlorous acid (chlorinated water, for example) is left to stand in an open container at atmospheric pressure. From the HOCl, it is the oxygen atom that is lost, leaving us with HCl or hydrochloric acid. This is why hypochlorous acid is known as such a powerful oxidizer, and why it is such a good disinfectant. As it oxidizes bacteria in water, that oxygen atom actually breaks through the outer cell wall of the bacteria, wreaking havoc with the DNA within.


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## Gratilla (Sep 11, 2013)

bswartzwelder said:


> Anyhow, as the reactor is in operation, it produces a byproduct which has a very short life span (on the order of a few seconds). This byproduct would rise with the heated water and as it broke the surface, it would set off radiation monitors in the area. The depth from the top of the core to the surface of the water was something like 9 to 12 feet. A few more feet of water meant the product would never get to the surface in a concentration that would set off the monitors as the radiation would decay to an acceptable level by then. The solution was to place a nozzle above the reactor core and blow water across the top of it. The radioactive byproduct now had to travel a longer distance by going at some angle other than the 90 degrees straight up. That was all it took to cause the byproduct to decay to safe levels before reaching the top of the surface.



Hmmm, something doesn't sound quite right here. The vertical speed of the byproduct (and thus the time to reach the surface) should be the same, irrespective of the added crossflow. True, the diagonal distance travelled would be greater, but the vertical component should be the same.

Take, for example, a plane travelling from A to B (in still air). If a crosswind is added, the ground speed would increase, but the airspeed would remain the same. [Of course the plane would now never reach its destination unless the plane's direction was changed to counteract the crosswind component.]

If adding the nozzles provided a solution though ... can't argue with that, but I would imagine some other "magic" was involved.


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## niteliteone (Sep 12, 2013)

Gratilla said:


> (snip)
> If adding the nozzles provided a solution though ... can't argue with that, but I would imagine some other "magic" was involved.


That one important aspect (magic) was "time". since the the radiation was forced to travel a greater distance to reach the surface, which would require more time, it decayed before it reached the surface.
Remember radioactive particles have mass, therefore must obey laws of physics.


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## Gratilla (Sep 12, 2013)

Agree
Agree
Disagree
Yes, but WHY???

The vertical distance remains the same.
The time to rise that vertical distance will remain the same.
The nozzles introduce a horizontal component and yes,
The distance travelled will be greater, and 
the speed (in relation to the container) will increase, but surely
The time to rise the vertical distance will still remain the same.

Now imagine you're a mini Einstein sitting on one of those rising bubbles (without affecting it in any way) ... ... ...

Hmmm, where does my logic break down???


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## niteliteone (Sep 12, 2013)

Gratilla said:


> Agree
> Agree
> Disagree
> Yes, but WHY???
> ...


So by your logic, a head wind vs a tail wind would have no effect on how fast a 747 could climb to cruising altitude, assuming no other variables were involved. (ie. ground speed and throttle position)

edit to add;
"So by your logic" is said in a good way, not confrontational.


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## solar_plasma (Sep 12, 2013)

Radiation against a flow of materia means, that the radiation, wether it is particle or wave radiation, has to pass more atoms per time without hitting them. So, setting a flow of materia against the radiation is pretty the same as shielding with materia of a higher density.


I hope this simple image isn't made impossible to understand caused my bad germ-english :lol: 


I just wonder, how fast must the flow be to take any effect, considering the speed of the radiation.


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## niteliteone (Sep 12, 2013)

solar_plasma said:


> (snip)
> I hope this simple image isn't made impossible to understand caused my bad germ-english :lol:


On the contrary. It made me think more about what I was getting at above and is right on target. Unlike my example :mrgreen:


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## g_axelsson (Sep 12, 2013)

niteliteone said:


> So by your logic, a head wind vs a tail wind would have no effect on how fast a 747 could climb to cruising altitude, assuming no other variables were involved. (ie. ground speed and throttle position)


Head wind or tail wind doesn't have any effect on the rise time as the airplane is moving relative to the moving air.



solar_plasma said:


> Radiation against a flow of materia means, that the radiation, wether it is particle or wave radiation, has to pass more atoms per time without hitting them. So, setting a flow of materia against the radiation is pretty the same as shielding with materia of a higher density.
> 
> I hope this simple image isn't made impossible to understand caused my bad germ-english :lol:
> 
> I just wonder, how fast must the flow be to take any effect, considering the speed of the radiation.


Any radiation is moving with relativistic speed, a flow of water is by all practical means stationary. To affect the radiation (beta, gamma, x-ray) you need to at least reach relativistic speed of the water before you see any effect.

Any radiation that can be stopped by a flush of cold water is short lived radionucleids carried up by the hot rising water.
If you flush the top of the water on the reactor with cold water you create a downward motion that exists before the heat flash, you also create some turbulence that will mix the hot and cold waters and reduce the temperature gradient, that will also slow down the speed of the hot water rising.

... I'm sorry, what was the question again? :mrgreen: 

Göran


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## solar_plasma (Sep 12, 2013)

makes sense, thanks

I already wondered, if any particles could be slow enough

now, getting the chance to ask a physician: for example beta particles exist at most different energies in eV, betas from H3 have such a small energy, typical instruments like FH40G do not measure them or at least not correct....where is that energy, is it the speed of the particle or is the particle itself some kind of stimulated or do we at this point have to understand it as a wave and its energy is given by the amplitude (since beta- is just a fast electron, which can behave like a wave)?


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## bswartzwelder (Sep 12, 2013)

Traveller11,
You did a great job of explaining and I think I have a very good idea of what is happening and how. Perhaps, I oversimplified my thoughts on the equipment, but the combination of the materials required (to withstand the reaction of the leach) and the necessary design to withstand the 60 PSI make this something that would be very difficult for a hobbyist refiner to build. Personally, if I had one, I would like for there to be a significant safety margin built into the pressure retention part. I simply cannot imagine what an explosion with HCl and chlorine gas would be like. However, if there was no open space in the rotating cylinder, there would not be much of an explosion. A company I used to work for used many aluminum castings. Sometimes, one would come through where the metal was porous and couldn't be used. The technician would seal both ends of the cylindrical casting. Then, it would be ALMOST filled with water. Next, he would submerge it into a tank filled with water and pressurized it with compressed air. If the casting was porous, air bubbles would escape into the tank and rise as the casting was rotated. With most of the casting filled with water, there was very little room for the air. If there would have been a catastrophic failure, there wouldn't have been much air to release and explosively expand. Had one failed, it could have blown anywhere on the casting, so the failure point could have been on top, on a side, or on the bottom, but it was ALWAYS under water. The air pressure was most likely well below the failure pressure since they were only looking for pin hole leaks. Still, the idea of chlorine and HCL under pressure demands much respect. 

In a way, I'm sorry about the reactor part of the thread. It isn't truly on topic, but I thought it was interesting and would be thought provoking. NOONE on this forum can honestly say they aren't interested in science and learning. If you look at the reactor, the core was cube (3 feet on a side) made up of fuel RODS approximately 1.375 inches in diameter and the Uranium was enriched to somewhere between 15 and 30% (sorry, I just can't remember the details). For the sake of argument, lets say the top of the reactor was 9 feet below the surface of the water. The byproducts, without a stream of water blowing them sideways had to travel a total of 9 feet vertically to the surface. Now, turn on the pump and blow a stream of water across the top of the reactor. Instead of travelling vertically, the heated water is travelling with both a vertical component AND a horizontal component. Again, I don't recall the actual numbers, but to make it easy, let's say the water jet was pushing from left to right with a velocity that will blow the water off to the side whereby once it reaches the surface, it has travelled 12 feet horizontally. Looking at these numbers, we have a triangle with a horizontal side of 12 feet and a vertical side of 9 feet. This is a classic 3-4-5 triangle. While the byproducts move 9 feet vertically, they are moving 12 feet horizontally. But the total distance travelled is neither 9 feet nor 12 feet, but 15 feet. The byproducts are moving along the hypotenuse of the triangle. It is still only 9 feet vertically, but with the 12 foot horizontal component, it works out to a total distance travelled is 15 feet. Nothing adds to the vertical speed. The pump merely adds a 12 foot horizontal component. This is an oversimplification, because we are talking about heat, velocity, distance, and the water medium. The true path is not a nice straight line. The water from the jet will spread out and the water rising from the core cools down as it intermixes with the rest of the water in the reactor due to turbulence. The actual numbers are not important, it's the idea or concept that I was trying to illustrate. A hot air balloon on a day with a crosswind might have been easier to visualize.

In the real world of power production, reactor cores are usually cubic and depending on power produced, some are 12 feet on a side. The fuel is formed into cylindrical pellets approximately 0.375 inches in diameter with both ends concave to allow for thermal expansion. (The enrichment of the uranium is very low. It used to be about 3% to 5%, but I think it is slightly higher now. The higher enrichment means you can run the reactor longer between refueling and therefore have less down time.) The fuel pellets are sealed in zirconium clad tubes. The cladding restricts the maximum temperature the reactor can reach safely. Get it too hot and the zirconium will come off. This is not a good thing. Then the tubes are arranged into bundles. Before they go into the reactor, you can actually walk right up to them without any danger. They are closely inspected visually before being loaded into the core. After they have been in the core and have produced energy, they become dangerous as the uranium has changed into other products. We had a discussion about this at work one day, and even the smartest people in the room weren't sure of the answer. The question was: "If you set a used fuel bundle in the center, of a football stadium on the 50 yard line, could you run fast enough to touch it before you died? Or, would your blood boil before you got to it? We could never really figure that one out. We knew the company wouldn't let us borrow a used fuel bundle, and no one would volunteer as a runner.


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## bswartzwelder (Sep 12, 2013)

You can Google Pennsylvania State University Reactor, and there is a link to YouTube showing the reactor when it is being pulsed. It is only about 16 seconds long, but you can see how the radiation in the vicinity of the core decays off after the pulse.


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## Traveller11 (Sep 12, 2013)

bswartzwelder said:


> Traveller11,
> You did a great job of explaining and I think I have a very good idea of what is happening and how. Perhaps, I oversimplified my thoughts on the equipment, but the combination of the materials required (to withstand the reaction of the leach) and the necessary design to withstand the 60 PSI make this something that would be very difficult for a hobbyist refiner to build. Personally, if I had one, I would like for there to be a significant safety margin built into the pressure retention part. I simply cannot imagine what an explosion with HCl and chlorine gas would be like. However, if there was no open space in the rotating cylinder, there would not be much of an explosion. A company I used to work for used many aluminum castings. Sometimes, one would come through where the metal was porous and couldn't be used. The technician would seal both ends of the cylindrical casting. Then, it would be ALMOST filled with water. Next, he would submerge it into a tank filled with water and pressurized it with compressed air. If the casting was porous, air bubbles would escape into the tank and rise as the casting was rotated. With most of the casting filled with water, there was very little room for the air. If there would have been a catastrophic failure, there wouldn't have been much air to release and explosively expand. Had one failed, it could have blown anywhere on the casting, so the failure point could have been on top, on a side, or on the bottom, but it was ALWAYS under water. The air pressure was most likely well below the failure pressure since they were only looking for pin hole leaks. Still, the idea of chlorine and HCL under pressure demands much respect.
> 
> In a way, I'm sorry about the reactor part of the thread. It isn't truly on topic, but I thought it was interesting and would be thought provoking. NOONE on this forum can honestly say they aren't interested in science and learning. If you look at the reactor, the core was cube (3 feet on a side) made up of fuel RODS approximately 1.375 inches in diameter and the Uranium was enriched to somewhere between 15 and 30% (sorry, I just can't remember the details). For the sake of argument, lets say the top of the reactor was 9 feet below the surface of the water. The byproducts, without a stream of water blowing them sideways had to travel a total of 9 feet vertically to the surface. Now, turn on the pump and blow a stream of water across the top of the reactor. Instead of travelling vertically, the heated water is travelling with both a vertical component AND a horizontal component. Again, I don't recall the actual numbers, but to make it easy, let's say the water jet was pushing from left to right with a velocity that will blow the water off to the side whereby once it reaches the surface, it has travelled 12 feet horizontally. Looking at these numbers, we have a triangle with a horizontal side of 12 feet and a vertical side of 9 feet. This is a classic 3-4-5 triangle. While the byproducts move 9 feet vertically, they are moving 12 feet horizontally. But the total distance travelled is neither 9 feet nor 12 feet, but 15 feet. The byproducts are moving along the hypotenuse of the triangle. It is still only 9 feet vertically, but with the 12 foot horizontal component, it works out to a total distance travelled is 15 feet. Nothing adds to the vertical speed. The pump merely adds a 12 foot horizontal component. This is an oversimplification, because we are talking about heat, velocity, distance, and the water medium. The true path is not a nice straight line. The water from the jet will spread out and the water rising from the core cools down as it intermixes with the rest of the water in the reactor due to turbulence. The actual numbers are not important, it's the idea or concept that I was trying to illustrate. A hot air balloon on a day with a crosswind might have been easier to visualize.
> ...



The method I mentioned where the container is completely filled with solution, excluding all air, does not build internal pressures equal to the 60 psi the other method is charged with. The release of oxygen from the hypochlorous acid will more than likely stop at a few psi above atmospheric pressure. Think of a bottle of Coke with the cap on. Carbon dioxide dissolves in water at 25 psi. With the cap on the bottle, there are no bubbles visible in the Coke. However, when the cap is removed, with an audible "pop" as the 25 psi pressure in the neck of the bottle equalizes with atmospheric pressure (14.7 psi), we begin seeing bubbles as the CO2 volatizes and comes out of solution.

This is quite easy to test. If a person takes regular 6% bleach, or industrial strength 12% bleach, or makes up his own bleach from calcium hypochlorite powder and water up to, say, 20%, and then lowers the pH with acetic acid to 7-8, he will have created a solution of roughly 50/50 hypochlorite/hypochlorous acid. With 4" ABS pipe fittings and a short piece of 4" ABS pipe, a vertical container can be made with a cap on the bottom and a cap on the top with an opening in the centre of it for a smaller pipe fitting. Through this pipe fitting hole, add the solution until the container is about 95% full. Reduce the pipe fitting down with plastic bushings until a pressure gauge with a 1/4" base can be threaded in, making the chamber airtight. As the HOCl loses oxygen, it should reach a pressure where the loss of oxygen from the HOCl is stopped altogether and the pressure goes no higher. I am willing to bet it is not much above atmospheric.


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## g_axelsson (Sep 12, 2013)

solar_plasma said:


> makes sense, thanks
> 
> I already wondered, if any particles could be slow enough
> 
> now, getting the chance to ask a physician: for example beta particles exist at most different energies in eV, betas from H3 have such a small energy, typical instruments like FH40G do not measure them or at least not correct....where is that energy, is it the speed of the particle or is the particle itself some kind of stimulated or do we at this point have to understand it as a wave and its energy is given by the amplitude (since beta- is just a fast electron, which can behave like a wave)?


Yes, the energy is contained in the speed of the particles released (alpha, beta, neutron, neutrinos, the nucleus... and so on) or in the wavelength of an electromagnetic wave (gamma rays). The energy released is mixed between all the parts in a decay so it can differ between the different parts.
For example in 3H the beta decay also releases a neutrino and it takes some of the energy away, the rest is shared between the nucleus, m1, and the electron, m2, conservation of impulse gives m1v1 = m2v2, as m1 >> m2 that leads to v1 << v2, the electron shoots off very fast and the nucleus just recoils slowly.

Let's look at the really low energy beta radiation from 3H. It has a mean energy of 5.7 keV, 1/2 to 1/3 of the energy of an electron in a CRT. In free air it would be stopped within 6 mm and even shorter in water 1. But it's still traveling with 15% of the speed of light 2.
To travel 6mm with 15% of C would take 0.13 nano seconds, I don't think the speed of the water would matter for the shielding effect. :mrgreen: 

I guess that the answer on your question if there is radiation (moving particle) slow enough to be affected by the flow of the water is definitely no. Nothing energetic enough to penetrate the water is moving so fast the water seems to be stationary even with the most powerful pump.

In the case of running towards a radioactive pile on a football field the question is... it depends. But I would say that you could do it but you may die afterwards. There are three accidents I'm thinking of to support my claim.
- In the clean-up operation after Chernobyl part of the core was blown through the roof and landed on top of the nuclear reactor. Conscripts were bussed in to manually shovel the pieces back into the reactor hall. With heavy protection gear they could work for 40 seconds each. All survived the day but many died from cancer later on.3
- In Los Alamos there were an accident when some researchers accidentally made a piece of uranium supercritical. They discovered it when the chain reaction started and the air started to glow from the ionizing radiation. One of the researchers took the device apart and probably saved the life of the other persons. He died nine days later.4
- Also in Los Alamos, a tank with plutonium became critical and people could see a flash of light from the radiation flash. The operator, Cecil Kelley, was standing next to the tank and caught five times a lethal dose. He died 35 hours later.5

1 http://en.wikipedia.org/wiki/Tritium
2 http://www.ou.edu/research/electron/bmz5364/calc-kv.html
3 http://en.wikipedia.org/wiki/Chernobyl_disaster#Debris_removal
4 http://en.wikipedia.org/wiki/Criticality_accident#Incidents
5 http://en.wikipedia.org/wiki/Cecil_Kelley_criticality_accident

/Göran


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## solar_plasma (Sep 13, 2013)

> To travel 6mm with 15% of C would take 0.13 nano seconds, I don't think the speed of the water would matter for the shielding effect. :mrgreen:
> 
> I guess that the answer on your question if there is radiation (moving particle) slow enough to be affected by the flow of the water is definitely no. Nothing energetic enough to penetrate the water is moving so fast the water seems to be stationary even with the most powerful pump.



Thanks, I have just got an idea of using this to my pupils as a homework next time we talk radiation. :lol:


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## bswartzwelder (Sep 13, 2013)

Thank you, Göran,

The very first accident involving a nuclear reactor was the SL-1 (Stationary Low Power Reactor #1) in Idaho. Three workers were performing some type of maintenance on the reactor, which was shut down at the time. One of the workers pulled out the "safety" control rod which kept the reactor safely shut down. As he did so, the water in the bottom of the reactor flashed to steam. The reaction was so fast (and so violent) that the water above the steam was forced upward and caused a "water hammer" effect. I'm not sure if the top of the reactor was blown off, but one of the workers bodies was not found for 3 days. It was found pinned to the roof of the building, having been impaled by the control rod.

In a nuclear reaction, the actual energy is released as the particles/waves from the reaction slow down. As it would take huge amounts of power to reach the speed of light (assuming it is possible), therefore, slowing down from near the speed of light releases tremendous amounts of energy. EVERY reaction that I can think of is energetic. Some require energy be added in the form of heat or electricity. Some give off energy such as mixing acids and bases (usually causes heat), or in nuclear processes by the slowing of the particles/waves involved. 

Just to put things into some kind of perspective, the amount of energy released from a reaction can be measured in electron volts. If I remember correctly from my college days, the very most violent chemical reaction produces about 20 electron volts and less violent reactions produce less. This would be for a single molecule reacting. The very smallest nuclear reaction produces energy on the level of millions of electron volts for a single atom/molecule. I believe nuclear reactions in the range of billions of electron volts have also been recorded.


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