# distilling nitric



## Anonymous (Sep 14, 2008)

I have been reading on distilling nitric, and I think I got it figured out.
Just want confirmation on 1 or 2 Facts? that I just got wind of.

If I make a dilute nitric with KNO3 and H2SO4 then try and distill it, that water will for the most part distill off until the azeotrope(spelling) cocentration of 68 percent is achieved, then the azeotrope will distill over.
I think this would cause me to lose acid unless I distill to dry KHSO4.
Also, does the acid itself degrade as the azeotrope distills? does the heat
at this temp decompose some of it?

thanks\
Jim


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## Noxx (Sep 14, 2008)

No, the water won't distill off...
The solution will distill, whatever the concentration of the acid is. If you have 15% nitric acid, and you use simple distillation, you will end with 15% nitric acid. My recommendation would be to make a higher concentration nitric acid. You should add just enough water to make 68% nitric acid.

Also, you will loose some acid because it decomposes when you distill it, unless you distill in vacuum.


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## Anonymous (Sep 14, 2008)

Steve, thanks,
I do not anticipate using a lot of acid and think that I would dilute it anyways, so I could work with the hopefully less reactive diluted stuff and only make enough for the task at hand.

I google search the distillation and the comments are from that, I have distilled other stuff and was suprized that the info provided stated that the water would distill off until the azeotrope was reached.

I got a distilling rig, all glass, do you just run water from the tap into the condenser, or does it need to be distilled to keep the gunk from building up?

jim


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## butcher (Sep 14, 2008)

If the concentration of acid is high in solution boiling, you will first distill the almost pure nitric first and very little water will distill out, the solution boiling will lower in concentration untill Azeotrope (68%) is reached, then you will start to distill out the 68% solution till done.

On the other hand if your starting solution was a week solution (weak nitric) the soution would distill mostly water until boiling solution reaches 68% then you would distill 68% off.

I collect 90% nitric in lil water from the NOX gas , then change the reciever to collect azeotrope (68%), but you can just collect 68% by alowing solutions to mix. see my other post for little more detail they are lil hard reading.


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## OMG (Sep 19, 2008)

I read that anhydrous magnesium nitrate is used to concentrate nitric. The anhydrous magnesium nitrate apparently sucks up the available water to make a hydrated form of magnesium nitrate (hexahydrate). I'm not sure if it would be possible to then just filter out the hydrated magnesium nitrate, but I'm sure you'd be able to at least boil off just the concentrated nitric (wiki says magnesium nitrate doesn't decompose until about 330 C).
If you can't get any anhydrous magnesium nitrate and were willing to sacrifice some nitric(as magnesium nitrate) you could probably just add some magnesium oxide.


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## Noxx (Sep 20, 2008)

Sorry I was wrong,

As butcher said, water will distill off first (with little nitric) if you have diluted nitric acid.

For example,
The firsts mL I got was 2% nitric
after 50mL I had 10% nitric
and my last mL are 50% nitric 

Concentration has been measured with specific gravity.


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## Shecker (Sep 20, 2008)

George Gajda's Book on gold refining refers to a system where nitric acid can be recovered from AR by using a refluxing condenser and bringing the solution of Ar to a boil. Nitric acid boils at a lower temperature than hydrochloric acid, allowing for a separation and recovery of the nitric acid.
Normally when I sit at my desk my copy of Gajda is over my right shoulder, but for some inexplicible reason it isn't there today. When I find it I will report on further details.

Randy in Gunnison


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## butcher (Sep 27, 2008)

Strong sulfuric acid acts as a dehydrator, using it can improve strength of nitric acid produced, but on downside it causes stains on your lab equiptment (Glass) when distilling. NOTE IF you try Distilling nitrate study it first make sure you understand process and safety, tools to use, dangers, poor mans nitric or Aqua regia works plenty good, easy and much safer.


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## Lou (Sep 27, 2008)

You're thinking of phosphoric. Concentrated sulfuric acid doesn't affect borosilicate glass up to its max working temperature of 400C.


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## butcher (Oct 16, 2008)

Lou when I distill I wasn't using lab glass, and the strong sulfuric salts stains my jar.probably attacking silicon in the glass? or maybe just leaving hard salt deposits?(of coarse I used sand bath) I have very limited supply of lab equiptment so far and save it where I can.


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## viacin (Nov 1, 2008)

butcher said:


> NOTE IF you try Distilling nitrate study it first make sure you understand process and safety, tools to use, dangers, poor mans nitric or Aqua regia works plenty good, easy and much safer.



I can only find two good posts on distilling nitric acid. I wish there was a tutorial on it. I have actually learned more on the subject from a youtube video and a 1950's chemistry book, than the forum. Am I missing a post somewhere, or has the whole process never been explained in full?


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## Noxx (Nov 1, 2008)

I think you are right viacin. I should make one, I distill nitric acid every two weeks.


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## butcher (Nov 2, 2008)

yes a post on distilling would be great maybe not just nitric, with data, principles ect,


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## Lou (Nov 2, 2008)

Go for it Noxx! I haven't distilled nitric in a long time, not since I ran out and only had KNO3!


Lou


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## viacin (Nov 2, 2008)

Noxx, I believe it would be appreciated not only by me, but by hundreds, if not thousands of members over time. Keep up the good work.


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## Anonymous (Nov 12, 2008)

since nitric passivates stainless could I just make my condenser from SS tubing? I have that stuff.

thanks

Jim


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## Harold_V (Nov 12, 2008)

300 series stainless is commonly used in packaging and distributing nitric acid. Unless Lou has an interesting comment, I see no reason why you can't use the material for distilling. Be certain that your choice is non-magnetic. You likely know that not all stainless is. 

Harold

Edit:

A question via PM from one of the readers gave me cause to add an additional comment. 

The use of stainless in this instance is restricted to the condensing unit only-----I would not endorse the use of stainless for the flask.


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## Platdigger (Nov 12, 2008)

So what will your boiling flask be made of?

If glass, how will you connect your tubing to the glass?

If stainless, think it will stand up to the sulfuric nitrate mix?

I hope this will work, it would definately cut some cost.
Randy


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## Harold_V (Nov 12, 2008)

Platdigger said:


> If stainless, think it will stand up to the sulfuric nitrate mix?


That was the one thing I wondered about, too. Given the stainless is not in direct contact with the mix, it may work. Connecting, as you alluded, could prove to be interesting, but a Teflon stopper would solve the riddle. Easy enough to make if one has access to a lathe. 

Harold


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## Anonymous (Nov 13, 2008)

glass for the boiler, connected to stainless. I have access to many sized, sheet, etc. I was going to use glass (a flask of one type or another) then fit with a condenser with teflon o-rings to seal.

Jim


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## butcher (Nov 13, 2008)

I use gallon pickle jar in sand bath, with teflon lid turned on lath & hole for tubing, clear hard plastic tubing chemical resistant, not sure of type but we use it to pump chemical for water treatment to the boilers at work, I coil this tubing in bucket of ice water for condenser, this same bucket of ice water is what the reciever jar sits in, I use teflon tape then electrical tape then cloth tape to seal reaction vessel, also tie down the teflon lid with wire to prevent pressure from pussing off lid, wire tie's to handles of the aluminum pot for sand bath. a hot plate for heat source.
CAUTIONS : 
do not change temperature on glass rapidly (thermal shock)
only fill boiling vessel one quarter full
do not use rubber nitric eats it

this works great for me.


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## Anonymous (Nov 13, 2008)

I am going to build a flange to mount to the flask ( a real flask) coil copper cooling line silver brazed to ss condenser so water can run all the time - basically the same as lab ware but made by me on the cheap from ss.

Jim


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## Harold_V (Nov 13, 2008)

james122964 said:


> I am going to build a flange to mount to the flask ( a real flask) coil copper cooling line silver brazed to ss condenser so water can run all the time - basically the same as lab ware but made by me on the cheap from ss.


You can also put a larger diameter piece of tubing around the stainless condenser tube, held in place by two discs. It could be copper or stainless. An inlet and discharge on each end, on the sides, provide for water circulation. I built my retort that way---it worked very well for distilling mercury. 

The exterior tube insures complete heat transfer, something that might be a consideration when using stainless, which is not a great conductor of heat. The assembly was silver soldered. 

Here's a poor picture of the retort, which shows the cooling tube and connections for cooling. 

Should you pursue a similar design, make the bottom the inlet with the top the outlet. That way you're assured of the chamber being full of water at all times. I used a small submersible pump and a 5 gallon bucket for my water supply. 

Harold


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## Oz (Nov 14, 2008)

Am I missing something? A copper cooling line and silver solder for distilling nitric.


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## Harold_V (Nov 14, 2008)

It's all very acceptable, Oz. It would be used strictly for the cooling circuit. The nitric would be eposed only to stainless. 

Harold


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## Oz (Nov 14, 2008)

I just had the wrong mental picture then. Thanks


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## Harold_V (Nov 14, 2008)

Welcome!

H


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## Anonymous (Nov 16, 2008)

Does anyone know the lowest concetration of nitric acid that is usable to remove silver and copper from inquarted gold? Is 10 percent feasible given no hurry for reaction to complete?

Also, under my name says expert gold refiner, I am not, could someone remove or change it to hobby level?

Thanks
Jim


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## Noxx (Nov 16, 2008)

Yes but you'll have a lot of diluted solution !


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## markqf1 (Nov 17, 2008)

James,
I too have tried to have my description changed from "gold refiner" back to " member " several months ago to no avail. Now I am an " advanced gold refiner"!  
I would prefer mine to just say member.

Mark


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## viacin (Nov 17, 2008)

lol, the description under your name is based on how many posts you have, not your actual refining level. All the phpbb forums have it. Consider it a badge of honor, I do. If I give advice on anything, I am sure to point out that I'm new at this too. I just have a big mouth and like to type  But if I didn't talk so much, I wouldn't have so many friends on here either. :!:


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## markqf1 (Nov 17, 2008)

I don't like misrepresenting myself.
Don't get me wrong, I do know how and have done a bit of gold refining , but, keep in mind that most of the gold mined from N. Ga is already pure enough for the gov't.

I try to learn about the pgm's and ,... if I get any info that I think anyone would be interested in, I pass it along.

At this point, I'm just a hobbiest .

Mark


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## butcher (Nov 18, 2008)

2NH4NO3 + H2SO4 --> 2HNO3 + NH4SO4
ammonium nitrate fertilizer and sulfuric acid,
little excess sulfuric would probably benifit reaction.
since (NH4)2 SO4 boils at 100 deg C,
and HNO3 boils @ 83 deg C, 
and excess H2SO4 will form NH4HSO4 right away,
and if distilling Nitric Acid with Ammonium Nitrate,
I assume the HNO3 boils first before Ammonium and if temperature is controlled the NH4 would not contaminate Nitric acid,
or maybe a way to test and remove residual ammonium from the acid?
Ammonium Nitrate fertilizer would be the cheapest.
and I have used it but always concerned about ammoinia portion in my recovery methods,when using this for nitric.

LOU or anyone Here have any ideas on this?


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## Harold_V (Nov 18, 2008)

markqf1 said:


> James,
> I too have tried to have my description changed from "gold refiner" back to " member " several months ago to no avail. Now I am an " advanced gold refiner"!
> I would prefer mine to just say member.
> 
> Mark


I moderate another forum, one that includes machining, welding, casting, and live steam (model steam locomotives). 

Early in the board's career they used to catagorize readers by the number of their posts, just as this board does. It can be very misleading----for some folks that may have considerable knowledge are chary of sharing what they know, while thers may have little knowledge but run their mouths (fingers, in this case) overtime, spewing garbage of little or no value. We have readers of both kinds on the other forum, and here as well.

From the above comment, you can conclude that the number of posts often has no relationship with the amount of knowledge contained in their heads, or of their willingness to share what they know, assuming they know anything. 

Unless Noxx decides to turn off that feature, it behooves each reader to not make assumptions based on that arbitrary title. It often does not represent the person in the least. 

Harold


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## Anonymous (Nov 18, 2008)

Mark


> I moderate another forum, one that includes machining, welding, casting, and live steam (model steam locomotives).



Harold, sounds interesting - what forum? If I may ask.

thanks

Jim


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## lamp (Nov 18, 2008)

I would like to know also ,I'm a bit of a train buff myself.


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## Platdigger (Nov 18, 2008)

Here three.......
Randy


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## markqf1 (Nov 18, 2008)

It's not a BIG deal.
Everyone that has been been here long enough, knows what the deal is.
I guess I'm guilty of talking so I can say something instead of talking because I have something to say.  

Actually, I have had many questions answered here and that is why I return frequently.

But, I freely admit that I am no expert of anything to everyone.
My advice is free but should be considered for what it's worth.

Mark


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## markqf1 (Nov 18, 2008)

If you wanted to know what I know about looking for gold in the mountains, I would tell you what I know from experience.

On the other hand, what I know about the tricks of the trade about gold refining, came from here.

Mark


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## Anonymous (Nov 18, 2008)

I have managed to leach nitric acid from calcium nitrate and sulfuric acid.

I mixed concentrated battery acid - boiled off to half of the original volume
then after cooling added to calcium nitrate, instant reaction forming white precipate. Placed this blob of acid and calcium sulfate into a homemade glass funnel that has glass wool losely packed in the neck. Then slowly sprayed with water to leach out the nitric. 

repeat with the using the leached acid to improve the concentration.

I ran the leach trough 3 runs.

Not to waste the nitric left in the calcium sulfate I rinsed and stirred it after leaching with excess water that will be my starting water for the next batch.

Not saying this is the best way, but it works without distillation.


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## Platdigger (Nov 18, 2008)

Plus, I remember Irons posting nitric made with calcium nitrate should be free of chlorides.

Were as nitric made from sodium or ammonium nitrate could have considerable chlorides.
Good job James. What was your ratio of acid to nitrate?
Randy


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## Harold_V (Nov 18, 2008)

james122964 said:


> Mark
> 
> 
> > I moderate another forum, one that includes machining, welding, casting, and live steam (model steam locomotives).
> ...



No problem, guys, there's room for many more. 

Here's a link to the board. 

http://www.chaski.org/homemachinist

You must be a registered user to post or to see pics. Registration is by approval, which I do not control. If you're interested, apply, and make mention of your interest in either machining or live steam. Approval generally takes a day, and is easy. 

The board experienced some serious spamming a couple years ago, at the hands of a user----so now applications must be approved by Marty. He's an OK guy, just trying to insure that we do not have another episode like the one we experienced previously. 

I keep close watch on the forum-------no foul language, no religion, and no politics and NO FLAMING. Immediate dismissal is the result of that violation. 

Any messages that violate the above restrictions are deleted immediately----and if members persist in violating any of the rules, they can be banned permanently. We've only banned a couple people in years, so I think you'll find the atmosphere very friendly. The restrictions eliminate wise guys that like to raise hell, just as they do on this board. 

Harold


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## butcher (Nov 19, 2008)

Harold I am a licenced boilerman, you mentioned live steam, are there discussion on modern boilers? I dont know much about the models, although have an interest in steam engines and would like to learn how the valves are timed to the pistons and the principles of operation.


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## Harold_V (Nov 19, 2008)

Not modern in the sense of commercial boilers, but boilers are very much a part of the hobby. To my knowledge, they are all fire tube boilers. 

We have at least one licensed builder on the board, and many build their own, some even doing their own welding. 
Sounds risky, but the models are generally so over-built that they are not known for catastrophic failures. There are no known fatalities from boiler failures here in the US, and the hobby is now more than 70 years old. Much older in the UK. 

The boilers are typically steel shells with K or L copper for flues. Some use steel flues as well. Some are coal fired, but oil and propane are taking over due to the difficulty of buying good quality coal, and the fire hazards. 

They boilers seem to work exceedingly well----and are operated up to 150 psi, although 125 is far more common. Boilers up to 12" diameter and down to as small as five or six inches, with the smaller boilers made of copper, silver soldered. There are even smaller boilers for the small gauge engines. The vast majority are engines built to 1½"/ft. scale, or 1/8" full size. There are smaller and larger scales, but the 1½" is the most popular. 

If you'd like to see some of the engines in operation, there's a track in Molalla, as well as one further south along I-5 (Brooks)
There is also a private track at a residence in Sherwood, but not open to the public. 

By the way, I envy you your welding prowess. I have studied welding and have passed x-ray vertical up 7018. I am far (very far) from being a weldor. 

Harold


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## Lou (Nov 23, 2008)

viacin said:


> lol, the description under your name is based on how many posts you have, not your actual refining level. All the phpbb forums have it. Consider it a badge of honor, I do. If I give advice on anything, I am sure to point out that I'm new at this too. I just have a big mouth and like to type  But if I didn't talk so much, I wouldn't have so many friends on here either. :!:




Actually, we all* apparently are reduced to active members now. I think Noxx's latest bit of code work has taken away individuality. How commie! We're all equals now 

*Steve's still the greatest and I mean that both ways!


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## viacin (Nov 23, 2008)

aww, your kidding me. I was proud of my meaningless rank, just like a military man with credentials but nothing to do. (  

Man, I want my rank back. :mrgreen:


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## markqf1 (Nov 24, 2008)

Sorry guys.  
I didn't mean to get everyone demoted, ... just myself.
Maybe some of you could start a survey on how skill descriptions should be dealt out.
As for me,... I'll stick with active member status.

Mark


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## Platdigger (Nov 24, 2008)

Yea Mark.....you even got Harold demoted!.....haha

No, really,I hadn't even noticed, makes no difference to me.
Randy


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## viacin (Nov 24, 2008)

I thought it did a pretty good job, assuming you didn't post a lot like me. For someone who reads for weeks, then runs a few batches, then begins posting, it's probably pretty accurate. For the odd ones (like me) who jabber on to buds more than they refine, then it may not apply so well. really it's impossible to have a one size fits all rank. Simply raising the rank levels is the easiest way, but I never saw where it was a problem. No one causing any trouble with it, so why really bother? It's not like some noob was posting incorrect info and people were believing him cuz of his rank. I see how this could happen, but thats when you just correct them. It's just a rank on a forum I guess, but I was proud of my stripes. 

Not being bias, but I do think that a few members should have special ranks. harold, steve, lou, gsp, noxx, etc. Perhaps anyone in the top 10 postings? Not just because they have the most posts, but I think that we can all agree that their knowledge on the subject surpasses most, and they should be treated as such.


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## Lou (Nov 24, 2008)

Viacin, that custom title might cut down on the disrespect factor that some newbies might have for the big posters.

To be honest, I can frankly give a damn whether my rank is "Forum Chemist" or "Forum Chili Cook". I've been fortunate to belong to forums where there are adults present who realize that some silly little user rank on a forum matters about as much as a hill of beans in the middle of a desert.


As far as talking and doing no refining goes, I know how that is. It's slow, slow business here on the PGM front. Most people don't want to sell, most people don't want to buy. Many are still holding their breath. I'm about ready to move to gold and silver and call it a day. Only time I need to do anything with the PGMs in the past month as been for making catalysts! It's hard getting platinum, let alone rhodium. I've been trying to get a contract with a photography supply house so that I can sell them metals salts, I'm hoping it'll come through--should give me enough labile capital to keep the noose from closing.


Ah well, when it rains it pours! A few months ago I was having the time of my life with Rh at 10K/oz!! Back to the basics!


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## butcher (Nov 25, 2008)

I am glad we have a chili cook on the forum.


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## Palladium (Nov 25, 2008)

Lou said:


> To be honest, I can frankly give a damn whether my rank is "Forum Chemist" or "Forum Chili Cook".



Let me see. Hummmm. I'll take two bowls one with beans and one without, let me get some crackers with that too please. :lol: 

Hey lou. :wink:


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## Lou (Nov 25, 2008)

Heheh, everyone knows real chili aint' got no beans in it!

Ralph, I found a cookbook somewhere, sometime online that was written by a chemist for chemists. Wish I could find it, I'd have some subtle hints to drop for a Christmas gift! It was all about the science of cooking, baking, grilling, braising, etc.


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