# Where is my gold? The gold is missing!



## [AuCl4]- (Jun 19, 2012)

Hello, I need help with this please.

I have a batch of fingers, cpus and pins that I dissolved with AR. I boiled the batch until all metal was dissolved. I didnt treat with HNO3 first because I didnt have that knowledge when I started this batch. When I poured the solution off, there was a green crystalline covering everything............It was quite beautiful but didnt take a picture but it looked like this........... http://en.wikipedia.org/wiki/File:Cupric_chloride.jpg

I then gently boiled down to a syrup and added a little HCl to get rid of HNO3 and added water.

I then filtered and put into 3 bottles and left overnight. The solution was very dark green almost black in the jars. I then pored off the solution leaving the white sediment in the jar. I then boiled lightly the solution and the cloudiness went to more sediment. I then left it overnight and the solution is dark green but very clear and no cloudiness. 

I filtered the solution and now I have 3 jars and all 3 test negative for gold with SnCl2. The SnCl2 was old so I made a fresh batch and tested again.........Negative for gold. 

I then thought that I messed up the test solution so I tested it on some left overs from the first batch before this botched one and it is nice and black..........positive!

So now here I am thoroughly confused staring at my 3 bottles. 

What happened to my gold? Where is it? Did I boil it away with the steam?


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## Geo (Jun 19, 2012)

its not a good thing to process all those mixed materials at once. when you did the dissolution, was there ANY base metal left undissolved? also, what kind of CPU's? if it was the fiber type, theres copper plates between the sheets of fiberglass. gold can cement to this copper and be trapped in the fiberglass sheets.the first thing to do when doing a dissolution on mixed material, is testing. make sure the gold is in solution before you continue. your gold could still be in the material left from the dissolution.

you said copper chloride crystal was on everything. put this in a container and cover with hcl and warm. im betting the gold is on base metal under the crystals.


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## patnor1011 (Jun 19, 2012)

Your 3 bottles can go to stock pot. Your gold is *on and in* whatever was left when you made them 3 bottles - container, bits of undissolved metal, filters, sediments....


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## [AuCl4]- (Jun 19, 2012)

Hello, Thanks for replying!



Geo said:


> what kind of CPU's?



I had 1 ceramic and 3 or 4 fibre plus north and south bridge chips. 



Geo said:


> was there ANY base metal left undissolved?



When I was boiling in AR I saw tiny metal swirling around but I kept boiling until I couldnt see any more metal.



Geo said:


> the first thing to do when doing a dissolution on mixed material, is testing. make sure the gold is in solution before you continue. your gold could still be in the material left from the dissolution.



That was a mistake that will never happen again!



Geo said:


> you said copper chloride crystal was on everything. put this in a container and cover with hcl and warm. im betting the gold is on base metal under the crystals



Oops, that poses a problem. When I saw the green crystals on everything that was left in the pot, I added water and swirled it around till it went into solution and poured it in a bottle. This bottle is aqua blue colour and the other two are dark green

I then put all the leftover cpus, chips......in a funnel wth filter and put it on a rinse bucked to get it out of the way but it fell into the bucket!

When I did filter the solution, I had white sediment, grey sediment and this fine black sediment with it. I never saw the grey and black in the first batch that I did successfully by pure blind luck.

Here is the sediment............


Here are my bottles...........#1 is more blue than green and it froze in the freezer. Too much water?
#2 is green 
#3 is direct pour after AR...........No other treatments -it looks black but dark dark green it is.


So shall I follow your HCl procedure on these sediments? Could the black sediment be gold?

Many Thanks!


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## [AuCl4]- (Jun 19, 2012)

patnor1011 said:


> Your 3 bottles can go to stock pot. Your gold is *on and in* whatever was left when you made them 3 bottles - container, bits of undissolved metal, filters, sediments....



Thanks for the reply...I was afraid that would be the outcome.

I inspected most of the large cpus and other pieces after AR and swirling to get the green crystals off. There was nothing stuck to the outside of any of the pieces. They were clean.
Do you think the black sediment might be gold?

Thanks............


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## patnor1011 (Jun 19, 2012)

More than likely yes. If solutions in bottles are negative in stannous test and your leftover cpus are rinsed clean, whatever sediment is left after may contain your gold. But from breakdown of your material I do not expect any sizeable amount of gold, in fact amount of gold powder resulted will be hardly visible.


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## Geo (Jun 19, 2012)

the first picture of the white and dark precipitate is where the gold would be hiding. throw nothing away until you find it. 

rinse the sediment in water until the water stays clear. then give it a good boil in water to remove any water soluble salts. remove the water and cover the sediment with hcl and observe. did the color change? it should turn green from copper contamination. test this solution with stannous chloride.if its negative, decant and add to your stock pot. add hcl to cover the material and add bleach by a few ml's at at time and wait a few minutes between additions and stir until all the dark sediment dissolves. the white sediment that didnt dissolve with the first addition of hcl will remain as is.test the solution with stannous. NOTE: the solution will have alot of chlorine and the color may not last but a fraction of a second. just watch for the color change as the stannous hits the swab.


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## patnor1011 (Jun 19, 2012)

I would incinerate sediment first. He used AR so there might be nitric present. If he just rinse with water he may dissolve some values - gold if it is there is super fine and some of it may get lost in rinse water.


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## Geo (Jun 19, 2012)

exactly, thats why i told him to test the hcl rinse. if its positive, he can just add the Cl then and finish the dissolution.


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## patnor1011 (Jun 19, 2012)

I reacted to this - I would incinerate before starting with this 8) 



Geo said:


> the first picture of the white and dark precipitate is where the gold would be hiding. throw nothing away until you find it.
> 
> *rinse the sediment in water* until the water stays clear. then give it a good boil in water to remove any water soluble salts. remove the water and cover the sediment with hcl and observe. did the color change? it should turn green from copper contamination. test this solution with stannous chloride.if its negative, decant and add to your stock pot. add hcl to cover the material and add bleach by a few ml's at at time and wait a few minutes between additions and stir until all the dark sediment dissolves. the white sediment that didnt dissolve with the first addition of hcl will remain as is.test the solution with stannous. NOTE: the solution will have alot of chlorine and the color may not last but a fraction of a second. just watch for the color change as the stannous hits the swab.


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## [AuCl4]- (Jun 19, 2012)

Hello,



patnor1011 said:


> I would incinerate sediment first. He used AR so there might be nitric present. If he just rinse with water he may dissolve some values - gold if it is there is super fine and some of it may get lost in rinse water.



I did the boil to syrup and add hcl and do it again- twice ---Nothing but white steam
I also put 3-8 grains of urea in as per Lasersteve(I think) suggestion -- no reaction

I followed all procedures to rid HNO3........

So shall I continue with the HCl + Cl procedure?

Thanks to all..........


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## Geo (Jun 19, 2012)

patnor makes a good point. if you incinerate the sediment before the hcl wash, it will reduce the copper to an oxide plus any stannic acid that may be present. then the hcl wash would be more effective.


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## [AuCl4]- (Jun 19, 2012)

Hello, I followed your instructions Geo...

Add Water...........Stannous test negative

Boiled with water and decant

Add HCl to cover sediment.................colour change was olive green




Tested again.............negative

Add Cl bleach 3ml at a time...........added total of 25ml

Test with stannous.............




YOU FOUND MY GOLD!! Im so happy again.

I have never tested any solution and got this colour...........A deep Purple almost black but it didnt disappear and the swab is still black after 30 minutes!

Thank You Geo and patnor X 1000

I'm gonna let this sit overnight(that wont hurt anything will it?).

And tomorrow if you would be so kind to help me, I will get the gold out!!

Later.................


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## Geo (Jun 20, 2012)

very good job. you are most welcome, glad i could help.


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## [AuCl4]- (Jun 20, 2012)

Hello, thanks for the help!

I am ready to proceed now. So from the forum search I have to remove Cl from the solution by heating with a cover but not boiling.

Do I filter the solution to remove the sediment before heating?
I have to heat for over an hour? 
How will I know when Cl is gone?
Do I add water to solution if it gets too low?

Thanks.............


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## patnor1011 (Jun 20, 2012)

I would add fresh HCl few times, if you heat slowly there will not be much of solution lost during heating. I would heat for about hour. Then I will leave everything to settle overnight, decant in the morning. Wash sediment with small bit of HCl and test with stannous. If negative then all gold is safely in decanted solution. Filter well, use funnel packed with some toilet paper tissue under coffee filter if you do not have proper filter papers. Drop with SMB. 
Your solution looks dirty so I would wash dropped gold with HCl and refine that again. On that second step your filtered solution will be nice yellow crystal clear and dropped gold powder should be tan brown colour.


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## patnor1011 (Jun 20, 2012)

One more thing - when heating solutions with some amount of sediment do it in a catch pan of some sort and stir well. That will prevent too much of heat being build where sediment is, your container if glass may break from that temperature. Catch pan is there to ensure you will not lose values in case of break. I am using big stainless steel pan with cloth on bottom, my glass container sit on that cloth and I always have 1-2 cm of water inside pan.

I quickly draw what I mean, I am not good at drawing but you will get a picture of what I mean.


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## [AuCl4]- (Jun 20, 2012)

Ok ,Thanks for the instructions patnor.

I will start and post my progress..............

Thanks again..........


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## Geo (Jun 20, 2012)

the reaction that actually dissolved the gold in the sediment was this : sodium hypochlorite (bleach) is dissolved and then decomposed by the hcl. this releases chlorine gas in the solution. chlorine gas will dissolve gold. 

chlorine gas (being a gas) will not stay suspended in solution at normal atmospheric pressure, it "gasses off" or the gas is actually under pressure in the solution. if left uncovered long enough undisturbed, the chlorine will leave the solution and the solution will be chlorine free. its hard to determine if all the chlorine is dissipated by looking at it. when you start to pour the solution into the filter, thats when you will know if theres chlorine left because there will be a strong smell of bleach. chlorine gas is heavier than the air and will fill a container without flowing out over the top, if you tip the container the gas will pour out like water.once its disturbed by pouring the liquid into a funnel, you will be able to smell the gas.

before you precipitate the gold : after you filter the AuCl solution and you are ready to precipitate, double the volume of solution with water. wait fifteen to twenty minutes and observe. did any white powder precipitate? if yes, filter again.if no, add a spoon full of SMB to 50 ml's of warm water and stir. it will dissolve quickly.add this to the solution and stir with a non-metallic utensil. the color should change within a minute and darken. stir again. wait for the powder to settle. since it was a dirty solution, it may take an hour or more. test with stannous chloride. if its positive at all, add half as much SMB as before and stir. if negative, you have precipitated all the gold.leave the solution uncovered and do not disturb until the solution is crystal clear.


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## [AuCl4]- (Jun 20, 2012)

Hello Geo, I am heating as I write. I just got back from the store and was thinking of the chemical reaction of NaClO and HCl while driving. I go into the 'lab' (garage), logon and you have explained it. What are the chances of that happening? 

Thanks for the info..........that clears up quite a lot.

Patnor, great suggestion about the fail safe drop pan. I have been thinking of rigging a water/liquid bath to heat evenly. Essentially, that is what your design is!!

Not only are you two steeped with refining knowledge, your mind readers too!! :lol: 

This forum just gets more amazing every day!!!


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## [AuCl4]- (Jun 21, 2012)

Hello, I have let the solution cool and sit uncovered for 18 hours. I notice a mild smell of Cl. When I swirl the solution I get a strong smell of Cl. I am going to let it sit for longer..... The solution is now fairly clear with a greenish yellow colour. The sediment at the bottom is now a dark green..............Thanks


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## patnor1011 (Jun 21, 2012)

You can heat that gently, chlorine will decompose faster.


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## [AuCl4]- (Jun 21, 2012)

Wow, you replied in seconds!

I heated the solution covered and noticed a lot of fumes building up in the container. Should I have heated it uncovered?

Thanks............


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## patnor1011 (Jun 21, 2012)

Heat gently, you have to see faint vapour not fumes. Open or it may explode from build up pressure.


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## [AuCl4]- (Jun 21, 2012)

patnor1011 said:


> Heat gently, you have to see faint vapour not fumes. Open or it may explode from build up pressure.



Thanks...got it!!


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## [AuCl4]- (Jun 22, 2012)

Ok, so the smell of Cl was mild after heating very lightly again. I filtered and washed the sediment and bottle with water and the solution turned a bit cloudy but now has cleared up.




I waited 30 minutes and a very tiny amount of white sediment was on the bottom. I washed the filter with HCl and tested SnCl2............Very faint purple almost pink.



I filtered the solution again with toilet paper under filter as you said patnor.. It is now crystal clear! 



Toilet paper under coffee filter was great idea! It trapped quite a bit of sediment that the filter did not!



I have to go now but I am very excited!! Many thanks to you both!!


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## Geo (Jun 22, 2012)

that doesnt look right to me.you didnt toss any of the sediment , did you? it should be very purple. for some reason, i believe the gold could be in the dark sediment. redissolve the sediment and check it with stannous chloride to be sure.


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## [AuCl4]- (Jun 23, 2012)

Im Back.........

Put one spoon Sodium Sulphite( Dont have SMB) into warm water and added to solution and stirred.

After 15-20 seconds the solution turned clear.

About a minute later it started to darken to a grey dirty colour.........



Tested with SnCl2............The colour is dark brown. Is this normal?



Added half as much SS..........test again...........dark brown



Colour of solution getting lighter/almost clear after 15 minutes...I can see black sediment on the bottom...........



Third stannous test..........Lighter brown...



Excitement has turned into nervousness.........I'm going to stop here. I really hope I didn't mess up again. Will wait for your input...........Thanks


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## Geo (Jun 23, 2012)

you definitely added too much sodium sulfite. brown stannous test is a false positive, it occurs when theres too much SMB added. that doesnt mean that theres no gold in the test, its just that the color was overpowered by SMB. give it a day and see what drops.


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## [AuCl4]- (Jun 23, 2012)

Geo said:


> that doesnt look right to me.you didnt toss any of the sediment , did you? it should be very purple. for some reason, i believe the gold could be in the dark sediment. redissolve the sediment and check it with stannous chloride to be sure.



Oops..I missed your post geo. No I didnt toss anything. I save everything. The light purple was the test on the sediments washed with HCl after filtering the olive green solution. These were patnor's instructions. I put about 10ml HCl through the filter with the sediments and tested. This wasn't the test on the yellow solution, just the sediments in the filter.........sorry about the confusion.


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## [AuCl4]- (Jun 23, 2012)

Geo said:


> you definitely added too much sodium sulfite. brown stannous test is a false positive, it occurs when theres too much SMB added. that doesnt mean that theres no gold in the test, its just that the color was overpowered by SMB. give it a day and see what drops.



NOOOOOOOOOOOOOO.........I had a feeling something was wrong. The first addition of sodium sulphite was a teaspoon and I got the brown test. Just one teaspoon. 

Ok.....I'll let it sit....................Thanks for your help!


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## Geo (Jun 23, 2012)

as a rule, only add equal amounts by weight you expect to get in gold (2 grams gold = 2 grams of sodium sulfite) i know that this being your first recover and refining, you have no idea how much gold was in solution. thats why testing is so important, add a few gram of precipitant and allow it time to work and then test. it cuts down on false positives due to too much sodium sulfite.


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## [AuCl4]- (Jun 23, 2012)

Geo said:


> as a rule, only add equal amounts by weight you expect to get in gold (2 grams gold = 2 grams of sodium sulfite) i know that this being your first recover and refining, you have no idea how much gold was in solution. thats why testing is so important, add a few gram of precipitant and allow it time to work and then test. it cuts down on false positives due to too much sodium sulfite.



Thanks, I understand my mistake now. So add a little at a time, wait and test. If positive add a little more and test until negative. Or calculate how much gold and add accordingly.

Is brown false positive test always too much ss/smb or can it also be something else?
Is the black powder gold or sodium sulphite that fell to the bottom because I added too much?

The solution looks pretty much the same as last night-it has been 12 hours.i notice a bit more black powder. I nudged it a bit and noticed that most of the very fine powder does not stay on the bottom but flows with the solution . There is some larger powder that settles quickly. The rest settles after about 5 minutes.




The stannous test is very faint light brown.........



Edit: there is considerably more black powder on the bottom not just a bit
Thanks much!


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## Geo (Jun 23, 2012)

a false positive can be caused by copper, it also gives a brown reaction, but the two look slightly different. sodium sulfite is a salt and will dissolve in water. i wouldnt think any of the black powder is sodium sulfite. any residual salts that are water soluble and will be removed in the first hot water rinse.concentrate all the black powder by tipping the pot up on one side and let the powder collect on the other side. gently decant the spent solution into a clean container and see if anything else precipitates (it may take a week or more). be sure to stop short of pouring out any powder. add water to the powder and heat. no need to boil yet. again, tip the pot to collect the powder and decant. neutralize this small bit of acid and discard. add a small amount of fresh hcl and warm.did the color change? it should darken or become green. allow to cool and test with stannous chloride. is it positive? if it is decant to a clean vessel and precipitate.if not, decant and add to your stock pot.now the powder should be a lighter shade of brown. if you want it really pure, you will dissolve it again with hcl/Cl and wait 24 hours and precipitate. follow with Harold's wash's and rinses. 

good luck.


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## [AuCl4]- (Jun 23, 2012)

Great, thanks geo.............I will get on that.

Do you still want me to redissolve the black sediment in the filter that I washed with 10ml of HCl. I'll probably do it anyway to get some practice and hone my testing. I need all the practice I can get!

Many Thanks.............


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## [AuCl4]- (Jun 24, 2012)

Hello, ok I let everything sit for 24 hours and tested with SnCl2.....negative, no colour change





geo said:


> concentrate all the black powder by tipping the pot up on one side and let the powder collect on the other side. gently decant the spent solution into a clean container and see if anything else precipitates (it may take a week or more). be sure to stop short of pouring out any powder. add water to the powder and heat.



Some of the powder was very fine so I waited half an hour and it settled.
Tip pot and decant/siphon into bottle








geo said:


> add a small amount of fresh hcl and warm.did the color change? it should darken or become green. allow to cool and test with stannous chloride.





The solution is slightly green and black powder has clumped together
Test with stannous - no colour change - negative



geo said:


> now the powder should be a lighter shade of brown.



The powder is still black/ dark brown

Is this colour a problem ? I remember reading in Hoke that it might be black

I'm gonna stop here - gotta go.................Thanks


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## Geo (Jun 24, 2012)

its still black because it has some impurities. its clumped together, which is a good sign, but only means it cleaned the outside of the large particles.now when you dissolve the powder and precipitate it again, it will leave even more of the impurities in solution. follow with Harold's washes and rinses, and you should have at the least 99.5 and at the most 99.99 but that would be if the final wash leaves the powder a light tan color.

do the next dissolution with hcl/Cl. add just enough hcl to cover the powder with the container tipped up. add bleach a drop at a time from a dropper, it should take only a couple of drops. with the amount you have, a test tube would work perfectly.


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## [AuCl4]- (Jun 24, 2012)

Great! Thanks geo!


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## [AuCl4]- (Jun 25, 2012)

Hello, 



Geo said:


> do the next dissolution with hcl/Cl. add just enough hcl to cover the powder with the container tipped up. add bleach a drop at a time from a dropper, it should take only a couple of drops. with the amount you have, a test tube would work perfectly.




I transferred to a small gIass and added HCl to cover powder. I added HClO bleach a drop at at a time. Some little grains of black powder would not dissolve even after agitating and a little heat. I let stand overnight and some white sediment was on the bottom.

I filtered and transferred to a little garlic bottle..


After filtration. 



Learned my lesson about adding too much SS  Put the bare minimum in 2ml water 



Added SS/Water to solution

stir solution...everything went cloudy brown and after 5-10 minutes all the light brown powder settled to bottom and solution was clear.



............test with SnCl2 -- negative!

Tan powder on bottom!!



IT WORKED!! I didnt mess up this time..............Thanks to your kind help.

My lasting gratitude to you geo and patnor...................Many thanks.........


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## jimmydolittle (Jun 25, 2012)

If I might suggest, your hot plate should be contained in a tub, ceramic if possible, if not then plastic. I’ve had my container break on the hot plate, and loose everything.


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## Geo (Jun 25, 2012)

you are most welcome. well,trial by fire and you came out alive. 8) what they say about teach a man to fish is really true.knowledge IS power.


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## [AuCl4]- (Jun 25, 2012)

Geo said:


> you are most welcome. well,trial by fire and you came out alive. 8) what they say about teach a man to fish is really true.knowledge IS power.



So true..........Many thanks!!


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## [AuCl4]- (Jun 25, 2012)

jimmydolittle said:


> If I might suggest, your hot plate should be contained in a tub, ceramic if possible, if not then plastic. I’ve had my container break on the hot plate, and loose everything.



Hello, thanks for the suggestion - I'm going to rig something like patnor's nice drawing...check back in the post for it. With his rig there is less chance of being electrocuted :shock: I was once zapped by 240v - not a good feeling :lol:


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