# Time for a good old fashioned interesting thread



## 4metals (Mar 24, 2016)

Things are getting rather sleepy around here so why don't we start a conversation about starting a refinery specifically for one scrap type. Or to put it differently, to add on another wing to our existing refineries to handle a specific scrap type. We can discuss what equipment and chemistries are needed and the most effective (and profitable) way to go about the refining. 

Then we can all discuss the requirements to build such a facility and totally dissect each and every post as thoroughly as only seasoned GRF members can. 

So first we need to come up with a consensus on what to refine. What is our feedstock?

Suggestions? Who knows if this works out we can consider adding on another wing for another scrap type. 

Open for balloting!!!!


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## alexxx (Mar 24, 2016)

boards boards boards...


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## solar_plasma (Mar 24, 2016)

Well, then we should look at something really new. Something that will have importance in future. I heard that the newest cars have or will have heavy gold plating in their black boxes. I can't remember why, but I got told a whole long story, why this heavy plating is necessary in exactly this new application. Has anyone heard about it?


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## upcyclist (Mar 24, 2016)

For "starting" a refinery, how about plain ol' karat scrap? It seems like quite often, people come here seeking info on e-scrap, but we remind them that e-scrap is not where to start if you want to build a sustainable business. So what if we started with karat scrap, then added wings for gold filled, gold plated jewelry/flatware, silver refining, e-scrap of various categories, etc... That would start us with chemical refining, and one (or several) of the later wings would add electrolysis processes.

I know karat scrap is old hat for many of you, but starting with karat scrap would also be an excellent library addition as it might become "how to build a modern refinery" as opposed to the pure Hoke process. In other words, all the stuff we'd do different from Hoke: waste stream processing, "newer" precipitants, vacuum filtration, etc.


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## 4metals (Mar 24, 2016)

> I know karat scrap is old hat for many of you, but starting with karat scrap would also be an excellent library addition as it might become "how to build a modern refinery" as opposed to the pure Hoke process. In other words, all the stuff we'd do different from Hoke: waste stream processing, "newer" precipitants, vacuum filtration, etc.



That has been discussed already on this thread;

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=9528

But a "Refinery" as described in the thread I just referenced, is the end point processing area for a lot of different scrap types which concentrate precious metals whether it is black powders from a sulfuric cell or anode slimes or table concentrates.


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## 4metals (Mar 24, 2016)

> I heard that the newest cars have or will have heavy gold plating in their black boxes. I can't remember why, but I got told a whole long story, why this heavy plating is necessary in exactly this new application.



Well this is what the current black boxes look like, e-waste in a zinc die cast box.


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## solar_plasma (Mar 24, 2016)

:roll: low-grade, nevertheless I'll keep an eye on this kind in future.


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## Shark (Mar 24, 2016)

The foundations for a smelting operation would be nice.


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## alexxx (Mar 24, 2016)

Shark said:


> The foundations for a smelting operation would be nice.



True


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## 4metals (Mar 24, 2016)

> a smelting operation would be nice.



Now that is one I would never have thought of! I am currently working on furnace plans for a refiner/smelter in Mexico, my design is a dual purpose bottom half tilt pour crucible furnace with a removable top which acts as an afterburner when needed. 

A medium sized version of what I am designing may be just what you need for this. Let's see if a few more members agree. 

BTW they are melting circuit boards.


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## rewalston (Mar 24, 2016)

4metals said:


> > a smelting operation would be nice.
> 
> 
> 
> ...



sounds good to me


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## acpeacemaker (Mar 24, 2016)

Working on an indirect heating chamber-furnace-afterburners. Consists of three large enclosed boxes and 5 ft enclosed pipe that lays in the middle box like an airplane in a hanger. 
Andrew


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## UncleBenBen (Mar 24, 2016)

The chemical reactions that take place when normally solid materials are heated to a liquid is something that has fascinated me for a LONG time. I guess since bringing home my first chunk of slag I found in the woods as a kid that came from one of Mr. Montgomery Bell's iron furnaces.

I know I'm not one of the seasoned members you spoke of, but smelting is something I absolutely want to learn more about.


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## ericrm (Mar 24, 2016)

is the subject limited to precious metal ?


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## FrugalRefiner (Mar 24, 2016)

I wouldn't mind seeing a good, comprehensive thread on smelting. It hasn't been covered nearly as much as wet chemistry. Kurt has given us a LOT of guidance, but I wouldn't mind learning more, even if I never smelt a lot. :lol: 

Dave


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## UncleBenBen (Mar 24, 2016)

FrugalRefiner said:


> Kurt has given us a LOT of guidance



Indeed! And thank you Kurtak for that. Kevin's (kjavanb123) work has helped shed some light as well. 

Whattaya say 4metals, smelting 101 followed by AP smelting?

Man, I'm getting as excited as a puppy with two peters!


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## Geo (Mar 24, 2016)

How about refining oxides and hydroxides. Waste that the hobbyist have to pay to get rid of, it can be refined for metal recovery.


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## Lou (Mar 24, 2016)

I think smelting is a good one. I think another good thread would be on ICP, AA, potentiometric and gravimetric methods for precious metals analysis. 

How about we do the design of...
--an incinerator
--a rotary furnace
--a (tilting) crucible furnace
--discussion on fluxes

I've built my gas fired furnaces, including my tilting 1MM BTU tilting furnace which holds up to a #130 that I use for silver. Actually a very quiet furnace.


As for a material to refine...spark plugs are a tough one


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## jonn (Mar 24, 2016)

Smelting is a good one. I'd really like to see your design for the unit you're working on 4metals :lol:


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## 4metals (Mar 24, 2016)

OK smelting it is.

First let me say that the majority of medium to the small side of large refiners today are running circuit boards today by smelting and refining the copper. The more time you can put into segregating and separating the material the better the payoff. That is why this is done in countries where labor is cheap. Having 15 or 20 sorters picking through the boards and cutting off components is effective at producing a feedstock which lends itself to electrolytic copper refining to concentrate the PM's in slimes. Poor sorting results in smelting lower grades of copper with metals like lead which are a nuisance metal in the copper refining process and they are a reason copper smelters will charge you extra when these metals are in the mix. 

So assuming we all have the sorting process down pat, we end up with boards and components which we need to burn. The ideal scenario is controlled pyrolysis, followed by incineration, and then either sifting or smelting. If we go the smelting route generally circuit boards need copper added to get up to about 15% metal weight for the best collection. 

When smelting the ideal system involves melting in a rotary kiln. These are pricey and not very versatile. 

So let's start out with me showing you a photo of a small tilting pour gas furnace, this is a center pivot furnace and this is about as small as they get.




The center pivot refers to the pivot points on the tripod stand which means the unit pivots from the center when pouring. These are the least expensive units to produce and they are challenging to pour bars with. As you tip the furnace more and more when pouring, the spout where the metal comes out moves closer to the furnace center line. At full tilt, you are under the furnace. So you have to move your mold to catch all of the pour. To define the challenge a little better, if you have a furnace 24" in diameter, the pour spout moves in an arc which will drop 12" down and 12" towards the centerline of the furnace. A hydraulic melt table will make this do-able but it has to be moved in and down as the pour proceeds. It's a skill you acquire with practice, or maybe spills and practice.

The alternative is a nose pour furnace which has the pivot point from the stand on the outside edge in a line tangent to the outside diameter of the furnace body. This results in less travel of the pour point when pouring bars. 

this is a catalog cut from a Baker gas nose tilt furnace.




So you might ask, why not a lift and pour crucible? My answer is capacity. I tend to work on bigger stuff so i think along those lines. Plus for a lot of members here on GRF who work alone, lifting and pouring a large crucible is a 2 man proposition. A tilting pour is a one man show. 

You could build a furnace into the ground. Just like the refiner in Thailand from this thread posted by Gaurav.http://goldrefiningforum.com/phpBB3/viewtopic.php?f=38&t=23609

To pour from this furnace they need to lift the crucible out and pour it. Generally a crucible is lifted with a pair of these tongs.



These can lift 2 ways, one by having one man on each end, and the other by using a hoist on the ring in the center, the hoist pulls up and the tongs cradle the crucible from the sides tapering to the bottom so it doesn't slip.  Then to pour it has to be transferred to a pouring cradle. 

That is why I like a tilt pour setup. 

The unit I am working on for my client in Mexico is a hybrid of 3 different pieces of equipment. It has a nose tilt crucible furnace which is poured by tilting the furnace with a hoist pulling on a cable attached to the lower half of the furnace 180 degrees opposite the pour spout. Pretty basic. 

Then there are different lids. The regular melting furnace lid, the limit the oxygen and deflect the smoke into the afterburner lid, and the actual afterburner.

Now here is a catch. These lids are refractory and quite heavy so you will need an overhead lift. I prefer this type of crane but an overhead I beam would do as well. In a smelting shop an overhead hoist is a blessing. When you shot metal into water, you need a good quantity of water and you don't want to change it often. (climate change, drought, California is a desert, you know the drill) So the shot tank has a rigid metal liner on chains that fits the bottom of the tank and after you pour, you hoist out the liner and all of your nice shot comes with it.

This is the style of hoist crane I prefer;



I made this furnace representation in Paint on my laptop so some of this makes sense. The red is obviously the flame. The bottom flame heats the crucible and its contents. There is no crucible shown in the sketch. I prefer nose pour crucibles but it will also take a standard crucible and you can add a launder to direct the molten metal. The top section is an afterburner. When using the unit for pyrolysis, a lid is added over the charge so all of the smoke comes out the center. The afterburner section is just an extended burn chamber with its own flame which I like to run with excess air as the combustion smoke is air starved at this point. This is pretty effective at burning the smoke off from the pyrolysis providing the hole in the top between the top and bottom (also not shown) limits the smoke and uncombusted fume discharge rate.




The rings on top of the top unit have a chain which is picked up by a hoist to remove the afterburner. A gas quick disconnect is helpful here. 

So to operate the unit with a batch of unburnt circuitry first the crucible is filled. Then the air restricting lid is placed on top with the hoist, then the afterburner is put in place. The afterburner fires first and when it is hot (glowing is nice) the lower unit is lit. For pyrolysis this is a low heat not full blast but warm enough to get the pyrolysis going. I toyed with the idea of putting a bottom on the afterburner unit to eliminate the need for the lid to control the smoke entering the afterburner. The bottom would obviously have a small hole to emit the smoke. I chose to not do that because I may need the afterburner for mild smoke conditions at some point and no lid would be needed, so for versatility I chose to keep it separate. 

When the pyrolysis is done, a # 150 crucible should take about 1 hour, the burners are shut off and the afterburner is removed, the inner lid is removed, and the furnace (bottom) is re-lit. Then the carbon is burned off to complete the pyrolysis/incineration process. I would be putting the afterburner back on for this process until you learn how long to burn to complete pyrolysis, but that's me, I've inhaled enough crap in my life already. 

The furnace can now be either emptied out to sift and flux the powders or flux can be added to the charge in place. A second lid for melting is placed on top of the furnace, it too is placed with the hoist. I added a pin at the rear opposite the pour spout so the lid doesn't slip off while pouring. The pin slides into an oversized sleeve on the furnace so it is easy to place the lid on. For the smelting part of the cycle, copper is added to get the metallic fraction over 15% and I like to rock the furnace. Remember it pivots, so getting the molten pool swirling by slow rocking using the tilt hoist will aid in collection. The molten charge is periodically slagged off by pouring into a slag mold. Large slag molds are sold by Legend and they attach to a buggy so you can roll them around.




After the furnace has melted all of the flux/sweeps charge, the majority of the slag is poured off until the metal starts to flow into a sample ladle then the charge is shot into water to make grain. 

The copper based grain is cast into anodes. The furnace is too large to make the high surface area thin anodes needed for the copper cells so that is why grain is cast. It is easily weighed out and cast into individual anodes. 

So that is smelting, we do need to cover fluxes and a few details but this is the hardware, the rest is chemistry. 

The actual furnace I just described is currently being cast, the 1/4 scale model worked very well, It takes a # 40 crucible. They plan on using the little guy as well as the one being built. The first unit was built by the maintenance crew at the shop from some rather crude drawings I had made, they completely understood the concept (not from my Spanish, from the boss's translation!) and went with it. The bigger unit is more of the same. So for a moderately handy person, this is definitely within reach.


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## 4metals (Mar 25, 2016)

This is the bottom section pivoting to pour




Please excuse my sorry representation of the flame path!


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## solar_plasma (Mar 25, 2016)

Geo said:


> How about refining oxides and hydroxides. Waste that the hobbyist have to pay to get rid of, it can be refined for metal recovery.



This would be my favorite. I already thought of if this could be done by aluminothermic means, but I have no clue. I like the idea of ending with harmless Al2O3 smoke and a massive piece of metal. Using carbon I would not feel comfortable with if nickel is involved since I don't know how and when this terrible nickel compound "liquid death" is formed and how to avoid it.


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## kurtak (Mar 25, 2016)

4metals said:


> OK smelting it is.



Ok - if we have decided on smelting as a discussion thread would it be a good idea to split it off (starting with 4metals last two post) as a thread titled "Smelting" posted in ether techniques or tutorials instead of here in help wanted & under the title asking the question of what would be a good discussion --- my thought being using the right thread title post in the right category will make it better of future researching/referencing :?: 

I will certainly contribute to this discussion with what I have learned over the 2 or 3 years but as well I hope to learn more about it in that as much as I have put it into play in my own applications I have by no means yet mastered it

Kurt


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## alexxx (Mar 25, 2016)

One can smelt many types of material. 
As I understand it, the success and profitability of the smelting depends a lot on material preparation.

Is this aspect of material preparation will be covered depending on the feedstock ? 

A few examples of various types of scrap one can get : 

-Circuit boards
-Sulfide ores 
-low grade PGM bearing material (car spark plugs mentioned earlier)


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## bmgold2 (Mar 25, 2016)

solar_plasma said:


> Geo said:
> 
> 
> > How about refining oxides and hydroxides. Waste that the hobbyist have to pay to get rid of, it can be refined for metal recovery.
> ...



After watching Geo's video on cementing copper, 

https://www.youtube.com/watch?v=0ZgWF_SepRk

I renewed my interest in this whole refining hobby. I just don't have enough gold containing scrap to be worth setting up a safe work space to process it yet. If the copper or other metals could be refined into a usable or saleable form, any precious metals would be a bonus.

It still might not be cost effective to refine the copper or other "wastes" produced but I would love to practice the refining using cheaper, more available scrap.

Another thought I have had was how to recover all the solder from the circuit boards. Besides just wanting the low melting metals, it could be good to remove the toxic lead before it goes to the land fill. In the process, I would imagine there could be a little bit of PM's mixed with the solder.

The smelter does sound interesting too. Any chance for more than one "interesting thread"?


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## 4metals (Mar 25, 2016)

> Any chance for more than one "interesting thread"?



Certainly, Kurt has suggested splitting off the smelting portion into another thread, a worthy suggestion which I am not so sure I have ever done successfully. Some other moderator help here would be appreciated. 

We can keep this thread going to see what members are wanting to discuss about recovery of other metals and waste.


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## kurtak (Mar 25, 2016)

bmgold2 said:


> The smelter does sound interesting too. Any chance for more than one "interesting thread"?



I see no reason why other "interesting threads" couldn't be started (other good ideas came up here) its also why I suggested splitting the actual discussion on smelting off to its own thread & in the proper category --- use this thread for suggesting the next "interesting thread" to be discussed - then when we have one that shows good interest get the actual discussion going in the proper category with a title that makes it easy to find in a search &/or when referencing back to it

I foresee some up & coming good additions to the library 8) 

Kurt


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## UncleBenBen (Mar 25, 2016)

I know I've seen lead mentioned several times as a problem metal for the copper refinery, and spoke of again here by 4metals. What are the other problem metals?

That might help me wrap my head around a little thought bubble that's trying to percolate, but right now my lips keep covering my eye teeth and i can't quite see what I'm trying to say.


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## justinhcase (Mar 25, 2016)

4metals,I always enjoy hearing how you are working with different people to help improve there system's
How do you approach fee's?
When I worked in the music industry I had great difficulty collecting full payment for services as I could not bill my client's until the conclusion of the event's.
Staging a performance is a strange mix of technical know-how,improvisation on the fly and access to the proper equipment.
Just the research and planning were a considerable investment let alone once you had committed equipment and manpower or trained up the clients personnel and rebuilt their rig.
People who started out as reasonable and friendly turned quite nasty.
Some very large venues that were going into bankruptcy became very profitable.
Never had a problem until they were up and running then finding one's self-flushed when they think they know enough. 
The venue would have a short term success but slowly slip back into bancrupsy as it takes a steady hand to manage all the variables.
I have had a similar problem when I tried to move from simply buying to helping a client develop a specialist process for their material.
How do you balance providing an open and honest service against guarding your own interests?


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## bmgold2 (Mar 25, 2016)

4metals said:


> > Any chance for more than one "interesting thread"?
> 
> 
> 
> ...



As a non-moderator, I would start a new thread and quickly make 2 or 3 placeholder posts. Then, knowing I had the first few posts to work with, I'd copy the posts from here that fit the new thread and edit (paste) them into the start of the fresh thread. Might be a better way to do it if you are a moderator but this way should work if done before it gets too long.

This could really increase the amount of information on this forum. Much of that information is already here somewhere if you hunt hard enough. Some stuff is only mentioned and never got a thread of its own. Specifically, I'm thinking of the PVC to HCl pyrolysis that NoIdea (Deano) talked about here:

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=60&t=10158&start=30

My own very small scale experiments with that idea were very encouraging. I just need a better way of trapping the gases produced in water. It also seemed to produce an oil or tar. A chain of bubbling chambers should trap the oil in the first stages and still allow enough of the HCl gas through to make cleaner acid in the later vessels of water.

Maybe I should make the "interesting thread" on at least a small scale DIY hydrochloric acid production? I happen to have some scrap PVC pipe laying around and I think the insulation on wires might be PVC. Not sure if any other common scrap plastics would work. Maybe a thread specifically about dealing with waste plastic would be good? Around here, plastic is hard to recycle. Only one recycling bin around (that I know of) even takes any and that is NOT for scrap plastic. Only the certain numbered plastic bottles. Even cleanly burning it as well as using the heat to do other work sounds better than dumping it in the ground. If it resulted in some free acid then all the better.


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## FrugalRefiner (Mar 25, 2016)

bmgold2 said:


> As a non-moderator, I would start a new thread and quickly make 2 or 3 placeholder posts. Then, knowing I had the first few posts to work with, I'd copy the posts from here that fit the new thread and edit (paste) them into the start of the fresh thread. Might be a better way to do it if you are a moderator but this way should work if done before it gets too long.


Splitting the thread is not a problem. I've already PMd 4metals about it and I'll split the smelting portion off after I get his response.

This thread will serve well to generate ideas and suggestions for other threads that we can split off as they develop.

Dave


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## 4metals (Mar 25, 2016)

> How do you approach fee's?
> How do you balance providing an open and honest service against guarding your own interests?



Justin,

I work as a consultant for a straight fee plus expenses. My fee is a daily rate and I try to give an accurate estimate of the time it will take to accomplish our goals. I always get a retainer and bill in pre agreed increments. If the client is happy with the end result they pay the last invoice, I have never had a problem with that. I do not charge for follow up support if it can be accomplished by email, text, or telephone conversation. And I support my clients as long as they need it. 

I do make sure they have the proper training to do the job. I had one client who thought he could learn it all in 2 days and receive a lifetime of support. Well if he had learned enough in 2 days I would have no problem. But he learned very little and thought he could just pester me ad infinitum. It don't work like that. He was told he needed at least 8 days of hands on instruction or the follow up support would be unfair to me. He balked, I didn't waver, and he does not refine today. He was the only one I ever had issue with. 

I always choose not to consider guarding my own interests. I will teach a client anything they want to know that I can help them with. I have found that even by giving information away for free here on the forum that business oriented people who are serious about processing on their own would rather just hire a consultant and pay the price. This may sound counter intuitive but it works for me. It may be different for others but it has been what I have experienced.


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## justinhcase (Mar 25, 2016)

4metals said:


> > How do you approach fee's?
> > How do you balance providing an open and honest service against guarding your own interests?
> 
> 
> ...



Unfortunately, my client simply did not have the temperament to let him advance within refining,very talented at arguing his superiority and getting kit but far to aspirational to be of much use in the lab.
It took me a year and a half to develop a system that I would consider effective.Most other refiner's consider the process worth keeping to them self's and I have never seen it discussed in detail.
So I thought a running percentage was in order as the offer was to run a well-funded lab.
oops.
I can understand someone as well thought of as yourself being paid a good flat rate by large refineries that are already up and running.
Something to aspire to after another twenty years study.


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## kurtak (Mar 25, 2016)

FrugalRefiner said:


> Splitting the thread is not a problem. I've already PMd 4metals about it and I'll split the smelting portion off after I get his response.
> 
> Dave



Thanks Dave --- I will be adding to the smelting thread after you have split it off to its own discussion so as not to clutter this thread 

Kurt


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## jonn (May 16, 2017)

Was this post Ever split? If not, can we continue with lid design and Fluxes please? Thank you 4metals


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## Shark (May 16, 2017)

Check here..

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=38&t=23680


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## jonn (May 16, 2017)

Thank you shark


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