Growing large silver crystals

[peter i]

I've been busy for a while with anything but refining.

I've restarted the experiments, basically with a reduced set of variables.

Low voltage (50-500 mV range)
Saturated solution of pure silver nitrate (dissolving electrolytic silver tested to be at least 99.999)
Controlled size of donor-ingot

The first conclusion:
Lack of copper does not lead to "fuzzy growth" (I knew that already, but experimental verification is so much more fun)

Grown over a couple of days @ a few hundred mV

More pictures to come

 

[DONNZ]

Beautiful pieces of art.

If not to fragile.

I do believe the least I'd attempt is dipping one in distilled water to clean, let air dry and give a clear coat of Krylon.

Should stay shinny and add a bit of strength.

All kinds of clear acrylic casting and molds out there. I have a crystal in a pyramid. Store bought.

 

[Topher_osAUrus]

Peter, thank you kindly for this thread and your detailed reports of what you have done. This was one of the first threads on the forum I read while studying to set up a silver cell. I have just reread the entire thing again, and hope you find the time to come back and share more with us. But, until then, the search must go on!

After talking the ears off of a couple of my good buddies on here, posting up pictures of my recent run, and then getting called by another member, I figured it would be good to get the input of everyone else as far as their observations and certainties when it comes to the silver cell, and the deposition of silver on the cathode.

(this is going to be a long one... sorry in advance)

So, I initially believed that the deposit of silver on the cathode was determined by several different variables.
*Saturation of electrolyte
--Ag saturation
--Cu saturation
--Other misc elements
*Cathode
--size
--shape
--composition (stainless{grade}, graphite, titanium, et al)
*Voltage
*Amperage
*Anode to Cathode
--size ratio
--distance
##possible variables##
--porosity of anode bag
--surface area of basket blocking path of electricity between anode to cathode(*1)
--temperature
--magnetic properties of cathode?

But, upon reading this thread again, something really jumped out at me, which would be
-path of electricity
Yes, I (kind of) had that in my original guessing game of variables, but when reading it here, something clicked.

(*1)- In my previous cell setup, I had a solid anode that was basically sitting on glass rods, inside of its anode basket. This run, gave me light "barnicle" type growths, they were clustered, but they would have some give if you tried to squeeze them.

This run, I actually used a platic strainer, that has small holes, maybe a half an inch apart from one another, and this gave me nice thick clusters. While I cannot say for certain that THIS is WHY I got the clusters (I am leaning more towards -my electrolyte evaporated off a good bit of distilled water, and I did not replace it)
But, a side thought
If one were to make a membrane cell, (for simplicity) say 2 palstic tupperware that had a half inch hole in each one where you could connect the two with a piece of pvc or other tubing, and had the anode in one tupperware, and the cathode in the other, would the flow of electrons stick to the constricted path of the tubing, or as soon as it got into the cathode tupperware, would it flare out? (forgive my naivete, I know very little of applied electrical theory)
---and would the length of the pvc between the tupperware have an effect on that as well?
---What if that connecting tubing tapered down to a minimal size? (I do believe that would be troublesome in its own right,[if "yes" is the answer to the electrons flaring out,] as the cathode would have to be very close to the small part of the tubing, leaving no room for growth of the crystals


I know I have also previously posted this picture of silver crystal deposits that was in an electrolysis book I read, where it shows without doubt, that a concentrated solution is most likely the best bet for getting a large dense crystal. BUT, in every one of the pictures, they all had branches to the tree base, and that is not what we are really going for here.

Although, in the bottom right picture, where it shows a depleted solution, it appears that the crystal gets HUGE, then tapers off into light feathery strings.




I am wanting to replicate the work of Harolds' friend. To hold a single crystal weighing an ounce or more would be incredible.

Other than the loss of water in my electrolyte, and the new anode basket, everything else in my cell was identical.

I would love to hear input from any and everyone with their experiences on the matter.
Thanks for making it through til the end!

Edit to add pics, fix continuity

 

[g_axelsson]

One trick in the plating business is to do polarity reversals, that tends to dissolve the fine dendritic crystals before larger. So 5-10% time reversing the polarity of anode - cathode every minute or so ought to produce more dense crystals, or maybe just a dense surface plating.

I think that lower voltages and stirring the electrolyte would also produce more solid crystals as this doesn't deplete the electrolyte further from the anode. Without any movement of the electrolyte the cathode furthest from the anode sees the lowest concentration and also the lowest electrical potential. Electricity always takes the shortest path possible, but resistance counteracts it, so a crystal point close to the anode would see a higher electrical field and more silver atoms would migrate there than compared with a crystal further away from the anode.

In my youth I managed to make some 2 cm large needle sharp silver crystals. As this was my first test of the silver cell I thought "Cool, this is normal." and melted it down... never succeeded to make that large crystals again. :evil:

Göran

 

[Topher_osAUrus]

One trick in the plating business is to do polarity reversals, that tends to dissolve the fine dendritic crystals before larger. So 5-10% time reversing the polarity of anode - cathode every minute or so ought to produce more dense crystals, or maybe just a dense surface plating.

I think that lower voltages and stirring the electrolyte would also produce more solid crystals as this doesn't deplete the electrolyte further from the anode. ...
Göran

Peter mentioned trying to stir the electrolyte, and it left with silver branches that grew with the direction of the stir.

I havent been able to find any quantifiable data on people reversing the polarity of the cell and its effect on the growth outcome of the crystals. Silver crystals anyway. It was talked about in this thread earlier, and I can see how it could be beneficial. But, I dont know if it would help to make just one long, solid, crystal. I wont know until I try it, at least.

 

[anachronism]

Not to go off topic but you can grow gold crystals too.

 

[Lou]

That's one of Ivan's. Very good chemist!

I believe he also made the osmium crystal for this watch:
http://luxatic.com/hublots-classic-fusion-tourbillon-firmament-osmium-crystal-dial/

Though I can say that I told Hublot first to use it back in 2012 or 2013, in writing

In any event, we can do a gold crystal thread some other time. The apparatus to make those is somewhat involved but the purities produced are exceptional. As feedstock for making the crystals you posted, I use sponge as prepared under the Ultra High Purity Gold thread.

Lou

 

[g_axelsson]

In any event, we can do a gold crystal thread some other time. The apparatus to make those is somewhat involved but the purities produced are exceptional. As feedstock for making the crystals you posted, I use sponge as prepared under the Ultra High Purity Gold thread.

Lou

Oh yeah, that would be fantastic! Can hardly wait!

Göran

 

[Topher_osAUrus]

Not to go off topic but you can grow gold crystals too.

That is a very beautiful crystal, but, (besides being gold), it is also done with vapor deposition opposed to electrolysis, correct?
..dont know if I have seen wohlwill crystals though, now that I think about it.

Back to it,
I am getting some silver recovered from chlorides and my latest inquart, and will be using it as an anode to test my split cell idea.

I believe that I will use 2 small tupperware, with a 1/2" pvc connecting the two, but, instead of having the cathode side flush with the cathode tupperware, I will extend it in some distance and with the first test, i will have the cathode (I will probably use a silver wire, with only a point showing) flush with the wall, opposite of the pvc opening (which will extend close to the far/opposite wall of the junction). The second test will be with the cathode point close to the opening on the pvc against the far wall.

I will be using the same electrolyte from my previous run, which has around 130g per L of Ag (maybe more, maybe less), and unknown copper and other contaminants.

I plan on trying as many things as I can without using additives in the electrolyte. Simply because I don't want to foul it prematurely and have to redo it before its a necessity. Hopefully I can get some progress on the data Peter has so graciously given as a starting point.

For the record, i will continue to use unbleached muslin cloth as an anode bag, doubled up and allowed ample time to get the electrolyte soaked in before turning it on. Voltage will be set at 3.3 and the amps I cant even pretend to guess what they will be, since there are too many open variables at the moment.

Would still love to hear any anecdotal evidence, of crystal growths that any of you have encountered, and what may have been different from the previous batches you ran.

 

[Palladium]

Silver crystals.
Scanning electron microscope.

 

[Palladium]

More

 

[FrugalRefiner]

I made some notes on growing big crystals over the years. It took me a while to find my notes.

Here are some parameters you can experiment with:
Anode to cathode spacing
Cathode surface area ratio to anode surface area
Anode purity
Voltage and amperage
Electrolyte concentration (silver and copper)
pH
Tartaric acid
Magnetic field
Silica gel
Agitation
Cathode shape
Temperature

Dave

Edit to add a couple more possible electrolyte additives that weren't in my notes:
Gelatin (gelatine)
Glue (like Elmers)

 

[Topher_osAUrus]

Thank you Dave, I was oblivious to a couple of those. Had not heard of the silica gel, or elmers glue being of use. I knew bone glue was a good thing to add into a copper cell, but had not read anything on silver cell effect.

pH is another one that I hadn't really given too much consideration, but in the past, I had added maybe 10 to 20mL all together, of straight nitric. But, I added them to the electrolyte that was IN the anode basket, and not the outside, so its immediate effect was upon the anode. I believe, that if I were to add it to the bulk of the electrolyte (outside the basket), or used a pipette to put it in the bottom of the bowl, it may attack the smaller crystals (I would hope). In practice though, I'm sure the nitric addition would not discriminate and would dissolve pretty much every size and shape crystal.

Agitation, I have tried. A few months ago it was SO cold out, I ended up having to heat up my stainless bowl with an old hair dryer. It gave the electrolyte some motion. To me, it seemed as if the crystals from that one, were nice and smallish, very easy to rinse and dry.

Looking at the scanning electron pictures is beautiful, but it just makes me realize how daunting of a task it is and will be, to find the right set up to grow a single large crystal. It would be interesting to see a couple of the big solid ones posted earlier in this thread, under that microscope. The large crystals, with the flat mirror finish, almost look like smooth metal...although, under the scope, I'm sure their imperfections would be readily seen.

I believe the more important factors will be cathode shape, anode to cathode distance, concentration, current density and voltage, as well as the electrical field.

I can hopefully get my anode melted and poured today. It is going to have quite a bit of palladium in it from the dental gold inquart, so I may be having to redo my electrolyte sooner rather than later. But, that would give me the chance to be more fastidious in my documenting of its contents. And allow me to possibly try a couple of the additive variables.

 

[kurtak]

The largest crystals out of my last cell run - though I have not weighed them all yet they should all run from 1 gram & up

The 5.6 gram crystal on the scale is also the one in the center of the pic of crystals in the pie plate (as size comparison)

Keep in mind I am - NOT - trying to grow large crystals - these are simply coming out of my cell run at normal parameters - other then I may be running my electrolyte a little more concentrated then considered normal

Edit to add; - the pics don't really do them justice (not the best lighting) the have MUCH more sparkle to them then the pic shows

Kurt

 

[Topher_osAUrus]

Lovely crystals Kurt! When you squeeze them, do they have a bit of give? Or do they have no budge what so ever? They look nice and dense. Very nice, now, I guess the trick is figuring out how or why they can grow.

An update on what I have been able to try so far

Attempt 1:
I concentrated my old electrolyte down a few hundred mL to have it as saturated as possible. In this attempt, I "kind of" tried the split cell/membrane cell idea, but I was lazy, and that laziness gave my result nothing good in return.

A simple little divided cell I made out of a dollar worth of garage sale tupperware.

In my haste to get it running, I neglected to seal the barrier to the inside of the larger tupperware, so there was "leakage" of the flow of electricity, and that caused a barnacle growth.
The "path" I wanted it to take, is the tiny little squeeze bottle tip that has been placed in the barrier, that has a pretty small hole in it.

After fail number 1, not only was my crystal a flop, but my electrolyte went foul too from the palladium in my (reclaimed) inquart silver anode. So, with that, I obviously redid my solution (am currently redoing my solution). I also took the whole 5 minutes to hot glue the barrier in place as well as the, uh, nipple?, for the electrons to scoot through and get to the other cathode compartment.

After talking to geedigity again last night about it, I am leaning more and more towards the control of the current, the directionality of it. I keep seeing in my head a "laser" for the flow of electricity that is depositing a silver ion repeatedly in the same spot, instead of (what i interpret in normal use) a ripple effect of the electricity having a tendency to take the least resistant path.

If attempt #1b ends up going bust, I will be toying around with theelectromagnetic effect upon electricity thats flowing through a solution.

I also have another little cell built already, that is of 2 single tupperware, connected by the worlds longest pipette. (believe it has another name than pipette, but its early and I am replying instead of getting my coffee. -idiot!-)

There's got to be a way... Just got to be..

 

[kurtak]

Lovely crystals Kurt! When you squeeze them, do they have a bit of give? Or do they have no budge what so ever?

Topher

Here is a close up of them - they start out in the cell as kind of little clusters that over time grow together to become hard & dense & solid - though some will sometimes have a sort of a branch that has a fairly stable grasp but can end up being broke off if you mess with it to much --- so I guess the answer is both - sold with no give - but sometimes a branch (or 2) that can break off if handle to rough

The one on the left is the 5.6 gram one & has such a branch on it - the one on the right is a nice sold piece

For what its worth - the big ones always grow out on the edges of my cathode plate & around the lock nut that locks the negative connecting rod to the plate - they never grow in the center of the cathode plate right under the anodes

Kurt

 

[anachronism]

They do look lovely Kurt.

 

[Topher_osAUrus]

For what its worth - the big ones always grow out on the edges of my cathode plate & around the lock nut that locks the negative connecting rod to the plate - they never grow in the center of the cathode plate right under the anodes

Kurt

It's worth a lot to me, Kurt! Thank you again.
For every little detail is pertinent in one way or another.

I did notice, per the underlined, the same on my batch runs. That it seems to have big bunches growing at the furthest point, or (what I would assume) to be the weakest point of current density.

I'm hoping to have test 1b, and test 2 going today, but washing more than a couple pounds of silver cement is a pain in the rear.

I appreciate you taking the time sir, I know you are a busy man!

Reverting back to what Harold posted on his memory of his friend's cell, I keep thinking, not only direction of electrons but the "closed loop system".

If only I knew what, or how, it was a closed loop system.

Simply closed off to all light, sound, vibration, any variation whatsoever?.. Or a pressurised closed system, much like a cars antifreeze system, etc.. ?..

I'm leaning more toward the former, since he also mentioned somewhere in this thread, that it was in a tupperware, and the cathode was close to the bottom, so the vessel could support the large crystal growth without fracturing the silver chunk.

Much to think about.
Thanks again dear friends

 

[kurtak]

Topher

I think you are way over thinking this whole thing with all of the membrane cell, closed loop cell, divided/two chamber cell additives, etc. etc. etc.

There was a local guy that lived about 12 miles from me (he has now moved to Oregon) that was growing LARGE crystals in a "standard" silver cell set up - his cell was a 1 gallon Walmart cookie jar with a SS cathode plate in the bottom & an anode basket hanging at the top

When I say LARGE crystals I mean crystals from 20 grams to as big as 3.5 ozt. (3.5 ozt. was the "biggest" one he grew - which I actually held in my hand) & as well I got to see other large crystals growing in his cell

His crystals looked more like the ones wct0415 posted here - instead of being like my big "cluster" crystals

:arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=1765&start=90#p107411

only MUCH larger

The "vast majority" of the crystals in his cell where the normal crystals that we are used to seeing grow in a cell (maybe a bit more dense) but he would have 3 - 5 or 6 of the "supper size" also growing

The thing is - I could never get him to tell me just how he was getting those supper sized crystals to grow in the cell - I just know he was doing it because I saw them growing & held them in my hand after he took them out - they where very hard/dense crystals that you could literally throw against the wall without them breaking (I actually saw him do that)

The point is - he was "not" doing it in a "special" designed cell (as mentioned above - it was a gallon cookie jar with a cathode plate in the bottom & anode basket at the top) he was "not" using any kind of additives or growing them from a single pin point as a cathode

So - just how he was doing it I don't know - I just know he was doing it

I do have some ideas - just have not had time to test them out

Kurt

 

[Topher_osAUrus]

Topher

I think you are way over thinking this whole thing with all of the membrane cell, closed loop cell, divided/two chamber cell additives, etc. etc. etc.
....
I do have some ideas - just have not had time to test them out

Kurt

Yes, yes I am. Far too much, on the overthinking.
Its a problem I have.

What might your thoughts be, as far as the "how"?

A gallon cookie jar probably had a pretty good distance between the electrodes, eh?