# Beaker burping fire



## Joeforbes (Aug 7, 2011)

So.. I've got a bit of a problem. 

I got a silver bowl from a garage sale. It was marked "Towle Silversmiths" and then below that it just said "Fine Silver". It surface tested to be pure silver, so I assumed it was all silver.

I'm pretty sure I was wrong about that.

I added the bowl to some 50/50 nitric. It dissolved just fine for a little while, but then I noticed that the bowl was black and no longer silver colored. I assume the silver was plated over some kind of base metal. The solution turned dark, with small bits of shiny metal floating throughout it.

The bowl finished dissolving, but the silver metal remained undissolved and nonreactive, and the next day it started to burp small bubbles of fire. I quickly dawned my chemical safety equipment and moved it to an outside area away from any structures and it burped about 10 more times over the hour that followed. After it hadn't expelled any fire for a few hours, I partially covered the top and left it outside, bracing it to be sure that it wouldn't tip over.

Now, what do I do with it? What was the likely base metal that would cause the explosions? I assume I don't want to continue to process it, but how do I dispose of it and be sure it wont explode or start on fire?

Sigh.


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## butcher (Aug 7, 2011)

I have had some type of aluminum pot metal make small popping explosion's, was not sure of makeup of this pot metal, but assumed it to be hydrogen gas explosions, this was with an acidic chloride solution.
(editto add ): there were sparks in the dark from these small explosions (very intertaining to watch).

was it actual fire or just small popping explosions?

sorry I do not have an answer, but some metals high in the reaction series can dissolve more violently.


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## philddreamer (Aug 7, 2011)

Joe, did you tried incenarating the bowl? I incenarated some "sterling" before digesting in 50/50, (distilled water/nitric) & found out that not all my items were sterling. Some were tin/silver. I tried digesting these in another batch & I ended up with a black soot on them & a mess to recover.

Phil


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## Joeforbes (Aug 7, 2011)

butcher said:


> I have had some type of aluminum pot metal make small popping explosion's, was not sure of makeup of this pot metal, but assumed it to be hydrogen gas explosions, this was with an acidic chloride solution.
> (editto add ): there were sparks in the dark from these small explosions (very intertaining to watch).
> 
> was it actual fire or just small popping explosions?
> ...



Small popping explosions. Wish I would have watched it in the dark haha.




philddreamer said:


> Joe, did you tried incenarating the bowl? I incenarated some "sterling" before digesting in 50/50, (distilled water/nitric) & found out that not all my items were sterling. Some were tin/silver. I tried digesting these in another batch & I ended up with a black soot on them & a mess to recover.
> 
> Phil



I didn't. I should have, but instead made a stupid assumption and went off of it. I should have done a better job... lesson learned I suppose.


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## element47 (Aug 8, 2011)

Boy that is kind of a weird story. As a small-sized yet long time buyer of sterling (including bowls, not just forks & spoons) I have never seen an item by Towle (certainly one of the better and better-known makers) stamped "fine silver"...and if I did, it would surprise me to the extent that fine silver is borderline too damn soft to make implements from. In fact I've never seen *anything* other than a .999 round or a bar or something that was clearly intended to have little function other than being a chunk of bullion that was stamped "fine silver". And by the way, it is probably of relatively recent manufacture because Towle generally stamped sterling stuff "925/1000" (as opposed to "STERLING") around the the turn of the 20th century into the nineteen teens. 

Not that I could or would have predicted it in advance, but I'd have to conclude that your bowl is PLATED with fine silver and is (or was) otherwise BRASS (of which there are hundreds and hundreds of different alloys) and you are seeing your nitric attack the zinc therein. Probably fairly violent and evolves hydrogen which periodically ignites from the heat of the acid attacking the zinc.


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## goldsilverpro (Aug 8, 2011)

It could be zinc based die cast (pot metal) plated with fine silver. I have seen this type stuff made from pot metal.


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## philddreamer (Aug 8, 2011)

Speaking about Towle's silvercrafts, I bought these 67 toz of "scrap" marked "Towle Sterling 1973", the disign is the Grand Duchess flatware, & I can't see myself melting them, (yet), after seaching & finding out the price of such flatware. I'm missing one dinner fork & 8 knives. The seller pull the handles off & got rid of the weight.
So I melted those & got a bit over 8 oz. 

http://www.silversuperstore.com/towle/sterling_silver_flatware/grand_duchess_silverware.html


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## element47 (Aug 8, 2011)

If you are saying that 8 qty knife handles yielded an ounce each, that is pretty fat. Typical knife handles are about 1/2 oz each, sometimes as heavy as 19-22 grams, but those are exceptions. 

That is a pretty fancy pattern and you appear to have a well-populated set. I am unfamiliar with that particular pattern in terms of it being a heavy or a light pattern, but that doesn't mean anything, there are zillions of patterns. I would price it at Replacements, Ltd, rather than at new, retail. Fork weights are dependent upon whether you have dinner forks or place forks or luncheon forks. Light forks are in the 42-44 gram range, 6-7/8" long, heavier and longer ones tend towards 7-1/2" long and weigh over 50 grams. If and when you wish to scrap them, I would recommend you contact a replacement service (like Replacements, Ltd) and offer to trade them your very good stuff for their junk. If it's all just going into a melting pot, you might pick up 15-20 oz or more in weight. If that is your wish. That might be a very attractive offer for them. Remember, ebay will cost you about 12% just in fees (67 oz * $40 * .80 = 2144 = $250 or so) if you decide to sell it that way. You *might* fetch a modest premium over scrap via ebay, but in general, I find ebay sales go through at just a little over scrap (and, my guess is that Replacements Ltd is generally the high bidder on the nicer patterns) 

I've bought hundreds of pounds of sterling on ebay but I do not any longer because I'm irritated by the selling process in which the refiner takes a pretty big slug out of the yield)


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## philddreamer (Aug 8, 2011)

There was more than just the the 8 knives handles, there were other handles & a bit of other scrap, I should have said "those handles & some other scarp that he added". Sorry! 
But it is a beautiful pattern & in great condition. 
I just weighed & measured one of each: 
dinner fork - 71g, 7-5/8" long; 7 total.
salad fork - 56g, 7" long; 8 total.
large spoon- 68g, 7-1/8 long; total 8.
teaspoon - 43g, 6-1/4 long; 8 total.
They add up to 1,833g or 58.93toz. + 8.5 toz (after melt) from handles & misc. = 67.4 toz. I have checked the prices @ Replacements, Ltd a couple of times when I first got them, trying to decide of keeping them & buying the knives & fork missing, or doing what you just recommended. Decision, decisions... :roll: :lol: But I won't sell thru e-bay, NO WAY! I'm familiar with them & their terms.
I refine it, & now I'm setting a cell for higher purity. I'll keep you posted on that.
Thanks for the information!

Phil

P.S. Where about in N. Ca. are you? I drive by on my way to my favorite gold prospecting river, & usually stopping in Yreka for the night. 8)


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## element47 (Aug 8, 2011)

I am in the Walnut Creek area...probably substantially further south than you are thinking. But I'd be happy to go gold seeking with you sometime if it can be arranged. 

That is a fearsomely heavy set with 71 gram forks, wow! That is Henry the VIIIth castle-grade stuff. That should I imagine fetch substantially above scrap...especially since it could not have been much of a popular set since it was such a 1: premium (cost) set and prolly many, many people would 2: reject it over its heaviness, and 3: it has only been made since 1973. Many of the "top ten" sets of sterling have been made since the 20's-30's. Eg; Gorham Chantilly, Oneida Heirloom, Gorham Buttercup, Gorham Strasbourg, blah blah, blah. NONE of those are 71 gram fork sets, though ANY 7-5/8 fork will be quite heavy. That is a monster sized fork. 

That would be my guess. As you might imagine, I have seen many many sets of sterling, some fancy, some "normal", some plain...and yet with few exceptions they are just their weight in metal to me. I happen to like Towle Craftsman which is probably one of the plainest patterns. 

When I was buying sterling, I developed a spreadsheet correlating length (since most sellers do not give WEIGHT but they give LENGTH) and thus I can know what the typical 7-1/4" fork weighs and what the average salad fork weighs. Sometimes I am over, sometimes under, but when I was buying it (mostly in the $11-$12-$17 silver range) it would average out OK. Of course, I deducted the "refiner's cut". I ended up with a couple hundred pounds of forks & spoons. When the ebay universe woke up to sterling silver, the market became viciously competitive.....all it really took was a coterie of people coming into the market ready to pay 92.5% of spot silver for a fork and not caring what it cost to ship stuff. In other words, ignoring the "refiner's cut" and not caring about freight.


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## philddreamer (Aug 8, 2011)

So you're close to 'Frisco? I go I-80 E. to Colfax, CA. We stop in Yreka just for rest after a 10 hr drive. In the morning we finish with a 6 hr drive or so.
I'll let you know when we'll be heading that way again; maybe late sept.

I was buying silver scrap a few months ago @ about 80%, but last month it went up to 90% or more, so I'm waiting... paying that high one has to wait in order to sell & make a profit. Silver in lagging behind below the $40. 
I friend of mine has a couple thousand oz's & wants me to help him refining it, so I might be in Orlando early sept.


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## element47 (Aug 8, 2011)

As I am not (yet) a refiner and was (until discovering this forum) dependent upon Midwest (ugh) I found two things: 

The only reason to buy sterling (for me) was to buy silver a tad under market. I've been buying silver since $6 and $7 and sterling since about $11. As the price rose and more newbies came into the market willing to overpay, all sterling deals just began to snap to market price or even higher and thus the advantage evaporated out of the *considerable* effort it took to find, guess or research the weight of, take the risk of loss/seller misrepresentation/randomness, etc; And that as the price of Ag rises, the 10% the refiner takes becomes a larger and larger number. At $40 silver, refining sterling costs $4 an ounce, which IMO is high. 

It is completely idiotic to overpay for sterling if you are just in it for the metal, as I was. Just dopey. If you (generic you) want silver, just buy recognizable and easily transactable .999 rounds or bars at 5% (or less) premium or junk silver coins at 0% premium and be done with it.


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## philddreamer (Aug 8, 2011)

I never had the time to buy nothing but booze & drugs. In 2000, when I was brought to my senses, I started spending what time I have left with my family. Good thing for me, since my oldest daughter passed away 4 years later @ the age of 35. 
After getting hurt @ work 2 years ago, & facing another knee surgery, I had extra time to search & I came across this great forum, so I started reading about how to buy scrap PM's & how to recover & refine them. I like taking junk & refining to purity. (I guess that's what happened to me.) Anyway, it also helps with some extra income every know & then. In oct. I should turn 61 & would like to be as independent as possible. This great forum could very well help me do so. 

By the way, did Joe ever "fixed" his problem?

P.S. I just read in Replacements Ltd. the big fork comes in 8" also.


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## element47 (Aug 8, 2011)

Well, per your signature, an 8" fork.........that's dreaming BIG!


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## philddreamer (Aug 8, 2011)

They have one & sells for $169.95.
http://www.replacements.com/webquote/TWSGRD.htm

I wonder how much it weighs.?


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## Joeforbes (Sep 9, 2011)

philddreamer said:


> I never had the time to buy nothing but booze & drugs. In 2000, when I was brought to my senses, I started spending what time I have left with my family. Good thing for me, since my oldest daughter passed away 4 years later @ the age of 35.
> After getting hurt @ work 2 years ago, & facing another knee surgery, I had extra time to search & I came across this great forum, so I started reading about how to buy scrap PM's & how to recover & refine them. I like taking junk & refining to purity. (I guess that's what happened to me.) Anyway, it also helps with some extra income every know & then. In oct. I should turn 61 & would like to be as independent as possible. This great forum could very well help me do so.
> 
> By the way, did Joe ever "fixed" his problem?
> ...



Time fixed it for me. After it hadn't burped any fire for a week or more, I filtered it out and added more HCl. The rest of the zinc dissolved, and I ended up with 71g of silver.


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## Goldfinger4 (Sep 10, 2011)

If you dissolve base metals in acids, hydrogen will be produced.. which burns 

3 HNO3 + Al/Zn/Sn.. -> Al(NO3)3 + 1,5 H2


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## Geo (Sep 10, 2011)

i read that silver nitrate and tin makes a type of explosive if mixed in the right proportions.


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## Lou (Sep 13, 2011)

Sounds like phosphine.


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## butcher (Sep 15, 2011)

The cast aluminum I had did have contact with the ground and could have picked up phosphate from fertilizers if the cast did not include aluminum phosphides.

The cast was very porous and could have been made from most any scrap aluminum so not much telling what all it was made from.

Seems there may be two spellings for aluminum and aluminium

Found this in wikipedia:
Main article: Aluminium recycling
Aluminum is 100% recyclable without any loss of its natural qualities. Recovery of the metal via recycling has become an important facet of the aluminum industry. Recycling was a low-profile activity until the late 1960s, when the growing use of aluminium beverage cans brought it to the public awareness.

Recycling involves melting the scrap, a process that requires only 5% of the energy used to produce aluminium from ore, though a significant part (up to 15% of the input material) is lost as dross (ash-like oxide).[26] The dross can undergo a further process to extract aluminium.

In Europe aluminium experiences high rates of recycling, ranging from 42% of beverage cans, 85% of construction materials and 95% of transport vehicles.[27]

Recycled aluminium is known as secondary aluminium, but maintains the same physical properties as primary aluminium. Secondary aluminium is produced in a wide range of formats and is employed in 80% of the alloy injections. Another important use is for extrusion.

White dross from primary aluminium production and from secondary recycling operations still contains useful quantities of aluminium that can be extracted industrially.[28] The process produces aluminium billets, together with a highly complex waste material. This waste is difficult to manage. It reacts with water, releasing a mixture of gases (including, among others, hydrogen, acetylene, and ammonia), which spontaneously ignites on contact with air;[29] contact with damp air results in the release of copious quantities of ammonia gas. Despite these difficulties, the waste has found use as a filler in asphalt and concrete.[30]


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