# Slime bags



## mikeinkaty (Mar 24, 2013)

The sterling I've been getting has been plates, bowls, sauce pans, and the like - pretty clean stuff. Usually the slime bags from my cell are almost void of material. The other day a 18 ozt Reed and Barton sterling bowl produced gobs of black residue in the slime bags. The cement filter papers also caught more stuff than usual. That really suprised me! I kept the bags and filters so will process it some day. Any ideas why it did this?

Mike


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## element47.5 (Mar 24, 2013)

Well, the thread title caught my attention right away. 

There is a style of sterling bowl, at one time perhaps the most popular style, known as the "Revere" style named after a type of bowl made by Paul Revere, who was a silversmith. It's a classic form, but I believe it is made from two pieces. How those pieces are (or were) attached together is...unknown, to me. Might have been a wire loop, preformed, then stuck into a furnace. Might be silver solder. Point being, that could be one possible source for your "pollutant". 

Another possibility, and this is just my opinion....is that silver was not a particularly expensive metal for most of US history. When the Comstock Lode came on stream, 1860's-1880's the market was so flooded with silver that Wm. Randolph Hearst successfully worked his political connections to get Congress to induce the US Mint to produce millions and millions of silver dollars, effectively monetizing much of (his) silver, and thus forcing the US Gov't to buy tons of (his) silver for use in coinage. If you look at silver dollar mintage figures, not every year, but MANY years, and MANY years in the 1880's and 1890's the production numbers are/were astronomical. And today, if you go to coin shows, you will see bazillions of silver dollars. There are many, many dates in the 1880's and 1890's that are ridiculously common, even today. There have been times in US history when silver was less in demand than copper, primarily during WW2. it might not have been PRICED below copper, but silver accumulated in stunningly large amounts on US Gov't warehouses. Look at coinage figures (google "Washington quarter mintage") from the WW2 years for US quarters. Hundreds and hundreds of millions were produced. When the first uranium separation chains were being constructed in Oak Ridge, TN, the amount of metal required to build the electrical coils was so large, yet the wartime demand for copper so great, that the coils were made from silver, not copper, as they would be under any other conceivable circumstances. 

So, you had numbers of commercial silversmiths who made flatware and bowls and candlesticks, and this was a good thing, they bought raw silver, alloyed it with copper (or, they bought pre-alloyed sterling somewhere) and went to town. 

*And quite frankly, I don't think that the commercial silversmiths (Towle, R&B, Gorham, Wallace, International, Century [Sears], Stately) were under the slightest misconception that they were in the business of working with analytical reagent-grade material. * I mean, I just do not think this was the core nature of their business. I don't think they thought there was a mass of folks out there who would be subjecting their forks or bowls to 4-decimal-place assay. And there weren't! And undoubtedly, they got weak batches from time to time, and no doubt they sampled them and rejected some and accepted some lower grade sterling. Or Copper, if they did their own alloying. Or Silver if they did their own alloying. 

Additionally, these brand names changed hands many, many times over the years. There were smaller brands, Preisner (just one who comes to mind, and I don't know if Preisner is or is not in business today) that went out of business and got absorbed by the bigger companies, just like in any kind of endeavor, and it's certainly conceivable that works in progress were just thrown into furnaces for re-melting and yada yada yada. Sears, Monkey Wards, all manner of department stores (and many large-scale jewelers eg; Bailey, Banks, and Biddle, to name one) had lines of sterling flatware and bowls. These items, over the years, have been scrapped and remelted and refabricated many times and again, I honestly don't think this was a lab-reagent grade exercise for most silvermakers. 

Again, this is just my opinion.


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## Woodworker1997 (Mar 24, 2013)

I thought this was going to be a thread about ebay! :lol:


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## necromancer (Mar 24, 2013)

Woodworker1997 said:


> I thought this was going to be a thread about ebay! :lol:




me too LOL


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## 4metals (Mar 24, 2013)

Was the bowl on a small base or did it have handles? Often these can be filled with a resIn. If you melt your anodes this is no issue but if you just clip them to the power supply the resin can snot things up.


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## mikeinkaty (Mar 24, 2013)

element47.5 said:


> Again, this is just my opinion.



And I think it is a very sound opinion.

Mike


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## mikeinkaty (Mar 24, 2013)

4metals said:


> Was the bowl on a small base or did it have handles? Often these can be filled with a resIn. If you melt your anodes this is no issue but if you just clip them to the power supply the resin can snot things up.



No base. It was a stamped piece, so no solder. The yield on that piece was around 88% which is average for the stuff i've been doing.

Mike


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## nickvc (Mar 25, 2013)

Mike much of the residues from your silver cell slime bags will be silver plus any metals that didn't react in the cell including gold and PGMs.
The bowl you say was stamped but could it have been spun rather than stamped, I ask because there are several types of alloy used for various purposes and spinning silver was an alloy that contained cadmium at one point, it might still be used but I can't confirm that, so it might be cadmium in the slimes or any other of the possible metals used to alloy the original silver.


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## mikeinkaty (Mar 25, 2013)

nickvc said:


> Mike much of the residues from your silver cell slime bags will be silver plus any metals that didn't react in the cell including gold and PGMs.
> The bowl you say was stamped but could it have been spun rather than stamped, I ask because there are several types of alloy used for various purposes and spinning silver was an alloy that contained cadmium at one point, it might still be used but I can't confirm that, so it might be cadmium in the slimes or any other of the possible metals used to alloy the original silver.


It was fluted so don't know if it was spun or not. Was pretty heavy for its size.

Mike


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## kurt (Mar 27, 2013)

nickvc said:


> Mike much of the residues from your silver cell slime bags will be silver plus any metals that didn't react in the cell including gold and PGMs.quote]
> 
> I have been wondering about this - awhile back - I was talking to another refiner & he told me - "don't forget you are going to recover traces of gold & PGMs from running sterling in a silver cell"
> 
> ...


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## mikeinkaty (Mar 27, 2013)

kurt said:


> I have never run sterling (by its self) in my cell
> So is there any truth that sterling will have traces of PGMs &/or gold
> Kurt


I have never run sterling in my cell either. Most everything other than silver and palladium will be caught in the filters while filtering the cement as I understand it. During electrolysis silver will plate out on the cathode while Palladium will be caught in the slime bag if the cell is run properly. However modern tableware type sterling from the better known manufacturers will have little if any Palladium.

Somewhere I read that modern sterling from 1st world countries will have little else in it except for copper. Sterling was most popular from the 1890's to the 1940's. During this most popular period there was no telling what else might have been alloyed with the sterling. Also no telling what might be in sterling produced currently by 3rd world countries. Note - in very recent years some companies have been putting other metals in sterling to make it harder. (Argentium Sterling contains Germanium)

I know this: Starting with highgrade modern sterling and disolving it with a 50/50 reagent grade nitic acid at ambient temperature, filtering the resulting solution through coffee filters, dropping the silver with clean pure copper bars, then filtering and rinsing the dropped silver carefully can produce some very high grade silver. I've gotten 99.95 silver this way. Electrolysis can then take it to 99.99 purity. Yesterday I took some of my bars to a PM buyer whose XRF gun said they were all 99.99 except for one poured from cement and it showed 99.95. 

Mike


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## element47.5 (Mar 27, 2013)

This (prior comment) is what I was envisioning when I said that sterling forks/bowls are not sold as a laboratory reagent-grade stuff. When you say "modern"...when referring to sterling...and I am referring US-made .925....lots and lots of sterling one might acquire as junk was made in the 1920's or 30's or 40's...or even earlier, 1890's. I am not saying old .925 is "full of" pollutants...but it should not surprise to lose a percent or two to pollution in the overall scheme of things.


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## 4metals (Mar 27, 2013)

I have seen gold in old sterling silver consistently run 0.3 PPT (or 1/3 ounce in every 1000 ounces) The explanation I've had is back in the day when gold was under $30 and silver was a quarter, it didn't pay to recover that 1/3 ounce, today it's a different dynamic. Plus often old sterling was often gold plated inside drinking goblets and on handles and that gold has long since been adsorbed into the silver. So old sterling can run even higher in gold. 

It is true that modern silver has either none or a trace of gold.

The gold is all gravy for the refiner, they never pay below 0.3 PPT and usually not below 0.5 PPT unless you are bringing in volume.


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## nickvc (Mar 27, 2013)

Another point to remember is that much of the silver been sold today comes from gold buying centres whose staff are not all that diligent so white gold, platinum and now palladium items do get into those lots and in manufacturing scrap staff rarely care if a bit of other material goes into the silver it's not their money, I have found platinum diamond set pendants, palladium rings and white gold of various karats some again diamond set commonly in sterling lots, to many one white metal looks like any other.


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## 4metals (Mar 27, 2013)

A strong incentive to refine ones own silver!


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## Anonymous (Mar 27, 2013)

nickvc said:


> Another point to remember is that much of the silver been sold today comes from gold buying centres whose staff are not all that diligent so white gold, platinum and now palladium items do get into those lots and in manufacturing scrap staff rarely care if a bit of other material goes into the silver it's not their money, I have found platinum diamond set pendants, palladium rings and white gold of various karats some again diamond set commonly in sterling lots, to many one white metal looks like any other.


I remember buying an assorted lot of silver off eBay, then come to find out that one of the rings was 14K white gold and I got a platinum nose/eyebrow pin. I can say it's very interesting doing your own silver, and buying sterling jewelry because chances are, you're going to get either some white gold or some other precious metals.

Kevin


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## mikeinkaty (Mar 27, 2013)

element47.5 said:


> This (prior comment) is what I was envisioning when I said that sterling forks/bowls are not sold as a laboratory reagent-grade stuff. When you say "modern"...when referring to sterling...and I am referring US-made .925....lots and lots of sterling one might acquire as junk was made in the 1920's or 30's or 40's...or even earlier, 1890's. I am not saying old .925 is "full of" pollutants...but it should not surprise to lose a percent or two to pollution in the overall scheme of things.



88% recovery after electrolysis is the best I have ever achieved from sterling. And that was just one batch where I was taking extra careful means to do it as best I could.

I got one batch of jewelry and quickly decided I had better things to do than to spend all day trying to clean it up! My grandaughters did enjoy a lot of it though!

Mike


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## FrugalRefiner (Mar 28, 2013)

testerman said:


> I remember buying an assorted lot of silver off eBay, then come to find out that one of the rings was 14K white gold and I got a platinum nose/eyebrow pin. I can say it's very interesting doing your own silver, and buying sterling jewelry because chances are, you're going to get either some white gold or some other precious metals.


Or perhaps some nickel silver, alpaca silver, Britannia metal, etc.  

Dave


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## element47.5 (Mar 28, 2013)

Yah. I think that's a heck of a lot more likely, Frug.


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