# .910 to .964



## rick310 (Dec 3, 2013)

I need a little help, kind of stumped. A customer handed me a kilo of .910 Ag and wants me to bring it up to .964 using only .9999 silver. How much would I add to every kilo? Thanks in advance!


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## nickvc (Dec 3, 2013)

It's fairly simple maths really but the logic is a bit strained.
1000 x .91 = 910 therefore you have 90 grams of none silver 
1000 x .964 = 964 leaving 36 grams of none silver
90 grams from your customers metal divided by 36 = 2.5 so multiply your original weight by 2.5 = 2500 less your original weight 1000 so you will need to add 1500 grams of fine silver.
2500 x .964 = 2410 plus the original 90 grams of none silver.
Easy :shock: :lol:


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## Lou (Dec 3, 2013)

Assay will be on the high side if you melt it without argon or some cover gas to prevent oxidation.


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## glondor (Dec 3, 2013)

Wouldn't it be 54g ?


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## rick310 (Dec 3, 2013)

nickvc said:


> It's fairly simple maths really but the logic is a bit strained.
> 1000 x .91 = 910 therefore you have 90 grams of none silver
> 1000 x .964 = 964 leaving 36 grams of none silver
> 90 grams from your customers metal divided by 36 = 2.5 so multiply your original weight by 2.5 = 2500 less your original weight 1000 so you will need to add 1500 grams of fine silver.
> ...


 I added 1600 grams and it came out to .957


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## goldsilverpro (Dec 3, 2013)

Nick got it right. Also, Lou was right, of course.

I prefer using algebra in this case.

1000 x .910 = 910 grams of silver to start
x = amount of silver to add 
Total silver at end = 910 + x
Total weight at end = 1000 + x

Therefore,
Total silver divided by the total weight must equal .964
OR
(910 + x) divided by (1000 + x) must equal .964 
OR
(910 + x)/(1000 + x) = .964

Solve for x
(910 + x)/(1000 + x) = .964
(910 + x) = .964(1000 + x)
910 + x = 964 + .964x
x - .964x = 964 - 910
.036x = 54
x = 54 divided by .036 = 1500 grams

You need to add 1500 grams of pure silver 

Proof

Total silver: 910g + 1500g = 2410g
Total weight: 1000g + 1500g = 2500g
2410/2500 = 0.964


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## nickvc (Dec 3, 2013)

Chris and Lou there is a huge amount involved...Do you both smell a rat or is it just me?
I hate to see members taken for a ride..
Pleases comment.


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## Lou (Dec 3, 2013)

I don't understand what you mean.

Seems like somebody asked if he could make a custom alloy, he's not confident of his maths and wanted help in the process. So far as I can see, he was taught how to fish, and given the first one for free.


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## nickvc (Dec 3, 2013)

Lou we are talking huge quantities, if it were me I'd ask why can't I use your huge amount of silver to refine and re alloy the rest ,not add massive amounts of fine silver to adjust the assay up at my cost and risk....


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## rick310 (Dec 3, 2013)

nickvc said:


> Lou we are talking huge quantities, if it were me I'd ask why can't I use your huge amount of silver to refine and re alloy the rest ,not add massive amounts of fine silver to adjust the assay up at my cost and risk....


 The only reason why we didn't want to refine is because of the loss of silver we take when we refine, but we might just have to and charge the customer the difference.


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## rick310 (Dec 3, 2013)

rick310 said:


> nickvc said:
> 
> 
> > Lou we are talking huge quantities, if it were me I'd ask why can't I use your huge amount of silver to refine and re alloy the rest ,not add massive amounts of fine silver to adjust the assay up at my cost and risk....
> ...


And because of the time and process


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## goldsilverpro (Dec 3, 2013)

Nick. I agree with Lou. He asked a question and it was answered. I can't see how the members would be involved.

Actually doing this could be a problem. Like Lou said, in a melt open to the air, some copper would oxidize and the silver content would be high. Also, if it's done in a gas furnace, the alloy would probably be non-homogeneous. To end up with a homogeneous bar that assayed exactly .964, no matter where you took the sample, would be very, very iffy. With an induction furnace and using an inert gas, I still have doubts that it could be done that precisely.


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## butcher (Dec 3, 2013)

Beside the problems mentioned.
It does not make sense to me to downgrade 1500 grams of .999, to upgrade 1000g of silver.
Washing the baby in dirty water.


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## cnbarr (Dec 3, 2013)

I've been following this thread, and I agree with butcher, it feels a bit strange! Why would anyone want to take .9999 fine silver to try and up grade impure silver?

It would be like someone taking 24k gold and alloying it with 18k gold to make it a little better! 

Why not refine it then alloy it to the purity you want? It doesn't make sense to degrade the fine silver.


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## niteliteone (Dec 3, 2013)

I'm more curious of why someone with a kilo of 0.910 silver would want/need silver of 0.964 :?: 

Seems to me that dissolving in nitric and cementing with copper, then slack a little on rinsing, would be cheaper and faster than trying to avoid this by adding over a thousand dollars worth of 0.9999 silver.
Both ways can be done in a single day.

But still, why 0.964 purity :?:


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## butcher (Dec 4, 2013)

I am glad the question was asked, I got a good math lesson. Thanks


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## CBentre (Dec 4, 2013)

niteliteone said:


> I'm more curious of why someone with a kilo of 0.910 silver would want/need silver of 0.964 :?:
> 
> Seems to me that dissolving in nitric and cementing with copper, then slack a little on rinsing, would be cheaper and faster than trying to avoid this by adding over a thousand dollars worth of 0.9999 silver.
> Both ways can be done in a single day.
> ...



I'm usually on the negative side when it comes to this stuff but just from reading it sounds like they want to upgrade it and try and pass it off as 0.999. I hope I'm wrong but I can't see any logic in it unless there is a specific application that requires 0.964 purity. Possibly a manufacturing company or the likes that would need it.

edited for spelling


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## glondor (Dec 4, 2013)

Hey guys. Thanks for the math lesson. I see it but it is still hard to wrap my head around. :shock:


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## nickvc (Dec 4, 2013)

glondor said:


> Hey guys. Thanks for the math lesson. I see it but it is still hard to wrap my head around. :shock:




It's the reverse of alloying down, when you have fine metals and want to make a karat alloy you know how much gold is needed for it to pass assay, say you want 18k its the weight of the gold x the assay.75, when you need to alloy up its the weight of the none value metal that's important because that's the fixed amount and the amount of values has to be moved to createthe right alloy.


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## rickbb (Dec 4, 2013)

But why .964? It seems such an odd % to shoot for.


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## nickvc (Dec 4, 2013)

They obviously have a specific use for that alloy but I'm afraid I'm not involved in this so have no real idea, perhaps it's an industrial alloy as it's not one I have ever encountered in jewellery or silverware.


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## rick310 (Dec 4, 2013)

Hey guys not sure why the customer wants it around .964 of course it's not going to be perfect, but I'll provide the service. I think they export it and has to do with something about the tax and export fees, I'm sure they refine it again to .9999 but not exactly sure. But I appreciate the help and input.


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## MysticColby (Dec 4, 2013)

I agree with previous math, I just prefer showing it in a simpler (in my opinion, at least) way, so here goes:
C1V1 + C2V2 = C3(V1+V2)
1000g x 0.910% + Ag x 0.9999% = (1000g + Ag) x 0.964%
910 + 0.9999 A = 964 + 0.964 A
0.0359 A = 54
A = 1504.178g (A is the mass of 0.9999 silver to add)

keep in mind this is all theoretical, in the real world metals get oxidized and scales are off, etc.
make sure to mix it thoroughly!


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