Silver from silver chloride?

[Astar1988]

1) Sorry for bad english.

2) Read that silver chloride dissolves to metalic silver and chloride in high temperatures.
explenation- i'm basically free time blacksmith, i have gas furnance and i can have strongly reductive atmosphere in it (I usually do), also usual "work temperature" is around 1000-1500C

So can i just skip zinc or alluminium part, and put AgCl in crucible, add borax and charcoal on top? Would not it will be faster in my sytuation? (and also, if it works, it eliminates HCL usage to dissolve left zinc powder)

At the moment i'm doing it by standard method (AgCl, zinc, HCL and like 2-3 days of slow reaction)

 

[nickvc]

Your English is very good and fully understandable.
The simple answer to your question is yes you can melt the chloride if you don't mind the loses, there are a few ways to convert silver chloride to metallic,choose one that suits your situation and the available chemicals.
If you tell us where the silver chloride comes from, is this material you are producing we may be able to help you find a better way to recover your silver.

 

[Astar1988]

Thank you for quick answer.

I'm geting silver chloride from dissolving it in HNO3 and precipitate it by HCL.

"Base" Material is mokume-gane, In simple words, it's copper heat-joined witch silver (similar process to damascus steel). So it's around of 40% mass of silver and 60% copper.

I have almost full acces to chemicals (without Cyianides and couple other dengerous or explosives-base material). Question is, how to do it cheap.

If silver costs around 2,2zł (my country currency) per gram, zinc costs arround 0,3-0,5 zl/gram and chloric acid around 40zl/liter. If i have losses in process (for example zinc dissolved in acid after reaction is finished) cost is not much less than buying rafined silver itself...

edit: so if just dissolving base material in acid, precipitate it by NaCL or HCL and just heat up AgCl will have 20% loss, it's better budget option than using zinc.

 

[FrugalRefiner]

I would recommend sulfuric acid and iron. As a blacksmith, you probably have plenty of iron scrap available. Put the AgCl, some iron scrap, and some dilute (5% to 10%) sulfuric acid into a container and tumble it. Something like a concrete mixer works well, but with your skills, you can probably put something similar together.

When the process is done, you can wash the material free of any remaining acid and remove any leftover iron with a magnet.

Dave

 

[Astar1988]

O, that's cheap and doable idea. Does iron (steel) needs to be acid resistant (inox, stainless) or just any random iron scraps will do?
Can my mixer be also from steel? (i have couple ideas and wielded metal will be stronger and easier to do than plastic)
And i assume, iron in this will be similar to zinc, so there will be gray silver dust, not silver plated metal (as in copper - silver chloride).

Btw really thank you for answers, and for grate response time.

 

[goldsilverpro]

After dissolving the silver in nitric, I would use copper to cement out the silver, instead of precipitating the silver as silver chloride.

 

[Astar1988]

But i will lose some silver on copper i think, or i will get worse purity if i will melt them together :/

 

[rickbb]

Since you already have the silver dissolved in nitric, cementing with copper bars, and done carefully, will yield you quite good quality silver for very little extra cost.

You need to use solid copper, like bars or plates, not wire, to help minimize the copper contaminate in the dropped silver.

Other wise if you continue with silver chloride then the sulfuric and iron method would be the next best thing to use.

 

[FrugalRefiner]

O, that's cheap and doable idea. Does iron (steel) needs to be acid resistant (inox, stainless) or just any random iron scraps will do?
Can my mixer be also from steel? (i have couple ideas and wielded metal will be stronger and easier to do than plastic)
And i assume, iron in this will be similar to zinc, so there will be gray silver dust, not silver plated metal (as in copper - silver chloride).

I answered your original question based on the assumption that you already have the silver chloride. As a couple of members have mentioned, you can recover the silver from solution by cementing on copper. It's much easier than creating silver chloride and all the steps that follow. While precipitating silver chloride may create a purer silver at the end, it involves more work and creates more waste.

In answer to your questions, the iron you use with the sulfuric acid process is consumed in the process. It is dissolved by the sulfuric acid, and trades places with the silver. So ideally you want to use plain iron. Steel will work, but the less carbon and other alloying metals the better. Don't use stainless or inox.

Since the iron is dissolved in the reaction, the mixer should not be steel or you will end up with quite a mess when the acid dissolves holes in the mixer.

Hope that helps.

Dave

 

[Astar1988]

At first, thanks one more time for all answers

I see there are LOTS of options, so i will better precise what i need (and sorry i didnt start witch that)

My current works are based on melting point, i need to know precisly in what temperature my silver is melting, and in what my gold/copper will melt. As u know, to do that i need to know precisly what is ingriediens and how much is in alloy (there is huge difference in melting point of 93% silver, 7% copper, 99,9% silver and i even a bit of zinc is lowering melting point 100C+ degrees)

Second most important thing is economy. So less of expensive chem is better.

1) how much copper will get into alloy from "copper from AgNO3"
2) any idea how much i will lose from "pure AgCl+borax+charcoal on top" i will lose? Anyone tryed it? (if not i will )

Also i'm bit worried about non-ferric stuff in steel (and pure iron is kinda hard to get, there is always % of copper, wolfram, chrome, silicon and others) Can i just instead of pure iron use FeSO4 (same as in gold process?) I have kilo of it somewhere.

 

[goldsilverpro]

Nothing in that group of metals (Au, Cu, Ag) can be separated by melting point. It just doesn't work that way. The only way to separate them would be chemically. The problem is that these metals alloy together at lower melting points. For example, gold melts at 1064C and copper at 1085C, but 21%copper-79% gold melts at 910C.

It seems like everything you say is wrong. Better to learn the right way from the members of this forum than continue in your misinformed ways. Were I you, I would forget everything you think you know and start over.

 

[Astar1988]

I didnt want to separate, i need to know when they melt, I'm making mokume, in shortcut, you take pieces of silver and copper or gold, and in reductive atmosphere heat to temp of lowest melting point, it creates one piece of multicolor material. To do that, i need to know when they melt, to know that, i need to know precisly what alloy ingredients are and what % of them.

 

[goldsilverpro]

You started talking about one thing and then switched to another.

40Cu/60Ag, the Cu/Ag alloy with the lowest melting point (called the eutectic), melts at 779C

http://www.tf.uni-kiel.de/matwis/amat/elmat_en/kap_2/illustr/t2_2_3.html

 

[Astar1988]

Ok, i see some languidge problems.

I wanted to answer, what i precysly need and why.

I need to get as pure silver as i can get from scraps. And anny unknown amounts of copper or zinc will be problem for me. If there will be known amounts, i need to know how much

Thats why i asked:
1) how much copper will get into alloy from "copper from AgNO3"
2) any idea how much i will lose from "pure AgCl+borax+charcoal on top" i will lose? Anyone tryed it? (if not i will )

Because first method is sugested as easiest, but if i will not know how much copper i have in it, it will be useless for me.
Second method looks like way to get most pure metal, but i need to know how much i will lose.

 

[FrugalRefiner]

Thats why i asked:
1) how much copper will get into alloy from "copper from AgNO3"
2) any idea how much i will lose from "pure AgCl+borax+charcoal on top" i will lose? Anyone tryed it? (if not i will )

Because first method is sugested as easiest, but if i will not know how much copper i have in it, it will be useless for me.
Second method looks like way to get most pure metal, but i need to know how much i will lose.

Unfortunately, no one can answer those questions. There are just too many variables in each process. They both depend on the experience and skill of the refiner, the materials and equipment available, etc.

If you really want pure silver, you should set up a silver cell. They can be made at a very low cost, and they can reliably refine silver to 999 fine or better. A search for silver cell should get you a lot of good results to study.

Dave

 

[Shark]

I'm making mokume

Mokume gane?
There is a lot of information available for making it. Very basically you layer various metals together by heating the compressed layer until they start to "sweat" (melt very slowly), once they do this you hammer forge them together. The temperature is normally something that is learned through practice over time. Once forged, the metal can be shaped and/or twisted to form better designs in the metal. It also makes some very beautiful pieces of metal that can be used in many items.

 

[Astar1988]

Thats why i asked:
1) how much copper will get into alloy from "copper from AgNO3"
2) any idea how much i will lose from "pure AgCl+borax+charcoal on top" i will lose? Anyone tryed it? (if not i will )

Because first method is sugested as easiest, but if i will not know how much copper i have in it, it will be useless for me.
Second method looks like way to get most pure metal, but i need to know how much i will lose.

Unfortunately, no one can answer those questions. There are just too many variables in each process. They both depend on the experience and skill of the refiner, the materials and equipment available, etc.

If you really want pure silver, you should set up a silver cell. They can be made at a very low cost, and they can reliably refine silver to 999 fine or better. A search for silver cell should get you a lot of good results to study.

Dave

Thank you Dave

I assume you are talkin about electrolictic proces? I tough about it for some time. It's a bit time consuming, if there is no other option, it is a best option

@shark yes, mokume-gane. I'm making it for some time. And thats why i so much need knowledge about purity of my rafined silver In silver-gold mokume i need to make gold alloy and silver alloy (or pure) stack, where difference between melting point of gold and silver is as high as possible. If there is 50 celcius difference, both start melting almost same time, and instead of workable material i get blob that i can only rafine back.

 

[kurtak]

2) Read that silver chloride dissolves to metalic silver and chloride in high temperatures.
explenation- i'm basically free time blacksmith, i have gas furnance and i can have strongly reductive atmosphere in it (I usually do), also usual "work temperature" is around 1000-1500C

So can i just skip zinc or alluminium part, and put AgCl in crucible, add borax and charcoal on top?

Astar1988

Let go back to your original post & talk about what I underlined

You are talking about doing a conversion of AgCl to Ag by way of a smelting process - however I am not sure if the borax/charcoal will effect the conversion or not --- I have never heard of it being done this way

Normally soda ash (alone - no charcoal) is what is used for the smelting process to convert AgCl to Ag

The AgCl & the soda ash needs to be "well mixed" before you put it in the crucible & then it needs to be put in the furnace & brought up to a temp "below" the melting temp & held there until the conversion is complete & then once the conversion is complete you bring the furnace up to melt temp (its been a long time since I have done this process & so I don't remember the "conversion" temp off the top of my head)

The problems with this method as others have mentioned is loss of silver (some of it goes up in smoke) & the toxic fumes produced during the conversion & its hard on crucibles

Charcoal is a reducing agent used in smelting - but it primarily works on reducing metal oxides as it works in braking the oxygen atom bond from the metal oxide thereby reducing it to the metal

As far as cementing silver with copper goes if you use the standard method of cementing (a large piece of copper like a copper bar) you can produce silver that is .98 plus --- if done right - but it can be much less pure then .98 if not done right --- normally cemented silver is then sent to the silver cell if you are after .999 silver

Here is a link to a discussion about good cementing method :arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=23441&p=246984&hilit=dilute#p246984

Read from this post down to the end of the thread

Also you can cement your silver with copper in a way that it will produce .99 plus --- this method requires using a "fine" copper powder --- the problem here is that unless you can produce your own fine copper powder - buying it is expensive --- If you are interested in this method I will post more details about it - & as a side note - it also works for cementing gold from solutions that can produce .99 plus gold

Kurt

 

[nickvc]

If you are looking to keep the melting temperature down then the more copper in your silver the better, sterling silver melts at 1640 while fine silver melts at 1760 and karat alloys of gold say 18k yellow melts at 1700 while fine gold melts at at 1945 so perhaps you are viewing this in the wrong way so perhaps you would be better using sterling silver and either fine gold or a 22k alloy, with the copper it melts at 1981 so you can use sterling silver and an 18k alloy, look at what you want to create and then choose the materials that will do the necessary job.

 

[Astar1988]

If you are looking to keep the melting temperature down then the more copper in your silver the better, sterling silver melts at 1640 while fine silver melts at 1760 and karat alloys of gold say 18k yellow melts at 1700 while fine gold melts at at 1945 so perhaps you are viewing this in the wrong way so perhaps you would be better using sterling silver and either fine gold or a 22k alloy, with the copper it melts at 1981 so you can use sterling silver and an 18k alloy, look at what you want to create and then choose the materials that will do the necessary job.

Yes, but for example last time i had 14k yellow gold, and in that case. It had almost same melting point as .93 silver (difference is 20 celcius). So i had to use pure silver as higer temp material. I worked on what i got and did not had chem to puryfy it yet, it was clients gold.

Atm i will work at pure gold and pure/sterling silver. But you know, I can always make .93 from pure, or .585, but i cant get pure from .93 so easly, so it's always better to have more options.


btw, didnt expect that i will find so many people who know what mokume-gane is and how to do it, in Poland there are less than 10 jevelers/smiths doing it