How Far to Refine Your Silver?

[Bushka]

As mentioned on another thread, I have a batch of silver chloride that should theoretically yield about 650 grams of silver. It seems there are a number of options I could take, but I do not know what I will end up with value-wise with each option. I see some options as:

1. Convert the AgCl to silver powder through lye or sulfuric and iron, etc and then sell the powder, or melt it down and sell the ingot, which might be less than 98% silver as I am not sure of what unknown contaminants might be carried along,

2. Convert the AgCl as above, then dissolve in nitric acid and drop out with copper, increasing the purity to maybe 99%,

3. Dissolve in nitric acid as above and set up a silver cell to try and get 999 or 9999 silver, maybe losing yield in the process.

4. Ideally it seems the best way to assure good purity is to dissolve in nitric acid, drop with copper and clean well, then redissolve and electrolyze in a silver cell to get 9999.

My problem is I do not know the economics of each method as I don't know how to sell the silver and what price it will bring in each form (powder or ingot). It appears that some go to jewelers to sell silver. Do you get the spot price?

If I use 2.8 ml 70% nitric/1g silver, I need about 1.8 liters of nitric acid, which costs at least $75 -- and I'd need to double that if I wanted to try option 4 above. Is it worth it to use relatively expensive nitric acid to bump up the purity a few percentage, or can I get decent money with something like 95% purity?

I should say that if it is a wash financially either way, I'd probably shoot for the highest purity. I'd like to try the nitric/silver cell method and see what happens. All in all, between nitric acid and buying a $50 MAPP torch for melting silver, it could cost over $200 just to produce a bit over 16 ounces of silver.

Any comments are welcome!

 

[etack]

If you are not getting nitric cheap then have it toll refined or sell it. If it costs 200.00 for 1# or 452 grams than you will lose money.

I personally don't refine silver I collect and send it on. You don't get paid any more for it and it just takes up time. Some members have success selling poured bars most will not get much more that 96% of spot.

Eric

 

[g_axelsson]

You do not need to dissolve all silver when setting up a silver cell. The only silver you need to dissolve in nitric acid is the silver for the electrolyte and that amount is depending on the size of the cell. The rest is melted into an anode.

Göran

 

[NobleMetalWorks]

I would convert the chloride to metallic, then retain until you have collected enough silver to make it viable to invest in the equipment required to refine it further.

If you do decide to run a Balbach-Thum, or Moebius cell, both use silver concentrations in the range of 30-150 g dm-3. And if you want to create large, well separated, non-adherent crystallites of silver, which makes it easier to remove, wash and dry the silver, you will also want to have CuNO3 (copper) present in your solution. So you need a good amount of silver and copper in order to properly operate a Blabach-Thum or Moebius cell. A lot of times, the expense of the silver/copper in your electrolytic solution is worth far more than the silver you are refining.

If you want to set up something small, which I think that is your intent, you might want to read the posts by Kadriver on the subject. He has done an excellent job documenting his experiences and has a lot of practical knowledge and understanding on the subject.

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=50&t=16132

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=50&t=11842&start=40

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=15603&start=20

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=51&t=12477

There are a lot of other people who have posted information as well. If you do a search you will come up with a wealth of information.

If I were you, I would set your material aside until you have enough to make it economically viable for you to refine further.

Scott

 

[goldsilverpro]

If I use 2.8 ml 70% nitric/1g silver, I need about 1.8 liters of nitric acid, which costs at least $75 -- and I'd need to double that if I wanted to try option 4 above. Is it worth it to use relatively expensive nitric acid to bump up the purity a few percentage, or can I get decent money with something like 95% purity?

To dissolve 1 gram of silver, it takes about 1.22ml of 70% nitric acid, at most, plus an equal amount of distilled water. The nitric usage can be reduced somewhat by covering the beaker, while dissolving, with a watch glass.

 

[mikeinkaty]

Edited 12/30/2012 9:48pm---
Here is a table I made using the 1.22ml/gram figure given by Goldsilverpro and my cost of nitric at $40 /Liter. It is also using 4.17ml/gram to disolve the non-silver (usually copper) components. 92.5% is assumed for the silver content. Figure about $1.80 per troy ounce of 925 Sterling for the Nitric acid needed. If you're figuring on the cost of silver going up, then you might win! Good reflux might make this cost go down. This is only an estimate and does not represent exact science! Remember that when all the metal is in solution, you ideally want all of the Nitric acid to have been consumed. Due to a lot of variables you never know exactly how much will be needed. Add the Nitric slowly!

Silver recovery from Sterling using 70% Nitric Acid that cost $40/Liter (Without reflux)
Multiply the cost figure below by X/40 where X is your cost per liter for 70% Nitric.

Ozt___Gms____h2o(ml)_hno3(ml)_Nitric_$
1_____31.1____45______45______$1.82___
2_____62.2____90______90______$3.65___
3_____93.3____134_____134_____$5.47___
4_____124.4___179_____179_____$7.29___
5_____155.5___224_____224_____$9.11___
6_____186.6___269_____269_____$10.94__
7_____217.7___313_____313_____$12.76__
8_____248.8___358_____358_____$14.58__
9_____279.9___403_____403_____$16.40__
10____311.0___448_____448_____$18.23__
11____342.1___493_____493_____$20.05__
12____373.2___537_____537_____$21.87__
13____404.3___582_____582_____$23.69__
14____435.4___627_____627_____$25.52__
15____466.6___672_____672_____$27.34__
16____497.7___717_____717_____$29.16__
17____528.8___761_____761_____$30.98__
18____559.9___806_____806_____$32.81__
19____591.0___851_____851_____$34.63__
20____622.1___896_____896_____$36.45__
21____653.2___940_____940_____$38.27__
22____684.3___985_____985_____$40.10__
23____715.4___1030____1030____$41.92__
24____746.5___1075____1075____$43.74__
25____777.6___1120____1120____$45.56__
26____808.7___1164____1164____$47.39__
27____839.8___1209____1209____$49.21__
28____870.9___1254____1254____$51.03__
50____1555.2__2239____2239____$91.13__
100___3110.4__4478____4478____$182.26_
200___6220.7__8956____8956____$364.52_

 

[goldsilverpro]

Here is a table I made using the 1.22ml/gram figure given by Goldsilverpro and my cost of nitric at $40 /Liter. It is also using 3.66ml/gram to disolve the non-Sterling (base metal) components. It is also using 92.5% as the pure silver content of the Sterling. Figure about $1.75 per gram of 925 Sterling for the Nitric acid needed. If you're figuring on the cost of silver going up, then you might win! Good reflux might make this cost go down. This is only an estimate and does not represent exact science!

(Goldsilverpro - is 3x to disolve the base metals about correct? let me know and I will change the table. If it should be 1x then the per gram cost would go down to about $1.50 per gram of 925 Sterling.)

Silver recovery from Sterling using 70% Nitric Acid that cost $40/Liter (Without reflux)
Multiply the cost figure below by X/40 where X is your cost per liter for 70% Nitric.

(Ozs)--(Gms)--H2o(ml)--HNo3(ml)-HNo3 Cost
1-------31.1----44------44------$1.78-----
2-------62.2----87------87------$3.55-----
3-------93.3----131-----131-----$5.33-----
4-------124.4---175-----175-----$7.10-----
5-------155.5---218-----218-----$8.88-----
6-------186.6---262-----262-----$10.66----
7-------217.7---305-----305-----$12.43----
8-------248.8---349-----349-----$14.21----
9-------279.9---393-----393-----$15.98----
10------311.0---436-----436-----$17.76----
11------342.1---480-----480-----$19.54----
12------373.2---524-----524-----$21.31----
13------404.3---567-----567-----$23.09----
14------435.4---611-----611-----$24.87----
15------466.6---655-----655-----$26.64----
16------497.7---698-----698-----$28.42----
17------528.8---742-----742-----$30.19----
18------559.9---785-----785-----$31.97----
19------591.0---829-----829-----$33.75----
20------622.1---873-----873-----$35.52----
21------653.2---916-----916-----$37.30----
22------684.3---960-----960-----$39.07----
23------715.4---1004----1004----$40.85----
24------746.5---1047----1047----$42.63----
25------777.6---1091----1091----$44.40----
26------808.7---1135----1135----$46.18----
27------839.8---1178----1178----$47.95----
28------870.9---1222----1222----$49.73----
50------1555.2--2182----2182----$88.80----
100-----3110.4--4364----4364----$177.61---
200-----6220.7--8728----8728----$355.22---

It takes 3.4 times more nitric for copper than for silver, per gram. That would be 4.15ml/g for Cu.

 

[Bushka]

If you are not getting nitric cheap then have it toll refined or sell it. If it costs 200.00 for 1# or 452 grams than you will lose money.

I personally don't refine silver I collect and send it on. You don't get paid any more for it and it just takes up time. Some members have success selling poured bars most will not get much more that 96% of spot.

Eric

Not sure what you are saying. You get the same price for unrefined silver (like say .98 silver powder) as you get for 999 ingots?

 

[Bushka]

You do not need to dissolve all silver when setting up a silver cell. The only silver you need to dissolve in nitric acid is the silver for the electrolyte and that amount is depending on the size of the cell. The rest is melted into an anode.

Göran

Good point. I believe my AgCl is probably much more pure than sterling, since it was prepared in a school lab, and probably not from sterling silver. I would guess that it could produce a pretty clean anode when melted. I'll do some more research on this forum, but maybe you can answer one question about the silver cell. I presume you cannot process all the silver in solution, but merely save it for the next batch of silver. However, if you only do one batch, how much silver can you expect to lose in solution? For instance, if I process 1 lb or 454 g of pretty clean silver ingot, how much will I likely lose to the solution when I'm finished?

 

[Bushka]

Thanks to you other guys for the advice. I couldn't find or remember GSP's figure of 1.22 ml nitric.

Where can I find information on prices for silver powder vs ingots and various purities?

 

[etack]

If you are not getting nitric cheap then have it toll refined or sell it. If it costs 200.00 for 1# or 452 grams than you will lose money.

I personally don't refine silver I collect and send it on. You don't get paid any more for it and it just takes up time. Some members have success selling poured bars most will not get much more that 96% of spot.

Eric

Not sure what you are saying. You get the same price for unrefined silver (like say .98 silver powder) as you get for 999 ingots?

Yep that's what I am saying. It all goes to the refinery that send it thought there cells so why waste my time on it unless it's just for fun.

Eric

 

[goldsilverpro]

You do not need to dissolve all silver when setting up a silver cell. The only silver you need to dissolve in nitric acid is the silver for the electrolyte and that amount is depending on the size of the cell. The rest is melted into an anode.

Göran

Good point. I believe my AgCl is probably much more pure than sterling, since it was prepared in a school lab, and probably not from sterling silver. I would guess that it could produce a pretty clean anode when melted. I'll do some more research on this forum, but maybe you can answer one question about the silver cell. I presume you cannot process all the silver in solution, but merely save it for the next batch of silver. However, if you only do one batch, how much silver can you expect to lose in solution? For instance, if I process 1 lb or 454 g of pretty clean silver ingot, how much will I likely lose to the solution when I'm finished?

The silver cell is not a one batch process. It is more of a continual process. You have about 20 oz of silver and at least 2 or 3 oz will be tied up in the solution. There will probably be some in the anode slimes. It will cost money to set up the silver cell.

Were I you, I would skip the silver cell. If the AgCl is fairly pure to start with, and it probably is, I would concentrate on getting 100% of it converted to silver powder. Then you could easily melt it. As others have said, the trick is to get it finely ground. As you probably know, once AgCl has been dried, it becomes crystallized and is much more difficult to convert.

The simplest way is probably the blender method, using NaOH and Karo syrup, which has already been discussed. I would suggest doing it in small batches, with the blender only about 1/4-1/3 full. For each 31.1 grams of AgCl, it will theoretically take about 15g of NaOH, 10ml of Karo syrup, and 100ml of water - tap water is OK. To be on the safe side, I always add an extra 10% of each, which would make it, for 31.1g of AgCl, 16.5g of NaOH, 11ml of Karo syrup, and 110ml of water. Therefore, the total volume occupied per 31.1g of AgCl would be about 130-140ml, or so.

Considering the state of the AgCl you have, even with the blender you may not get 100% conversion. Incomplete conversion will promptly show up when you try to melt the silver. It's not pretty and breathing the toxic fumes coming off the molten AgCl is quite hazardous.

You can easily test for unconverted AgCl in the Ag powder. It's better to test it while it's still wet. This is a sensitive test. Before starting, everything you use must be clean and well rinsed with distilled water.

(1) Dip out about a gram, or so, of the Ag powder and put it into a 100ml beaker. Add about 20ml of distilled water and stir well. Allow to settle and pour off only the water. Repeat 5 or 6 times. You must rinse out all of the chloride. Hot distilled water would be best. With each rinse, also rinse down the inside of the beaker with distilled water from a squirt bottle. To test for complete removal of the chlorides in the rinses, put a few ml of the rinse water in a small beaker and add a drop or two of silver nitrate solution. A white cloud indicates chlorides and more rinsing is needed.

(2) When all the chlorides are out, pour off the rinse and add a little nitric acid (2 or 3 ml) and an equal amount of distilled water. When the Ag has completely dissolved, the presence of a white cloud or a settled white powder indicates unconverted AgCl.

 

[Bushka]

You can easily test for unconverted AgCl in the Ag powder. It's better to test it while it's still wet. This is a sensitive test. Before starting, everything you use must be clean and well rinsed with distilled water.

(1) Dip out about a gram, or so, of the Ag powder and put it into a 100ml beaker. Add about 20ml of distilled water and stir well. Allow to settle and pour off only the water. Repeat 5 or 6 times. You must rinse out all of the chloride. Hot distilled water would be best. With each rinse, also rinse down the inside of the beaker with distilled water from a squirt bottle. To test for complete removal of the chlorides in the rinses, put a few ml of the rinse water in a small beaker and add a drop or two of silver nitrate solution. A white cloud indicates chlorides and more rinsing is needed.

(2) When all the chlorides are out, pour off the rinse and add a little nitric acid (2 or 3 ml) and an equal amount of distilled water. When the Ag has completely dissolved, the presence of a white cloud or a settled white powder indicates unconverted AgCl.

Thank you for the advice, GSP. In step 1 I assume you are removing chlorides from the conversion of AgCl to AgO and ultimately to Ag. This would form NaCl and I'm sure other Cl- species. This is what we are rinsing out of the Ag, right? I guess my question is why is step 1 necessary? Are chlorides likely to precip out or otherwise interfere with seeing any residual AgCl in step 2?

One other concern I have is that I've always assumed I'd have all the AgCl in a dissolved liquid state at some point (Probably after dissolving the cemented silver in nitric acid). That is when I was going to filter the solution to remove any small debris. I don't believe I have a lot of foreign material, but I do believe there are some very tiny bits of wood and dust there. Maybe these will just burn off and be taken care of by the borax?

 

[goldsilverpro]

You can easily test for unconverted AgCl in the Ag powder. It's better to test it while it's still wet. This is a sensitive test. Before starting, everything you use must be clean and well rinsed with distilled water.

(1) Dip out about a gram, or so, of the Ag powder and put it into a 100ml beaker. Add about 20ml of distilled water and stir well. Allow to settle and pour off only the water. Repeat 5 or 6 times. You must rinse out all of the chloride. Hot distilled water would be best. With each rinse, also rinse down the inside of the beaker with distilled water from a squirt bottle. To test for complete removal of the chlorides in the rinses, put a few ml of the rinse water in a small beaker and add a drop or two of silver nitrate solution. A white cloud indicates chlorides and more rinsing is needed.

(2) When all the chlorides are out, pour off the rinse and add a little nitric acid (2 or 3 ml) and an equal amount of distilled water. When the Ag has completely dissolved, the presence of a white cloud or a settled white powder indicates unconverted AgCl.

Thank you for the advice, GSP. In step 1 I assume you are removing chlorides from the conversion of AgCl to AgO and ultimately to Ag. This would form NaCl and I'm sure other Cl- species. This is what we are rinsing out of the Ag, right? I guess my question is why is step 1 necessary? Are chlorides likely to precip out or otherwise interfere with seeing any residual AgCl in step 2?

One other concern I have is that I've always assumed I'd have all the AgCl in a dissolved liquid state at some point (Probably after dissolving the cemented silver in nitric acid). That is when I was going to filter the solution to remove any small debris. I don't believe I have a lot of foreign material, but I do believe there are some very tiny bits of wood and dust there. Maybe these will just burn off and be taken care of by the borax?

The chlorides, of course, are part of the liquid in the converted Ag powder. If you don't rinse them out completely, they will combine with the dissolved silver in step 2 and form silver chloride. This will always indicate, or give a false positive, that the conversion wasn't complete, even if it was.

Silver chloride is not soluble in nitric acid. It is soluble in cyanide, thiosulfate, ammonia, strong sodium chloride solutions, and very slightly in full strength aqua regia. That's about it for common things.

 

[Bushka]

You can easily test for unconverted AgCl in the Ag powder. It's better to test it while it's still wet. This is a sensitive test. Before starting, everything you use must be clean and well rinsed with distilled water.

(1) Dip out about a gram, or so, of the Ag powder and put it into a 100ml beaker. Add about 20ml of distilled water and stir well. Allow to settle and pour off only the water. Repeat 5 or 6 times. You must rinse out all of the chloride. Hot distilled water would be best. With each rinse, also rinse down the inside of the beaker with distilled water from a squirt bottle. To test for complete removal of the chlorides in the rinses, put a few ml of the rinse water in a small beaker and add a drop or two of silver nitrate solution. A white cloud indicates chlorides and more rinsing is needed.

(2) When all the chlorides are out, pour off the rinse and add a little nitric acid (2 or 3 ml) and an equal amount of distilled water. When the Ag has completely dissolved, the presence of a white cloud or a settled white powder indicates unconverted AgCl.

Thank you for the advice, GSP. In step 1 I assume you are removing chlorides from the conversion of AgCl to AgO and ultimately to Ag. This would form NaCl and I'm sure other Cl- species. This is what we are rinsing out of the Ag, right? I guess my question is why is step 1 necessary? Are chlorides likely to precip out or otherwise interfere with seeing any residual AgCl in step 2?

One other concern I have is that I've always assumed I'd have all the AgCl in a dissolved liquid state at some point (Probably after dissolving the cemented silver in nitric acid). That is when I was going to filter the solution to remove any small debris. I don't believe I have a lot of foreign material, but I do believe there are some very tiny bits of wood and dust there. Maybe these will just burn off and be taken care of by the borax?

The chlorides, of course, are part of the liquid in the converted Ag powder. If you don't rinse them out completely, they will combine with the dissolved silver in step 2 and form silver chloride. This will always indicate, or give a false positive, that the conversion wasn't complete, even if it was.

Silver chloride is not soluble in nitric acid. It is soluble in cyanide, thiosulfate, ammonia, strong sodium chloride solutions, and very slightly in full strength aqua regia. That's about it for common things.

OK, I see how the test is contaminated by Cl when you add the nitric. Thanks again!

 

[Bushka]

GSP -

1. Regarding your test for unconverted AgCl in the Ag cement: I do not have nitric acid, and therefore also no AgNO3. I had an alternate idea for testing residual AgCl. I do have ammonia (I am well aware of the hazards). How about doing this instead: Wash the silver cement with several batches of hot water to assure most of the chlorides are flushed out. Then, add ammonia to the silver. Some heat will help any residual AgCl to dissolve. Pour off the ammonia through a filter and drop a clean piece of copper in the solution. If nothing happens, then there was no AgCl left. If it plates out silver, then there must have been some AgCl left. Also, I can look for a bluish tint which would indicate copper ions entering solution. Anything wrong with this method? (Again, observing the hazards).

2. My silver chloride has some dry HCl in it from when I originally cleaned it up. Is this likely to interfere with the NaOH/syrup conversion? I know the HCl will neutralizer the NaOH, but I didn't know if residual HCl would be enough to worry about.

Thanks!

 

[goldsilverpro]

GSP -

1. Regarding your test for unconverted AgCl in the Ag cement: I do not have nitric acid, and therefore also no AgNO3. I had an alternate idea for testing residual AgCl. I do have ammonia (I am well aware of the hazards). How about doing this instead: Wash the silver cement with several batches of hot water to assure most of the chlorides are flushed out. Then, add ammonia to the silver. Some heat will help any residual AgCl to dissolve. Pour off the ammonia through a filter and drop a clean piece of copper in the solution. If nothing happens, then there was no AgCl left. If it plates out silver, then there must have been some AgCl left. Also, I can look for a bluish tint which would indicate copper ions entering solution. Anything wrong with this method? (Again, observing the hazards).

2. My silver chloride has some dry HCl in it from when I originally cleaned it up. Is this likely to interfere with the NaOH/syrup conversion? I know the HCl will neutralizer the NaOH, but I didn't know if residual HCl would be enough to worry about.

Thanks!

1. Sounds logical, if the copper will dissolve. I've never tried to cement silver from an ammoniacal complex.

After filtering the ammonia solution, you could re-acidify it with a little HCl. If silver is present, AgCl will form. Make sure everything you use has been well rinsed with distilled water before making any of these tests.

2. I can't see a little HCl causing problems with the conversion.

 

[Bushka]

GSP -

1. Regarding your test for unconverted AgCl in the Ag cement: I do not have nitric acid, and therefore also no AgNO3. I had an alternate idea for testing residual AgCl. I do have ammonia (I am well aware of the hazards). How about doing this instead: Wash the silver cement with several batches of hot water to assure most of the chlorides are flushed out. Then, add ammonia to the silver. Some heat will help any residual AgCl to dissolve. Pour off the ammonia through a filter and drop a clean piece of copper in the solution. If nothing happens, then there was no AgCl left. If it plates out silver, then there must have been some AgCl left. Also, I can look for a bluish tint which would indicate copper ions entering solution. Anything wrong with this method? (Again, observing the hazards).

2. My silver chloride has some dry HCl in it from when I originally cleaned it up. Is this likely to interfere with the NaOH/syrup conversion? I know the HCl will neutralizer the NaOH, but I didn't know if residual HCl would be enough to worry about.

Thanks!

1. Sounds logical, if the copper will dissolve. I've never tried to cement silver from an ammoniacal complex.

After filtering the ammonia solution, you could re-acidify it with a little HCl. If silver is present, AgCl will form. Make sure everything you use has been well rinsed with distilled water before making any of these tests.

2. I can't see a little HCl causing problems with the conversion.

OK. Maybe acidifying with HCl would be better. I could try both. I just did a small batch per your recipe, and while everything turned dark grey, there are little chunks of white remaining. I didn't put anything in the blender - just in a beaker to see what happens. I'm leaving the solution to sit for awhile to see if the white chunks begin to convert to AgO.

 

[Bushka]

OK, so here's where I'm at:

Last night I added lye to 31 g silver chloride. I found that there were lots of small white chunks still there, so I added a little more lye to see what happened. I noticed that the precip was grey, but when I sprinkled lye onto the surface of the precip, it turned black wherever the lye touched. I would mix this in and add more lye and the same thing would happen. It almost seemed like the dark spots turned back into grey after some time, though I'm not sure about this. I didn't want to add too much lye, so stopped playing around with it. I probably had about 1.5 times the recipe of lye. This morning it looked like there were still plenty of white chunks still there, but I think some of them did convert. It's hard to quantify any of this. I added syrup this morning and the mixture did heat up. I probably added 1.5 times the recipe. After continued stirring and then letting it sit for about an hour, I took the photo below. There seems to be a light grey layer with little bits of shiny silver, and then a dark powdery layer on top, with a greenish/orange liquid above.

I'm trying to figure out what I'm left with here. Is the dark powder also converted silver, or is it AgO awaiting more syrup? I thought of adding more syrup and checking the temperature with a probe to see if it heats up again. Before going any further I thought I'd ask people who've done it before.

I should add that the silver chloride did have HCl dried in it from a previous clean up wash. I flushed the HCl with some water, but there's still plenty dried with the silver chloride, if that matters much.

Thanks!

 

[goldsilverpro]

The color of the solution is normal in this process.

I'm not 100% sure, but I think the darker powder on top could be finely divided silver and the gray is more chunky. Often, with metal powders, the more finely divided, the darker the powder. Since you did nothing to break up the dry crystallized silver chloride, it is very possible that the gray particles are a gray coating covering some unconverted silver chloride. It's hard to tell, but it sort of looks like that to me.

Converting dried silver chloride is always a problem. As a precaution, I would probably transfer everything in the beaker to a blender and let it run for a few minutes. Hopefully, the blender seals will stand up to the excess NaOH. They probably will be OK. You shouldn't need to add any more chemicals, since there is already an excess.

After this, if silver chloride appears when testing for completeness, you might filter and rinse the powder VERY WELL and then try to leach the AgCl out of the entire lot of powder with ammonia. Filter and rinse well. If that works, you could avoid the dreaded presence of silver chloride when you melt the silver. You could then acidify the ammonia solution with HCl and then collect the AgCl that forms.

I'm not guaranteeing anything. That's my best bet at this time. This might change depending on your results.