Is this the correct ratio nitric?

[adam_mizer]

On a post written by GoldenChild in another thread:

Another piece to the puzzle. When making poor mans AR....
If you distill your own nitric it takes 255 grams of high purity (98-99%) sodium nitrate to produce approximately 125ml of red fuming nitric. Distillation should in theory produce 100% pure nitric acid. In reality the home refiner will only be able to produce 92-96% pure nitric. Let's use 90% to be safe.
If you take your 125ml of 90% nitric and cut it with 36ml of distilled water you will now have 161ml of 70% nitric.
((90/70) * 125) - 125
Thanks to GSP for helping me figure that one out.
Using these numbers you can now more accurately guess how much nitric acid you are putting into the HCL to prevent excess nitric additions.

Now trying to use the approach above with the silver bars I have.
The bars are 94.5% silver. EDIT(base them at 94%)
If I take 1 of those bars weighing 54 grams that = 50.76 grams silver + 3.24 grams copper (lets use copper but I'm not sure).
Now I have distilled and condensed my nitric and its aweful red fuming, I estimated 95% but as the above post states 90% would be a safe guess-timate.
Now if it takes 1.17ml (edit) 70% nitric per gram of silver and 3 times more per gram of copper then should I use XXml of the distilled/condensed nitric.

(50.76gr silver x 1.17ml (70%) nitric + 3.24gr copper x (3x1.17ml) = 3.51x1.17ml=11.37ml (70%) nitric) = 70.76ml (70%) nitric for that bar.

It appears I need 70.76ml 70% = so how many XXml's of 90% would equal the 70.76ml of 70%?
Whats the math ratio?
If a person has different amounts of ml's as not stated in the above quote, I need help with the math basing it all on the 90% value.
Somehow it seems simple enough but I just can't figure it out right now.

(I added a picture maybe we could make a comparison on the percentage of nitric?)
This is just over a 1 liter bottle.

Lots of edits and another: I know the contaminent is nitrogen dioxide what I don't really know is can I just release this fuming contaminent or does it even matter much?
Changed the picture, added some more home brew. Found out with my setup (bunson burner) it can process much faster with smaller amounts (100ml sulphuric) rather than trying to process several 100ml's at a time.
Is there a weight measurement that can be done to determine the percent strength of the nitric? Might not matter and I'll probably just use only a few ml's extra.
To answer my own question on the amount I can just break the 125ml above down into increments and figure exactly what I need, maybe by doing this I'll get the ratio math answered.

 

[adam_mizer]

I proceeded to make a test batch from the fuming nitric that was made.

Somehow I was hoping for a better result, but this test is incomplete.
Added 54 gram 94% silver bar, there is roughly 6% of another metal. Added distilled into 500ml beaker just to cover over bar, this brought water to 75ml in the beaker. Roughly 50ml water was added. Added 10ml of my nitric and allowed it to react, next day added 10ml again and several hours later added 10 ml again. Next day added some heat.
I thought this should at least reduce the size of the bar by near 1/2.
Now I have taken some of the bar into solution but there is also a fine powder build up on the bottom of the beaker.
It just seems odd to me there is this powder on the bottom and I'm not sure but it doesn't seem like silver chloride unless it could be such a fine looking powder.

 

[goldsilverpro]

To get an idea of the strength, measure the volume of some (I would measure out at least 25 ml) as accurately as you can and then weigh it. Divide the weight in grams by the volume in ml to determine the specific gravity. Use this chart to determine the approximate strength.
http://www.handymath.com/cgi-bin/nitrictble2.cgi?submit=Entry

The graduations on a glass beaker can be off as much as 5%. For what you want, though, that is probably accurate enough - if you use a small beaker and fill it to a mark that is about 1/2 to 3/4 full. A graduated cylinder is more accurate. When measuring, sight at a level angle and use the bottom of the meniscus - see this link.
http://morrisonlabs.com/meniscus.htm

 

[Palladium]

see this link.
http://morrisonlabs.com/meniscus.htm

Good link Chris. I remember a whole class devoted to this in school. One of the few things i can still remember. lol

 

[adam_mizer]

Thanks GSP,
This is what I come up with. Seems pretty close.

Empty container weight = 15.8gm
Container with 20ml water in it appears right at the upper shoulder of container fill.
Nitric filled to approximately same level to shoulder of container.
Weight now at 45.8gm.
Temp approximately 75-78F in garage right now, just over 20c.
Specific Gravity 15. Percentage = 95+.
Very close not perfectly accurate but appears I have 95% strength.

Also because of actually measuring 20ml's I may not have used as much as I think in my test but it was close.

 

[adam_mizer]

Here's a picture of the bar with a thick build up of chloride on it.
Maybe the distilled nitric still contains salts, and needs a second distillation at a lower temperature?

 

[goldsilverpro]

NOTE: I wrote all this before seeing your last post and assumed that your solution only contained nitric and water. However, at least you can now see things can be calculated. When you make up a fresh batch, you can easily test for chlorides with a drop of silver nitrate (Note: I originally said HCl here and this was edited). A white cloud indicates the presence of chlorides. Be very careful with this super strong nitric, as it will burn you bad.

Actually, the specific gravity is 1.5 g/ml (not 15) and therefore a liter will weigh 1.5 x 1000 = 1500 grams.

When using 70%, it will take about 1.2 ml to dissolve a gram of silver and about 4 ml to dissolve a gram of copper.

To determine how much stronger your acid is than 70%:

One liter of your 95% acid weighs 1500 ml. Therefore, the total weight of nitric in one liter is 1500 x .95 = 1425 grams.

The molecular weight of nitric, HNO3, is close to 63, as we'll soon discover.
(1) HNO3 contains 1 hydrogen, 1 nitrogen, and 3 oxygens.
(2) Look up the atomic weights of these 3 elements - H=1, N=14, and O=16.
(3) Therefore, you have 1x1 + 1x14 + 3x16 = 63.
(4) When expressed in grams, this number, 63 (in this case) is called a MOL. Therefore one MOL of HNO3 weighs 63 grams.
(5) Therefore, there are 1425/63 = 22.6 MOLs in one liter of 95%.

I won't go into the math but, one liter of 70% HNO3 contains about 15.8 MOLs of nitric. Therefore, your 95% acid is 22.6/15.8 = 1.43 times stronger than the 70%. Therefore, it will only take 1/1.43 = .70 or 70% as much - 1.2 x .7 = .84ml/g of silver or 4 x .7 = 2.8ml/g of copper.

Please note that, on the chart, the S.G. doesn't change much with the higher percentages of nitric. Therefore, a small error in volume measurement can make a big difference in the percentage estimate. Therefore, the figures we've calculated should only be used as a guide. The most accurate way to determine the HNO3% would be a simple titration.

 

[goldsilverpro]

I have never made HNO3, and hopefully never will. It's just too easy and inexpensive for me to buy it. However, I would think that, if you made the nitric from sodium nitrate and sulfuric, instead of hydrochloric, you certainly wouldn't have the chloride problem.

 

[adam_mizer]

I have never made HNO3, and hopefully never will, because it's too easy for me to buy it. However, I would think that, if you made the nitric from sodium nitrate and sulfuric, instead of hydrochloric, you certainly wouldn't have the chloride problem.

The ingredients were Sodium Nitrate prilled and Sulphuric 96.5% 1 distillation and condensate.
The chloride build up on the bar does not appear like the build up I have seen with the other poorman nitric method. This chloride was also much easier to remove/flake off.

I'm taking care of handling pretty good mostly taking extreme precautions.
Just a note to others, a small amount touched my nitrile gloves, the gloves at that contact point turned a silver like color. "Extreme handling must be observed".
Should be using a different material glove?
Also now that I know the percentage I can get pretty accurate on mixing it down to a weaker percentage of nitric with distilled water.

GSP you may have posted that link before somewhere but at that time I may have not been ready with a process in mind so I could not think it through. Somehow I am starting to notice how forgetfull I am becoming. Is that a sign of aging or a dissease asscociated with aging? :|

 

[goldsilverpro]

Somehow I am starting to notice how forgetfull I am becoming. Is that a sign of aging or a dissease asscociated with aging?

I've got it too. It's called CRS - Can't Remember Sh**

So, where is the chloride coming from and is the crust really silver chloride? Sounds very doubtful since I see no chlorides in the system. Are you diluting the nitric with distilled water before dissolving the silver? If not, it's very possibly copper nitrate (and maybe some silver nitrate) crystallizing. It looks like copper nitrate to me. At that strength of undiluted nitric, I would guess that it would take very little dissolved copper (and/or silver) to saturate it. See if the crust will dissolve by soaking it in some hot distilled water. When using the 95% acid to dissolve silver/copper, you should use about a 35/65, by volume, ratio of your 95% nitric to distilled water. That is about equivalent to a 50/50, by volume, solution of 70% nitric and distilled water. That is the most effective strength for this application and you will get no crystals forming.

If I were you, once you know the strength, I would add enough distilled water to reduce the strength of the nitric to about 70%. It would be a lot safer to store and handle that way. Also, I know of no refining application requiring anything stronger than 70%.

 

[Barren Realms 007]

I've got it too. It's called CRS - Can't Remember Sh**

So, where is the chloride coming from and is the crust really silver chloride? Sounds very doubtful since I see no chlorides in the system. Are you diluting the nitric with distilled water before dissolving the silver? If not, it's very possibly copper nitrate crystallizing. That's sort of what it looks like to me. See if the crust will dissolve by soaking it in hot water. When using the 95% acid to dissolve silver/copper, you should use about a 35/65, by volume, ratio of your 95% nitric to distilled water. That is about equivalent to a 50/50, by volume, solution of 70% nitric and distilled water. That is the most effective strength for this application and you will get no crystals forming.

If I were you, once you know the strength, I would add enough distilled water to reduce the strength of the nitric to about 70%. It would be a lot safer to store and handle that way. Also, I know of no refining application requiring anything stronger than 70%.

If he is using Hi-yield nitrate of soada it tends to have some chloride in it and this could be causing his problem.

 

[goldsilverpro]

If he is using Hi-yield nitrate of soada it tends to have some chloride in it and this could be causing his problem.

Very possible, Barren. I didn't think of that. However, the color sure looks like copper nitrate. Maybe a mix of copper nitrate and AgCl.

 

[adam_mizer]

Thanks alot GSP, I have mixed up some nitric solution and will keep working on this bar and the small 34gm bar I added.
Earlier I already flaked the crust off the bar and put it back into the beaker with the other bar, thinking I did not use enough distilled and have a over pregnant solution.
Added more nitric mix mix now, will wait and see and work on these 2 bars for a while.

88gm 94% silver + 6% other metal.
So it looks like I should of had approximately 240ml of 35% nitric solution in here.

 

[Barren Realms 007]

If he is using Hi-yield nitrate of soada it tends to have some chloride in it and this could be causing his problem.

Very possible, Barren. I didn't think of that. However, the color sure looks like copper nitrate. Maybe a mix of copper nitrate and AgCl.

Yes I agree it does, it looks like the mix you described plus possibly some cemented silver on the bar.

adam_mizer

Thanks alot GSP, I have mixed up some nitric solution and will keep working on this bar and the small 34gm bar I added.
Earlier I already flaked the crust off the bar and put it back into the beaker with the other bar, thinking I did not use enough distilled and have a over pregnant solution.
Added more nitric mix mix now, will wait and see and work on these 2 bars for a while.

88gm 94% silver + 6% other metal.
So it looks like I should of had approximately 240ml of 35% nitric solution in here.
Thanks alot GSP, I have mixed up some nitric solution and will keep working on this bar and the small 34gm bar I added.
Earlier I already flaked the crust off the bar and put it back into the beaker with the other bar, thinking I did not use enough distilled and have a over pregnant solution.
Added more nitric mix mix now, will wait and see and work on these 2 bars for a while.

88gm 94% silver + 6% other metal.
So it looks like I should of had approximately 240ml of 35% nitric solution in here.

It would help if your bar was in shot so the nitric could work on it better. Also if you put it on heat on a vigirous boil with a top on your container it will help. Keep a check on your solution and add distilled water if you loose over 1/3 of your solution. If you get to a point that your silver is not dissolving any more change your solution and wash the silver with distilled water till you have removed most of the silver chloride and then add a new batch of your nitric solution and continue down your road.

Remember Hi-Yield Nitrate of Soda has chlorides in it so if you try to use it to make poor man's nitric also to remove base metal's you will have a good chance of putting some of your gold in solution.

 

[goldsilverpro]

88gm 94% silver + 6% other metal.
So it looks like I should of had approximately 240ml of 35% nitric solution in here.

That's what it figures out, assuming that you have exactly 95% to start with.

Also if you put it on heat on a vigirous boil with a top on your container it will help.

I assume you're saying this to help dislodge any AgCl that forms. I'm not a big fan of boiling solutions. I would keep it under the boiling point, were it me. I don't think boiling it would help much and it could boil over, especially if it starts working too vigorously on the silver. With a lot of heat, I would use at least a one liter beaker for 240 ml of acid solution and I would cover it with a watch glass (or an acid proof saucer). Everybody has a little different way of doing things, though. Whatever works.

 

[adam_mizer]

The solution appears to be working well now.
It was a matter of getting more liquid in with the metal, the mix was way over pregnant with metal.
Now it seems very much under control and I may have done a stupid thing adding a little of sterling to make it 100grams of metal. Why I had 100 in mind, I don't know.
After checking it and seeing that it was proceeding very well, 1 bar gone a tiny bit of the second bar, and now some little bit of the sterling necklaces that I wanted to get rid of. (Almost done).
Well I was thrilled with the reaction that I made3 another batch up and this time 214grams of contacts that may have PM variety.
Wow I'm really sticking it to myself to pull this off.

Also at the same time I tried a 6 gram piece of an unknown metal I purchased in a scrap deal. The 6 gram piece was done in aqua-regia (too-much) but okay it was just to see if anything was in there.
It appears a canary yellow powder has precipitated from a green solution. A stannous test and looks like some palladium.
I'm very new at this type of metal. Wonder if the green solution is nickel?

One more item(s) is also near ready to process in the yellow container are honeycombs that are ready.

Maybe finally I will slowly get aquainted with metals other than gold/silver/copper etc...

Thanks to this forum once more for help, you guys just seem to keep me interested and pushing along.
The posts are great but you have to do a little searching and the answers are all there within the posts.

 

[adam_mizer]

The last post was not my first palladium.
After playing with this stuff and the residuals from the batch of contacts, checking other posts and info pretty much tells me this yellow powder is the tungsten.
I have a lot of yellow powder in the residual contacts.
From the 214gm contacts there was 70gm of non-silver left-overs. Remainders can be broken easily in your fingers with plenty of yellow.

The silver was processed by chloride, HCl, NaoH, sugar, filtered/washed. The powdered metal is almost completely dried and I'll get a weight before its melted maybe.

Now I'm working on some cats.