Need some chemistry help please

[Ragnor]

Today I got finally got my hands on some nitric acid. I had some mystery metal nuggets I wanted to dissolve to figure out they're content. So I dissolved them in the nitric acid. I was rather disappointed that after the reaction stopped I had very little material left over. So I decanted the reaction mixture. The liquid was almost a blue black solution. Midnight blue? I tried adding copper wire to the mixture to precipitate any silver. Problem is I did not know how much nitric to use and the mixture was still hot. It ate all the wire. The silver would cement out and then reabsorb. My bad. I'm learning.
So I consulted youtube. I found a video showing the precipitation of silver nitrate as silver hcl using muriatic. My brother wanted to see that, so I grabbed some hydrochloric I had stashed away and added that untill I detected an excess. Sure enough I got a nice white cloud of precipitate and a wonderful cloudy blue liquid.
So now I have some horrible mixture of hcl and nitric and copper and a white precipitate. But my brother is satisfied.
Now the video says the next step is to neutralize the mixture with sodium hydroxide to form silver oxide and then to turn it to a metallic state with sugar.

Now i know I screwed up dumping random amounts of acid together. I was all excited and got careless. I been waiting to dissolve this stuff forever. So that is where I am at.

My question is this. If I neutralize the mixture with lime is it going to drop the copper out also? Should I filter the solution before I neutralize it?

Also I have a fair bit of black slime from the first reaction that I decanted. This should be platinum slime , yes?

 

[kernels]

If you leave the solution for a few days, the silver chloride will settle on the bottom, you can then siphon the solution from the beaker carefully and then follow whichever process to convert the silver chloride to metallic silver.

Do you have any idea what the metal blobs were that you dissolved ? Was there any gold in there ? Platinum group metals ? If your blobs were basically silver based, then your leftover solution is pretty much copper based, which is toxic and would need to be treated appropriately before disposal. There is a thread around that details the waste treatment process quite clearly.

It's too late now, but it would have been much much easier to not overdo the Nitric acid, then simply cement the silver out onto some copper bar or pipe. You could also have tested for Silver in the solution by taking a small amount of the solution, and adding a drop of HCl to see if the white cloud formed.

 

[Ragnor]

The blobs I dissolved are from a hydrothermal vent. The area was an island arc formation that is now inland. The area now hosts a porphyry copper deposit with accessory gold veins. The mines listed are copper,silver,gold,lead nickle,platinum group elements in varying amounts.

The metal blobs from the old vent are scattered around the area. They seam to be primarily copper. Some appear to be fairly high in gold Others still are mostly lead. Some however are bright silver when they come out of the cracks.

It's a pretty cool deposit, if not a little weird.

Most of what I dissolved today were what appeared to be lower grade copper/silver.
I was hoping to see more gold after dissolving them, but these didn't leave much behind.

 

[Ragnor]

Also I would like to recover the copper from the solution. I just dipped a bit of aluminum foil in some of the blue solution expected it to exchange that for the copper, but nothing happened?

Aside from activated carbon, what are my options for recovering the copper from solution?

 

[kernels]

Often the problem with Aluminium is that it is too reactive, it forms a protective oxide layer very quickly. Simple iron (or mild steel) works fine to cement copper out of solution, the problem you will find is that the copper could be relatively impure since iron will cement all elements below it on the reactivity series.

Unfortunately I have zero experience with naturally occurring metal deposits, hopefully somebody with more experience will be able to advice you some more.

 

[kurtak]

Ragnor

First of all - how much of this metal(s) do you have &/or how much of it are you trying to dissolve at a time in your "testing" of these metal(s) --- &/or are you trying to dissolve metal(s) taken as different samples in one batch

I ask because it sounds like you are trying to dissolve larger amounts of metal then is necessary for "testing" &/or trying to dissolve multiple samples of differing character in the same test

Though I may be wrong - if this is what you are doing - you are going about your testing all wrong

First of all - nitric acid is NOT the cure all go to acid to answer your questions to an unknown metal as nitric reacts with some metals - does not react with some metals & creates a "mess" when it reacts with other metals

Sooo - you "don't" want to just go throwing a bunch of nitric at a large sample of metal until you know how the (unknown) metal is going to react to nitric

When testing (an unknown) metal you want to start with "small" samples - a gram is all you need "for testing"

other wise you are "wasting" acid only to find out that ether it is not the right acid &/or only to find out that that acid is going to create a BIG mess

Also - testing a small (1 gram) sample is going to tell you (once you have determined you are using the right acid) how much acid you need to dissolve a larger amount of the same metal - because when you do the test - you add the acid in small amounts (keeping track of the amount you add each time) until all the metal (that will dissolve) is dissolved - then you can do math to determine how much acid you need to dissolve a larger amount of the same metal - so you don't waste acid dissolving the larger amount of metal

I "highly" recommend you read Hokes book - she does a VERY good job explaining how to go about testing different metals &/or there alloys - it is written in easy to understand instructions

you can find it here at the bottom of FrugalRefiners first post in this thread :arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798#p201558

Now - concerning the silver chloride you have created - you do NOT want to just add sodium hydroxide to the solution that you already precipitated the silver chloride from --- that will precipitate "every other metal that was dissolve in the solution as a hydroxide of those other metals --- you will then have those metal hydroxides "mixed" in with your silver & you will have a BIG mess

You - FIRST - need to decant the solution off the silver chloride - AND - wash all the solution out - then make a solution of (dissolved) NaOH (sodium hydroxide) to add to the silver chloride to convert the silver chloride to silver oxide - then decant & wash the NaOH out - then dissolve corn syrup (not plain sugar) & add that to the silver oxide in order to convert the silver oxide to silver --- Note; - when working with silver you "need" to use distilled water - NOT tap water

Or - you can dissolve the silver oxide with nitric - then cement the silver with copper - thereby skipping the sugar (corn syrup) step - which is what I would do

There are other ways to go about converting the silver chloride to silver - but I am not going to go into all that

Lime will not convert the silver chloride - you need to use NaOH --- lime will drop metals out of solution like NaOH does except that it is slower in doing so & it drops them as carbonates rather then hydroxides

Aluminum is NOT the recommended metal for cementing metals from solutions - for one thing - aluminum does "not" react with nitric so (as kernels said) it won't even work in nitric solutions - copper is used for cementing PMs - then iron &/or zinc are preferred for cementing base metals from solutions --- aluminum will only work in a HCl solution but even then it is not the recommended choice

Zinc can be found as "scrap" (at any scrap yard) as "die cast" --- die cast is zinc &/or an alloy of zinc that is "high" in zinc - high enough in zinc to be used for cementing purposes

Finally - do NOT rely on getting good info about refining from You Tube - it is about the "worst" souce of info you can go to - although there are "some" good You Tube videos - they are far & few between - MOST of them fall FAR short of giving you the complete info needed to actually do this & many of them are flat out mis-information & the odds are using them as your source of info is going to do nothing but get you into trouble - which we then have to help you out of

To be blunt - most You Tube videos are nothing more then people seeking "their" 15 minute of fame on social media (look at me - see what I can do) they have NO interest in actually providing anything instructional

Start using this forum as your source of info (with doing research here) & ask your questions here - it will save you a lot of problems

Kurt