I’m Getting Worse/Dumber

[Ryno9000]

Hi guys!

I don’t know how, but I am getting worse results with better material and more knowledge. Since I’m posting this perhaps I have less knowledge
The process I use is HCL and hydrogen peroxide to dissolve the base metals as first stage. I have had success in simply melting the gold filtered from stage one and success refining further with AR and precipitating with SMB.
Attached pictures show my current solution which was high quality pins and pieces from old 1970’s/early 80’s servers and survey equipment. I had about 7 ounces after stage 1.
I now have a blue fluid which looks like what silver refining would look like, but the AR was only applied to gold material post base metal dissolving. Everything looked to be pure gold!
Any ideas on what happened? I am trying to cement part with copper which is producing a white/silver chloride looking precipitate and have set aside half of the solution to use SMB. Is that wise? Any help is appreciated, sorry I am so dumb.

 

[butcher]

It does look like a copper nitrate solution by the color.
I would check the HCl you used?

I wouldn't suspect silver from the pins but if involved it would take the chloride as it made silver chloride.
Do you get a milky solution of silver chloride if you add more HCl?

Did the gold dissolve, is there any gold flakes or black powders?

How did you make the aqua regia?

I do not have an answer only more questions.

 

[Ryno9000]

Thanks Butcher!
The hcl is just muriatic acid from Home Depot, not lab grade but it is what I have always used. the glassware was clean, and the nitric is lab grade from the science Company. everything did dissolve and I guess AR might be the wrong term since it wasn’t 3:1 But instead I added it slowly to the HCl solution with the gold because I’ve had problems in the past using unnecessary amounts of nitric.

There is a very fine white precipitate, not chunky, that has settled into the bottom of both containers overnight.

Is there a way that I can recover what seems to be the silver and then use SMB to try to recover what gold would be in the solution still? This is all very strange as my methodology has been the same and always hold a nice golden solution.

 

[pokermandown]

I am going to give you my $0.02 and then have the heavy weights (Knowledge wise, and quantity of gold refined) set me straight.

I work with a lot of material from old electronics from mid-1960 to 1980s. My guess is the blue is from Nickel not silver. The white powder when I get it is usually lead. For the old stuff, there is lead in the solder, so I often get a significant amount of white precipitate. I suspect that you did not leave the pins in the CaCl2 for long enough and you still had some metal in the pins. The really old stuff has much thicker gold plate and as a result, you need to either cause nicks or holes in the plate (I use my Blend-Tec) or leave them in the solution for much longer. I use the same HCL from Home Depot. It works well. I usually leave them in for 3-4 weeks agitating the material every day or two even though I keep a bubbler in the bucket. If I get impatient, I get a solution that looks like your pic or has more green in it (I think because of copper.) the quick solution for me is to just drop the gold and then re-refine it. The second time through, the colors of the solutions look the they way they should.

Keep going don't worry so much about the color, just test early and often with stannous.

 

[Ryno9000]

That is great input I appreciate it and I think is accurate. These were very thick plates pins, I must have got impatient. The question is can I still use SMB or what is the method to drop the gold from the blue solution with a bunch of nickel and lead in with it?

 

[anachronism]

Hi could you show us a picture of your stannous test result?

 

[kurtak]

The blue is MOST certainly copper - always - & the only metal that gives a blue solution - whether pure copper or copper alloy like brass or bronze - other metals in solution can cause the (copper) blue to shift to green

The milky white is likely NOT silver - it is more likely (stannic) tin &/or maybe lead

the stannic tin is likely from the pins being made of "bronze" - &/or solder that was not fully dissolved in step #1 (the AP/CuCl2 process)

Bronze is an alloy of copper & tin --- brass of an alloy of copper & zinc

So if the pins were bronze - & they were not FULLY dissolved in step #1 - then stannic tin was created when you dissolved the gold foils with AR that still had "some" of the bronze in with the foils (&/or if there was still "some" un-dissolved solder) --- Edit to add; - or if the dissolved tin from step #1 was not "completely" washed out before going to AR - which is next to impossable

the stannic tin is created by the nitric in the AR

stannic tin is a problem because it is VERY fine - so - it does not like to "completely" settle - also - because it is VERY fine it likes to go through filters - & if there is a lot of it - it likes to plug the filter--- in other words it is "difficult" to get it "all" out

Let the tin (stannic) settle for a couple days (most but not all will settle) then decant the mostly settled solution through a "Charman plug" filter (a VERY slow filtering process) then filter the settled tin through the same filter --- may take a couple days to filter

Kurt

 

[jarlowski1]

The blue is MOST certainly copper - always - & the only metal that gives a blue solution - whether pure copper or copper alloy like brass or bronze - other metals in solution can cause the (copper) blue to shift to green

The milky white is likely NOT silver - it is more likely (stannic) tin &/or maybe lead

the stannic tin is likely from the pins being made of "bronze" - &/or solder that was not fully dissolved in step #1 (the AP/CuCl2 process)

Bronze is an alloy of copper & tin --- brass of an alloy of copper & zinc

So if the pins were bronze - & they were not FULLY dissolved in step #1 - then stannic tin was created when you dissolved the gold foils with AR that still had "some" of the bronze in with the foils (&/or if there was still "some" un-dissolved solder) --- Edit to add; - or if the dissolved tin from step #1 was not "completely" washed out before going to AR - which is next to impossable

the stannic tin is created by the nitric in the AR

stannic tin is a problem because it is VERY fine - so - it does not like to "completely" settle - also - because it is VERY fine it likes to go through filters - & if there is a lot of it - it likes to plug the filter--- in other words it is "difficult" to get it "all" out

Let the tin (stannic) settle for a couple days (most but not all will settle) then decant the mostly settled solution through a "Charman plug" filter (a VERY slow filtering process) then filter the settled tin through the same filter --- may take a couple days to filter

Kurt

I agree with kurt. A "wick" filtering may also work although I have never had to use it for this purpose I thought I would suggest it and maybe someone can chime in. It can be a very effective method otherwise.

 

[Ryno9000]

Sincere thanks to all of the input and apologies to those who took time to respond without me providing what was requested. I wasted a LOT of SMB and time and energy and have a lot of waste material I don’t know what to do with. I came out with this, picture attached. I don’t know the official content but scratch test is telling me around 14k.
The process raised other questions based on temperature as I’m in Colorado and there was precipitate one day and then no precipitate/greenish solution another day when temperature dropped and we got snow, some of which went into the beaker...topic for another day

 

[butcher]

Follow up with the topic "Dealing with waste in the safety section, If you have questions just ask.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=1300