Purple mud and solution

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Mountain Man
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Purple mud and solution

Post by Mountain Man » May 23rd, 2020, 4:26 pm

Hello everyone,

I have been putting what I learned over the last 6 months or so to work and I must thank you all again for your help. It has truly been an eye opening and confidence building epereince. It is nice to feel like I am really getting it now and it is all because of your willingness to share your time and wealth of knowledge and experience. I have been having much more success now. Thank you.

I have a question though. I have stopped using smb all together and use only copper powder. It was interesting in the beginning but now I am totally sold on it. All my solutions are now testing 0 for gold content after I recovered all the gold. It is fast, works awesome and easy to separate with nitric.

Anyway, I had something I have not seen before. When I drop the gold not always but sometimes I get a purple/brown mud. Very heavy. I let it settle and have been washing it over and over. It is removing the purple cloud but the mud still has a purple color and so far I don't seem to be getting anywhere. I do not think I am losing any of the gold mud, but there is this purple color that seems to be the actual color of the mud. It is something that just started happening recently although I do think it has shown up in the past but I did not know what to do with it so it is gone except I have 2 beakers that have a fair amount of it in each beaker.

Anyone know what it is or if it has gold mud mixed in with the purple or is it still the gold but purple?

jarlowski1
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Re: Purple mud and solution

Post by jarlowski1 » May 23rd, 2020, 6:21 pm

What was your feed stock?

Lino1406
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Re: Purple mud and solution

Post by Lino1406 » May 23rd, 2020, 10:35 pm

Test again with nitric - supposed to be copper

Mountain Man
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Re: Purple mud and solution

Post by Mountain Man » May 24th, 2020, 10:10 am

I have been trying a new to me technique where I use AR to strip the gold off of gold plated fittings, pins, top plates from cpus. Basically anything gold plated. I use low dose mixture of nitric and muriatic. That way it runs out of the nitric before it dissolves all the base metals. Twice now I have ended up with a heavy mud that has purple color to it. I use pure nitric to refine it like I do the others materials I process. When I add the nitric to other batches it immediately reacts and attacks all the base metals just as I would expect. When I do the same to the purple mud it has no reaction of any kind. After rinsing the material many times it still is purple mud. Not the solution but the mud. During the rinsing process there is some purple coloration in the rinse water that looks like salts but the end result after lots of rinsing is still purple mud.

Any idea's?

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FrugalRefiner
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Re: Purple mud and solution

Post by FrugalRefiner » May 24th, 2020, 10:51 am

I have two thoughts, but I don't know if either one is right.

Colloidal gold can be purple. Since it is metallic gold, nitric wouldn't react to it. AR would dissolve it.

Silver chloride can turn purple when exposed to light. It also wouldn't react to nitric. You can confirm/rule out silver chloride by exposing a small sample to strong sunlight. If it darkens/turns black it would be silver chloride.

Just guessing on both.

Dave
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Re: Purple mud and solution

Post by jarlowski1 » May 24th, 2020, 11:26 am

Just a suggestion why don't you make a sulfuric stripping cell for that material. Just a thought

Mountain Man
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Re: Purple mud and solution

Post by Mountain Man » May 24th, 2020, 12:22 pm

The sulfuric stripping cell is how I have been doing it since I got involved with gold recovery. However, I have not had good luck with it and I don't know why. It strips fine, but when it is time to smelt it has never worked. I must be missing a step or something. I used ammonia in the past to remove base metals but it did not do very well either in removing the base metals. I think the black powder was contaminated and possibly the gold was colloidal. I was considering doing that process again but I wanted to see if I could do it with AR.

I have heard mixed expectations with the sulfuric method. Anywhere from 3 grams per pound to 3 grams per ounce. I have not had very good luck with the process but I am certain it is something I am missing in the recovery phase although I am very detail oriented and can't seem to isolate why I can't get it into gold form again. Any thoughts?

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Re: Purple mud and solution

Post by Mountain Man » May 24th, 2020, 12:56 pm

As far as exposing it to strong sunlight, it has actually be sitting on the window sill of my gold production out building for several days and has been exposed to strong sunlight and it has had no effect on it. It still remains purple and is a very fine mud. Much finer than the gold powder when it is ready to smelt. If it is colloidal gold what do I do with it or can it be smelted the way it is?

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Re: Purple mud and solution

Post by jarlowski1 » May 24th, 2020, 1:01 pm

With any type of material you will certainly have different yields and especially if you are just mixing all different types of material versus what you may have read that individual could have been stripping just 1 type of material. The black slime after you are done with the batch should be separated from the sulphuric acid whether by means of letting it settle (will take a long time since sulphuric acid is viscous) or by diluting it with water and letting that settle out. Then you should refine this by AR or Hcl/Bleach and precipitate with your choice method. The precipitated powder should then be washed as per the outlined wash method on this forum (I believe Harold had a thread about this somewhere). Now if it were mine I would refine it once more but at this stage you could melt it and end up with 99.5 gold. Washing the powder is extremely important in order to obtain fine gold.

jarlowski1
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Re: Purple mud and solution

Post by jarlowski1 » May 24th, 2020, 1:06 pm

I probably would incinerate your powder and refine it from there. Incineration takes place with the powder being heated up to red hot but do not melt it, then let it cool back down and refine it with AR or Hcl/Bleach. You might also want to try precipitating with Smb on this refine. Anyone else agree on this course of action?

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Re: Purple mud and solution

Post by kurtak » May 24th, 2020, 2:12 pm

Hmmm - not exactly sure - but bases on your feedstock ((starting material) it sound like you are having a problem with stannic tin (not the same thing as the stannous chloride we use for testing gold in solution)

Lets see if we can solve the problem (&/or if I am right)

First - how much (gold) mud are we talking about ? --- just a couple/few grams - or 7 - 10 or more grams (doesn't need to be a "dry" weight - just a "guess" still wet - based on other drops you have done)

If its only 2 or 3 grams - re-dissolve it what AR - once re-dissolved - is the solution "a bit" cloudy &/or after letting sit for awhile for settling is there some whitish/yellowish sediment settling in the bottom of your beaker --- if its more then just a few grams - then first run this test with a few grams to see if (as I suspect) it's a stannic tin problem

Kurt

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Re: Purple mud and solution

Post by Mountain Man » May 27th, 2020, 1:11 pm

Sorry Guys. I have been away from my computer for a day or so.

Okay, I tried the nitric only on the purple powder and it did absolutely nothing. No reaction of any kind. I then washed the mud again and removed the nitric so I had a fresh start.

I then reintroduced it (the powder) back into a AR fresh solution. I immediately turned yellow and clear meaning no powders or anything. Just yellow. I did a Stanous test and it shows saturated with gold color. (Black and Purple in the test). I am now going to neutralize the solutions and drop with copper powder.

Does that sound like a right plan to follow?

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FrugalRefiner
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Re: Purple mud and solution

Post by FrugalRefiner » May 27th, 2020, 3:20 pm

Mountain Man wrote:
May 27th, 2020, 1:11 pm
I am now going to neutralize the solutions and drop with copper powder.

Does that sound like a right plan to follow?
What do you mean by "neutralize the solutions"? There is no need to neutralize AR prior to dropping the gold.

Dave
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Re: Purple mud and solution

Post by kurtak » May 28th, 2020, 9:59 am

I am going neutralize the solution and drop with copper powder
I hope you did not just go forward with that plan (in other words hope you are waiting for advice

First - as Dave said - "what do you mean by neutralize" ? --- please explain what/how you intend to do this

Second - are you "absolutely" sure the solution is clear

A solution can "look" clear under normal lighting

Stannic tin can be VERY ultra fine - so it may or NOT settle (meaning you may not see any of it settle) &/or it may take a day or more for "some" to settle

In other words - depending on how there is - it (some) may - or not settle --- & as well - depending on how much there may be - you may - or not see it as a cloudy solution - under normal lighting

In order to make sure the solution is truly clear you want to shine a light through the beaker from the side of the beaker - then look through the solution/beaker from the front moving your head back & forth side to side (in other words different angles) to see if it shows even a "bit" of cloudy

Stannic tin is/can be a real problem for a refiner & it only takes a VERY small amount to be a problem - & a problem that will continue to follow you when you drop your gold unless (once you determine you have it) you deal with it to get rid of it --- & its not easy - but can be done
This may - or not be a stannic tin problem - we need to figure this out because you should not be getting a "purple mud" with your gold drop - even with copper

So don't get in a hurry - lets figure this out

Kurt

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