# Precipitation for newbs



## Jmk88 (Apr 23, 2020)

Dear All,

Firstly... ever throw away filter papers for your gold chloride... 

I got 4.8 grams from 6 batches of refined karat.

Second....for all newbies... there is nothing more disappointing than going to precipitate and that penny drops that you’ve messed it all up when nothing but a cloud of S02 comes your way....

Please see this link. Use option one/a. 

http://www.freepatentsonline.com/3856507.html

I find hydroxide mixed at a far less ratio than they say here to be fine... I use 30 grams per 150ml of distilled water. This raises the ph to around 3 which is what you need for precipitation to occur efficiently. I use this per 500ml of aqua Regia.

As long as you haven’t used a ridiculous amount of excess nitric, it should also kill what’s left. If you are careful with your nitric additions it will

Hope this helped.


----------



## g_axelsson (Apr 23, 2020)

No, sodium hydroxide doesn't remove nitric acid, it changes the pH.

If you have excessive nitric it will create a problem for you and SMB doesn't work if the pH is too high. I've precipitated gold from full strength HCl without problem other than the SMB turns into gas really fast. The only time I had problem with SMB was when I had too high pH, the gold came right out when I added HCl.

Patents doesn't have to be correct to be granted, it just have to be somewhat novel. It's also a lawyer describing an industrial process in legaleese so it doesn't make for easy to follow instructions. It is written to block competition from doing something people have done for ages.

Yeah, my view of patents doesn't smell of roses.... :twisted: 

Look, if you add lye to nitric acid you neutralize the acid but are left with nitrates in solution. You now have sodium nitrate in solution. If you add acid to that mixture you will form nitric acid again from the nitrates. That's the base (pun not intended) of making poor mans aqua regia.

That's why I always gets upset when people talking about neutralize the nitric acid instead of using the correct word that would be "destroy", "remove", "eliminate", "denox".... Neutralize brings thought to neutralize an acid and the ignorant to add baking powder, sodium hydroxide or other bases to their gold chloride and then we have to clean up the mess here at the forum.

Göran


----------



## Jmk88 (Apr 23, 2020)

Thanks Goran....

I too hate lawyers.... we call them solicitors here.... they solicit misery then profit from it.

Back to matters... I do not add lye as such in an aggressive way... I dribble a few millilitres at a time and stir then I check the ph with litmus. The second I get a 3 reading I stop. I never have an issue with salts.

Another thing I do do though, which I know you jedis discourage and I fully intend to stop doing, is I use a drop of adblue until i see no fizzing. I actually do this prior to the addition of lye.

But I struggled in my early days to achieve precipitation and have found my last few batches a lot better using this approach.


----------



## g_axelsson (Apr 23, 2020)

Adblue, I guess that's urea?

It works sometimes but if you have used poor mans aqua regia (ie nitrate salt + HCl) then it might not work. I've never used urea myself but I've seen people I admire using it, but only people that used nitric acid and knew what they were doing.

But, if it works for you I might learn something new from your experience.  
We are all (many of us at least...) here to share knowledge.

Göran


----------



## galenrog (Apr 23, 2020)

Adblue is a diesel exhaust treatment, which in most countries marketed, consists of about 35% urea, with the remainder being deionized or other purified water. Percentages differ a bit from place to place.

Time for more coffee.


----------



## Jmk88 (Apr 24, 2020)

Galenrog is correct regarding the adblue.

In terms of the hydroxide, I really do add a minimal amount. It’s a trickle, maybe 1-3 ml at a time, stir, check ph and target a 3 reading. I am told by my mentor that 2.8 is optimal. 

I have seen precipitation of copper, especially when I made the above button as it was from old dirty papers. However, as long as you maintain an acidic ph the hcl is still strong enough to re-dissolve it upon stirring. It’s visible for less than 10 seconds.

At this point I have added 1/20th of my solution volume in adblue which kills the nitric before raising the ph. Each time I have done this I have had precipitation immediately and I achieve it with a 1:1 ratio of sulfite to expected gold. 

I’m fairly open about my beginner mistakes and use of excess sulfite was a problem for me.


----------



## butcher (Apr 24, 2020)

Nitric acid and urea (or urea and water diesel exhaust treatment fluid), forms a salt of UreaNitrate.
urea will not remove nitric acid. but it will convert it to a nitrate salt...


https://en.wikipedia.org/wiki/Urea_nitrate

Sodium or potassium hydroxide will not remove nitric acid it converts it to a salt of sodium or potassium nitrate salt and water...
NaOH + HNO3 --> NaNO3 + HOH (H2O)

Hydroxides, alkalines, carbonates...also convert the acidic nature we need into the water, The Acids (hydrogen or hydronium ions) needed for several reasons, besides for De-Noxxing the solution and keeping base metals in solution during precipitation, or when it is needed to provide acid for some other reagent and its chemical reaction we are using in the process...) to water...

H+ + OH- --> HOH (H2O)

These will reform nitric acid in solution with any acid.
NO3 + H+ --> HNO3

So you have added chemicals that will not do the intended purpose and now have salts from those chemicals and reactions... Just more trash in with no work done...

PS I Would be careful about heating and evaporating the solution with Urea-nitrate it could be dangerous to do in glassware...

Both are useless for what you are trying to do and only add other complications...


You would be better off cementing your values out of this mess using copper and spend you time studying.


----------



## Jmk88 (Apr 25, 2020)

Thanks Butcher. 

I personally have never ever had an issue with salts but I distill my own nitric I don’t use poor ar. I produce pure and dilute. 

I use a minimal amount of base; I’m advised by a guy on you lots level that it is the “professional” way of raising your ph and if you know what you are doing you can apparently do this with ease without even litmus just by watching the solution. 

I obtain nearly pure gold with this method and therefore see no reason to cement. I only ever cement as a last resort myself. 

I will video this process this weekend as I have another dozen filter papers to process. I will video it all from the point when I have finished filtering my AR which is when this process starts.

Again, I do not neutralise anything at all. I merely raise my Ph to an optimal level which is 2.8 - 3.4 i am advised. The denox using this process should really take you less than 60 seconds.

The precipitation should also occur before you’ve even had a chance to scoop that second spoon of sulphite. 

As I say I will video and post this for anyone interested. I’m a bit manic trying to build my fume hood right now but will find time this weekend.


----------



## Jmk88 (Apr 25, 2020)

I’ve also seen so many discussions centred around why sulphite isn’t dropping gold which then evolves to discussions around temperature of solution which is a waste of everyone’s time.

The solution temp should always be similar to human comfort levels and there really is very little to say on that beyond that. I’ve seen pages of discussions regarding this.... then you have Poe saying crap like “it must be boiling”. Then newbies have the mess of what comes after boiling gold chloride plus potential losses.

I see no reason at all to boil anything after your nitric recovery. I never boil. So many reasons not to.

My point is the ph reading of your AR is important and I see a lot more discussion on temps than this.

You can skin a cat many ways, as you can manipulate Ph. I use hydroxide. A weaker base can be just as affective.


----------



## butcher (Apr 25, 2020)

Thanks Butcher.

I personally have never ever had an issue with salts but I distill my own nitric I don’t use poor ar. I produce pure and dilute.

You must not have understood a word I said, You do not know what salts do you? 

What does distilling nitric have to do with anything?

Basically all you have if you reacted metals and acids are salts of both...Salts are formed in many different chemical reactions, often the reagents we use are salts themselves when we recover or refine gold we are dealing with salts. all kinds of different salts... 

If you have never had an issue with salts then you have never had an issue in recovering or refining gold or any other metal.

I see no benefit in raising pH.

Yes, I can skin wildcats in many different ways, but the best cat hides are always done in specific ways. and processing it with Hydroxide only makes cat leather, the caustic de-furs the hide, and you no longer have a decent cat hide, but I thought we were discussing refining, not de-furring wild cats.


----------



## Jmk88 (Apr 25, 2020)

I have not had an issue with salts in the context of the discussion; via denoxing using adblue. I have had salts in my recovery process, sulphate salts due to my cold nitric....

I’ve had lead salts drop out of my AR following sulphuric additions. I have dealt with salts many times.

However not in my process I have described. If I do I will post what I experienced. 

Back to the base... unless you were to bring the Ph above 4 which starts to enter neutral zones, precipitation only requires an acidic solution. I have never neutralised my pregnant solution and I use soda to deal with waste. You can use distilled water to manipulate ph. I just prefer base. It’s quicker and keeps your volume down.


----------



## Jmk88 (Apr 25, 2020)

And also. I can’t see why you would even need to add heat following the adblue. I certainly have never. 

This would be pointless. Once you have dropped gold and tested your solution with stannous, at this point it can be regarded as waste and treated accordingly.

You may even have some base left over to do so.


----------



## butcher (Apr 25, 2020)

Many metal salts are water-soluble including gold salts, most all of your solutions are dealing with salts in solution... 

You may not see the salts that you get when you add urea to a solution, the explosive salt of urea nitrate is pretty soluble in solution...

What Benefit is there from raising pH? Why.

Why do you believe urea does any good?

II guess I am just wasting my time in this discussion,

Heck lets just dump some carbamide and caustic in there and see if we can get something, anything that might be gold... If that does not work we can always dump in more chemicals its bound to come out sooner or later?



Fell like I am bagging my head against a concrete wall here, I think I go back up in the mountains, I found a nice section of the ancient river bed on top of a mountain close by too here, after running some of the concreted conglomerates through the ball mill and panning the first pan full had four flakes of gold, nothing exciting but better than beating my head up against this wall.


----------



## Jmk88 (Apr 25, 2020)

Ok...

So the reason I would do it... is to achieve optimal conditions and therefor outcome. Why would you not if it doesn’t ruin your process and takes you all of 5 minutes? 

Why would I ignore someone that I’ve watched for two years produce the best quality gold in London? 

Hoke even discusses urea. I hope in the not too distant future my ability to be able to use my experience with nitric additions to avoid it. 

The bottom line is it works. And it works well. 

Why would I cement everything over days and start over again? That doesn’t make sense when I can use the above method and get nearly pure gold. It’s a waste of time and materials and doesn’t produce you nearly pure gold. You then need to clean, re dissolve, and precipitate which if you aren’t experienced with you’re not going to be able to do the above with excess nitric.

Evaporation is not something for beginners either.


----------



## anachronism (Apr 25, 2020)

Raising the pH of Ar to around 2.8 (meter reading of 2.5 if I recall correctly) makes the SMB more selective for gold. I've tried it, it works and I mentioned it a few years ago on here. 

Edit: It's important to note that I mean denoxxed AR and I don't use Urea. 

That given It's not something I do as a rule because I can clean my gold well enough to avoid this step. 

It takes one heck of a lot of base to raise a pH 1 solution to pH 2. That I know from pH balancing for Formate precipitation of Pd.


----------



## g_axelsson (Apr 25, 2020)

Jmk88 said:


> I will video this process this weekend as I have another dozen filter papers to process. I will video it all from the point when I have finished filtering my AR which is when this process starts.





> As I say I will video and post this for anyone interested. I’m a bit manic trying to build my fume hood right now but will find time this weekend.



I'm looking forward to that. Good luck with your build.

In certain situations urea will work, no doubt about it, but in other it won't. Evaporation to drive off excess nitric will always work. This might explain the negative stance we usually take to urea.
It's easier to help newbies with easy and proven methods that never fail than adding more chemicals to an unknown mixture.
It is also another chemical to get for the newbie, but evaporation doesn't require any additional chemicals. Another win for the first time user.
Another advantage with evaporation is that it shrinks the volume of the liquid, adding base will increase the volume you need to keep all the salts in solution.

For a professional setting using other chemicals and methods makes sense if you factor in time, space in the lab, throughput and so on... that leads to other choices of methods. Also if you aim for pure gold that goes into alloying or just 99% because your buyer pays on assay and will refine it with other gold in a larger batch will also affect your choices.

Personally I've never used urea, sometimes I use sulfamic acid, sometimes I evaporate. But I try to conserve nitric acid so most times I go straight to precipitate the gold with SMB. The only time I've had problem was when I did evaporate and used water in the final dilution. I had to add HCl and the gold came back in seconds.

I've said it several times before, bur this summer I hope I will get my lab up and running. I got two fume hoods, a place to put them and several fans. If the Covid-19 situation doesn't change drastically I'll also have the time to put everything together. Then I will be able to shoot some videos showing some of the methods we are talking about here.
One fun experiment would be to do a comparison between dropping gold at different pH but everything else the same. I'll put it on the list.

Göran


----------



## Jmk88 (Apr 25, 2020)

Thanks Goran. I have the fans and have built the bottom section of my cupboard. 

I’ve connected it to a plastic container with a mister fixed to the underside of the lid with an outlet 300mm from the bottom. 

I have only needed to add roughly 20ml of base at the most. Having done a fair amount of research, I suspect if the test was done by someone like yourself there would be little to no difference as you would not make the error of excess nitric.

Sulfamic acid I’ve used but the amount you need is not the most economic which is why I was advised to use adblue.


----------



## kurtak (Apr 25, 2020)

Jmk88 said:


> I have seen precipitation of copper, especially when I made the above button as it was from old dirty papers.



What make you thing the copper contamination was because the button "was from old dirty papers" :?: 

I suspect it was the result of raising the Ph with hydroxide :!:

Kurt


----------



## kurtak (Apr 25, 2020)

Jmk88 said:


> Why would I cement everything over days and start over again? That doesn’t make sense when I can use the above method and get nearly pure gold. It’s a waste of time and materials and doesn’t produce you nearly pure gold. You then need to clean, re dissolve, and precipitate which if you aren’t experienced with you’re not going to be able to do the above with excess nitric.



You are SOOOO wrong about that

I have produced MANY ozt. of gold at no less then 990 & as high as 999 using nothing but copper - from VERY dirty solutions - there is "a bit" of a learning curve to controling the use of the copper - followed by the washing process - of which (the washing process) NEEDS to be done anyway

Copper has been my go to method for MANY years now with AR solutions that are VERY dirty & have LOTS of free nitric in them & can hit 995 - 997 (so near pure) most if not "all" the time

And it does NOT take days - I can go from dirty AR with free nitric - to a poured bar in a day or less

That means drop (with copper) let settle - decant - wash - dry - melt & pour to a (near pure - if not pure) bar in a day or less

Kurt


----------



## butcher (Apr 25, 2020)

iron will also start precipitating at the pH range of around 2.5 to pH 4...

Where are you getting this advice?.

Although you may be able to recover your gold from this mess, it is not good advice or practice, when there are much better and easier ways to precipitate gold from the solution...

Note urea is basically useless and will only complicate matters unless you do not overuse nitric in the first place, Urea will only deal with NOx gases in solution, but any free nitric in solution would make urea nitrate which would lead to many other issues or problems, in later steps, including safety.

There is no reason to add hydroxide or some other chemical alkaline like baking soda to raise PH, again you are just making things more complicated.

This is not the way to teach new members how to precipitate gold.
You would be better off teaching them how to recover the gold from that mess using copper.


----------



## jarlowski1 (Apr 25, 2020)

There should be a video section where members can upload material (I don't know if the forum has space for that or not). 1 video I certainly would like posted is the use of nitric acid and how to avoid using too much nitric in the first place. I believe that too many (especially newbies) people get impatient with the speed of a reaction and then just "throw" more nitric into the beaker just to speed up the reaction when that is not always the best thing to do.


----------



## butcher (Apr 25, 2020)

For many purposes, I do not understand why every new member thinks they have to use a sled-hammer like aqua regia (or using nitric) when most of the gold (even base metals for that matter) will go into a solution with a tack-hammer approach such as HCl and sodium hypochlorite (bleach).

When working with most of this the gold or other metals or alloys are finely divided ( placer gold, electronic scrap...) are fairly easily dissolved with their high surface area and the cupric chloride Copper II Chloride leach miss named the acid peroxide process) works well to dissolve copper and most base metals from much of the sources of electronic scrap to recover the gold, and the finely divided gold can easily be put into solution with HCl and chlorine gas making things much simpler...


----------



## Jmk88 (Apr 25, 2020)

“What make you thing the copper contamination was because the button "was from old dirty papers"

Because I filtered copper chloride through some of them.

I do not precipitate using hydroxide. I simply raise the ph. I would never start to cement before I had tried what I have described.

It created far more work than needed - its a last resort for me. I’m looking for the best outcome I can every time. I have never had any of the issues that have been identified in this post. 

I have thoroughly tested materials and reactions with various things and am very much aware of the oxides formed upon excess base. I’ve never had this.

Diluting hydroxide at 30g per 146 grams of water allows me to manipulate ph and keep solution volume down. It doesn’t get used to precipitate or enough to.


----------



## Jmk88 (Apr 25, 2020)

I have no adversity to using bleach either, which I do. That just wasn’t really the purpose of the post to begin with.

I find bleach more than effective however, when you have a lot of material it is not efficient and you can significantly increase volumes and need to evaporate. 

My first three refines were using bleach on recovered gold filled material which was fine.


----------



## butcher (Apr 25, 2020)

jarlowski1,

Many of our members have made some very good videos, they normally upload it in a post they made concerning the subject, several of these members have made many videos that will show the techniques they use in the lab (Streetips is one member that comes to mind you may enjoy his videos) but there are many.

Try this experiment in a small beaker (50ml) on a coffee cup warmer, or hot plate in a corning dish...
Add 1 gram of gold (powder, flakes, shot...).
Add 4ml HCl (little more would do no harm),(noting that one teaspoon of a solution is around 5ml).

Now we can expect to use up to 1ml of nitric to put the gold into solution,(noting about 20 drops of nitric is around 1ml) this in most cases would give us an excess of nitric acid which in some cases we may need to get the shot or larger pieces of gold into solution with a high loss of the nitric as gases evolving from solution.

Add HNO3 by few drops giving time for the reaction to slow.

Adding heat to warm the solution will help to drive off the water (water from the acids used and any produced in a chemical reaction), this will also help to consume the nitric used, increasing its ability to dissolve the gold, as it concentrates the solution.

{Here you can do some experimenting, try a stannous test (where you know you have some gold in solution), and after you add a few drops of nitric, Now with free nitric (the test would be negative as the gold cannot be reduced in the test). Now heat the solution a while letting the nitric getting consumed dissolving gold, with some gold still left undissolved after concentrating the solution take another reading with stannous chloride, with the free nitric consumed the test should show positive...}

Now remembering we only had a gram of gold in about a spoonful of aqua regia.

We can continue to periodically add drops along with using heat, until almost all of the gold is in solution.

We want to stop using nitric when we have a little gold left undissolved, with the heat we can normally finish consuming the gold and the free nitric...
At this point you may already have a concentrated gold chloride solution (almost red), if not concentrating the spoonful of liquid will most likely finish consuming the gold with just the heat of evaporation.

Using heat and a gold button to de-NOx a solution was Harold's trick, Here we are using the last portion of our undissolved gold to de-NOx the solution before we finish dissolving it...

With gold in solution and minimal nitric usage, add a few drops of HCl to the warmed concentrated solution, paying close attention to any red fumes of NOx, let it sit to evaporate the water from the few drops of acid you just added, and then try another few drops of HCl watching for the red cloud, after that water evaporates and the solution re -concentrates, after the third evaporation and HCl cycle, and no more indication of NOx evolution, you can take another stannous chloride test, (if free nitric the test may show negative for gold, or may show positive Purple of Cassius and then disappear to a negative for gold), (if the free nitric is consumed and the gold chloride solution is de-NOxed the test will show positive as the gold can now be reduced from solution using your choice of reducing agent...

Try a few different expieriments to gain a better understanding (and you can always scale up), but doing things in small experiments can teach you much, and not make such a big mess......
Do small experiments as Hoke taught in her book to get acquainted...
Do a few more experiments of your own, you can take some of the gold chloride solutions as a reagent to verify the effectiveness of your SnCl2.

Add some excess nitric to a sample of the gold chloride, do some other experiments with urea, sulfamic acid, different reducing agents...

In a spot plate test dish try testing the solutions with different reagents, for example, the Stannous chloride (will not de-NOx the solution your testing for gold) while in another spot of the dish copperas will de-Nox the solution as it tests for gold.
Using FeSO4 is helpful to precipitate where NOx gases or some free nitric is an issue, although SMB can overcome some NOx in the solution if the excess of reagent is used, it is not helpful where free nitric is involved...

You are only limited by your imagination and your test-tubes...


----------



## anachronism (Apr 25, 2020)

Butcher do you still really think it takes 1 ml of Nitric to put a gramme of gold powder into solution?

I'm using your analogy above not a dirty dissolve.


----------



## FrugalRefiner (Apr 25, 2020)

butcher said:


> Now we can expect to use up to 1ml of nitric to put the gold into solution,(noting about 20 drops of nitric is around 1ml) this in most cases would give us an excess of nitric acid which in some cases we may need to get the shot or larger pieces of gold into solution with a high loss of the nitric as gases evolving from solution.





anachronism said:


> Butcher do you still really think it takes 1 ml of Nitric to put a gramme of gold powder into solution?



Do you actually read his posts, or are you just so anxious to discredit what he writes that you have to say something?

Dave


----------



## anachronism (Apr 25, 2020)

I'm not anxious to discredit anything Dave. 

My point is that the old adage of 1 ml of Nitric to dissolve 1g of gold has been disproved therefore why even use it?


----------



## butcher (Apr 25, 2020)

Jon,
I find it takes as much nitric as it takes, every circumstance is different.


In general terms, or speaking in general then, yes it takes approximately 4 fl oz. (118,29ml) HCl: 1fl oz (29.57ml) HNO3 to dissolve an ounce of gold just as C.M. HoKe so eloquently proved.


Although just like gas whether you drive a big truck or a small economic car, the gas may take you further in one, then the other. One batch of gold is not necessarily the same as all others...

Much depends on the conditions but generally speaking this will get the job done and the gold dissolved, even under some of the more extreme cases (gold and PGM's...), will this be an excess of nitric? Yes for most circumstances, Can we and should we use much less HNO3 than this calculated amount? Yes, we should, and we can as we have discussed thousands and thousands of times.

So can I dissolve a gram of gold using less than 1ml of HNO3? Yes in most cases with much less nitric usage, but depending on many factors such as the physical size of the gold, the alloying of other metals with the gold (silver, PGM's...), temperatures, pressures, concentrations, for speed of reactions hours versus weeks or months, ability to contain the volatile gases in solution which are what is doing the work chemically, the chloride salts contents... The mileage will vary widely of how much nitric acid is actually needed or how much would be an excess...

It does not take large volumes of acids to put gold into solution, and there is no set amount of acid for a set amount of gold unless you controlled all other factors, and you only worked in a very tight window of conditions...

How much is a mute argument? it takes what it takes.
How much to expect is useful not only in our discussions but also in understanding and in our practical work...


----------



## Jmk88 (Apr 25, 2020)

I think for me personally evaporation is a difficult one. Especially for someone starting. As I’ve got more used to things I can tell by the colour change when I need to remover the heat and add hcl. 

However again, similar to cementing, I don’t see the value in this when what I initially explained can get you the desired outcome.

I’ve not had contaminating salts in with my gold and have filtered and melted straight after flushing with two litres of boiling water. 

My intention was to share something I use and find fairly simple that does indeed precipitate pure gold. That’s why I posted the pic as you can see even after the first refine it’s not bad at all.

Certainly pure enough to refine again straight into AR.


----------



## jarlowski1 (Apr 25, 2020)

Thanks Butcher for you time writing your post. I have been refining gold for the past 6 years (thanks to you and many others here). I have made mistakes before, but nothing that could be fixed with patience (set things aside and study). I don't make too make mistakes nowadays. What I meant as I seem to always fail to articulate what I am thinking is; we have a dedicated section where we can post videos on the basics. I feel that many people are impatient and their quick thinking is "Ok well I will just add more nitric" (or sodium hypochlorite if dissolving using that method) when all they would have to do is gently warm the solution and watch for the reaction. I feel a video with commentary might be able to show the newbies what they are supposed to be looking for. I do enjoy Sreetips videos as well as Owltechs (keep up the good work). Hope this clears up what I meant


----------



## Jmk88 (Apr 25, 2020)

I suspect Butcher the reason why they use nitric is they read Hoke and as advised follow. That’s why they use nitric over bleach.

However as someone who is experienced will know, recovery is where you do 80% of your work which a newbie rarely understands before losing gold, and coming to guys like you to clean up the mess. Like I have. Trying to use AR if it’s overly contaminated is not something a beginner wants to be dealing with in my opinion. 

They then go to dissolve the gold and have all sorts of problems as they have more base metals in than they should and therefor need more acids to do the job. I had a friend who ended up with 3 litres of crap from 3G of 18k gold. It was unbelievable. 

They then end up with excess nitric and precipitation won’t work. When I tried to pass on advice to my friend that I had received he wouldn’t listen and proceeded with evaporation. It was a sight to behold. 3 litres. He was doing it for weeks. Then he cemented and ended up with .4 grams after 3 months. It was painful.


----------



## Jmk88 (Apr 25, 2020)

Streetips is like the new age Hoke....

Or the Beethoven of refining.... such finesse, and grace. 

He makes it look like making toast.


----------



## butcher (Apr 25, 2020)

Jmk88,
You can get gold in the method you are describing, and you could get it to high quality.

Although adding urea, and hydroxide, large volumes acids and solutions, and ... It is just not what you should be working towards, or pointing our new members towards...
it is just basically trying to fix some other problem and getting into another...

Forget using Urea, it will not do what you think it will...
Forget adding caustic soda to your gold solutions...

Let's learn how not to create the problems if possible, and learn how to recognize a problem if it does rear its head, and have an understanding of how to troubleshoot and correct it,


----------



## anachronism (Apr 26, 2020)

Richard

In the context of your last post to me - we're not a million miles apart to be honest. We both agree it's down to the specific set of circumstances with the dissolving at hand. 

Where we disagree is that if you had 100g of gold powder to dissolve then simply assuming that it would take 100ml of Nitric and working according to that would be incorrect and leave a lot of excess.

That given I accept that putting the Nitric in in smaller stages would alleviate this to a large degree but people tend to blindly follow prescribed recipes no matter how many time we tell them otherwise.


----------



## fishaholic5 (Apr 26, 2020)

I've used Sodium Hydroxide to adjust pH for dropping Gold from Ore Leaches where it was hard to get a clean precipitation.
This is a pic from one of those precipitations during rinsing of the Gold.


It may not be necessary in the refining stages but it gave me a better precipitation and larger particle size when I was having trouble precipitating from some very dirty solutions.

Cheers Wal


----------



## Jmk88 (Apr 26, 2020)

Looks nice! That’s exactly the result I get; instant precipitation the second the sulphite touches the surface and then the solution is clear within 30 minutes.

The gold comes out like a beige brown and you just know you’ve hit the nail on the head.

Thanks for the post. I can only talk from experience and I have nothing but good results.


----------



## fishaholic5 (Apr 26, 2020)

My solutions from this ore are never clear after precipitation, mostly red or brownish from Cobalt and other metals still in solution. This was after rinsing several times with water.
I still use the same process with new ore samples for rough wet assay results where I have mixed metals and excess acid in a HCl/ Hypochlorite leach to save time.
The remaining solution gets cemented for PGM's using Copper

Cheers Wal


----------



## Jmk88 (Apr 26, 2020)

Nice.

I can’t see why there seems to be so much adversity to it!


----------



## fishaholic5 (Apr 26, 2020)

There are some very skilled refiners here whose focus is helping and educating people with the best, most effective and safest methods for recovery and refining.

As a refining process using Sodium Hydroxide to adjust pH for precipitation is not necessary or best practise but it works in your process and there is a place for it in mine.

They are just discussing things and putting forward better methods to help you and others.

Cheers Wal


----------



## kurtak (Apr 26, 2020)

Jmk88 said:


> “What make you thing the copper contamination was because the button "was from old dirty papers"
> 
> Because I filtered copper chloride through some of them.
> 
> I do not precipitate using hydroxide. I simply raise the ph.



You missed my point - you originally said your button was contaminated with copper because it came from dirty papers (in other words the AR had copper in it because the papers had copper in them - therefore when you precipitated the gold - copper also came down - because copper was in solution from the copper in the papers)

There is NO reason for copper to come down with your gold simply because copper is also in solution when you go to drop the gold - IN FACT - you can drop you gold - as near pure - if not pure --- by ADDING copper

That is why I followed up the question about the dirty papers with --- "I suspect it was the result of raising the Ph with hydroxide"

In other words - by raising the Ph of your AR to Ph 3 - you have made the acids that are keeping the metals in solution weaker (in this case the copper) - therefore - the weaker acid - that is having trouble holding the metals in solution - are going to be MORE likely to come down WITH the gold when you go to precipitate the gold

In other words - the acid is no longer strong enough to keep the more reactive metals (like copper) in solution when you go to drop your gold --- which is why you ended up with a button contaminated with copper - which is why you now need to re-refine the button

WEAK acids WILL cause base metals to come down with your gold - whether the acid is made weak by raising the Ph of the acid - or by "over" diluting the acid with water

You are doing both - you are adding urea that is dissolved in water (30% urea 70% water) and then adding hydroxide dissolved in water - so you are making the acid weaker with the hydroxide addition to a Ph of 3 - plus diluting the acid with water (the water may not be enough to make a difference - but raising the Ph certainly makes a difference)

The very reason you ended up with a button contaminated with copper - that needs re-refining - because it's not near pure

Let me put it this way - I have "cemented" MANY ozt from VERY dirty solutions with nothing but copper & turned out gold no less then 995 & as pure as 999

Last year when I spent a week in Jon's lab - I did a batch of ceramic CPUs (so VERY dirty solution) I showed Jon, Goran, Nick, & Pat how to drop the gold with copper - we were expecting 53 grams of gold from that batch & we hit the 53 grams on the nose & the gold came down right at 995 --- with nothing but copper & the batch was done from start to finish in a day - & for what it is worth the gold could have been brought up to 999 by putting a "pinch" of potassium nitrate in the melt of the powder (didn't do that)

Bottom line - & as Butcher has told you - adjusting Ph (up) is NOT a "better" way & is likely to cause problems --- especially with "dirty" solution

So I suggest you stop pushing this narrative that you have come up with a "better" way - when in FACT it's just not true - we try to teach "new" members "age old" methods that are tried & true - & NOT methods that can/will cause problems

Not saying your method wont work - but it "most certainly" has the potential to cause problems 

Bottom line --- there is NO need to add hydroxide to drop ALL your gold - & drop it "very" near pure - from VERY dirty solutions 

ALL of us - that have been doing this for MANY years - have been doing it with out the "need" to add hydroxide & we have OFTEN had to help new members clean up their mess - "because they added hydroxide 

So again - I suggest that you stop telling our new members to use a method - that we KNOW is going to get them into trouble - & then we have to fix their problem - because they followed your BAD advice

For new members following this thread --- you DO NOT need to add hydroxide to drop your gold - DO NOT follow this advice - it is bad advise that is likely to cause problems we will then need to fix - we spend a lot of time fixing problems without having to add another possible problem to what we do - there are better whys to deal with dirty solutions & or solutions with free nitric in them

In both those case's - cementing happens to be my go to method - it's not the only why but it is my way & yes you can hit near pure - if not pure gold --- there is "a bit" of a learning curve with using copper - which I have posted about several times here on the forum --- you will be better served following my advice to cement with copper (or other methods discussed) - then following this advise to add hydroxide

Kurt


----------



## Jmk88 (Apr 26, 2020)

Kurt,

Who said I had come up with a new way and who said I use hydroxide to drop my gold? 

Think I’ve clearly said the opposite mate quite a few times.


----------



## Jmk88 (Apr 26, 2020)

And for that matter... if you said to a professional refiner that you’re preferred method was to cement with copper, they would laugh you out of the room.

Fact.


----------



## kurtak (Apr 26, 2020)

Jmk88 said:


> Kurt,
> 
> Who said I had come up with a new way and who said I use hydroxide to drop my gold?



You did not say you are using hydroxide "to drop the gold" - nor did I suggest that is what you are doing

nor did ether one of us call it "a new way"

However - what you have "pushed" here - is that by raising the Ph with hydroxide you get a "better" result of droping the gold

And the FACT of the matter is that flat out is NOT true

Kurt


----------



## butcher (Apr 26, 2020)

I am not laughing, not even a chuckle, using copper as a reagent to precipitate gold from solution contaminated with base metals is just good common sense, any good refiner would have in his toolbox.

I would keep the copper in my toolbox, and dump the urea for fertilizer (urea really not that great of fertilizer either) ...


----------



## Jmk88 (Apr 26, 2020)

I’ve got the copper in my toolbox...

It’s used as a last resort. Like I said.... you said to a professional refiner that your preferred method was cementing on copper you wouldn’t be spoken to for very long.

If anything I think that’s bad advice to newbies that want to learn to do it professionally. 

Copper cementing is for mess ups and stock pots. No other refinery or gold chemistry book would advise you to do this. Why are you so obsessed with cementing on copper?


----------



## butcher (Apr 26, 2020)

fishaholic5,
I do not know how to say this?
I can understand when working with ore, there may be more of a reason to tweak around with the chemistry more, and can there be circumstances where adjusting pH, or using a carbon-based chemical reaction like carbamide, or some other reactions may be helpful or even almost necessary.

I would most likely have a whole different opinion and discussion if we were discussing recovery from ore or something else...

But not with precipitating gold for new members...

Jmk88,
Once you have done this as long as Kurt has, and spent as much hard work to learn his trade, and have gotten as skilled, then you will be able to answer that question and many more...


----------



## FrugalRefiner (Apr 26, 2020)

Guys, come on. Urea has been used by professional refiners for decades. Cementing with copper is also used by professional refiners. They're just two different methods. Saying that either method would get you laughed at by professional refiners is pointless. Some people prefer to drop gold with sulfite. Others prefer ferrous sulfate. Others may prefer oxalic acid, hydrazine, ascorbic acid, etc. Saying that one way is the right way and other ways are the wrong way doesn't help anyone. I'm here to learn from everyone.

Yes, we usually promote tried and true methods because even novice refiners can usually enjoy success with them. It doesn't mean we can't keep open minds to discuss other methods. If we didn't, we would never have learned to use sulfamic acid to deNOx AR.

Dave


----------



## Jmk88 (Apr 26, 2020)

I have no further comment.

Completely agree with Dave.


----------



## kurtak (Apr 26, 2020)

Jmk88 said:


> And for that matter... if you said to a professional refiner that you’re preferred method was to cement with copper, they would laugh you out of the room.
> 
> Fact.



That is NOT a fact --- in fact - 4metal - who is in fact - a "professional" refiner - is the one that taught me to cement gold with copper from VERY dirty solutions that also have free nitric in them 

Following "his" instructions on how to do it with results that achieve near pure - if not pure gold - is the very reason it has been my method for YEARS now

In other words Jmk88 - the method (cementing with copper) is NOT the method for "all" solutions - it's a method that works "well" for solutions that are DIRTY &/or have free nitric in them (sometimes "lots" of free nitric) --- & when done "right" you can/will achieve high purity gold

A (very) professional refiner did not laugh me out of the room - he taught me how to do it - & how to do it "right"

you should spend more time listening to & learning from "professional" refiners - instead of pushing a narrative of what you "think" works better

You "do not" need to use hydroxide to help drop your gold - & you will likely get a cleaner drop without the hydroxide

Kurt


----------



## kurtak (Apr 26, 2020)

Jmk88 said:


> Why are you so obsessed with cementing on copper?



Because it works - it works well & it works every time - especially with "dirty" solutions &/or that have free nitric & it gets ALL the gold

Kurt


----------



## butcher (Apr 26, 2020)

Using a metal, to use up the oxidizer (HNO3) in a solution that may have been added in excess, (and the metal we are adding to the solution is the same metal you already have in that solution) such as gold to de-NOx a solution, only makes good sense, you are not adding anything you do not have already in solution, you are not altering the chemistry to form salts or other impurities, you are not adding trash to get the gold out...

Using a metal like copper to recover or displace gold from a solution that already has base metals as well as copper in solution, again is just good common sense, the only portion of the added copper that will go into solution as copper ions are the amount it takes to consume the excess acids, at the same time providing electrons for the gold ions to form clusters of gold atoms large enough to precipitate from the solution, with copper ions as well as other base metals in solution the copper added just added a few more of what was already in the soup, we did not add any new trash, or salts... (drag down or the gold quality from this would most likely not change if you were to use a different reagent to precipitate the gold from this solution...).

Copper will not displace metals that are more reactive than it is or donate electrons to them...

Basically you are not adding trash to get gold out of the trash, you are just adding electrons and using the copper the same metal that is in solution already to provide electrons for the gold ions and form a bond with the chloride ions (the gold was once bonded to), to form a copper salt, only adding a little to the copper salts already in solution...

The more base metals making salts in solution the more reactions are occurring between them and the acids...

Carbamide (urea) will remove NOx gases (the different decomposition gases of nitric acid) from solution (de-NOxing the solution)...

But with nitric acid, it does not eliminate the nitric in solution but changes it to a salt, which can become a problem in later operations, it forms a salt of urea nitrate, a salt that reforms nitric acid with hydrogen or hydronium ions from acids...

Urea will remove the gases of the decomposition of the nitric acid, and any excess nitric acid in solution with the urea just converts into urea nitrate salts...
Urea is not removing the free nitric in solution it is just changing it to nitrate salts in solution (with the acids)...

Adding sodium hydroxide bonds with hydronium ions in solution to form water, and the sodium bonds with chlorides and or nitrates to form more salts, and as discussed raises the possibility of precipitating other base metals, or dragging them along...


----------



## kurtak (Apr 26, 2020)

butcher said:


> Using a metal, to use up the oxidizer (HNO3) in a solution that may have been added in excess, (and the metal we are adding to the solution is the same metal you already have in that solution) such as gold to de-NOx a solution, only makes good sense, you are not adding anything you do not have already in solution, you are not altering the chemistry to form salts or other impurities, you are not adding trash to get the gold out...
> 
> Using a metal like copper to recover or displace gold from a solution that already has base metals as well as copper in solution, again is just good common sense, the only portion of the added copper that will go into solution as copper ions are the amount it takes to consume the excess acids, at the same time providing electrons for the gold ions to form clusters of gold atoms large enough to precipitate from the solution, with copper ions as well as other base metals in solution the copper added just added a few more of what was already in the soup, we did not add any new trash, or salts... (drag down or the gold quality from this would most likely not change if you were to use a different reagent to precipitate the gold from this solution...).
> 
> ...



That is correct - which is why I like copper - for DIRTY solutions &/or solution with free nitric

With "clean" solutions (like dissolved foils or clean karat scrap) that may have free nitric - I put a gold button in (with heat - on the hot plate) until the free nitric is used up (no more reaction)

Then the ONLY other chemical needed to drop the gold is SMB

Kurt


----------



## g_axelsson (Apr 26, 2020)

kurtak said:


> Jmk88 said:
> 
> 
> > Why are you so obsessed with cementing on copper?
> ...


Not every time. :wink: My cyanide mess I made when visiting Jon, boiling in aqua regia for hours and precipitated with copper came back as a mess again. It did it with SMB, FeSO4 and ascorbic acid too. It took me ten times boiling in ammonia and decant to get it even to a point that it looked like dirty gold. When I melted it I ended up with a dirty gold button.

Every tool fails in some conditions. There is no perfect tool, but the professional collects enough tools to handle most situations and experience enough to judge when a certain tool is the best to use.

Göran


----------



## g_axelsson (Apr 26, 2020)

Jmk88 said:


> They then go to dissolve the gold and have all sorts of problems as they have more base metals in than they should and therefor need more acids to do the job. I had a friend who ended up with 3 litres of crap from 3G of 18k gold. It was unbelievable.
> 
> They then end up with excess nitric and precipitation won’t work. When I tried to pass on advice to my friend that I had received he wouldn’t listen and proceeded with evaporation. It was a sight to behold. 3 litres. He was doing it for weeks. Then he cemented and ended up with .4 grams after 3 months. It was painful.


And you think your friend that wouldn't listen and follow easy instructions would have fared any better if he tried to add NaOH to adjust the pH? If it takes him 3 liters of aqua regia to dissolve 3 grams of 18k gold then I would not hold any hope he would manage to adjust the pH to 4 without overshoot and precipitate the gold as a hydroxide.

And evaporation, that's not hard. Give me an old style coffee maker for a coffee pot and I can finish that in a day or two. There's a thermal switch that keeps it from getting too hot. A wide and low evaporating dish on top and it's fire and forget. Top it up every hour and if you forget about it the salts will dry out but not overheat. Just dissolve it in HCl again, and you are probably close enough to filter and drop your gold after you dissolved the crust. Anything not dissolved in HCl is probably not gold, but whipe it up and put it with the filters in the burn pile.

Gold(III) hydroxide can precipitate between pH 3 to 8. 


> ...pH range (8–3), which is most favorable for gold(III) hydroxide precipitation.


https://www.researchgate.net/publication/257541621_Properties_of_GoldIII_Hydroxide_and_AquahydroxogoldIII_Complexes_in_Aqueous_Solution

Evaporation is easy, there isn't a lot of ways you can mess it up. In contrast, adjusting pH takes some chemical knowledge, a light touch and patience. Three things few newbies have. That is why I wouldn't recommend this "adjust the pH method" to a newbie.

Göran


----------



## Jmk88 (Apr 27, 2020)

Thank you all as always.

Everything has been considered. As always.


----------



## butcher (Apr 27, 2020)

We all learn something every day, it keeps life interesting, and we are not just sitting around with a dead brain, but using it to discover lifes mystery and wonders. 

I have been learning these skills for several years, almost all of my old notebooks are useless, yes they have some very relevant information, but they were written as I was learning, so I would make notes on what I had learned at the time, years later I would learn much more, and the old notebook would need to be rewritten.

I find I have to always be updating notes or my thinking as I learn more.
as I learn more I also learn that what I learned in my youth may need to be revised..,
Like shedding old skin and growing a new one.


----------



## Jmk88 (Apr 27, 2020)

That’s what I always say to people when they ask why I’m so solitary.... I find it baffling how one can be interested in people when life has so much to offer. 

I’m always ahead of the curve... I’ve been social distancing since I was an early teen. 

Any links to Kurts method would be much appreciated.


----------



## kurtak (Apr 28, 2020)

Read ALL of this thread - it will get you STARTED on cementing with copper

:arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22203#p232016

Kurt


----------



## kurtak (Apr 28, 2020)

Also read this

:arrow: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=28635&p=302186&hilit=cementing#p302186

Kurt


----------



## Jmk88 (Apr 28, 2020)

Thanks Kurt,

Much appreciated. I will read now.

On a separate note, I told someone what I/we do today and there response was “yea... I love doing things like that. I make my own beer.”

I’m still mortified and that was 6 hours ago.


----------



## jarlowski1 (Apr 28, 2020)

Jmk88 said:


> Thanks Kurt,
> 
> Much appreciated. I will read now.
> 
> ...




Care to elaborate why you would be mortified.... Maybe this person enjoys science/chemistry.


----------



## FrugalRefiner (Apr 28, 2020)

I make my own beer when I have time too.

Dave


----------



## Jmk88 (Apr 28, 2020)

It’s not really comparing apples with apples though is it....

Is it good Dave?


----------



## jarlowski1 (Apr 28, 2020)

Ehh.. Not really comparing apples to apples but to someone who may not be so skilled in chemistry it may seem really cool and they get the added bonus of hopefully succeeding and tasting some really tasty beer. To each his own


----------



## FrugalRefiner (Apr 28, 2020)

Jmk88 said:


> Is it good Dave?



I've had a couple of batches that didn't turn out so well in the beginning, but for the most part it's very good.

Dave


----------



## Jmk88 (Apr 28, 2020)

I don’t drink but could be fun I suppose.

I’ll stick to the gold!


----------



## galenrog (Apr 28, 2020)

Beer = Grain+water+yeast+hops

Bread = Grain+water+yeast+salt

I prefer the latter, but to each their own. And I, too, have batches that do not work out well.

Time for more coffee.


----------



## JoeyJoystick (Apr 29, 2020)

Dear all,

Like many I came to this forum as a complete and total novice. You read a little and than a little more and than you're hooked. There are few places on the web where soo much knowledge is being shared by so many people whom have so much experience. On any subject may I add. I have come to admire and look up to this vast wealth of knowledge and experience, and the people whom represent this and make this possible. And many of the main players are professional refiners or semi-professional refiners who have years and years of experience doing what they are doing.

I applaud the warnings to the newbies who at occasions clearly have little idea what they are doing. The guidance being given to them to steer them in the right direction while at the same time keeping them safe. Fantastic!

But, where I come from , we say there is many roads that lead to Rome.

When someone walks into the forum and has some experience and gained knowledge from an experienced refiner as he claims than this may add something to what is already known. To shoot down somebody like this simply because he does not work the way you work is truly disgraceful. And this is done by some of the most respected members of the forum. To make matters worse they mention other members by name on a few occasions to give their own statements more force (a big thank you to these guys for staying out of this...)

Sorry guys, I am very disappointed by the lack of communication skills you have displayed. The inability to open your mind and the willingness to publicly try to shoot down someone who is just sharing something new and different. And, may I repeat, this is NOT a newby who doesn't know what he is talking about. Even though he may not be at the same level as yourselves.

I am kindly asking you to stop this. Please sit back and reread this thread in its entirety. And than give it some more thought keeping in mind the above.

I myself, for one, am very disappointed. I know the chances are low because people tend to be too proud to admit wrong, but I am hoping to see some kind of reconciliation the next time I look. Right now I am thinking that I may not even come back and look for this, but I know myself, I will be back once I have cooled down.

Some of you have fallen of the pedestal you were on. Please get your act together and get back on your pedestals where you belong and let me look up to you again.

Joey


----------



## Jmk88 (Apr 29, 2020)

Joey,

A fellow Joe.

I understand where you’re coming from.... I myself am Irish. We tend to say something between ourselves, argue, and then unite.

However, we are there for each other no matter what.

I for one, have never had a time where one of the senior members/jedis have failed to respond to my PMs. Even butcher when he is struggling with arthritic conditions he still takes time to write me txt that has taken a long time to do and probably has done in pain.

I would rather look stupid than be considered ignorant or obnoxious.

I think the discussions in this thread are testament to the respect people actually have for each other here.

And keep it in context... I think what they’re saying is some newbies do not have patience or finesse and could end up oxidising everything if not careful with my approach! Which I fully understand.

Either way, let’s continue the good work. You listen to these guys and you will go far.... that’s said from someone who has gone from nothing to Producing 99.99 purity based on these people’s advice.


----------



## Jmk88 (Apr 29, 2020)

Also for me.... I respect this in a way that I haven’t respected something before... it’s becoming my passion.... it’s beginning to challenge the female population as my number one passion....

My main thoughts always arise from that.... this isn’t something you should be doing for money or profit. You will not succeed at it and you’ll likely destroy your health and environment.... like lunatics frying mercury in their kitchens or poisoning their neighbours.

You need to respect everything about doing it along with yourself. This isn’t like brick laying or carpentry in the sense you can get there without having passion and respect, via using it as a means of money making. That doesn’t mean it can’t make very good money.

Compare it to a sportsman.... he never got to the elite league because he was a businessman. He got there through passion and dedication and lots of set backs. 

And the harsh reality is, although we can always have ideas and share those, you would be completely misguided to not take on board these comments, even when the tone can be slightly unfriendly. These people aren’t stupid.... if they identify the above is in you they will help you.

If they can see you’re here for a quick buck.... I suspect they do the opposite. 

And at the end of the day.... as long as you are safe you are at liberty to try what you please. No one other than you will lose sleep over lost gold... and believe me I’ve lost enough to lose sleep about.


----------



## butcher (Apr 29, 2020)

We are just trying to help each other, heck we all learn from each other...

I Like making my own, almost everything you name it.

I was sitting on the hill today looking over the spring woods, and thought about, having to revise what we learn and know, and how we do not know what we do not know (until later after we learn or experience more in life.

How as a kid if I only knew a small portion of what I do now, I could have done many small things that would make a big difference, like say take an ole ford truck water pump and the ole truck and make a pump, to pump spring water to the house and put in indoor plumbing, or when the crops needed to be watered for lack of rain, oh how a small bit of education or experience could have saved so much of that hard labor it took to survive...

I work hard to see where I may have to revise what I (think) know and understand, or look to find where I am wrong. Just like the notebooks of old that needs re-written, just about as much of learning more is also revising much of the old information we knew or understood...


----------



## JoeyJoystick (Apr 29, 2020)

Dear Butcher and Jmk88,

You can see from my writing that I was upset, I may even have overreacted. Admittedly I am a little emotional lately because life is rather tough at the moment. Reading your replies made me so happy that I am now writing this with tears in my eyes. Call me an emotional prick. I don't care. 

I am glad to see that you wrote what you wrote. It makes me happy. Very happy.

Most of you do know that this forum is extraordinary in the sense that there is a lot of information available. But there is really not many places on the internet where so many people try to help each other in a completely selfless manner. And it is this what makes this place so special. In todays world where most people care more about themselves and money, this is an extraordinary thing to have achieved. And I am glad to see that it is obviously still like that.

Again thanks for the response. I hope you guys are not mad. 

Joey


----------



## Jmk88 (Apr 29, 2020)

No not at all mad! I completely get where you we’re coming from. Like you say sometimes txt conversation can be a bit misleading as the body language and facial expression that normally deformalises the conversation to a degree.

And that’s what I think we’re all here for. To discuss and then reflect on the discussion which I think everyone sensible will always take things from, whether they publicly declare or not.

I hope things aren’t too tough at the moment. It’s a very strange time for everyone. The unknown always affects us and how we interpret information. 

Keep well Joey.


----------



## butcher (Apr 29, 2020)

This is a very difficult way to communicate with each other.

We cannot see so we are blind.

We are limited to our typing and the words we can muster.

Many members have to resort to translating, as many of us speak different languages, and have different customs in the way and sometimes say thing or even differ in the meanings of the words or phrases we use.

You cannot see a grin or wink or twinkle in the eyes or the wrinkles in the forehead, we cannot hear a tone or chuckle or growling or gritting of the teeth.

It is easy enough for us to misunderstand someone who you have full communication with, and difficult to be understanding totally of those you are blinded too and have very limited ability to communicate effectively with.

The forum members are a special breed and they work hard to overcome these problems...


----------



## Jmk88 (Apr 29, 2020)

Exactly that... and in consideration I think all do a fine job.


----------



## JoeyJoystick (Apr 29, 2020)

For the communication I know exactly what you're talking about. I've left my country 27 years ago. The last 15 years here in Thailand. My language learning abilities are not good so I do not speak Thai, which, yes, is a disgrace after 15 years. But the result is obviously that we all talk in English. Broken English or Tinglish as some call it here. And than on top of that you also get the cultural differences between people from different countries. And surely the difference between Asian cultures and western cultures is very big. But we should also not underestimate the difference between western cultures (or between Asian cultures for that matter). I am Dutch and I see you are from the US and Ireland. Here too we have some fairly noticeable differences between us.

Anyway, I have interrupted this thread enough as it is. So I will keep my mouth shut for the rest and keep on reading, ask questions and try to open my mouth about things I actually know something about.

See you around guys.

Joey


----------



## Martijn (Jun 26, 2020)

Friends, not sure if my question is in the right section, but since it's about precipitation, and i'm such a noob: :wink: 
I have experienced something new  : i was melting my buttons together and noticed triangular crystal patterns in the bottom side of the button, i suspected PGM's. 
Redissolving the buton slowly in AR(10 gr of gold in 50ml HCL and about 6 ml HNO3, in small addittions) the button almost dissolved in a closed erlenmyer flask overnight, leaving the reaction on low heat, +\- 50 C.
This morning, there was a small bit of gold left undissolved, and i found a light colored precipitation around the button. 
These were small buttons already refined in AR, so silver can be ruled out, since no AgCl formed during earlier AR baths. No lead fell out upon adding ad drop of sulfuric acid. So no lead present. 

Is my assumption correct that these are one or more PGM's that fell out onto the gold because of the reactivity series? 
If so, would a PGM stockpot be an idea to separate the PGM's from Auric Chloride in solution before going to the "regular" stockpot? a 'dirty' piece of gold contaminated with PGM's would refine itself eventually, leaving only PGM powders left? 
The cemented gold in the regular stockpot would then be almost free of PGM's?
Or am i mistaken and does this not apply to the most noble metals in the reactivity series? 
The last bit of undissolved gold will also have a bit of the same PGM's left, but much less compared to what the whole bath would have contained? 
Maybe someone has experienced this while using gold to consume the last bit of free nitric from the pregnant solution. 
Consuming all the nitric by adding enough gold would prevent redissolving of these powders back into solution if nitric is still present. 
I would like to hear your thoughts on this.
Martijn. 

The button almost dissolved and the powder laying in the middle after giving it a swirl. 
I will filter the powder before all the gold is dissolved and redissolve that in AR to test with stannous, should give a clear answer, if Pt or Pd is present. 
Martijn.


----------



## FrugalRefiner (Jun 26, 2020)

I wouldn't totally rule out AgCl. A bit of silver can sneak through AR, especially if the solution is concentrated and high in Cl-. Remember that Harold developed a washing procedure using ammonia to eliminate his because he always precipitated from very concentrated solutions. The easy way to test that will be to try an ammonia wash on the precipitate, followed promptly with addition of HCl to the solution after filtering any remaining precipitate.

If there is remaining precipitate following an ammonia wash, I would keep it separate and add to it any time you have a similar situation. Gather it till you have enough to make it worthwhile, then process it as a PGM concentrate.

Dave


----------



## Jmk88 (Jun 26, 2020)

I reckon Dave is right.

What was the original material it came from? Was that likely to have Pgm? 

If this is the second refine only it’s almost certain to have silver in my opinion. If I’m lazy with my recovery and don’t clean with lots of water before placing in AR I always get lots of silver chloride (I say lots, enough to see) the second refine if I’ve melted the dust from the first.

No matter how much I wash my first refine and incinerate between procedures I can never get my finish as nice as a second process. And I’ve never seen any on the third.

I reckon it’s silver chloride.


----------



## 4metals (Jun 26, 2020)

This has been hashed out here many times before but repeating it can’t hurt. Silver chloride is soluble in aqua regia. But not highly soluble. And solubility is a function of temperature. The colder the solution is before you filter it, the more of the silver chloride will become insoluble. If the solution is even moderately warm silver chloride dissolved in the solution will pass through the best filter paper because it is in solution. Chill it, and it becomes insoluble and the filtration will catch it. I tell refiners to add ice before filtering and that usually eliminates high silver in the final product. 

One of the pieces of equipment I advise refiners to acquire is an ice maker, they are often available used at auctions. A 5 gallon pail of aqua regia loaded with metal needs a gallon scoop of ice to do the deed.


----------



## goldenchild (Jun 26, 2020)

I don't know why hydroxide would be used in Au precipitation (especially in dirty solutions) but I _can_ speak on using urea. I also won't discourage anyone from trying/using it if they can make it work properly. That being said, I've used urea many many times. For me the key was keeping the solution cold. Adding ice to a crystal clear solution and then adding urea in small increments until there was no more reaction. I used urea in prill form and this worked in both dirty and clean solutions.

An observation I made is that you definitely don't want heat when using urea. I once, for one reason or another heated a solution that had the gold precipitated and contained urea. I either did it out of curiosity or to get the gold to clump up. Either way what happened was that AR was formed once more and digested the precipitated gold. This speaks to what others were saying throughout this thread about urea not eliminating nitric but just changing form. So theoretically you could use urea to actually denox. The same can be done with SMB but too much SMB creates other problems. But no need to denox if you use the urea properly. End rant.


----------



## Martijn (Jun 27, 2020)

Thanks guys. I think thats it. And 4metals, it's always good to repeat basic information like that. As much as i've read, the fine details of refining have to be witnessed to understand and remember. Practice makes perfect. At least for me. 
The silver must have come from the first button. It was my second one from some time ago when i did not cool with ice before filtering. So ruling out silver was my mistake. Ican remember another thread where someones button had the same triangle pattern. Palladium or platina was suggested as the culprit. Can silver cause that aswell? 
Anyway, cold filtering left a beautiful clear dark yellow juice. The silver chloride turned dark in the sun. Now to washing and maybe a third AR bath. SMB drop went by the book. (As far as I know)  

But theoretically: Can gold push out PGM'S like copper pushes out gold? Not that i have any....apparently. 

Martijn.


----------



## jamad46 (Jul 29, 2020)

I have been putting some CPU chips in a dilute nitric bath to get the gold foils off. That is working fine but I also get a lot of mud ( at least that what it looks like ). Should I include this mud in aqua regia or try to separate it from the foils? Thanks for any help.
The Newb


----------

