so ; smb maximum hot

[steyr223]

Hey guys
did we ever come to an agreement
about smb and temperature

After white precipitates at bottom
(what Dr Poe had said )
I'm really confused
1rst maximum hot means as hot as you can get it
or only get it a maximum hot which is what temp?
And "if to hot as soon as the temp changes the drop
Will occur instantly . Why not just start near boil
Stir, add smb ,let temp drop
Anyway can someone put this in a non-geo chemist process
On the best way to use smb
thanx steyr223 (using phone. Wont let me scroll in post.

 

[nickvc]

Well I don't use SMB but in most precipitations it's advisable to do it with cold solutions as it avoids boil overs,as the reaction is exothermic i believe, and wasting the gas that produces the precipitation, I think that when using oxalic acid it has to be hot to work properly but I have never tried it so I might be mistaken. Harold has stated that he always used ice to cool his solutions and if it was good enough for him......

 

[Geo]

im sorry if i misunderstand, you said non-geo but i will reply anyway. :lol: using SMB should be done in a cold solution because SMB reacts with water and creates sulfur dioxide gas bubbles in the solution, its these bubbles of SO2 gas that causes the gold to come out of solution. the solution should be cold for a number of reasons but the main reason is heat will drive the SO2 gas out of solution before it has a chance to react to the gold. tiny bubbles of SO2 gas will collect gold particles to the outside of the bubble until the particles get large enough to settle. at the end of the reaction any left over particles that didn't settle will tend to rise with the bubbles to the surface and be deposited on the surface and held up by surface tension (floating gold powder). using an excess of SMB can have a somewhat opposite effect and at the end of the reaction, instead of bubbles rising will hold these finite particles suspended in solution. when this happens heat the solution to drive out the SO2 gas and the finely divided gold particles will settle slowly.

 

[steyr223]

Thanks.
That was quick
I guess since I don't have a mass spectrometer
I probably don't have to worry to much about
nano particles or nucleation theory

Geo I like the joke
I'm. Starting a new process this week
It will include gold plated boards hi yeild
Pins ,fingers cable type connectors(heavy. Plated)
All cleaned)
I've read in a few posts people like to process each
type separate
why
I'll try not to make iron chloride this time
thanks
By the Way I've recovered over a gram from the
iron chloride. It seems the strips of gold were
Thick enough to Peel off the microwave. Chips
Most had.not. been stripped away.

 

[Geo]

just keep the magnetic scrap separated from non-magnetic scrap as much as possible and process separately. working with ferric chloride isnt that much different from copper II chloride but there are some reasons for doing each in different vessels. the limits on AP are contamination by iron and nickle, even tin can be removed from solution and im working on an experiment to totally clear the solution and ill share that as soon as i work all the bugs out. ferric chloride cant be rejuvinated the way AP can and the only way to get more action from it is to add more hcl thus making more waste. magnetic scrap in my opinion makes up a small percentage of electronic scrap and ferric chloride is the way to go when processing it because it dissolves the iron based metal faster.

 

[Dr. Poe]

Hey guys
did we ever come to an agreement
about smb and temperature

After white precipitates at bottom
(what Dr Poe had said )
I'm really confused
1rst maximum hot means as hot as you can get it
or only get it a maximum hot which is what temp?
And "if to hot as soon as the temp changes the drop
Will occur instantly . Why not just start near boil
Stir, add smb ,let temp drop
Anyway can someone put this in a non-geo chemist process
On the best way to use smb
thanx steyr223 (using phone. Wont let me scroll in post.

We were both right. :mrgreen:
I came to the conclusion that concentrated solutions of gold reduced with SO2 or with sodium metabisulfite should be done within a vessel within an ice bath. Concerning 18 oz's per 4 liters he was right. However with dilute solutions (1-2 oz per 4 liters) One should use my method and preheat the solution first. Gold chloride merges with 4 waters of crystallization, any water added constitutes dilution. The real difference between methods was only concentration. Gold solutions don't increase in weight, but the increase shows up as an increase in volume.
Dr. Poe

 

[steyr223]

Thanks again
I need to get to work
So doc could you please elaborate
I don't speak for all but I would be on the
1-2 grams/4 litre side
4 waters? Do we want preheat when diluted
To help the exothermic process or are we doing
Something to make up for dilution
do we want gold.chloride to crystallize with
4 waters or not to? At what point does this happen
And the smb plays what part?

Sorry about the chemistry. Lessons!
thanks again

Steyr223. PS someone. Why can't I see the poster on my left anymore

 

[butcher]

Here is my view of the tree in the forest.

SMB sodium bisulfite, or sodium sulfite will need water to make SO2 gas.
Temperature does play a role in how fast a gas will escape, or how much gas a solution will hold, (different types of gases and solutions these parameters differ).

(Dilution also helps me to rid silver in prior steps).

Personally I do not worry much about the temperature of my solution when using SMB to precipitate gold from my dilute solution, (as long as it is not terribly cold or very hot) in cold winter out doors I may warm solution, if solution is fairly pure and clean I see no need to be too concerned with certain temperature (time, seems the difference in my mind, unless solution has other problems).

Stirring well (keeping gas bubbles mixing with gold in solution), and some warming can help as gases rising helps the chemical reaction to complete, not necessary but very helpful.

Also some times I may need to heat, or even boil a solution to help a reaction (usually with dirty solution, colloids, or other problem getting a precipitation to occur).

Harold speaks of using highly concentrated gold solutions and using SO2 gas to precipitate gold from these solutions, (the chemical reaction generates heat that can give him trouble), here He speaks of adding Ice to cool this solution, to help him in his process.

I may not have the best view of this tree in the forest; it’s just how I see it.
(I do not see need to over analyze the process here).

 

[philddreamer]

"(I do not see need to over analyze the process here)."

I agree with you Butcher.

They way I learned almost 2 year ago, after reading the information that has been safely & simply explained in this great forum, as long as there's no excess of nitric or chlorine, I get a precipitate at ambient temperature. I use some cold water to dilute or ice in the summer.
I tried once to precipitate after filtering the hot solution & the SMB fizzled on top of the solution & very little gold precipitated. I added some ice, & tried it a few minutes later after cooling the solution & the gold dropped instantly.
The pic is of my last "drop"; early one morning,
1) I filtered my solution;
2) added 2x water;
3) then added dry SMB.
As soon as the SMB hit the bottom, the gold started to precipitate & the brown "cloud" started rising. A few seconds after snapping the pic & stirred & allowed 30 min.; solution stannous tested negative for gold.
It can't get any simpler than that. Just my 2 centavos...

Thank you Gold Refining Forum! 8)

Phil

 

[TXWolfie]

The question I was going to ask was does or did anyone ever try to take a temp reading of the liquid while dropping in SMB without using ice. I am just curious on how hot the liquid actually gets. I was always under the assumption the ice was used to drop the temp of the solution to stop it from breaking the cylinder cause it gave so much heat. But now after reading these posts it has come to my realization thats its mainly alot to do with dropping of the gold and how it affects it.

Rich

 

[steyr223]

Thanks butcher and phil and of course Geo
surprised. Harold didn't .....

From my perspective you guys are my holke
So your words are Biblical.
But then sometimes even the greatest minds
Overlook the simplest solutions
(Something about a 9th planet comes to mind)


And yes smb at room temp has worked for me
If I get 18oz ill take docs advise
Thanks again. Steyr223

 

[Harold_V]

The question I was going to ask was does or did anyone ever try to take a temp reading of the liquid while dropping in SMB without using ice. I am just curious on how hot the liquid actually gets. I was always under the assumption the ice was used to drop the temp of the solution to stop it from breaking the cylinder cause it gave so much heat. But now after reading these posts it has come to my realization thats its mainly alot to do with dropping of the gold and how it affects it.

Rich

The use of ice is dictated by the level of concentration. If you have but an ounce in a liter, no cooling is required, even with ambient temperature water in summer heat.

There's no better way for any of the readers to gain an understanding of the results of hot water when precipitating than to emulate the setup I used to use. I precipitated my re-refined gold in a cylinder, or a 4,000 ml beaker. Each held the same volume, the only difference being the cylinders were slightly smaller in diameter, and a little taller. I used a 3/8" glass tube that extended nearly to the bottom. When the SO2 gas was introduced to the solution, the bubbles were clearly evident, as was the fact that cold solution has a greater capability of absorbing the gas than does a hot solution. At first, bubbles didn't rise to the surface. They were absorbed so quickly that they were gone before they neared the top. As the solution warmed, that stopped happening. I had to slow the introduction, then a point would be reached where they were being partially expelled at the surface. All of this, of course, took place in the mouth of my fume hood, so the fumes were removed from the work space.

As precipitation proceeded, the temperature of the solution reached a point where vapors were being expelled. Way too hot to handle, and, keep in mind, three liters of small cubed ice was added to the cylinders prior to precipitation. Can't tell you what temperature was achieved, only that the solution got so hot that precipitation would cease, so there were many times when I'd have to add a little more ice to complete precipitation. It was this feature that dictated how large each refining batch should be.

In spite of anything you may have read about precipitating with SMB and heat being required, it is my opinion that it is not, and it is desirable that the solution NOT be hot, so it absorbs the SO2 instead of discharging to the atmosphere.


If you precipitate from solutions that contain less than three ounces/liter gold, you really have little with which to be concerned. It's doubtful you'd have any issues with heat.

Harold

 

[TXWolfie]

I must say Harold I do wish I lived on your block I would and could learn so much, I am one of those types that has difficulties learning from books needs the hands on learning. So as I read this and correct me if I am wrong. If I was to have say a solution with roughly 3 ounces of gold I would have to worry about heat and cold. But if I was to have 3grams it would have little to no effect. Also the cold solution absorbs SO2 bubbles as they rise to the top and the taller the container the longer SO2 bubbles stay in the solution to be absorbed. That is basically the information I gained from what you wrote.

Rich

 

[Harold_V]

I must say Harold I do wish I lived on your block I would and could learn so much, I am one of those types that has difficulties learning from books needs the hands on learning. So as I read this and correct me if I am wrong. If I was to have say a solution with roughly 3 ounces of gold I would have to worry about heat and cold.

It most likely would precipitate without issue. It may even get quite warm, but not so warm as to stop precipitation.

But if I was to have 3grams it would have little to no effect.

That as my experience, yes, and on many occasions. Icing was required only when concentration was excessive.

Also the cold solution absorbs SO2 bubbles as they rise to the top and the taller the container the longer SO2 bubbles stay in the solution to be absorbed. That is basically the information I gained from what you wrote.

Correct. With the iced solution, the bubbles were absorbed long before they reached the top. I had to be careful about the volume dispensed, because I used the gas directly from the bottle, with no regulator. A simple (chemical) valve was used, which permitted good regulation, however, so I'd adjust the valve such that the bubbles came out as individual bubbles, but fairly rapidly. As the solution heated, I'd have to cut back, so they came with less frequency and were slightly smaller in size, so they were better absorbed by the solution.

Bear in mind, I did this on a daily basis for years. There is no doubt in my mind---when precipitating with SO2, heat is not a requirement, and it can work against you. It would take something monumentally huge to change my mind on this subject.

Harold

 

[steyr223]

Thanks Harold
I've been waiting for your 3 cents
I'm curio's how tall would a beaker have to be
In order to drop all your gold with one bubble of
So2 or would that matter on the amount of gold
And I don't think Geo ever received an answer about
making so2 with items on hand so as not to directly. Add
Smb to solution

 

[Harold_V]

Unlike the educated guys on the forum, I'm unable to make a correlation between volume of gold in solution and the volume of SO2 gas required to precipitate a given quantity of gold. A single bubble may precipitate a small amount, but you likely understand that it takes more to recover anything beyond a trace.

The one thing I'd like to mention where SO2 is concerned is that it is very convenient to use. I had my bottle plumbed to the lab, so it was always turned on, ready for use. A small chemical valve equipped with a hose barb, located at the fume hood, allowed me to hook up and be precipitating within seconds.

For those who are serious about refining and are able to overcome the problems of buying or leasing a cylinder, I endorse its use heartily. It served me very well for many years.

Harold