consolidation of Loss Gold thread

[4metals]

If the reaction is fairly violent then any piping and the end recipient vessel could have gold solution in them , have you tested them ? A simple stannous test will confirm if you have small amounts there or larger amounts that could be some of your loses.

This is absolutely true, every refining system will trap values in exhaust ductwork, good systems keep it to a minimum. But that is not something you can change while operating a system, it is something that is minimized by design.

The reason I asked for photo's of the front of the system is to see where your condenser is and where the fumes exit the reactor. The sooner the fumes hit the cold condenser the better it performs its job.

The Italian. made systems use glass condensers and they are located directly above the fume exit point and drip directly back into the reaction vessel. They do not condense into a duct and run back down hill to the reactor as that will do as Nick cautioned, trap values.

these are a few photos of the condenser and its location on the Italian system.

here you can see the relationship between the condenser and the reaction vessel.
and here on a larger system. on both systems the glass condenser is directly above the high end of the reactor. Minimal piping connecting all condensate to the reaction.

 

[nickvc]

4metals i hope you agree a step by step diagnosis of the processes should help us to help him find the areas of loses or possible ones .

 

[4metals]

Absolutely, this is why I am trying to
go through it slowly and systematically. Once we have a better idea, hopefully reinforced with photos, we can move on to the chemistry, which has room for improvement.

 

[4metals]

This is one of the smaller tumbler plants I have ever been involved with. This one has a capacity of about 6kg of karat scrap.

The reason I am showing these is because they all operate on the same principle as the plant we are discussing here, albeit from a different manufacturer. By seeing different systems we can gain a broader perspective.

Since this system is more compact it is easier to see the condenser and its location, and the filter under the reactor where the loaded solutions are filtered before being pumped to the precipitation tank. All very similar to the OP’s system.


View attachment 6AB52EED-2F28-4C20-B68B-5BC68002868B.MOV

 

[Gold.refinery]

At the earliest opportunity, I will prepare a bottle containing gold and AR to test the correctness of the stannous .

The photo shows the way of the fumes to the condenser.

 

[Elemental]

This is a simple piece of advice, but have you given any thought to running a known standard through your system? (This would be a control run.) Weigh and measure our XX grams of gold, silver, PGMs, copper, iron, rock, etc. and then conduct your process to recover the gold/silver/PGMs. If you have an accurate input, let's say 100 grams of gold as input, then you can run your system and you should recover near 100 grams of gold as output. If/when you don't, work your way back through your system testing/diagnosing where the gold is getting hung up in the process.

Elemental

 

[Gold.refinery]

According to previous information from the machine manufacturer, the volume of the Tumbler is 25 kg of scrap gold.
The volume of Tumblr is more than 200 liters.

 

[4metals]

According to previous information from the machine manufacturer, the volume of the Tumbler is 25 kg of scrap gold.
The volume of Tumblr is more than 200 liters.

I think there is some B.S. going on with the manufacturer. If the tumbler was 200+ liters you would have a capacity of refining 1500 ounces or 46+ kilo's per lot. Looking at the photos of your staff leaning on the system, that guy is either a giant, or the capacity of the vessel is 200 liters upright, but at the angle it rotates the volume is at least halved. But at 100 liters working capacity you have room for 20 kg of karat and room for the reaction to rise without risk of sucking values into the condenser.

The short length of duct connecting the tumbler vessel to the condenser is short and likely will not hold excessive quantities of dried solution. In addition The Hydrochloric acids and Nitric acids are added through that ducting as well. This will effectively rinse any condensate back towards the reactor vessel. Rinse water is also added through that pipe, I assume. This provides additional rinsing of the duct. The thin hose, I assume, connects to your dosing pump to add peroxide to the reaction.

I am reasonably confident that you are not losing values up the stack. I hope you can rinse sufficiently to clear all of the liquids out of the tumbler and into the Silver Chloride filter beneath. Most of the silver chlorides are fine particles and the lumps which are encrusted gold are much larger. One trick I have used is to make from a 5 gallon pail (remember refiners love 5 gallon pails) a holder for polypropylene mesh paint strainers which sits on top of your filter paper and keeps the larger chunks confined and easier to collect. These photo's should help you to make one.
Cut the bottom off a 5 gallon pail and make the half circle cuts so the solution flows out freely
add one of these paint strainers made to fit on a bucket

This prescreen sits on the filter, the fine silver chlorides and all of the solution goes through easily and quickly into the filter below and the larger chunks are trapped. They can be rinsed clean into the filter and allow you to quickly collect any insolubles.

A question about your silver chloride filter. How is the paper attached to the plate of the filter? Is it by suction or by a gasket inserted into a space between the plate and the vertical wall of the filter?

 

[4metals]

Providing you rinse all of the retained solution from your filter and properly drain or rinse clear the piping leading to the tank where you will drop your gold, you will have taken the necessary precautions to assure as much of the gld laden solution is where it belongs as possible. It would be wise to test a small bit of the last of the rinse waters falling into the with stannous chloride to be sure it is negative, meaning all of the solution with gold has been rinsed clear.

You can see you will be using a good quantity of rinse water. I suggest you do not add extra rinse water to the reactor before filtering. I would add a bag of ice cubes to cool the acid before filtering. This will lower the solubility of the silver chloride and allow more of it to be caught on the filter. The rinse waters used to assure all of the liquid holding gold should serve as the liquid you added to the vessel before filtration earlier.

Please provide a photograph of the tank you are using for the precipitation of the gold. And from here we can address the chemistry to drop the gold.

 

[Geo]

The last time we spoke about it, he had lowered the loss of gold to 9 grams total. The AgCl was collected from the same solution in one go. There is a high probability that the AgCl still contains metallic gold that was collected along with the AgCl, as he said there was a tan color in the AgCl solids. I tried to guide him to do an aqua regia wash of the AgCl but his concerns are the AgCl will dissolve in the AR and be carried away. He want's to convert the silver and cast it into anode bars and part them in a parting cell to recover the gold that way. When I was explaining to him that the parting route would take much longer than leaching in AR, that is the last time we communicated.

From the description as he described it to me, the gold could very easily be tied up in the AgCl. I can't think of any other tan powder it could be. I advised him to change the process to where he leaches the material in nitric acid to remove the silver, and any other metals nitric acid would remove, with nitric acid first before going to AR. I think there is a language barrier.

 

[Geo]

Make your gold standard at 1 gram per liter. You can dilute this solution several times to get differing quantities to test against. Just testing viability of stannous chloride is simply getting a positive test result. If you practice with differing concentrations, you will learn to judge quantities of metal in solution up to the point where the test instantly goes black.

 

[Lou]

This is wisdom from Geo.

Making a series of known concentration gold lets you ball park a variety of things. Even more useful than in refining is knowing how to do this quick and dirty educated guess work in recovery.

 

[4metals]

There seems to be more going on here than we all have been told. What I do know is Gold Refinery has a commercially made refining system which is capable of refining the karat material he is planning to process. But what he does not have is the knowledge to process the material and maximize his success. Nor does he have an ability to figure out where his losses were or how to end them.

Gold Refinery, you cannot expect half a dozen people to help you when you give everyone a different part of the story. The only way this can work is to keep all the information about successive lots and losses together lot by lot. Gold in Silver Chloride can be recovered, actually without much difficulty, and you were given those instructions on another thread.

You have a commercial refining system, an induction melt furnace, and some analytical capability in XRF or fire assay. And I am quite sure they came at considerable cost to you. But you cannot pull it all together if you can't focus and work this through. Nobody here on the forum will have any more or less gold tomorrow if this doesn't work out for you. You however, will have less gold. And, before long, start to question the wisdom of setting up a commercial venture without knowledge of the process.

You could spend a lot of capital paying someone to teach you what we are trying to teach you here for free. That little tip Geo gave you about standardizing your gold standards to get a better idea of the quantities of gold you are finding will be quite useful in bringing about the success of your operation. And he offered it freely. It's about time you open your eyes and start to respect what's being given to you here. And the only price you have to pay is describing your process so we can assist you better.

 

[4metals]

Thank you Geo.

Make your gold standard at 1 gram per liter. You can dilute this solution several times to get differing quantities to test against. Just testing viability of stannous chloride is simply getting a positive test result. If you practice with differing concentrations, you will learn to judge quantities of metal in solution up to the point where the test instantly goes black.

This takes stannous chloride testing to the next level, much more useful than the simple yes there is, or no there isn't, test. But it is also a technique which becomes a useful tool with practice.

This works most effectively if you make up your test solution the same every time. Consistency will matter especially at the lower detection limits of the solution.

This is how I prefer to make the solution.

2 grams stannous chloride crystals
1 gram of tin metal
40 ml of water
5 ml of hydrochloric acid

Store this in a small air tight dropping bottle (opaque if possible)

And remember if your first test of the day turns out negative, test the testing solution.

 

[Gold.refinery]

I think there is some B.S. going on with the manufacturer. If the tumbler was 200+ liters you would have a capacity of refining 1500 ounces or 46+ kilo's per lot. Looking at the photos of your staff leaning on the system, that guy is either a giant, or the capacity of the vessel is 200 liters upright, but at the angle it rotates the volume is at least halved. But at 100 liters working capacity you have room for 20 kg of karat and room for the reaction to rise without risk of sucking values into the condenser.

The short length of duct connecting the tumbler vessel to the condenser is short and likely will not hold excessive quantities of dried solution. In addition The Hydrochloric acids and Nitric acids are added through that ducting as well. This will effectively rinse any condensate back towards the reactor vessel. Rinse water is also added through that pipe, I assume. This provides additional rinsing of the duct. The thin hose, I assume, connects to your dosing pump to add peroxide to the reaction.

I am reasonably confident that you are not losing values up the stack. I hope you can rinse sufficiently to clear all of the liquids out of the tumbler and into the Silver Chloride filter beneath. Most of the silver chlorides are fine particles and the lumps which are encrusted gold are much larger. One trick I have used is to make from a 5 gallon pail (remember refiners love 5 gallon pails) a holder for polypropylene mesh paint strainers which sits on top of your filter paper and keeps the larger chunks confined and easier to collect. These photo's should help you to make one.
View attachment 50219Cut the bottom off a 5 gallon pail and make the half circle cuts so the solution flows out freely
View attachment 50220add one of these paint strainers made to fit on a bucket
View attachment 50221
This prescreen sits on the filter, the fine silver chlorides and all of the solution goes through easily and quickly into the filter below and the larger chunks are trapped. They can be rinsed clean into the filter and allow you to quickly collect any insolubles.

A question about your silver chloride filter. How is the paper attached to the plate of the filter? Is it by suction or by a gasket inserted into a space between the plate and the vertical wall of the filter?

You guessed it, acids are added from the same tube, but water is not added from there.
The silver chloride filter is a fabric. Polypropylene fabric.
It is fixed with a washer (large ring the size of a filter).

 

[Gold.refinery]

Providing you rinse all of the retained solution from your filter and properly drain or rinse clear the piping leading to the tank where you will drop your gold, you will have taken the necessary precautions to assure as much of the gld laden solution is where it belongs as possible. It would be wise to test a small bit of the last of the rinse waters falling into the with stannous chloride to be sure it is negative, meaning all of the solution with gold has been rinsed clear.

You can see you will be using a good quantity of rinse water. I suggest you do not add extra rinse water to the reactor before filtering. I would add a bag of ice cubes to cool the acid before filtering. This will lower the solubility of the silver chloride and allow more of it to be caught on the filter. The rinse waters used to assure all of the liquid holding gold should serve as the liquid you added to the vessel before filtration earlier.

Please provide a photograph of the tank you are using for the precipitation of the gold. And from here we can address the chemistry to drop the gold.

You said not to add extra water to the reactor before filtering, why?
Instead of adding ice, we have 2 Celsius water. And add some before filtering.

 

[Gold.refinery]

The last time we spoke about it, he had lowered the loss of gold to 9 grams total. The AgCl was collected from the same solution in one go. There is a high probability that the AgCl still contains metallic gold that was collected along with the AgCl, as he said there was a tan color in the AgCl solids. I tried to guide him to do an aqua regia wash of the AgCl but his concerns are the AgCl will dissolve in the AR and be carried away. He want's to convert the silver and cast it into anode bars and part them in a parting cell to recover the gold that way. When I was explaining to him that the parting route would take much longer than leaching in AR, that is the last time we communicated.

From the description as he described it to me, the gold could very easily be tied up in the AgCl. I can't think of any other tan powder it could be. I advised him to change the process to where he leaches the material in nitric acid to remove the silver, and any other metals nitric acid would remove, with nitric acid first before going to AR. I think there is a language barrier.

We can not recover silver chloride with cells. We do not have cells.
There must have been some gold trapped in our silver chloride.

One of our most important questions:
In the following, I will ask for help for the most suitable method of recovering trapped gold, silver from silver chloride.



Help me make different samples to test the tin .. !!!

 

[orvi]

In big drum connected to filters, pipes and condensers, there is plenty of opportunity to lose gold. As 4metals said, half a cup of pregnant liquid will make you unacceptable losses you are experiencing. Altough this is only one of the possibilities where the gold can be. As we all suggested, follow the route of the gold, stepwise from part to part in you apparatus and rinse every part clear with water. Then test this water with stannous chloride to make sure it is gold-free.

My opinion on this is, that the loss will be a puzzle of more than one or two failures or hidden faults in the process. We already debunked incomplete precipitation/sedimentation and find around 3,5g of lost gold. That is promising thing. Now, it is time to find other faults.

From my view, there is maybe one strange question: do you wash your tumbler and filtering apparatus after every use ? or you left them as they are and proceed with another dissolution ?
If you do wash your system, gold trapped in the way will come out in washes. If you do not wash all the piping, it will stay there to the next run. This will make a huge difference in output.

 

[orvi]

We can not recover silver chloride with cells. We do not have cells.
There must have been some gold trapped in our silver chloride.

One of our most important questions:
In the following, I will ask for help for the most suitable method of recovering trapped gold, silver from silver chloride.



Help me make different samples to test the tin .. !!!

If the silver chloride isn´t snow-white colour, there is very high possibility gold in tumbler produced dust that is mangled in between AgCl.
Easiest way is to dissolve AgCl in ammonia. But I must point out that for large scale this is far far from good technique to recover lost gold. You need quite a bit of ammonia to dissolve silver chloride cake.

For large scale I would advise to fully dissolve the gold. Make some AR, put it together with AgCl and let it react till there is no gold left in the cake. You can then filter the reaction and recover the impure gold, which could be added to the start of the next batch.

But as test for AgCl locked gold, it´s a very good thing to use NH3. Firstly, you need to be sure no gold solution is present in AgCl and that it is rinsed COMPLETELY from the gold solution. Do not add any water or do not use a dripping wet sludge - solubility of AgCl sharply decrease with ammonia concentration going down.
Take a sample (like a teaspoon) to the beaker, pour few mLs of NH3 and stirr. Eventually, with slow addition of NH3 and stirring, all AgCl should enter the solution - which should be colorless, if AgCl was pure. If any gold is present in AgCl - it won´t dissolve and left as precipitate in the beaker.

If this is the case and you have leftover gold in AgCl, than i bet there will be significant portion of the lost gold percentage. Inform us how it went.

 

[Gold.refinery]

Thank you Geo.

This takes stannous chloride testing to the next level, much more useful than the simple yes there is, or no there isn't, test. But it is also a technique which becomes a useful tool with practice.

This works most effectively if you make up your test solution the same every time. Consistency will matter especially at the lower detection limits of the solution.

This is how I prefer to make the solution.

2 grams stannous chloride crystals
1 gram of tin metal
40 ml of water
5 ml of hydrochloric acid

Store this in a small air tight dropping bottle (opaque if possible)

And remember if your first test of the day turns out negative, test the testing solution.

Stannous chloride solution made by machinery manufacturer in our refinery.
He has given us white powder.
He dissolved 50 grams of that white powder in 2 liters of water.
I do not know if it is true or not?