Help with seperating precipitants from ore

[captain1]

Hey would like some help. Not sure I am doing everything right. I am appealing to the refining Gods in the forum for some Ideas and critism on this. Your knowledge an Ideas are extremely valued by me. I am just needing some help and ideas.
Here is how I am starting out. First I leach my ore with hcl/cl salt saturated for 48 hours hot.
I have on some batches 80% or more platinum group metals mixed with the gold. I decided to drop everything out of this solution to consolidate it down. I tried zinc powder this weekend. It cemented really fast once the ph was adjusted towards 4 ph. I used soda ash to do this. Then I washed and dried to make sure all the chlorine was gone.
This would not melt. Then I put everything into a nitric acid boiling to take out any palladium or trace silver and other junk. Filtered any solids out. Put the solids into AR. Did not heat this. Was hoping to leave the platinum group undissolved in Ar. I was left with 4 inches of brown stuff in a coffee pot. So hopefully my gold is alone in AR. I put what was left undissolved in AR into a fresh batch of AR and boiled it. It seemed to take up some of it. But I am left with still allot undissolved. What do I do with it? It should be the part of the platinum group also. Is there a way like boiling in formic acid and ammonium chloride to convert them to metal and just melt them all together? I am hoping to denox and dilute , adjust ph and drop gold out with ferrous sulfate from my first solution clean with not much drag down. Clean up and melt to pretty gold.
The second one should have pt and rh in it. So I can consolidate this down denox and precipitate with ammonium chloride for platinum and then add zinc for rh.
So I guess what would be nice is. If there is a way to get all the platinum group together and melt them into silver balls. And let the big guys refine them. Or do I just have to process them out separately. That's fine also. Just will take lots of time to do that. Hoke says to drop platinum first and then gold. I did that last week and had lots of drag down. I was unable to melt the platinum after calcining it. I think it was contaminated with gold. Went to a red muddy slag. Really brittle. I wish everything was easy like Silver in nitrate to get back to metal with copper. I must be missing something in my process. Because my gold won't melt and my platinum won't melt. I was wondering if adjusting the ph with soda ash was messing me up. It seems like nothing falls until I am about a 4 ph. Diluting 3x or more is crazy because I am already working with over 50 gallons of hcl/cl to start out with off my ore.That's why I cemented everything out of hcl/cl. However I concentrate that down to about 5 gallons of precipitant after Nitric acid.
So I figure I must have to get everything by them selves. Extremely clean to be able to melt.
Here is what questions I am asking I guess.
1. Is there a way to cement everything down to metal and melt everything together? Then part them.
2. Is there a method to get all the platinum group metal converted at the same time and melt all together?
3. Should I put gold and pt all up in AR? Then cement out pt first.
4. What do I do with the platinum group that does not go up into AR?
5. Should I give up and go somewhere else where there is not as much Platinum metals?

I have tried knocking out the junk before I leach with nitric acid,hcl, sulferic but that is very expensive. I do size my material down to 200 mesh. I end up with the same results. I figure well why not leach everything. Cement everything out. Then Nitric acid to remove the nasties, silver and palladium. Then work on what is left out of AR. I think I am moving in the right direction. I know lots of the people on the forum don't work with ore much. But hey I love it. It's fun watching all the reactions of the chemicals. And exploring new finds and different areas. This is my third spot I am working on. And it seems to be possibly very profitable.
So please be rough with your comments or be nice if you like. I want any ideas. It all helps.

 

[lazersteve]

Captain,

For starters check your zinc powder for Cab-O-Sil.

Weight out 10 grams of the zinc powder and dissolve the zinc dust with diluted HCl. Filter out the remaining gray-brown powder (if any ), heat dry and weigh. This will give you a good idea of how much of your powdered zinc is contamination, usually Cab-O-Sil or silicon dioxide, aka Sand.

Let us know what you find and also report on how much zinc you are using in your cementing step. This will give you a better idea of what you may be looking at in the insoluble residues.

Steve

 

[butcher]

sorry I may not be much help here, my expierience with ore is limited,
wont melt? sulfides?
try a small bit with a flux
borax (5),soda ash (5), crushed glass or silica sand (25).
(ratios) of each of these can varie widely, as a starting point
if sulfides are trouble try some iron, if sulfides Iron will collect them in melt.
if you need to oxidize metals in the melt nitre works.
flour or charcoal, a carbon source can reduce metals that may oxidize in the melt like copper.
was this ore roasted well, > 700 deg for an hour exposed to air to oxidize the material?

silver is a collector of Platinum in melt, lead litharge also a collector of metals in melt.

I would try a small sample in flux with litharge , cupel the button, then use acids to seperate metals to see if values actualy there.
also have you tested solutions for values with stannous?

once the ore is roasted well and metals are leached and seperated from junk rock, the process is not that much different, although you are working with very dirty solutions, contaminated most of the time with alot of base metals, are you sure you have leached the values? with ore the base metals can overwhelm your leach and the values can still be with the rock.

 

[captain1]

No cab o sil 100% pure zinc powder from high mountain chemical. I am adding a table spoon of zinc to 4 gallons of leach hcl/cl. Not roasting at this time still running some sample runs. This came from red clay. Not much Iron in it either. I tried roasting some it didn't smell like rotten eggs or sulfur. This is really strange ore. Going to keep running some small sample runs till I find something that works. Might have to take it up and down a few time with ar. Will it work with zinc to drop everything then nitric it? I have put it in some silver and recovered gold. But it doesn't like do go into silver very well. I think maybe it hasn't quit converted over to metal or is in a wrong state. Would the ph adjustment with soda ash cause a problem? Also is there a good book or info on converting the platinum metals over to be able to melt them. I think I am going to have to learn how in order to make this work. Hey was wondering if I dropped the platinum out first. What effect does the ammonium chloride have on the ar solution? Can I drop gold after that with no problems?

 

[captain1]

Just a thought here. If I was able to separate the gold out into it's own ar. And drop it with zinc. It should come down as metal right. So here is my thoughts maybe I am wrong. If I was able to take up the platinum in it's own ar solution. Will it come down also as metal if I use zinc to precipitate it out? Or do I have to bring it down with ammonium chloride. To get it to metal to melt.

 

[aussco999]

Hey Captain:

My refining knowledge is way below the level of deity, but I do have a bunch of years experience at getting ore out of the ground and extracting their values. Keeping in mind that in the mining business, ore is loosely defined as; “a mineral of sufficient value as to a quality and quantity which may be mined at a profit”. So before jumping directly into your leach procedure, what exactly is your ore? Is it hard-rock head ore from a mining project, and can the values be concentrated? Or, is it a concentration of heavy minerals from some other process, or is it something else completely different?

As it would be very difficult to impossible for me to suggest what you are doing right or wrong, without first knowing what you are dealing with. So I have to ask, how many and what types of analytical tests (fire assay, AA, ICP-MS), have been completed on your ore, and what were their results? It looks like you are trying to use a chlorine leach to extract the PM, but you have to keep in mind that several base metal contaminates (plus silver), in the ore can also be converted to a chloride and will become somewhat insolvable to further leaching.

I’m a big believer for including the 50+ element mass-spec analysis on both head ore and concentrations as this test gives you a better view of not only what you are looking for, but also the other elements that may interfere or mask the PM.
Another big benefit of using the mass-spec test when dealing with PGM ore is the listed percentages of iron, nickel, and cobalt. Over 95+% of the PGM hard rock mines in the world have high nickel and some cobalt in the ore. But, if the mass-spec shows high iron content with no nickel, then you are probably getting a false positive test results for PGMs. High iron content has fooled a many technician for a many years.

Don’t take me wrong if I’m preaching to the choir on what the proper definition is of ore, but if you are having problems on what sounds like a straight forward leaching procedure, then logically you need to back up a step and find out if there is a hidden element, mineral or base metal in your ore that may be creating the leaching problems.

It sounds like an interesting project, keep us informed and good luck, :mrgreen:

John

 

[captain1]

Hey haven't had an much test run on this yet. I had a local guy that mines a bit run some of his tests and came back 80% platinum group metals. I don't Know what test he used. This is a new spot on the mountain I am trying to work out. The other spots I have worked went well. However this one seems allot different to work with. I think I am leaching very well so far. Not much for silver here. My field tests have been positive for gold and platinums. However like you said there some things in there probable throwing some kinks in there. I am trying a couple of things this weekend. One I am dropping everything out of hcl/cl with zinc. Then putting it into ar after a good nitric bath. Then I will precipitate one sample with Ferrous first for gold. Then concentrate it back down and try platinum with ammonia chloride. I will do a sample like Hoke says and drop the platinum down first, then precipitate the gold. After I will wash and do a hcl bath to. Hopefully something will be left. Is there a need for an annealing process on the gold precipitation? Never have done that yet. But I really haven't been able to melt anything strait outright without having been in silver and then parted.

 

[butcher]

ores are rock they can contain sulfides, carbonates arsinic and others, this can make extraction difficult by wet means, you will need to first figure out what you have in the rock what acids and metals they are made of.

example a sulfide say chalcopyrite ore, if I got a rock of sulfide ore and tried to leach it without a good hot roast I may not be able to get the gold out of it no matter how strong my acid, even two rocks from the same mine can be different, say one exposed to water and air may be oxidized over time and I may be able to leach a portion of its value, the part not oxidized I may not, also the majority of the ore may be base metals, this may deplete my leach long before it can dissolve the valuble metals, which are very hard to oxidize and dissolve. so even if grind fine concentrate and I drive out the sulfides with fire, I may only be leaching Iron and copper using up my leach and never touching that little bit of gold or platinum left in the rock.
old hard rock miner's tested for what type of rock, many done this in the field with small lab kits (sometime stocked with chemicals they mined from the rocks around the area) they also done assy's to determine the metals involved, it is not a simple as get a rock and leach out the gold, and go to the bank.

 

[WIZZARD]

captain1, glad you asked this question as I have been dealing with simulator problems.
butcher, has explained and provided some very intriguing answers to these problems.
I found a procedure that I would like to suggest and with help of butcher might find even more problems solved.

This thread is hitting the nail on head and this why I joined the forum in the first place.

I learned some fluxing procedures out of Bugbee's book on fire assaying and I believe butcher outline them in his post.

I used 10 time silver to suspected noble metals in the flux, no niter and got two buttons from the same pour, one on top of the other. The lower button contained the silver and some of the values. The top button was hard shinny metal and is my logo when I post. Silver melted off and left the very hard top button. When I added niter I ended up with just a loaded silver button. I was adding 100g of silver to 100g of ore and fluxes. I know I needed more thinning flux, borax, as some silver did not come down, however the silver button is loaded with NM.




I remelted the silver into a long flat bar I placed it in a solution cell of silver nitrate and used a pure silver Cathode and use the loaded silver as the anode. Placed the anode in a anode bag and applied 2 volts and got silver to plate on the cat. The anode broke down to black/brown mud. The weight of the mud just a little more than the suspected Nobel Metals. I heated the mud to 800F and placed the mud in AR, 50% went into solution and remaining residue was Ag, Rh, Ir, Ru. The AR contained the Au, Pt, Pd and Au however the ratio of Pd was very high and I had some problems with Pd coming down with my Au. I put this on shelf felt some day I go back to it, switched gears to ion exchange risen. With your post I'm looking forward the feed back. I added nitric to mud and learned not only will I take the Ag but some Pt too.

Other problems included the silver on the cat had a lot of gold on it and solution contaminated with precious metals. I some times over charged the voltage to speed up the process, opps. I think that's what caused the gold on the cat an in the solution.? Help!

I hope this help you and quite frankly .......me too.

WIZZARD