Alternate Precipitation Methods for Gold

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Kreis412

Kreis412

Kreischtech
Joined
Dec 5, 2020
Messages
42
Location
Ohio
I apologize if this is a repeat thread but i couldn't find it. I was wondering about different chemicals or substances i could use to drop gold and why they'd be good or bad. Such as ive seen you can use ferrous sulfide so why not ferrous oxide. I don't know maybe it seems dumb but i find it interesting. Or maybe someone here has a book or PDF with all the different methods. I guess specifically I'm interested in the ferrous sulfide and also zinc. I've even heard sugar can be used.
Well thanks, and if it's a bad thread just delete it. I get there's probably more important things to do.😔
Nah just kidding i wont be sad lol
 
Kreis412 said:
I apologize if this is a repeat thread but i couldn't find it. I was wondering about different chemicals or substances i could use to drop gold and why they'd be good or bad. Such as ive seen you can use ferrous sulfide so why not ferrous oxide. I don't know maybe it seems dumb but i find it interesting. Or maybe someone here has a book or PDF with all the different methods. I guess specifically I'm interested in the ferrous sulfide and also zinc. I've even heard sugar can be used.
Well thanks, and if it's a bad thread just delete it. I get there's probably more important things to do.😔
Nah just kidding i wont be sad lol
Click to expand...
I doubd Ferrous Oxide works since it is basically “rust” and Zinc is cementing but it is not selective.
You have SMB which is basically SO2, Ascorbic Acid and Oxalic acid and so on. It is all in here.
If you want to cement it out better use Copper since it is “selective” for PMs

But use the search function it is all in here.
 
Kreis412 said:
I apologize if this is a repeat thread but i couldn't find it. I was wondering about different chemicals or substances i could use to drop gold and why they'd be good or bad. Such as ive seen you can use ferrous sulfide so why not ferrous oxide.
Click to expand...
I've never heard of using ferrous sulfide. Ferrous sulfate works. Tiny differences in chemical names can make all the difference.

Dave
 
Hydrazine
Oxalic acid
Ascorbic acid = Vitamin C
Sodium nitrite
Hydroquinone
Sodium and potassium sulfites, metabisulfites, hydrogensulfites etc. (all work effectively)
Sucrose (used by Krastsvetmet russian refinery, they just claim it, never tried myself)
Ferrous sulfate
SO2 gas - for me, the best choice in terms of price, use and produced Au quality

FeO is not very soluble, hard to say how it will show up in real life. If it is some hydrated oxide form (which I doubt is easily available commercially), maybe. But it will consume acid upon addition, so I won´t be very excited about it´s practical use.

List of less selective reducing agents with good selectivity over base metals - often precipitate all PMs included :
Copper (copper cementation of gold works pretty nicely, precipitate fall off the copper surface pretty nicely, but it reduce whatever PMs you have in solution)
Formic acid/formate - also, all PMs will drop alongside gold.
Stannous chloride - bad for precipitations (best for testing), but it does reduce gold. Not recommended.

Stripping agents used for SX of gold from solutions:
Diethyl ether - low end, very hazardous due to insane flammability, but works
Butyl diglyme
Methyl isobutyl ketone (MIBK)
These usually require special conditions to achieve good results, but can be extraordinarily selective. Subsequent stripping is needed, followed by precipitation (or combined "precipitation stripping" is applied). Flammable, forming peroxides, sometimes cumbersome to handle. Require extraction apparatus to proceed.

Complexing agents for gold:
Pyridine.HBr can precipitate gold from organic liquids, but only to some extent.
Ethylenediamine (N,N´-dimethyl) bis-benzamide - very effective relatively selective precipitant for gold, recent advance, precipitate gold complex, which is subsequently filtered, stripped, and precipitant reused.
SuperLig products - very expensive molecular recognition complexing agents, supported on solid phase. Highest end of current technology. Virtually exclusive selectivity towards the target element (they produce selective resins for individual PGMs, Au and also for barrens toxic elements removal such as Hg)
 
Kreis412 said:
I apologize if this is a repeat thread but i couldn't find it. I was wondering about different chemicals or substances i could use to drop gold and why they'd be good or bad. Such as ive seen you can use ferrous sulfide so why not ferrous oxide. I don't know maybe it seems dumb but i find it interesting. Or maybe someone here has a book or PDF with all the different methods. I guess specifically I'm interested in the ferrous sulfide and also zinc. I've even heard sugar can be used.
Well thanks, and if it's a bad thread just delete it. I get there's probably more important things to do.😔
Nah just kidding i wont be sad lol
Click to expand...
Oh and even more speci
orvi said:
Hydrazine
Oxalic acid
Ascorbic acid = Vitamin C
Sodium nitrite
Hydroquinone
Sodium and potassium sulfites, metabisulfites, hydrogensulfites etc. (all work effectively)
Sucrose (used by Krastsvetmet russian refinery, they just claim it, never tried myself)
Ferrous sulfate
SO2 gas - for me, the best choice in terms of price, use and produced Au quality

FeO is not very soluble, hard to say how it will show up in real life. If it is some hydrated oxide form (which I doubt is easily available commercially), maybe. But it will consume acid upon addition, so I won´t be very excited about it´s practical use.

List of less selective reducing agents with good selectivity over base metals - often precipitate all PMs included :
Copper (copper cementation of gold works pretty nicely, precipitate fall off the copper surface pretty nicely, but it reduce whatever PMs you have in solution)
Formic acid/formate - also, all PMs will drop alongside gold.
Stannous chloride - bad for precipitations (best for testing), but it does reduce gold. Not recommended.

Stripping agents used for SX of gold from solutions:
Diethyl ether - low end, very hazardous due to insane flammability, but works
Butyl diglyme
Methyl isobutyl ketone (MIBK)
These usually require special conditions to achieve good results, but can be extraordinarily selective. Subsequent stripping is needed, followed by precipitation (or combined "precipitation stripping" is applied). Flammable, forming peroxides, sometimes cumbersome to handle. Require extraction apparatus to proceed.

Complexing agents for gold:
Pyridine.HBr can precipitate gold from organic liquids, but only to some extent.
Ethylenediamine (N,N´-dimethyl) bis-benzamide - very effective relatively selective precipitant for gold, recent advance, precipitate gold complex, which is subsequently filtered, stripped, and precipitant reused.
SuperLig products - very expensive molecular recognition complexing agents, supported on solid phase. Highest end of current technology. Virtually exclusive selectivity towards the target element (they produce selective resins for individual PGMs, Au and also for barrens toxic elements removal such as Hg)
Click to expand...
Thank you, i didnt think sodium nitrate would work. Isn't that salt peter? Anyway, thank you i really appreciate the help.
 
I just used the search bar as i was told to, and i saw vitamin C works. Wouldn't that make it more acidic? Or is it to kill the nitric acid?
 
Yes that is vitamin C. It is pretty specific for gold. Better than some more common precipitants.

It is sodium nitrite (to drop gold) not sodium nitrate ( to make poormans AR).
 
Shark said:
Yes that is vitamin C. It is pretty specific for gold. Better than some more common precipitants.

It is sodium nitrite (to drop gold) not sodium nitrate ( to make poormans AR).
Click to expand...
Man those ates and ites always screw me up
 

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