Mintek process

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

HAuCl4

Well-known member
Joined
May 26, 2010
Messages
1,105
Location
Location. Location.
Hi guys. I found this online. Apparently these people are using a one step leach process to produce gold of high purity in large batches.

Notice that they are not using DBC as the extractant, but another cheaper solvent. Anyone knows what they use?.

Maybe we can dissect this process for the benefit of all forum readers and adapt it to small batches?.

Cheers!.
 

Attachments

  • mintek.pdf
    518.1 KB · Views: 235
nothing new except the miracle organic extractant. now let's see: "Although the organic extractant is highly selective for gold , metal species with similar charge-to-volume ratio as the gold chloride species are also extracted. Extracted metal impurities are subsequently removed from the loaded organic phase by 'selective stripping' in the scrubbing section" . :shock: if this is " highly selective for gold" i'll give up ! :mrgreen:
 
In my interpretation, each step, the extraction, the scrubbing, the stripping, and the precipitating, add a little extra purification to make a very fine end product.

If nothing of this is new to you, maybe you can tell us the steps in detail and how to adapt it to small batch jobs?.

It is all new stuff to me, and not widely disseminated information. I mean there isn't a Hoke's book about it or anything like that, as far as I know. Is there?.
 
http://books.google.com/books?id=plRuO9NvIsEC&pg=PA485&lpg=PA485&dq=selective+for+gold+and+easily+stripped&source=bl&ots=8M7Fko-URH&sig=HhLoLbWEZHnJOs5QD9sb3Qxxs_o&hl=en&ei=2SwLTJPuH4H6lwfg1OSJDw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CCQQ6AEwAw#v=onepage&q=selective%20for%20gold%20and%20easily%20stripped&f=false
 
HAuCl4 ,the process has too many steps to be adapted on small batches. the dissolution and the precipitation have nothing new , to 'break my mouth' with. all is inside this forum already. if you want something unusual i'll give you a challenge: take a piece of scrap carat gold and soak it in a mix. of concentrated ammonia and strong peroxide. tell me your results. luck to you !
 
HAuCl4,

I am deleting your last post. On this forum, we won't allow anyone to attack another member.

Chris

EDIT:

machiavelli976 wrote:
if you want something unusual i'll give you a challenge: take a piece of scrap carat gold and soak it in a mix. of concentrated ammonia and strong peroxide. tell me your results. luck to you !

Oz just PM'd me and suggested that the reaction between karat gold and conc. NH4OH + strong H2O2 could result in explosive fulminating gold. If this is true, I owe a big apology to HAuCL4. And, if this is true, machiavelli976 will immediately be permanently banned from the forum. Provoking someone to possibly become injured will not be tolerated.

Lou, and anyone else that is qualified, please give us some expertize on this. Unfortunately, I am quite ignorant concerning the chemistry of explosives. I can't understand what in that mix would dissolve the gold, but I do note that in the formula I found for fulminating gold, (OHAuNH2)2NH, everything is there.

Chris
 
I do not know.

i would think the gold would not dissolve, but it would attack silver for sure, and would need acidifying the solution for safety, I would think the gold would need to be dissolved say in a chloride before it would create a dangerous compound, but again this is a guess, and we should never tell someone to do something dangerous.

http://www.buehler.com/application_support/tech_note_pdf/vol2_issue5.pdf

fulminating gold Prepared by gold chloride and aqueous ammonia, the explosive precipitate is largely (ClAuNH2)2NH, but on washing with ammonia hydrolysis to the more explosive
(OHAuNH2)2NH.
http://chestofbooks.com/science/chemistry/Matches-Colored-Fires/Chapter-XXXVIII-Fulminating-Compounds.html
 
I no explosives expert, but the very second I read his post about the ammonia, I immediately thought about the possibility of forming explosive by products. I also had the gut feeling that he meant it maliciously. I then dismissed my gut reaction thinking that no one on the forum would suggest a method for the sole purpose of harming another member.

Steve
 
When I wrote GSP I expressed that I greatly dislike “tit for tat” disagreements on the forum, but that in this case I could see some justification in HAuCL4 being peeved if he understood the potential results of what was being suggested to him as a course of action. Mixing concentrated ammonia and strong peroxide may or may not form gold fulminate in this case (it is not how I would do it) but as GSP pointed out “everything is there”. One better really know what you are doing if you mix concentrated ammonia and strong peroxide playing with metals as it can prove dangerous and fatal.

Like lazersteve I had the gut instinct it was meant maliciously as to intent. My reasoning being that I can see no benefit by doing what machiavelli976 suggested , but do see great hazard. Then there is of course that it was presented as a challenge and “luck” was wished, almost a dare to try it.

I would like to hear machiavelli976 give a plausible reason for what he suggested other than intent to do harm. Anything less in my opinion is criminal.
 
I commented, recently, on the potential explosive power of some gold solutions. You can verify the fact by reading the Merck Index that some are so unstable that they exist only in theory.

I am not a chemist, so I am unable to make a determination of the hazards of combining ammonia and hydrogen peroxide with metallic gold, but if there's the slightest chance that what has been suggested would be hazardous, an immediate banishment is in order. There is no room on this forum for anyone that willingly puts others at risk, nor is there room for those that can't control their mouths and feel they must get in the last word.

We have a strict policy of good behavior on this forum. It is not a place where readers can troll, nor a place where they can post offensive statements. Be on your best behavior, or leave.

Harold
 
Oz said:
I would like to hear machiavelli976 give a plausible reason for what he suggested other than intent to do harm. Anything less in my opinion is criminal.
I propose that a time limit be placed on this issue. If it is met by silence, that will be construed as guilt, and calls for immediate banishment once we have passed the time limit.

If it is met with an explanation, we should react according to the information provided.

Issue such as this are normally handled on the Moderator's forum, but the implication here is such that all readers may have been put at risk. Therefore, all readers should express their views. Do use manners in doing so, but state your case.

Harold
 
Personally im with the time limit suggestion and if no response is forthcoming then i think its fair to assume that this was a malicious and dangerous post and i can see no other way than to banish him from the forum.I for one will openly admit im no chemist but im fully aware that many of the chemicals we all use are dangerous and need to treated with the greatest respect and care,posting of possible dangerous ideas and processes can not be allowed as far to few of the members fully understand the likely outcome but in ignorance might try them.
 
I agree with nickvc and Harold, I would be in favor of a time limit. Since machiavelli976 posts near daily I do not think it would need to be excessively long. I would also agree that any silence would be damning.

I should also note that while I focused on the gold in my PM to GSP, the silver and even the copper typically found in karat gold are not trivial in this case either. So I will reiterate that you better really know what you are doing and have good reasons if you mix concentrated ammonia and strong peroxide playing with metals as it can prove dangerous and fatal.

There are now several here with more than a little refining experience under their belts (probably over 100 years cumulative knowledge so far) that have commented, many more that have read it, all of whom would have spoken up if they saw any redeeming value in what was proposed despite the implied hazard. It is the intent of machiavelli976 that is important to me here. If he was trying to set someone up for injury it does not matter whether he got it right or not in trying to do so. The question is if his intent was malicious.

It does not help the overall picture when you see this thread that machiavelli976 wrote later the same day http://goldrefiningforum.com/phpBB3/viewtopic.php?f=58&t=7277&p=65893#p65893
machiavelli976 writes “HE sucks ! :evil: picric acid is my favourite :mrgreen: :twisted: :mrgreen: “. Those of you that know explosives need no further explanation, nor do I care to see one on the forum.

I should state that the old pineapple grenades are cast iron and threaded so as to be a reasonably inexpensive and expedient retort vessel whether they are dummy or de-milled. And that I by no means wish to implicate Irons in a negative way when one reads that thread as he was just trying to keep people safe if they happened to try it with an old grenade that was de-milled and not a dummy. Be thankful we have people like Irons keeping us safe. It is the picric acid reply by machiavelli976 that concerns me in this other thread.

In this light I would think it only proper for machiavelli976 to be required to site reliable sources as to why he felt the procedure he was suggesting would help instead of possibly maim or kill to show what his true intent was. Because intent is my concern I would be far more interested in Lou's (or any other qualified member) interpretation of any explanation that may be given and its validity more than anything else.

Cautions are very necessary on the forum as some bonified refining does indeed come close to inadvertently making unstable compounds, but discussing how to do so intentionally has no place here.

If somehow a proper and sound explanation is forthcoming from machiavelli976 I would be the first to humbly apologize for the disturbance I have created. If not, I stand by my statement that what was done is criminal.
 
I believe what he proposed creates fulminating silver, and if solution is not kept cold, it'll detonate. Gold needs not participate in the reaction.

Apology accepted.

Now back to the extraction, scrubbing, stripping described by Mintek. Does anybody think the steps could be taken in a separating funnel of sorts, for application in small batches?.
 
Hello everybody there !i am trully sorry for disturbing this forum. as i see people here are very scared about any particular thread involving ammonium hidroxide. far from me any malicious behaviour and need to appologise to everyone got threated by my posts. sorry for the user name but this is my nickname since i was 2 yrs. old. didn't know anything about pyrotechnics by that time. the challenge adressed to HAuCl4 is a real one based on my past experience about 20 years ago . here's the story: i decided one day to clean my wedding ring with conc. ammonia to get rid of some dirt from the gapes of its design. after cleaning i've had the idea to pour some 30% peroxide. instantly the ring start fizzing and i had to pull it out. the shine was gone and a dull yellow came out after rinsing. everything took two seconds i think. i wanted to repeat this years after but i quit for several reasons. i'll do it again when i'll get some peroxide. where did you get the idea with the fulminate? as far as i know a fulminate is a salt of fulminic acid: HONC !!!! the silver fulminate should have the formula AgONC, and mercury fulminate Hg(ONC)2. WHERE IS THE CARBON ATOM COMMING FROM in this thread? if i am wrong please show me the light !! sorry for the late response but i have to work for living.
 
machiavelli976 said:
Hello everybody there !i am trully sorry for disturbing this forum. as i see people here are very scared about any particular thread involving ammonium hidroxide. far from me any malicious behaviour and need to appologise to everyone got threated by my posts. sorry for the user name but this is my nickname since i was 2 yrs. old. didn't know anything about pyrotechnics by that time. the challenge adressed to HAuCl4 is a real one based on my past experience about 20 years ago . here's the story: i decided one day to clean my wedding ring with conc. ammonia to get rid of some dirt from the gapes of its design. after cleaning i've had the idea to pour some 30% peroxide. instantly the ring start fizzing and i had to pull it out. the shine was gone and a dull yellow came out after rinsing. everything took two seconds i think. i wanted to repeat this years after but i quit for several reasons. i'll do it again when i'll get some peroxide. where did you get the idea with the fulminate? as far as i know a fulminate is a salt of fulminic acid: HONC !!!! the silver fulminate should have the formula AgONC, and mercury fulminate Hg(ONC)2. WHERE IS THE CARBON ATOM COMMING FROM in this thread? if i am wrong please show me the light !! sorry for the late response but i have to work for living.


http://en.wikipedia.org/wiki/Fulminating_silver

http://en.wikipedia.org/wiki/Silver_nitride

http://en.wikipedia.org/wiki/Silver_azide

"Silver nitride is an explosive chemical compound with symbol Ag3N. It is a black, metallic-looking [1] solid which is formed when silver oxide or silver nitrate [2] is dissolved in concentrated solutions of ammonia, causing formation of a silver-amide or imide complex which subsequently breaks down to Ag3N. The standard free energy of the compound is about +315 kJ/mol, making it an endothermic compound which decomposes explosively to metallic silver and nitrogen gas.[3]"
 
machiavelli976 said:
... WHERE IS THE CARBON ATOM COMMING FROM in this thread? if i am wrong please show me the light !! ...

Here's a page listing the formula for Fulminating Gold (about 1/3 the way down the page):

Explosive Mixtures

There is no carbon in it.

Last night I checked a chemistry encyclopedia that states it is made by adding ammonia to gold hydroxide.

Steve
 
Back
Top