powder containing gold and iron

[arthur kierski]

how can i separate gold from iron (chemically ,without a magnet) ?

 

[qst42know]

HCL or Nitric. One or the other.

 

[arthur kierski]

i used nitric and the powder is still magnetic---now i left it in hcl and tomorrow i will see what happened

 

[qst42know]

If you did not incinerate between acids you will dissolve values. Do not discard your solution before testing.

 

[Harold_V]

You can also boil in dilute sulfuric.

Harold

 

[arthur kierski]

i will do both sugestions( test for values hcl solution +dilute h2so4 if magnetic)thanks to both of you

 

[arthur kierski]

i did all the sugestions recomended and still have iron in the powder-- i started with 13,75 grams and after passing throw all the sugestions it became 6,7grams;fed up i made ar and the powder became4,4grams(still magnetic) and i had a yeald of 2grams of gold(precipitated with smb)--with the 4,4grams left i did all the via crucis again (with nitric-hokes pg 72) and the powder became 2,18grams(still magnetic)---put this 2,18 grams in ar again(brown fumes come out) and went home-on monday i will continue ------any sugestions if the powder continues magnetic?

 

[lazersteve]

Arthur,

What was the original source material?

Steve

 

[arthur kierski]

my original material was 1kilo of ceramic processors--- i put this 1kilo in a plastic becker and covered it with 2liters of hcl + 500cc hno3 --left for 2hours---added water and fitrated the solution----the flat processors in the filter paper was washed individually(38 processors) and withdraw for further processing(crush into powder).became 850grams-----the filter paper was incinerated and 13,75 grams of the powder containing iron (magnetic),silver and gold gave origin to this thread---

 

[jsargent]

Arthur- Try oxalic acid as per this study:
http://eprints.utm.my/3474/1/SKMBT_60007052214460.pdf

Use at pH 1.3-1.4. Extremely effective at dissolving iron and being a commonly used precip agent for gold, your values will remain safe

 

[jamthe3]

Is it possible that some of the gold plating was originally on a ferrous metal & two hours wasn't enough to achieve full seperation. If the 850 grams were crushed fine, perhaps what you thought was seperated gold only looked that way and needed a bit more time in the leach.

If values were still left in solution when you changed acids w/o incinerating and in a rush perhaps didn't use a dilute nitric to boot, that might explain the diminishing mass & the "powder" still being magnetic.

You process such vast amounts of different product on a regular basis perhaps you just "overlapped" processes or got in a rush. Please understand I'm not trying to be rude or sarcastic; just trying to offer what little help or insight I'm capable of in response to the more knowledgeable help and experience you were kind enough to share w/ me previously.

Wish I was more knowledgeble and could return the help better.

Salud,
John

 

[arthur kierski]

john; the 38processors(1kilo) was put directly in ar and from the ar solution after filtration i had a yeald of 1,56grams of gold-----what i am trying to say is that after the leaching i was left with 850grams of now flat processors and 13,5 grams of a magnetic powder containing gold ,iron and silver;from these 13,5grams after doing all the recomendation by qst42 and harold i have another 2grams of gold and the 2,18grams of powder left is still magnetic---so up to now i got 3,56grams of gold +850 grams of processors to be crushed and then withdraw the metals from the crushed ceramic-----steve asked me the origin of this material and i told him that it was from ceramic processors ----
the thread is powder containing gold and iron----the ceramic processors just came in because of steve question-----i did process this way before and my yeald (total) is 5 to 6grams per kilo of au

 

[jamthe3]

My mistake, your response read like you did the Hcl for two hours first & the AR at the end in frustration to come back to Monday. And I misread that they were already crushed.

 

[jsargent]

Arthur- Is there any possibility this magnetic material could be cobalt, nickel or some magnetic metal besides iron? I understand that even platinum is weakly magnetic by itself and some alloys and some coins of platinum contain enough iron to be attracted to a magnet. An iron-containing platinum alloy might explain the problem.

 

[arthur kierski]

jsargeant,the powder came from ceramic procssors---if they where cobalt,nickel or platinum,they should be dissolved during the various experiments that i did-- or not? i think that is an iron oxide--fe203 or fe3o4 which does not dissolve in the various acids----the 2,18grams left is now in ar again--if i continue to obtain a magnetic powder i will boil it with concentrated h2so4 which might dissolve it and if gold is in this powder, it will get together in the acid(COALESCE) AND THE IRON!!! SHOULD DISSOLVE---THANKS FOR THE ATTENTION---