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arthur kierski

Well-known member
Joined
Feb 10, 2008
Messages
1,119
Location
são paulo---brazil
i have the powdered and incinerated chip-----instead of separating these material , i throw this powder in ar-----the liquid after the ar process is tested with stanous chloride and the result is blank(no gold)------the powder is dissolved once again in ar and the results of stanous chloride test gives the typical gold results(deep purple,almost black collor)-----this second ar is diluted 10 times and smb precipitate the gold-----the brown precipitate is washed with hot water ,dried and then boiled in hcl-----filtrate the gold powder and the hcl is tested for gold----sometimes the test gives gold but most times is blank(no gold)-----the gold powder obtained from the second ar is repurified with ar,but a brownwish magnetic powder remains in the filter paper------ with time i have over 800grams of this powder which i suspect that there is a lot of gold in it---------
even with these brown magnetic powder that is left behind and i suspect lots of gold in it(and need help and advice how to deal with it) i am happy with the gold yeald and am passing to the members of this forum----- one kilo of the powdered and incinerated chip is giving an average of 3grams of gold----- i do the process this way because separating manually the powder is time comsuming and i deal with at least 5kilos of these chips daily------thanks and wish help with the powder left behind the ar purification
Arthur
 
Arthur,
I am sure you are eliminating nitric before you test, but that could be one problem, the other may be base metals the first run are cementing values, lf this is the case I would consider removing them before doing aqua regia, with all of the deposit left Ash and ceramic residue it is hard to tell when all metals are dissolved, you may need to do a base metal leach to rid most base metals wash and do another roast, I believe the ash can possibly still contain some carbon the first leach, and this will make carbonic acid and may neutralize much of the acids making CO2 gases (speculating here from what I have done in the past)

The powder may be Iron (brick red) (sometimes yellow crust),
(If green iron chloride is heated strongly it will form the yellow first
(Yellow I think is iron oxide)
Then forms the red
(Red I think iron hydroxide)
This iron is very insoluble as a oxide or hydroxide, acids even aqua regia does not seem to dissolve once this red powder forms again just a guess. (Gold will dissolve easier than this Iron hydroxide), if this is what you have it may be iron (one of base metals giving you trouble also with first leach.

A magnetic separation of iron after the first incineration, would not be too much trouble if this is the problem here,

Maybe you need a break working too much a man has to play sometime.
 
butcher

Iv'e processed quite alot of these chips and don't remember i ever found ferrous metal in theme...
but anything is possible, i guess...

Arthur, are those just regular square black chips found on mobo's and cards? how to you remove them from boards?

Have you done any tests to this powder? how does it react with chemicals (hno3,hcl, ar)? maybe inciniration and then a chemical test?
have you tried melting some of it?

Does it stick real herd to a neodymium magnet or just budge slightly? the reason i ask is since i have noticed that dry gold powder can sometimes be effected and move/jump around due to electrostatic forces of the glass...
 
Arthur could you please post a representative picture of the chips you processed?
 
some answers:the chips are black square chips equal to the pictures(fotos) that partnor showed us in one of his thread on black ic chips----these chips are withdrawn from the boards with a heat gun------from 100kilos of these boards and cards i obtain about 10kilos of chips and around 30grams of gold-----after doing the process,the powder left is put in hcl-cl and the rest of the gold that did not come out with the method described----goes to the solution and some more gold is obtained increasing the 3grams that was obtained per kilo----the method that i use is a copy of partnors method with the diference that he separates the gold wires and the magnetic material from the incinerated and milled powder----i because of bigger quantities , choosed to do the 2ar method---
 
Samuel,the powder left is magnetic,i tried many experiments with this powder---incineration,then nitric, ar , hcl~cl and always some gold comes out----tested with stanous----but as an example ,10grams of this powder becomes 9grams and gives 0,2 or 0,3grams of gold-----i thank you and Butcher for giving me some ideas ----like melting , etc----Butcher the powder left is reddish(iron oxide or hidroxide-------once i dissolved this powder with hf(very dangerous) but the powder left was gold -----that is why i said that i suspect much gold embedded in these iron oxides---
 
arthur kierski, are you sayin you dissolve the iron hydroxide in HF?

I have been wanting some chemical (thiocyanate), Hokes describes on page 100 to test this red powder (she also talks about this iron), reading this may give you some Ideas.

I was wondering how phosphoric acid would work with this Red Iron hydroxide, (I was thinking it may help to convert it back to an Iron form we could dissolve with dilute H2SO4) (?? any thoughts??), I have a jar of this Iron Rouge and sure would like to be able to dissolve it covert it and understand it better.

I also want to understand the chemisty (reactions of) of Iron better.
 
Butcher,i did dissolve the rouge powderin hf once and the gold remained as a powder(which i dissolved in hcl-cl---------i read in wikipidea that hf dissolved metals oxides and silica---that is why i did it-----to day i did something that worked parcially,i reduced this rouge powder the following way:i took around 20grams of this rouge powder and put it in a beaker with 100cc of water---to this beaker i added 10grams of zinc powder(like one deals with agcl to transform into silver) and mixed----then i added some h2so4----the mixture almost boiled over----to dissolve the excees zinc-
by doing this,i deduced that the rouge powder was reduced to metal----this powder was then dissolved in ar and the solution tested with sncl2 indicating gold which was locked in the rouge powder----it worked-------as you have plenty of rouge powder ,you could try this experiment and see what happens-----perhaps i found a solution to the problem
regards and thanks for the help and advice you are giving me
Arthur
 
arthur kierski,
Brilliant so simple why didn't I think of that, Here I was banging my head up against the tree, looking for a tree in the forest,

Thanks.
 
since oxalic acid of choice in both indoor and outdoor rust removers, might it be an option for removal of the ferrous residue left after incineration?
 

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