Basis of the bisulfite method

[LUDWING]

Hi, it's probable that my doubts are resolved in several topics, if so I apologize.
I read the articles written by "Harold_V, goldenchild", "Barren Realms 007" and "gold4mike" where used HSO3- as reducing agent for precipitating the AuCl4- . I have some technical doubts about the procedure that I would like to help me clarify:

- I can not get where I live (legal issues) concentrated hydrochloric acid (12M) I can only get 6M, I can not heat the solution because I have not the right elements, I have understood that I will not have major drawbacks to prepare aqua regia and that going to work under these conditions, I am right?

- What really happen whith the HSO3- and the AuCl4- ? the only what I know is bisulfite in acid medium decomposes in SO2. All cations are reduced in these conditions?

- Analyzing my scrap (chips and connectors) I know that after oxidation of Au the AuCl4 - will be accompanied with a soup of cations such as Fe 3 + Sn 4 + Pb 2 + may Cu2 + and Al3 +, I understand that it is crucial,once precipitated all cations, the step where it is washed with HCl to re-oxidize the cations (but not gold), but metallic copper is not oxidized with HCl, ill have to use HNO3 and heat if I have Cu present?

- Anyone know what happens when Sn +4 and AuCl4 are present in the solution? - I'll be able to use the gold detector?

Thank you very much

 

[butcher]

As the book stated eliminate the base metals before dissolving gold, that way you are not just dissolving trash with your gold and precipitating back out trash with your gold, just going in circles, and you are not loosing valuable gold to the base metals (as powders or solutions going out the window), base metals will plate out gold, or replace it from solution, and even stay in solution clinging to base metals in solution like colloids, eliminating the base metals is an step that should not be overlooked.

tin in chloride solution with gold will make purple of Cassius.

SO2 will precipitate copper and some base metals if solution is loaded with them, and also if you use more reactant than needed for reaction.

you have more study ahead of you.

edit: I do not understand you cannot heat a solution you do not have the right elements? do you mean tools or stoves? there are many ways you can heat,
put me in the woods and I can heat anything I wanted to with what I found out there.

 

[LUDWING]

Are you suggesting me to take off the tin before applying aqua regia? that's a good option but the core of the microprocessors pins will also be oxidized by aqua regia and I will have other metals in solution too.

In terms of the heat problem, I can not do this because my beakers are pure material and I do not want to have a risk since it is not Pyrex

 

[Barren Realms 007]

Are you suggesting me to take off the tin before applying aqua regia? that's a good option but the core of the microprocessors pins will also be oxidized by aqua regia and I will have other metals in solution too.

In terms of the heat problem, I can not do this because my beakers are pure material and I do not want to have a risk since it is not Pyrex

You can get you some coffee pot's that are glass and put them in a sand bath over the heat to reach your objective.

 

[LUDWING]

Are you suggesting me to take off the tin before applying aqua regia? that's a good option but the core of the microprocessors pins will also be oxidized by aqua regia and I will have other metals in solution too.

In terms of the heat problem, I can not do this because my beakers are pure material and I do not want to have a risk since it is not Pyrex

You can get you some coffee pot's that are glass and put them in a sand bath over the heat to reach your objective.

yes, but aqua regia does not work at 60F or room tempereature? i can wait. (my solution will be 3:1 HCl 25% and HNO3 50%)

 

[butcher]

I would forget about recovering or refining gold for now, at this point you'll just be loosing gold, collect material, and study for a while, do the expieriments getting aquainted Hoke suggested, by doing this you will gather much more gold and valueable metals (studying will show you more places to find them), you will learn way's to get by without spending much on things you do not need, and tools that are all around you, you will learn to make some of the chemicals you will need, the best ways to process your materials, and how to get your gold and not be wondering what you did wrong to loose all that gold.

I know its hard not to just jump in an try this, but sometimes it is better to spend some time learning how to swim, before you go jumping off of high bridges into deep waters.

 

[LUDWING]

Yesterday I digestion and AR worked in these conditions, the temperature was raised to 125 F, the solution I got is green, probably due to Ni2 +. Not all the pins from the CPU was dissolved, were "lining" of gold and pins floating. This afternoon I will precipitate with MBS the gold. I did not lose gold at the moment.

 

[butcher]

How are you sure your not loosing gold?
Are there any metals undissolved? (even inside the ceramic?).
Are you using standard test proceedures?

You may not loose much gold with CPU's with your method this time, but unless you eliminate base metals, and follow many of the other proceedures you will learn on this forum and from reading Hoke's book, then I can gaurantee you will be losing gold and stumbling through the dark.

turn on the light, READ HOKE"s BOOK.