# how much hydrogen peroxide and sulfuric for copper



## future gold refiner (Nov 17, 2010)

Hello a simple question,

How much diluted sulfuric ( acid content variable up to 50% ) and hydrogen peroxide ( content also variable up to 50% ) are necessary to dissolve 1 g of copper totally. ( I have a big amount of auriferous copper granules [low gold content] )

please no stoichiometric amount -> practical !!!!

i would prefer a short reaction time

PS: {please no nitric procedures :lol: }

Thanks a lot.


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## Anonymous (Nov 17, 2010)

future gold refiner said:


> How much diluted sulfuric ( acid content variable up to 50% ) and hydrogen peroxide ( content also variable up to 50% ) are necessary to dissolve 1 g of copper totally.
> 
> please no stoichiometric amount -> practical !!!!
> 
> i would prefer a short reaction time


Is there some reason you are not researching this yourself?
No offense but you are asking for a tall order,and not asking humbly IMHO.
If I were you I would consider doing some small scale testing,or using the search function in the top right hand corner of this page.


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## HAuCl4 (Nov 17, 2010)

practical = 110% x stoichiometrical !.


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## goldsilverpro (Nov 17, 2010)

HAuCl4 said:


> practical = 110% x stoichiometrical !.



I agree. I've added 10% to most everything all of my life. It's almost always better to overdo, a bit, than underdo. There are occasional exceptions, however.


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## future gold refiner (Nov 17, 2010)

mic said:


> Is there some reason you are not researching this yourself?
> No offense but you are asking for a tall order,and not asking humbly IMHO.
> If I were you I would consider doing some small scale testing,or using the search function in the top right hand corner of this page.




1. i tried some tests with 7g Cu at 95°C with 100 ml 40 % sulfuric acid and additional small amounts of ~ 40-45 % hydrogen peroxide by time but i have the feeling (hope it´s the rigtht word ^^ ) it reacts very slowly. -> the great excess of sulfuric is acceptable because i want to get the copper back by electrolysis and reuse the sulfuric.

a other test was 7g Cu at 95 °C with oxygen air-bubbles ......veryyyy slow

2. sorry when it sound´s not humbly -> I wanted to annoy nobody. 
my maxim clear question - clear answer :mrgreen: 

3. under normal circumstances i search a long time before i ask a question but i have to decide fast for a technique ( buy the copper or not ) -> iss it practical and economical to refine it or not -> so hoped for a fast answer to calculate the cost´s 

.......so the main reason for my question is my feeling that it reacts very slowly -> beacuse i do something wrong


EDIT: i forgot: normally the cheapest way is to make a Anode + H2SO4 - stainless steel cathode ... but i found that it needs days ( up to 21) to make this ....and if i buy this copper ( it is a lot of copper ) it comes regular (hope it´s the rigtht word ^^ ) so i need a fast technique to refine it


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## Harold_V (Nov 18, 2010)

Well, it might interest you to know that dilute sulfuric acid is the acid of choice for pickling copper. 

Reason?

Because it won't dissolve copper---but dissolves copper oxide with a vengeance. 

You may wish to rethink your "no nitric" idea. 

Harold


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## nickvc (Nov 18, 2010)

I think you are going to chase your tail on this.
Harold I know has tried to refine copper as have I and several other members and no one has yet succeeded to do it efficiently. Copper refining seems simple but in truth from my and others experience it's not. Small scale set ups just don't seem to work the main problems seem to be the quality of the feedstock and maintenance of your plating solutions and even if you succeed you will still only get scrap price for your copper.
I fear your going to have to do a deal with a large copper refiner who may well be interested if you have large volumes,tonnage, and the gold content is worth chasing!
Whether you can get a fair deal? The only way to ensure you do is to be present on melting and weighing and taking samples from each as it's melted and from each bar or melting and assaying each one yourself but your going to need to cast huge bars or the assay charges will be eating your profits rapidly. 
Another point to be aware of is that turnaround times aren't quick usually months,I gather advances can be available but interest is charged and deducted from the settlement.


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## future gold refiner (Nov 18, 2010)

Harold_V said:


> Well, it might interest you to know that dilute sulfuric acid is the acid of choice for pickling copper.
> 
> Reason?


1. Sulfuric is really really cheap for me and it is preferred in the following electrolysis to get cathode copper 



Harold_V said:


> Because it won't dissolve copper---but dissolves copper oxide with a vengeance.


2. i know - that´s the reason why i add hydrogen peroxide (it is clean and don´t pollut my solution ->>> reuse)



Harold_V said:


> You may wish to rethink your "no nitric" idea.


3 . I used nitric several times in inquartation [with copper or silver] ( like it -> very fast ) but i know (and hate) the amount of toxic NOx fumes.

-> if i think about to dissolve 100kg or 1 ton of copper with nitric I feel bad - no very bad :mrgreen: . 

- other point is that 59 % HNO3 is three times more expensive than 96 % H2SO4 (without molarity - per kg !!!)


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## future gold refiner (Nov 18, 2010)

nickvc said:


> I think you are going to chase your tail on this.
> Harold I know has tried to refine copper as have I and several other members and no one has yet succeeded to do it efficiently. Copper refining seems simple but in truth from my and others experience it's not. Small scale set ups just don't seem to work the main problems seem to be the quality of the feedstock and maintenance of your plating solutions and even if you succeed you will still only get scrap price for your copper.



that´s the reason for electrowinning the copper out of solution ( with support by electrowinning machine constructing company )



nickvc said:


> I fear your going to have to do a deal with a large copper refiner who may well be interested if you have large volumes,tonnage, and the gold content is worth chasing!



sorry but they are all cheater :lol: -> that´s the reason to do it myself




nickvc said:


> Whether you can get a fair deal? The only way to ensure you do is to be present on melting and weighing and taking samples from each as it's melted and from each bar or melting and assaying each one yourself but your going to need to cast huge bars or the assay charges will be eating your profits rapidly.



it comes out of a melting furnace and i have to decide to get a bar or granules



nickvc said:


> Another point to be aware of is that turnaround times aren't quick usually months,I gather advances can be available but interest is charged and deducted from the settlement.



that is the main reason why I am think about to dissolve the granules and refine the copper later (out of solution)
-> the fast access of PM sludge (big refiners also think so)


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## Gold (Nov 18, 2010)

http://www.intec.com.au/public_panel/copper_process.php


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## Platdigger (Nov 18, 2010)

"it comes out of a melting furnace and i have to decide to get a bar or granules"

Well, if you can get your copper as granules, you could roast this with access to air to oxidize the copper first.
Then you will not need the H2O2.


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## nickvc (Nov 19, 2010)

It might help if we knew the gold content of the material your trying to refine,is it 0.1% or more ?is it consistent throughout or does it vary? I'm still not sure your going to find an economic way to achieve your aim unless the gold content is reasonable but I do understand why you hope you can find a process to do this yourself.


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