Saturation point of HCL / Bleach

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Gold Trail

Well-known member
Joined
Feb 6, 2009
Messages
113
Location
Central PA
I was wondering what the saturation Point of HCL / Bleach is?

IE how many milliliters per troy ounce of gold powder?

I just disolved about 4.3 Troy ouces of gold powder and it took about 1 gallon HCL and 1/3 gallon bleach

just seemed like a lot

I know Aqua Regia can hold quite a bit, but it seems the HCL / Bleach doesnt seem to match up.

ive had AR almost candy apple red with gold saturation before, but i could not seem to get the HCL / bleach
much more than dark yellow bordering but not quite orange in color

Thanks in advance

Ryan
 
Good question Ryan.
I think it would be a matter of how much the hcl will hold, as all of the free chlorine is eventually expelled.

I usually can boil an hcl/cl solution down by about a third before nacl crystals start to form.
Maybe this means I could have reactivated it with more(bleach)chlorine, and gotten it to absorb one third more pm's.
Reuseing and reactivating leach solutions until they are fully loaded, has to be cost effective.


Steve, Lou?

Mark
 
The saturation level depends on temperature and water content mainly.

If you want to get it really saturated use a higher concentration bleach -- household is only 2-5% bleach, industrial bleach is 5-12% hypochlorite or better. Dry bleaching powder (calcium hypochlorite) is very near 100% dry bleach by weight.

Steve
 
Thanks for the tip Steve.
I make my own "super clorox" :lol:

Any idea as to how much the solution will hold?

Mark
 
Gold III Chloride (AuCl3) is soluble to 68 g/100 ml in cold water according to wiki.

Since Gold III Chloride is about 65% metallic gold by weight that equates to about 44.2 grams of gold in 100mL of cold water.

Gold Chloride forms a dimer with HCl to yield chloroauric acid (H[AuCl4]) in a one to one molar ratio. This means that in the presence of HCl and water even more gold chloride would be dissolved.

Since HCl is soluble in water up to 38% by weight you could roughly calculate the maximum amount of gold a concentrated solution of HCl would hold as:

38% HCl =12.39 Molarity

12.39 x ~197 g/mol (molar mass of Au) = 2440.83 grams Au per liter as chloroauric acid dimer;

now we need to add the mass of Gold III Chloride that will be dissolved by the water content of the acid:

Density of 38% HCl = 1.189 g/mL x 1000 mL/L = 1189 g/L (grams per liter of 38% HCl)

Mass of 1L 38% HCl - mass of HCl gas = mass of water :
1189 g - (12.39 moles x 36.46 g/mole) = mass of water
1189 - 451.74 = 737.26 grams of water =~737 mL of water
737ml / 100 mL = 7.37
7.37 x 44.2 g/100 mL = 325.75 g Au

Finally, ignoring any gold complexes with the free chlorine in the solution, the maximum amount of gold that a 38% cold solution of HCl can hold is roughly:

2440.83 g (as chloroauric acid dimer) + 325.75 g ( as gold III chloride in water) =

3011.41 g Au per liter or approximately 96.83 Toz per liter. :shock: :shock:

or about 3 grams per mL in a 'cold' solution.

This sounds like an awful lot of dissolved gold to me, can anyone else verify this figure or tell me where I'm going wrong? If other salts (NaCl, NaOCl, KCl, etc) are present the solution would obviously hold less. Even if you ignore the gold III chloride in the water you have 78.5 Toz of gold per liter of 38% HCl as the dimer chloroauric acid.

Interesting....


Steve
 
Thanks Steve,
Talk about heavy!
Imagine what a two liter bottle of it would weigh.

Maybe a mistake at wiki. :lol:

Mark
 
Rule # 1- Never doubt Steve!
Rule # 2- Never doubt Steve!
I'll let you guess what rule # 3 is. :lol:

Mark
 
That's just to much math for me. :p
I was waiting on someone to verify it, It was interesting. I assume that the numbers reflect at or near 100 % conditions ?
And to think i thought battery acid was dense. :shock:

Great job steve :!:

I wonder :idea:
Could that be made into a spread sheet for other metals like say copper ? Silver ?
 
Gold said:
I wonder :idea:
Could that be made into a spread sheet for other metals like say copper ? Silver ?

Yeah, before someone say's something about the silver hcl thing, I meant for each acid. Like Hcl, Nitric, AR.
The maxium amout of metals each would hold at a certain acid concentration. Is that possible ?

Who's the spread sheet guy ?
 
Wow, Steve, thats quite the equation there. It does seem like alot.

I was asking the question more less to balance my mixing ratios. I had recently disolved a little over 3 tr oz and ended up with close to three gallons of Auric cloride due to little knowledge of its saturation point (and my impaitiantness)

I guess the question i intended to ask, is how many ml household bleach and how many ml HCL per tr oz of gold powder.

I have no doubts to your math and chemisrty skills (I have 0 chemistry experiance ) But, i just dont see 78.5 Toz in 1 liter of household bleach and HCL

I have had close to 3 Toz in a less than 1/2 full coffee pot of AR with it pushing blood red. i just couldnt seem to the the bleach / HCl much more than canary yellow

Thanks for your indepth research into this matter, had i known it went that deep, i would have asked the question differently.

. i assumed it was one of those things you just knew.

but that what I get for assuming things.

Ryan
 
Goldtrail,

The bleach plus HCl limits are lower due to the formation of sodium chloride. The use of HCl and chlorine gas at around 90C will get you closer to the theoretical maximums.

With the HCl and bleach you'll have to evaporate out the water and remove the sodium chloride that precipitates to get better concentrations.

Ralph,

A while back I started a spread sheet with various base metals and acid combination to determine solubility limits, but I never finished it 100%.

Steve
 
Back to the top with this one...

May be I missed something but. NaClO is actually a weak base .

Clorine is not the by product but clorine dioxide (ClO2)

The problem you are running into is not the saturation of the solution...
But you are actually neutralizing

NaOH is a intermediary product.


I believe I found some equations to back this up.
 
DNI, did you get my last post in response to your P.M. about resin beads.
Anyone who p.m.'s me on my Aflac account, I can't receive p.m.'s from Aflac.

:arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=2269&p=49325#p49325
 
Wow. You made my day. To be honest I thought you were just being ..a poop. :)
Thanks for going out of your way!

It is really great to see they recommend XAD-7.
I attached a document I found helpful
Thats what I have been considering.
I bought a sample.
Not enough to fill my columns though. Do you have a good source for volume? Sigma is the cheapest I have found but it takes a lot of hoops to get registered.
any suggesttions

I have 7 columns that I plan on running in an array. 5 cm diameter 60 cm length. ( I also have some 6"x5ft units, cant afford to fill them )
I have some peristaltic metering pumps that control multivalve rotary solenoids to change solvents and outputs.
By stagering them in procession (load,rinse,wash,rinse,elute,regenerate,wash) I would be able to create fine gold every few hours automatically.
I am pumped!
 
Your welcome D.N.I.
I have been busy putting together my next chapter in my life. Sorry it took so long. Give me some time to do some more research and i'll get back to your on the resin's and beads.

Thanks
 
http://www.wipo.int/pctdb/en/wo.jsp?IA=AU1993000312&DISPLAY=DESC

The resin's are made of polystyrene divinyl.

http://www.dow.com/PublishedLiterature/dh_0045/0901b803800455a5.pdf?filepath=specialtymonomers/pdfs/noreg/503-00002.pdf&fromPage=GetDoc

I have a background in Commercial chemical coating technology and this stuff is starting to look like several products i have researched recently. The chemistry is almost that of an Elastomeric roofing product i have been talking to them about at Rohm and Haas.

Another company who make these polymers is ICI or now known as I.C.I Dulux paint company here in the states. They also own name brands like Liquid nails. They make the scent that goes in perfumes, the dye that colors your cokes and drinks; They make dyes to color glass. They make pharmaceutical grade products. They just make it all.


http://en.wikipedia.org/wiki/Imperial_Chemical_Industries
 
From looking at the linked PDF, it seems that if someone had a very fine silt with gold in it that this mixture , if stirred, would dissolve the micro gold in the silt, in about 4 hrs.
My question is if you let the solution settle and decant the clear solution, it should have a conservatively, 95% of the available gold in solution, correct?
Also they were using sodium hyperchlorate, I believe. Would there be any difference in the reaction using calcium hyperchlorate pool bleach(I believe this is correct)
I was just thinking about the beach placers in different places, where you could concentrate the fines down to a 5 gal bucket and finish at home.
Any thoughts, Wyndham
 
lazersteve said:
The bleach plus HCl limits are lower due to the formation of sodium chloride. The use of HCl and chlorine gas at around 90C will get you closer to the theoretical maximums.

With the HCl and bleach you'll have to evaporate out the water and remove the sodium chloride that precipitates to get better concentrations.



Steve; I have a HCL/CL solution now that after boiling the solution to drive off any excess chlorine, salts have formed after cooling.. I think from your statement this would be sodium chloride, I have not had these salts form before, should they be expected allways ? or only if the solution is lacking enough water..(boiled away)..here is a picture of the salts formed.. total amount of solution 25ml before heating..amount of gold in solution un-known..HCL  CL    SALTS.jpg
 

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