chlorine leach recipe problems

[Barren Realms 007]

But what starts the reaction with just HCL?

I'm no chemist but I would guess that dissolved oxygen could start it. This would dissolve a little copper to produce a little copper chloride which would act as an oxidizing agent to dissolve more and the rate would build. All in all, though, it would be a slow process.

Ok I can go along with that with pins in a crock pot with HCL and a bubbler, the oxygen can get in thru the bubbling action.

But how does the disolved oxygen get in with HCL and CPU's or pins on a hot plate with no bubbler? Is the HCL grabbing oxygen from the air just thru surface contact? And if that is so then if we put a top on our container to where no more oxygen can get in after the initial oxygen is depleated then will the reaction stop?

 

[Anonymous]

Copper that has been in air has a oxide coating however thin it may be. H+ and Cl- are dissoiated in water forming H3O+ and Cl-
the Cl- can react with copper(s) and put it into solution. This will be a slow reaction since the copper is not actually replacing the hydrogen.
I also think the oxider actually may oxidize the insoluble CuCl which would form on the surface of the copper allowing it to go into solution and make available more copper to the chlorine and that could be why it goes faster when there is an oxidizer present.

Thats my take on it. I however am only a basement chemist, as they say, I know just enough to get myself in trouble.
I am sure that Lou or one of the other "Real" chemist will eventually enlighten us.

Jim

 

[aussco999]

Hey Captain Kirt:

After reading your posts a couple of times, I'm guessing your "ore" is from a dredging operation, and I want to congratulate you on 4 oz. gold recovery for every 5 gallon bucket of cons. If all things are relevant, that sounds like a good number. The question I'm not sure of is, exactly what are you trying to leach, the head material going into the dredge, the tails coming out of the dredge, the 5 gallon bucket of cons or the recovered gold?

A chlorine leach is an effective and powerful method to convert several elements to a higher valance, but it can sometimes be a bit confusing to the neophyte chemist. The ideal chlorine leach converts molecular chlorine to nascent (new born) chlorine, then back to molecular chlorine for continuous reuse. This is normally done in a nanosecond using a secondary acid/oxidizer, like nitric acid.

It's during the nascent phase that the chlorine attacks (puts into solution) the metal. Unfortunately, the nascent phase is not gold specific. On the EM Series there are several metal that will go into solution before gold and can/will use up your leach potential. Keep in mind that a lot of good info on this forum relates to some form of already refined gold and may not work as well on your material. But, the basic info that Harold, GSP, Steve, 4Metals and all the others, keep trying to pound into everyone's head is to get rid of, or control the base metal contaminates, still applies to ores.

My expertise is in the mining and metals extraction from placer/hard-rock ores on a large scale (XXX TPH), so I don't normally refine the metals beyond the first pyrometallurgy pour. Maybe I can help get your ore to a better leach stage, and then some of the other forum members can take over for the refining. You mentioned using a roasting procedure. Does your material contain any sulfides or tellurides that need roasting? And, what exactly is being assayed, heads, tails, cons or the gold, and what type of assay are being done?

I always do a lot of homework on my mining projects to try eliminating as many of the problems before they happen, so I may ask a lot of question before I can pass along any helpful info. In regards to a safety issue, I will say stay away from the muriatic (HCl) acid and mercury combination, as they can produce some nasty chemical mixtures that will stunt your longevity. Maybe you could post a start-to-finish flow chart of your operations, up to the "it-ain't-working" point. There might be some earlier steps in your process that can be changed to improve the gold recovery ratio.

And, don't get discouraged. From the numbers, it sounds like you might be on a good enough mining project to make a living.

Good luck,

John

 

[Rhodium]

John, What is your area of expertise ?

Thanks.

 

[Harold_V]

John, What is your area of expertise ?

The fourth paragraph of his post starts out saying "My expertise is in the mining and metals extraction from placer/hard-rock ores on a large scale (XXX TPH),"

A great deal of wisdom is apparent in his comments.

Harold

 

[Rhodium]

I guess a better way to put it would be job description.

 

[captain1]

Let me say all your comments were very help full. This weekend I did some more research and testing with my ore. I came across a comment made by someone in the forum. Can't remember who made it. But the comments on copper oxide got me thinking. What was said is that the base of my recipe had Lye(caustic soda) in it. When you have a base mixed just right with a acid will create metal oxide. or salt. I had that problem. I was leaching my metals and dropping as salt, instead of gold chloride. So I have now dropped that recipe and I am now using the recipe lasersteve has. Results were great just as I expected. However I am wondering now if I need to dilute my HCL/cl solution or put UREA in it before I precipitate my solution with ferrous sulfate? And how long is the standard to let your solution sit after your add the ferrous sulfate. And also would it be beneficial to make up some poor mans AR to clean up my first drop with. Or should I just use HCL/Cl to re-dissolve and drop with SMB or oxilic acid the second time. I'm sure it's covered somewhere in the forum. But the comments made on my questions are invaluable to me. I never would have gotten this far without the help of everyone so far.
Thanks everyone This forum rocks. Kirt

 

[Barren Realms 007]

Let me say all your comments were very help full. This weekend I did some more research and testing with my ore. I came across a comment made by someone in the forum. Can't remember who made it. But the comments on copper oxide got me thinking. What was said is that the base of my recipe had Lye(caustic soda) in it. When you have a base mixed just right with a acid will create metal oxide. or salt. I had that problem. I was leaching my metals and dropping as salt, instead of gold chloride. So I have now dropped that recipe and I am now using the recipe lasersteve has. Results were great just as I expected. However I am wondering now if I need to dilute my HCL/cl solution or put UREA in it before I precipitate my solution with ferrous sulfate? And how long is the standard to let your solution sit after your add the ferrous sulfate. And also would it be beneficial to make up some poor mans AR to clean up my first drop with. Or should I just use HCL/Cl to re-dissolve and drop with SMB or oxilic acid the second time. I'm sure it's covered somewhere in the forum. But the comments made on my questions are invaluable to me. I never would have gotten this far without the help of everyone so far.
Thanks everyone This forum rocks. Kirt

Steve is definetly the one to listen too, he helps a lot.

Heat your HCL/CL soultion till the clorine disipates. Dilute 1 part HCL/cl 3 parts water and add SMB to drop your gold. You don't add Urea to HCL/cl, you use Urea on AR.

This post might help you get more PM's out of what you are looking for.
http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=6026

nickvc,
I want to appologize for saying you were wrong in your earlier post on this thread
. You were correct. I'm sorry for that.

 

[nickvc]

nickvc,
I want to appologize for saying you were wrong in your earlier post on this thread
. You were correct. I'm sorry for that.

Hey no problem this forum is about learning and the posts that followed i found useful, and hopefully we can point Captain in the right direction to be able to make his mine pay.

 

[Harold_V]

That was a well handled exchange, for which you gents have my compliments.

It pains me to see readers lower themselves to the level of junior high kids when dealing with questionable postings. We all learn from these things---some because they're right, and some because they're wrong. When corrections are offered in a mannerly fashion, such as we've witnessed here, everyone benefits.

Harold

 

[nickvc]

That was a well handled exchange, for which you gents have my compliments.

It pains me to see readers lower themselves to the level of junior high kids when dealing with questionable postings. We all learn from these things---some because they're right, and some because they're wrong. When corrections are offered in a mannerly fashion, such as we've witnessed here, everyone benefits.

Harold

Thank you Harold. This forum is too valuable a resource to spoil for personal bickering or point scoring. Ive learnt more here in the short time as a member, than in the many years in the refinery that i ran,im not an expert and dont really have a good understanding of the chemistry involved so i listen to the many memers of this forum with respect and if i post a incorrect statement i expect to have it corrected ,and to learn from that correction,in this case i was right but thanks to the challenge to my post i gained a better insight.

 

[captain1]

Can I drop my solution before it is diluted down,with ferrous sulfate? Or do I need to dilute always before I use a precipitant. And is smb the better precipitant? It would be nice if I could drop without diluting first. Then I would be able to continue use of some of my solution.

 

[Barren Realms 007]

Can I drop my solution before it is diluted down,with ferrous sulfate? Or do I need to dilute always before I use a precipitant. And is smb the better precipitant? It would be nice if I could drop without diluting first. Then I would be able to continue use of some of my solution.

I think Steve and the rest of the guru's here will say to use SMB,since it is recomende here so much I will say it is better than ferrous sulfate. Not sure about the ferrous sulfate and it's abilities someone else will have to answer that. I think I have seen Steve or Harold post about using SMB (in a soild form no water added to disolve) without diluteing and it was stated that ice cubes were added to the percipitation process to keep the heat generated by the reaction down.

Steve gave me the best advice when he told me to add the clorox to the HCL soultion slowly because it is the bubbles that are produced that actually cause the reaction to disolve the gold. That was why I sent you to the link on the thread so you could look at what was happening. When he told me that I sent the material I was working with thru 3 process of HCL/CL and recovered gold each time. You might want to possibly try sodium hypoclorite mixed with water in a vessel to produce the clorine gass and then bubble it from that thru a tube into the material you are working with.

But what do I know I'm just the local idiot with a dunce hat setting in the corner like a bad boy!!!! :mrgreen:

 

[Harold_V]

I think I have seen Steve or Harold post about using SMB (in a soild form no water added to disolve) without diluteing and it was stated that ice cubes were added to the percipitation process to keep the heat generated by the reaction down.

Regards icing, unless you have a concentration of gold that exceeds maybe 2 ounces per liter, there is no need for ice. You can probably achieve success when it's as high as 3 ounces/liter. Precipitation is an exothermic reaction, but if you have adequate volume of solution, it will absorb any heat released. For the typical batch, where you may have a half ounce in a liter, you don't even notice a change in temperature.

Ferrous sulfate is generally applied by pre-dissolving. That alone tends to increase solution volume adequately in all but the most heavily concentrated solutions.

I believe Steve has commented several times on using SMB directly out of the container, no prior dissolution.

Harold

 

[lazersteve]

I use dry SMB exclusively when precipitating gold.

In this case the ice is not added to prevent the solution from overheating when SMB is added, but instead, it's for cooling the solution down to lower the solubility of the dissolved silver chloride. It can either be added into the solution directly or the beaker can be placed on ice to lower it's temperature. I usually add a handful of cubes into the solution. I learned this little trick from 4Metals !

DO NOT place a hot beaker directly into an ice bath or it will shatter! Let the beaker cool to room tmeperature first.

Steve

 

[Barren Realms 007]

I use dry SMB exclusively when precipitating gold.

In this case the ice is not added to prevent the solution from overheating when SMB is added, but instead, it's for cooling the solution down to lower the solubility of the dissolved silver chloride. It can either be added into the solution directly or the beaker can be placed on ice to lower it's temperature. I usually add a handful of cubes into the solution. I learned this little trick from 4Metals !

DO NOT place a hot beaker directly into an ice bath or it will shatter! Let the beaker cool to room tmeperature first.

Steve

I guess you are useing regular tap water for you ice cubes so you are dooing a double whammy on the silver cloride by useing the clorinated ice cube and dropping the temp and this does a better job of dropping the silver cloride.

Does this percipitate fine silver cloride? I ask because I have seen it mentioned that you add warm water and the silver cloride will clump together more isn't that correct?

 

[Platinum]

8)

 

[Anonymous]

hi i am new here and have been reading every ones comments , charles butler at butler labs has provided info on a clorox and vinegar leach that i have found works well on pgms and gold as well . it consists of equal parts clorox and 5% white vinegar @ 150 degrees , it typically does its job in a 2 hr time frame , precipitate with zinc and smelt , the orp runs at about 1145 at its peak and the ph runs around 1 or 2 , do not use an iron vessel as your irons will be in a foam . if this needs to be said , do not breathe the fumes these are household ingredients and should be enviromentaly friendly happy trails

 

[shyknee]

they are not environmentally friendly just because they are household product

They can still kill you or do you harm

take precaution

be safe