Help with chlorine
- Thread starter jrpincctx
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philddreamer
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Jr., you don't want to boil your HCl/Cl solution; in order to evaporate the chlorine, you want to apply heat until you see vapor coming off the surface. Keeep track of the amount of chlorine added to the HCl, that way, when it comes time to evaporate the bleach, just watch the volume of your solution as it returns to the initial HCl level. At this point, most of the chlorine, if not all, has evaporated. Then add a bit of water and your SMB.
Take care and be safe!
Phil
Take care and be safe!
Phil
ok i am using 100 mil of muratic and 100 mills of chlorine after the gold flake i add in is dissolved i should at 200 mil of distilled water and add low heat till my volume is reduced back to 200 mil of solution and then add my solution of dissolved smb into it correct
How many ounces of gold are you trying to dissolve?
That sounds like an awful lot of solution, and way sounds like way too much sodium hypochlorite (bleach), why add a ton of water, the acid and bleach have way more water than you need already.
If this is gold free of base metals ( and fine foils or powders) I would cover it in HCl, add NaClO (bleach) in small increments, on a low mild heat (heat not needed but will help reaction to progress a little faster), let react and add a little more NaClO, until gold is dissolved, once gold is dissolved heat to drive off chlorine gas from solution, let cool (let insolubles settle overnight is best), decant and filter solution, then you can use your SMB to precipitate your gold.
That sounds like an awful lot of solution, and way sounds like way too much sodium hypochlorite (bleach), why add a ton of water, the acid and bleach have way more water than you need already.
If this is gold free of base metals ( and fine foils or powders) I would cover it in HCl, add NaClO (bleach) in small increments, on a low mild heat (heat not needed but will help reaction to progress a little faster), let react and add a little more NaClO, until gold is dissolved, once gold is dissolved heat to drive off chlorine gas from solution, let cool (let insolubles settle overnight is best), decant and filter solution, then you can use your SMB to precipitate your gold.
jrpincctx,
If we were using Aqua regia Hokes states approximately:
4 fluid ounces of HCl (118.29ml)
And
1 fluid ounce of HNO3 (29.57ml)
To dissolve a troy ounce of gold
So if we divide this by 31.103 (grams in an troy ounce) we can see how much we need to dissolve a gram of gold:
118.29ml HCl / 31.103g/t.oz = 3.8ml HCl (32%)
And
29.57ml HNO3 / 31,103g/t.oz = 0.95ml HNO3 (68%)
To dissolve a gram of gold
Or
3.8ml HCl + 0.95ml HNO3 = 4.75ml of aqua regia to dissolve a gram of gold.
Taking this a little further:
About 68% water in HCl, and about 32% water in HNO3, and water also forms in the reaction.
From the 4.75ml aqua regia, only about 2.88ml is pure acids and about 1.87ml is water in these acids, not counting water created from the reaction with a gram of gold.
Subtracting this water 2.58ml pure HCl and 0.30 ml of pure HNO3 in 2.88ml water react to dissolve one gram of gold.
Now with the HCl / NaClO (sodium hypochlorite bleach) method, it is a bit harder to determine how much to use, because the sodium hypochlorite bleach is a basic solution and will neutralize some of our acid to salts. so we may need a little more HCl per gram to begin with, and the sodium hypochlorite is only about 3 to 6 % dissolved chlorine in over 90% water so it will dilute solution as well as it may not be as strong of an oxidizer as the nitric is on our gold, so I would begin with a little more HCl per gram of gold.
the reaction with HCl should be fairly close (except for some lose of acid in reaction with base, and it may take more sodium hypochlorite because of the small amount of oxidizer, and with all of the water involved your ending solution would be of greater volume.
Other consideration's with this method is the chlorine gas will begin to leave the solution as gas, as soon as acid and hypochlorite are mixed, if heated the chlorine evolves even faster, here is where adding small amounts also helps to keep chlorine in solution longer, and reacting longer with our gold, instead of being wasted as gas.
Do not forget the neutralizing effects on our acids. we may need a little more HCl to keep our solution acidic, it is the acid and the water becoming acid that produces chlorine with the added NaClO (bleach), if we had a neutral or basic solution of gold and gold chloride, we would not generate much chlorine by adding NaCLO, as we do when we add it to the acid solution.
When I use the HCl / NaClO method I do not use a suggested recipe of how much, but I believe there is one here on the forum it may be in the general reaction list, or forum handbook.
If we were using Aqua regia Hokes states approximately:
4 fluid ounces of HCl (118.29ml)
And
1 fluid ounce of HNO3 (29.57ml)
To dissolve a troy ounce of gold
So if we divide this by 31.103 (grams in an troy ounce) we can see how much we need to dissolve a gram of gold:
118.29ml HCl / 31.103g/t.oz = 3.8ml HCl (32%)
And
29.57ml HNO3 / 31,103g/t.oz = 0.95ml HNO3 (68%)
To dissolve a gram of gold
Or
3.8ml HCl + 0.95ml HNO3 = 4.75ml of aqua regia to dissolve a gram of gold.
Taking this a little further:
About 68% water in HCl, and about 32% water in HNO3, and water also forms in the reaction.
From the 4.75ml aqua regia, only about 2.88ml is pure acids and about 1.87ml is water in these acids, not counting water created from the reaction with a gram of gold.
Subtracting this water 2.58ml pure HCl and 0.30 ml of pure HNO3 in 2.88ml water react to dissolve one gram of gold.
Now with the HCl / NaClO (sodium hypochlorite bleach) method, it is a bit harder to determine how much to use, because the sodium hypochlorite bleach is a basic solution and will neutralize some of our acid to salts. so we may need a little more HCl per gram to begin with, and the sodium hypochlorite is only about 3 to 6 % dissolved chlorine in over 90% water so it will dilute solution as well as it may not be as strong of an oxidizer as the nitric is on our gold, so I would begin with a little more HCl per gram of gold.
the reaction with HCl should be fairly close (except for some lose of acid in reaction with base, and it may take more sodium hypochlorite because of the small amount of oxidizer, and with all of the water involved your ending solution would be of greater volume.
Other consideration's with this method is the chlorine gas will begin to leave the solution as gas, as soon as acid and hypochlorite are mixed, if heated the chlorine evolves even faster, here is where adding small amounts also helps to keep chlorine in solution longer, and reacting longer with our gold, instead of being wasted as gas.
Do not forget the neutralizing effects on our acids. we may need a little more HCl to keep our solution acidic, it is the acid and the water becoming acid that produces chlorine with the added NaClO (bleach), if we had a neutral or basic solution of gold and gold chloride, we would not generate much chlorine by adding NaCLO, as we do when we add it to the acid solution.
When I use the HCl / NaClO method I do not use a suggested recipe of how much, but I believe there is one here on the forum it may be in the general reaction list, or forum handbook.
thank you butcher that was a very helpful explination. i do have the solution dissolved in a 50 50 ration or bleach and muratic . it is about 20 mil. smallest amount i could measure out. My dam pippette broke. now that all the flake is dissolves in in i could apply a low heat and some dissled water in small amounts to get rid of the bleach now? after i do not smell any more bleach i casn add my smb solution to drop out the god?
Chlorine will dissipate in a warm solution over time faster at a little higher temperature.
As we discussed earlier the hypochlorite being basic neutralizes the acid forming salts (table salt) NaCl, when heating sometimes these soluble salts will begin to precipitate as water is removed, this is not much of a problem as they are water soluble and will dissolve when water is added later (if needed), for the SMB to work some water is also needed in solution.
After you vapor off free chlorine from solution, a little water may be needed, to keep NaCl salts dissolved, this will also help to precipitate silver chloride if involved, a drop or two of sulfuric acid can help if there is a trace of lead in solution, letting the chlorine free gold chloride solution sit overnight it will usually clear up the foggy solution.
Precipitating the insoluble NaCl, PbCl, AgCl and other insoluble material (note I have made several posts on how to separate these white salts from each other, will not go into detail here).
Decanting (for 20ml use your pipette, oops you need another one), filter the solution to a very clean vessel (not even finger prints inside jar that would leave oils), I would do a stannous chloride test, just good practice at this point, but it can also give you an indication if you still have free chlorine re-dissolving your gold if the violet color appears then disappears, if stannous chloride reduces your gold to the violet color it is a good indication your SMB will also reduce the gold with no problem, add SMB about as much in wt as you expect gold, if you do not know how much gold it is best to start with a little SMB with good stirring, and use your stannous tests to determine when all of the gold is reduced to metals, when the stannous test goes from positive to negative.
Let the very fine gold metal settle well, the majority will settle fairly fast, but some of this fine gold can take longer (also depending on how clean the solution is), it does not hurt to let it sit overnight and retest with SnCl2 before decanting and washing your gold powder's (using Harold's gold wash found in getting your gold pure and shining)
As we discussed earlier the hypochlorite being basic neutralizes the acid forming salts (table salt) NaCl, when heating sometimes these soluble salts will begin to precipitate as water is removed, this is not much of a problem as they are water soluble and will dissolve when water is added later (if needed), for the SMB to work some water is also needed in solution.
After you vapor off free chlorine from solution, a little water may be needed, to keep NaCl salts dissolved, this will also help to precipitate silver chloride if involved, a drop or two of sulfuric acid can help if there is a trace of lead in solution, letting the chlorine free gold chloride solution sit overnight it will usually clear up the foggy solution.
Precipitating the insoluble NaCl, PbCl, AgCl and other insoluble material (note I have made several posts on how to separate these white salts from each other, will not go into detail here).
Decanting (for 20ml use your pipette, oops you need another one), filter the solution to a very clean vessel (not even finger prints inside jar that would leave oils), I would do a stannous chloride test, just good practice at this point, but it can also give you an indication if you still have free chlorine re-dissolving your gold if the violet color appears then disappears, if stannous chloride reduces your gold to the violet color it is a good indication your SMB will also reduce the gold with no problem, add SMB about as much in wt as you expect gold, if you do not know how much gold it is best to start with a little SMB with good stirring, and use your stannous tests to determine when all of the gold is reduced to metals, when the stannous test goes from positive to negative.
Let the very fine gold metal settle well, the majority will settle fairly fast, but some of this fine gold can take longer (also depending on how clean the solution is), it does not hurt to let it sit overnight and retest with SnCl2 before decanting and washing your gold powder's (using Harold's gold wash found in getting your gold pure and shining)
