too much NaNo3 as a prticipian?
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How many processors are we talking about here?
If it's only a few then the top picture is likely to be fair representation on the gold you would get.
If it's only a few then the top picture is likely to be fair representation on the gold you would get.
Again we are discussing different chemicals NaNO3 (sodium nitrate) and NaNO2 (sodium nitrite), although both salts of the same acid they act very differently in solution or with acids, even the concentration of the acid and its temperature can play a major role in how these salts react in solution.
Lets look at the nitrate first:
Hydrogen from an acid react with NaNO3 (sodium nitrate) to form nitric acid HNO3 and a salt of the acid used, example:
H2SO4 + 2NaNO3 --> Na2SO4 + 2HNO3
above we have sodium sulfate and nitric acid (neither of these will dissolve gold).
HCl + NaNO3 --> NaCl + HNO3 (note this one would dissolve gold because of the chlorides involved similar to the SSN leach, and especially if more HCl was used, making a poor mans aqua regia).
Sodium nitrite with cold dilute acid (from the hydrogen of the acid involved) will form Nitrous acid HNO2 (a light blue solution)in solution with acid or hydrogen from the acid, but only if cold and the acid is dilute, this HNO2 is only found in solution,it is also very unstable, and will quickly decompose.
2NaNO2 + dilute H2SO4 --> HNO2 + Na2SO4
HNO2 decomposes in solution to nitric oxide, nitrogen dioxide and water:
2HNO2 --> NO2 + NO + H2O
note this will give a brown gas of NO2 as the NO mixes with the air above the vessel:
2NO + O2 --> NO2 (g)
The NO2 can combine with water in the dilute solution forming Nitric acid and more nitrous acid:
2NO2 + H2O --> 2HNO3 + HNO2
In warm or concentrated acid or solutions the reaction produces nitric acid, nitric oxide and water:
3HNO3 --> HNO3 + 2NO + H2O
sodium metabisulfite will not make nitric acid in solution.
The orange salts look strange to me I still suspect iron (but I could be wrong) the color could come from a number of metal salts.
If you heat a sample of these salts strongly do you see a brown gas evolve? like NO and NO2?
if so I would probably try an incineration, because gold powders incinerated with chlorides is volatile, I would wash powders in a solution of NaOH and wash out the salt formed well with water before trying to incinerate the dried powders to remove the previous acid,and form metal oxides of the base metals involved, then wash the powders with boiling water, , (they will contain base metals, a boiling wash in HCl should dissolve the base metal oxides, helping you to remove the majority of them before you dissolve the gold again, to try to recover gold from them again.
Did you test the solution with stannous chloride or a ferrous sulfate crystal in a spot plate, to see if solution contained gold?
if you suspect nitric is involve a little sulfamic acid added to the test solution in the spot plate, and retry the test again, (GSP has been talking about diluting the solution with free nitric before retrying the test, I have not experimented with it but I believe what he has suggested).
If there is any gold was still in the solution it should cement out of solution using copper, a brown powder would form with the copper if gold was still in solution.
Sorry I cannot help more with precipitating gold using NaNO2, I never tried it and have read just a little about it, I do not think it is popular as I have not seen that much about it.
SMB will precipitate gold from solution, ferrous sulfate also called copperas will also work well and can be made at home with iron ( not steel) and dilute H2SO4 (if you are curious how to make it I have made posts of how I make mine).
Lets look at the nitrate first:
Hydrogen from an acid react with NaNO3 (sodium nitrate) to form nitric acid HNO3 and a salt of the acid used, example:
H2SO4 + 2NaNO3 --> Na2SO4 + 2HNO3
above we have sodium sulfate and nitric acid (neither of these will dissolve gold).
HCl + NaNO3 --> NaCl + HNO3 (note this one would dissolve gold because of the chlorides involved similar to the SSN leach, and especially if more HCl was used, making a poor mans aqua regia).
Sodium nitrite with cold dilute acid (from the hydrogen of the acid involved) will form Nitrous acid HNO2 (a light blue solution)in solution with acid or hydrogen from the acid, but only if cold and the acid is dilute, this HNO2 is only found in solution,it is also very unstable, and will quickly decompose.
2NaNO2 + dilute H2SO4 --> HNO2 + Na2SO4
HNO2 decomposes in solution to nitric oxide, nitrogen dioxide and water:
2HNO2 --> NO2 + NO + H2O
note this will give a brown gas of NO2 as the NO mixes with the air above the vessel:
2NO + O2 --> NO2 (g)
The NO2 can combine with water in the dilute solution forming Nitric acid and more nitrous acid:
2NO2 + H2O --> 2HNO3 + HNO2
In warm or concentrated acid or solutions the reaction produces nitric acid, nitric oxide and water:
3HNO3 --> HNO3 + 2NO + H2O
sodium metabisulfite will not make nitric acid in solution.
The orange salts look strange to me I still suspect iron (but I could be wrong) the color could come from a number of metal salts.
If you heat a sample of these salts strongly do you see a brown gas evolve? like NO and NO2?
if so I would probably try an incineration, because gold powders incinerated with chlorides is volatile, I would wash powders in a solution of NaOH and wash out the salt formed well with water before trying to incinerate the dried powders to remove the previous acid,and form metal oxides of the base metals involved, then wash the powders with boiling water, , (they will contain base metals, a boiling wash in HCl should dissolve the base metal oxides, helping you to remove the majority of them before you dissolve the gold again, to try to recover gold from them again.
Did you test the solution with stannous chloride or a ferrous sulfate crystal in a spot plate, to see if solution contained gold?
if you suspect nitric is involve a little sulfamic acid added to the test solution in the spot plate, and retry the test again, (GSP has been talking about diluting the solution with free nitric before retrying the test, I have not experimented with it but I believe what he has suggested).
If there is any gold was still in the solution it should cement out of solution using copper, a brown powder would form with the copper if gold was still in solution.
Sorry I cannot help more with precipitating gold using NaNO2, I never tried it and have read just a little about it, I do not think it is popular as I have not seen that much about it.
SMB will precipitate gold from solution, ferrous sulfate also called copperas will also work well and can be made at home with iron ( not steel) and dilute H2SO4 (if you are curious how to make it I have made posts of how I make mine).
butcher said:
This is what I will try to do with salts,
I tried before when this happen two mounts ago when I first started with AR but I tried to melt it and got dark staff with gold particles inside.
I tried with some other CPUs again and got some fine gold but not everything from solutions (still keeping the solutions) I stopped adding NaNO2 so it would not form the same salts, now I made the same mistake.
Interesting is that in a first adding of NaNO2 there is a brown fumes second adding no brown fumes and no gold and adding more NaNO2 again brown fumes and brown mud
again like never did it before. I successfully recover some gold from jewelry waste about 1,5 grams of waste 0,8g of gold, dissolved in AR boiled 3 times to get of excess of nitric acid (and had a little problem the beaker cracked cause I boiled too much) but put some HCl and water and NaNO2, color changed from yellow to colorless and brown gold was at the bottom of the beaker.
My be that I use too much acids and less boiling (now afraid of cracking).
I found smb and next is to learn how to use it.
cvikatore,
May I suggest you work first with a more pure metal, when learning to use the sodium metabisulfite? Working with a more pure solution with fewer problems will give you a better understand of the reactions involved.
Memory fingers, the gold plated copper edges on computer memory cards are a good source of gold, Close cut the fingers from the cards to avoid tin or solder, the copper is easily dissolved from the gold foils using HCl and 3% hydrogen peroxide, this forms a copper II chloride leach that will dissolve copper, this leach has been misnamed acid peroxide here on the forum, so many people on the forum discuss its use with this name or sometimes they use AP as an abbreviation, once this solution is made an air pump for fish tanks can supply oxygen, this copper II chloride leach is reusable and can be regenerated as long as copper is dissolved (base metals higher in the reactivity series like iron will contaminate the solution and it will not then be reusable to dissolve copper), (Google the reactivity series of metal this study will help you understand recovery and refining better), the copper II solution is light green color, as it dissolves copper and becomes darker brown when saturated with copper I chloride from dissolving copper into solution, as long as you do not overuse H2O2 there is little chance of dissolving gold with this copper leach, when dark brown adding a little HCl and air will put Copper I chloride back into solution as copper II chloride ready to dissolve more copper, Laser Steve's web site has a document that anyone using this leach should study, to learn how to use it properly.
This will give you some gold foils which after washed can be dissolved, I also suggest not using aqua regia to dissolve these foils for this test, aqua regia can be hard to learn how to use, and unless you understand well how to use it, it can be troublesome because of free nitric acid, (after studying the forum for a while you will learn tricks to eliminate this problem, and learn better how to properly use aqua regia (it is not as easy as the internet lead people to believe).
Try using HCl and sodium hypochlorite (common household bleach) to dissolve the foils; chlorine gas is generated by the NaClO (bleach) in the HCl acid, which will dissolve gold, read up on this and do not overuse the bleach, chlorine gas is much easier to remove from the gold chloride solution than free nitric acid is, heating it for a while will drive off free chlorine as a gas, then you can let the gold solution settle till it clears up, decant the pretty yellow gold chloride solution, and filter it, then you can use the SMB to precipitate the gold, use about as much SMB as you have gold, you can dissolve it in hot water, i would add it in portions with stirring and watch for a reaction, when you get enough SMB in solution you will notice brown gold powder forming from the yellow solution, just a little excess of SMB at this point and a good stir, let gold powder settle well, overnight is good, test the solution with the stannous chloride test, if you still have gold in solution a little more SMB will be needed, to precipitate the gold (I would mix up a fresh small batch of SMB if needed), and use the stannous chloride test to avoid using too much SMB, overuse of SMB can reduce copper from solution, and give a false positive in the gold test with stannous chloride (giving a brown reaction instead of the normal purple color of being positive for gold, this false brown reaction may be due to the copper being reduced in the reaction of the test.
Doing a study of the above techniques I suggested above will help you, learn easier how the reaction with SMB works, and it will help you get a better Idea of ways to deal with electronic scrap, and help you more in learning to recover and refine gold remember we do not want to dissolve gold with base metals, tin or solder are always bad in solution and should be avoided, you never want tin and gold dissolved in the same solution doing so is just a good way to lose your gold.
Keep studying Hokes book, it will teach you the basic principle, these are the most important things you can learn, if you understand them, you will understand basically how to recover and refine gold. You will understand how to keep from forming troublesome mixes, and even when you do form them, you will understand how to get back out of the problem.
May I suggest you work first with a more pure metal, when learning to use the sodium metabisulfite? Working with a more pure solution with fewer problems will give you a better understand of the reactions involved.
Memory fingers, the gold plated copper edges on computer memory cards are a good source of gold, Close cut the fingers from the cards to avoid tin or solder, the copper is easily dissolved from the gold foils using HCl and 3% hydrogen peroxide, this forms a copper II chloride leach that will dissolve copper, this leach has been misnamed acid peroxide here on the forum, so many people on the forum discuss its use with this name or sometimes they use AP as an abbreviation, once this solution is made an air pump for fish tanks can supply oxygen, this copper II chloride leach is reusable and can be regenerated as long as copper is dissolved (base metals higher in the reactivity series like iron will contaminate the solution and it will not then be reusable to dissolve copper), (Google the reactivity series of metal this study will help you understand recovery and refining better), the copper II solution is light green color, as it dissolves copper and becomes darker brown when saturated with copper I chloride from dissolving copper into solution, as long as you do not overuse H2O2 there is little chance of dissolving gold with this copper leach, when dark brown adding a little HCl and air will put Copper I chloride back into solution as copper II chloride ready to dissolve more copper, Laser Steve's web site has a document that anyone using this leach should study, to learn how to use it properly.
This will give you some gold foils which after washed can be dissolved, I also suggest not using aqua regia to dissolve these foils for this test, aqua regia can be hard to learn how to use, and unless you understand well how to use it, it can be troublesome because of free nitric acid, (after studying the forum for a while you will learn tricks to eliminate this problem, and learn better how to properly use aqua regia (it is not as easy as the internet lead people to believe).
Try using HCl and sodium hypochlorite (common household bleach) to dissolve the foils; chlorine gas is generated by the NaClO (bleach) in the HCl acid, which will dissolve gold, read up on this and do not overuse the bleach, chlorine gas is much easier to remove from the gold chloride solution than free nitric acid is, heating it for a while will drive off free chlorine as a gas, then you can let the gold solution settle till it clears up, decant the pretty yellow gold chloride solution, and filter it, then you can use the SMB to precipitate the gold, use about as much SMB as you have gold, you can dissolve it in hot water, i would add it in portions with stirring and watch for a reaction, when you get enough SMB in solution you will notice brown gold powder forming from the yellow solution, just a little excess of SMB at this point and a good stir, let gold powder settle well, overnight is good, test the solution with the stannous chloride test, if you still have gold in solution a little more SMB will be needed, to precipitate the gold (I would mix up a fresh small batch of SMB if needed), and use the stannous chloride test to avoid using too much SMB, overuse of SMB can reduce copper from solution, and give a false positive in the gold test with stannous chloride (giving a brown reaction instead of the normal purple color of being positive for gold, this false brown reaction may be due to the copper being reduced in the reaction of the test.
Doing a study of the above techniques I suggested above will help you, learn easier how the reaction with SMB works, and it will help you get a better Idea of ways to deal with electronic scrap, and help you more in learning to recover and refine gold remember we do not want to dissolve gold with base metals, tin or solder are always bad in solution and should be avoided, you never want tin and gold dissolved in the same solution doing so is just a good way to lose your gold.
Keep studying Hokes book, it will teach you the basic principle, these are the most important things you can learn, if you understand them, you will understand basically how to recover and refine gold. You will understand how to keep from forming troublesome mixes, and even when you do form them, you will understand how to get back out of the problem.
Take a little of the mud dissolve in AR or HCL/Cl and test with stannous. Should always do a second refine anyways, to achieve fine quality Au.
Tyler
Tyler
I would avoid aluminum, it gets very messy, and can form a gelatinous compound which can easily trap values, the reaction with acid solutions can be violent as the hydrogen leaves the acid as hydrogen gas.
Aluminum is also harder to deal with in treating the waste solutions.
I would choose copper or zinc depending on the goal.
Copper will only cement the more precious metals from solution.
Zinc is much more reactive and will cement a wide variety of base metals (zinc will also displace hydrogen from acid).
Aluminum is also harder to deal with in treating the waste solutions.
I would choose copper or zinc depending on the goal.
Copper will only cement the more precious metals from solution.
Zinc is much more reactive and will cement a wide variety of base metals (zinc will also displace hydrogen from acid).
