What does Muriatic acid and SMB make?
HCl + Na2S2O5 ---> 2NaCl + H2O +SO2 (gas)
The problem is not what the HCl and sodium meta-bisulfite makes, the salt formed is no problem the water formed is no problem and the sulfur dioxide gas is not a problem if your solution only had dissolved gold.
steyr223, the problem to me sounds like you just "Butchered your gold", it sounds to me like you had dissolved base metals and some un-dissolved base metals and some un-dissolved gold fine powders and the dissolved some of the gold into solution and just made one big mess and then tried to precipitate this colloidal mess by adding SMB.
As you are learning now why we keep saying remove solder and tin and other base metals before you try and dissolve gold, we are just trying to explain how things will work and how they will not work. Or you can continue to try things your way and continue to "Butchered" your gold and ask for help to get out of the mess you made. (ok I just had to Butcher you some, that’s enough, lets see if I can help now).
There are several ways you could recover the gold, and without being there and seeing exact circumstances, it is harder to give advice, so my advice is given from what little I understand you have.
Well from pictures and description I am not sure what you have, but let’s just say for the fun of it that you have some very fine gold powders (un-dissolved and possible dissolved gold) and tin, and heavy copper and base metals in solution, maybe even traces of gold that tried to dissolve.
And you cannot get it to precipitate.
I will not tar and feather or butchered you, but it looks like you butchered that batch.
Let just act like it is a colloid.
In casserole dish on hot plate, add a little sulfuric acid (we just want to get acidity up), a copper bus bar and boil it good remove copper bar brushing off anything that cements onto bar off into solution, rinse bar, and put in plastic bag for use later, let solution cool and sit overnight, decant solution (suction bulb), from any powders (filter this solution, it may be slow because of tin) we will treat solution after the powders. add just enough water to cover powder, add a little bit of sodium hydroxide and stir we want to try and get pH close to neutral, if you do not have a pH meter or test papers try and get water fairly clear (not enough hydroxide your copper will color solution, close to neutral will clear, too much hydroxides and solution will get color again with base metals hydroxides), warm up solution and stir well, then add a little more water and let powders settle, siphon off this salt water, and add more water repeat at least two more washes, after removing salt water last time let powders dry, do not raise heat to where it bubbles and splashes, as it dries you may raise heat some, we want to eventually get the powders dry and crush them cook at high heat until no more smoke, then get them glowing red hot with propane torch (careful not to blow powder out of dish) heat red hot stirring them now and then (we are trying to drive out the acids, and oxidize the base metals like tin), let cool with lid, after cool I will spray them with fine mist of water just to wet and wash powder on side of dish down, cover with HCl and raise heat slowly till low boil. dilute a little with water (not too much), lower heat under boil but keep hot, and let powders settle well, then decant solution, rinse powders with hot water (just under boil but let them settle), until water comes off clear, (the HCl wash will help to remove tin as chloride, and copper chloride, the hot water washes will also help to remove lead chloride, you may see lead form crystals when it cools again, we have now cleaned up the powders considerably (depending how much base metals you had in these powders you may need to repeat the above washes, the colors of solutions can be a clue to what you have.
once the powders are fairly cleaned of base metals and the tin the problem, (I normally do a nitric acid wash), if you do not have nitric acid) you may try the acid peroxide on powders to see if you get copper into solution or if it just stays black to brown powders of gold and then you can dissolve the gold powders and treat them as you normally would.
The solution we will test with stannous chloride for values, and treat accordingly, if values in solution we may need to add back the copper bar and concentrate to get gold to cement, if no values treat as waste.
There are other methods to deal with this solution and what kind of mess it is will usually determine the action taken.
But it is best not to butchered you’re your gold and create this kind of mess, it is much easier to take the proper steps to begin with than to waste your time trying to save your gold from the mess you make.
Sorry about that did not mean to tar and feather you today, guess I just can not help myself.
:mrgreen:
