copper metal put into your solution, is what we call cementing out values.
What happens when we do this?
The acid solution may contain our gold, it may also have other base metals dissolved in solution with our gold, and may have excess nitric acid, these metals are dissolved in the acid as ions or dissolved salts of metals, the atoms of these metals are missing electrons, by us putting the copper metal into this solution we provide electrons for the metals in solution, which are less reactive than the metal copper, (study reactivity series of metals on Google for a better understanding of this very important process), the copper will give up electrons and become ions dissolved into the acid, the more noble metals will gain the electron copper gives up, and these more valuable metals will change back into an full atom of metals as a powder we call cement (this name comes from when we do this with silver and silver powder looks gray like cement), our powder here will probably look black from the dirty gold, so the copper is oxidized (lose of electron) and dissolves into solution, the gold is reduced (gain of electron) and becomes an elemental powder of gold metal, the copper will also use up any free acid in solution as it is dissolved into solution, after excess acid is used up and all of the gold or more noble metal is reduced, the copper will not dissolve more or give up more electrons, this may take time depending on conditions.
After all of the gold is reduced we brush off the black powdered gold (into the solution) from the remaining copper bar, put the copper bar back into solution for a period of time to see if more gold comes out of solution making more black powder onto the copper bar, if it does not and the copper bar stays a clean copper color we can brush off the copper one more time into the solution rinse the copper off dry and store it in a plastic bag for later use, the solution we let settle well, to let all of the fine black gold powder settle, then we can remove liquid without moving the gold powder, the liquid tested with stannous chloride to prove no gold left in solution is then treated for waste.
Iron is added to the waste solution to cement out the copper, this iron solution is removed from the copper powders which formed, to the decanted iron chloride solution we add sodium hydroxide to raise the pH to 9.5 let the iron hydroxide settle, decant the solution and lower pH to 7 with small acid additions, at this point we have a clear salt water we can dispose of safely, we also have the metal powders which need to be dried before disposing of, these hydroxide powders if heated or incinerated will form the safer less soluble metal oxides, so we can the dispose of the oxide powder, with less harm of poisoning someone.
Now back to your gold powders, they will be dirty, and need to be cleaned before we can recover and then refine the gold from the powders.
My suggestion for you at this point is to dry these powders and save them, so you do not loose your gold, I could spend a lot of time trying to tell you what to do now, but you will still have troubles, because you have not studied enough yet to understand, this would only cause you and me both more troubles, dry your powders and spend time doing your study, the gold will still be there and you will learn how to recover and refine gold, without study all you will do is make mess after mess, and keep losing your gold, with study you will learn how it all works, so that you can recover and refine gold, and be able to answer your own questions.
What happens when we do this?
The acid solution may contain our gold, it may also have other base metals dissolved in solution with our gold, and may have excess nitric acid, these metals are dissolved in the acid as ions or dissolved salts of metals, the atoms of these metals are missing electrons, by us putting the copper metal into this solution we provide electrons for the metals in solution, which are less reactive than the metal copper, (study reactivity series of metals on Google for a better understanding of this very important process), the copper will give up electrons and become ions dissolved into the acid, the more noble metals will gain the electron copper gives up, and these more valuable metals will change back into an full atom of metals as a powder we call cement (this name comes from when we do this with silver and silver powder looks gray like cement), our powder here will probably look black from the dirty gold, so the copper is oxidized (lose of electron) and dissolves into solution, the gold is reduced (gain of electron) and becomes an elemental powder of gold metal, the copper will also use up any free acid in solution as it is dissolved into solution, after excess acid is used up and all of the gold or more noble metal is reduced, the copper will not dissolve more or give up more electrons, this may take time depending on conditions.
After all of the gold is reduced we brush off the black powdered gold (into the solution) from the remaining copper bar, put the copper bar back into solution for a period of time to see if more gold comes out of solution making more black powder onto the copper bar, if it does not and the copper bar stays a clean copper color we can brush off the copper one more time into the solution rinse the copper off dry and store it in a plastic bag for later use, the solution we let settle well, to let all of the fine black gold powder settle, then we can remove liquid without moving the gold powder, the liquid tested with stannous chloride to prove no gold left in solution is then treated for waste.
Iron is added to the waste solution to cement out the copper, this iron solution is removed from the copper powders which formed, to the decanted iron chloride solution we add sodium hydroxide to raise the pH to 9.5 let the iron hydroxide settle, decant the solution and lower pH to 7 with small acid additions, at this point we have a clear salt water we can dispose of safely, we also have the metal powders which need to be dried before disposing of, these hydroxide powders if heated or incinerated will form the safer less soluble metal oxides, so we can the dispose of the oxide powder, with less harm of poisoning someone.
Now back to your gold powders, they will be dirty, and need to be cleaned before we can recover and then refine the gold from the powders.
My suggestion for you at this point is to dry these powders and save them, so you do not loose your gold, I could spend a lot of time trying to tell you what to do now, but you will still have troubles, because you have not studied enough yet to understand, this would only cause you and me both more troubles, dry your powders and spend time doing your study, the gold will still be there and you will learn how to recover and refine gold, without study all you will do is make mess after mess, and keep losing your gold, with study you will learn how it all works, so that you can recover and refine gold, and be able to answer your own questions.
