precipitating with ferrous sulfate

[Ravi Pal Singh]

hello again guys…
Need your help …
I dissolved some clean gold in AR to refine it more cleaner. Denoxed the solution with Sulfamic acid and heated the solution to 80 C mixed some ferrous sulfate in distilled water and heated the beaker to 70-80 C. Prepared the solutions and put the ferrous inside the AR gold bearing. To my surprise the Gold solution was not denoxed properly and the color changed back as I poured the ferrous. I again took the Sulfamic acid denoxed again and again added the ferrous sulfate solution. This time the color changed to brown. After 5-6 hours there was gold settled at the bottom. I tested the solution with stannous and the test was negative. But I am suspicious that there is more gold in the solution so I added more ferrous but no gold…. Am I too suspicious and there is no gold ? What should I do to precipitate if any gold is left ….

 

[FrugalRefiner]

What should I do to precipitate if any gold is left ….

That's what the stock pot is for.

Dave

 

[Yggdrasil]

hello again guys…
Need your help …
I dissolved some clean gold in AR to refine it more cleaner. Denoxed the solution with Sulfamic acid and heated the solution to 80 C mixed some ferrous sulfate in distilled water and heated the beaker to 70-80 C. Prepared the solutions and put the ferrous inside the AR gold bearing. To my surprise the Gold solution was not denoxed properly and the color changed back as I poured the ferrous. I again took the Sulfamic acid denoxed again and again added the ferrous sulfate solution. This time the color changed to brown. After 5-6 hours there was gold settled at the bottom. I tested the solution with stannous and the test was negative. But I am suspicious that there is more gold in the solution so I added more ferrous but no gold…. Am I too suspicious and there is no gold ? What should I do to precipitate if any gold is left ….

As Dave says, that is what we use the Stock Pot for.
And when we process that, we Cement with Copper first.

 

[4metals]

If you are testing with stannous chloride and you did not test positive for gold you should be good. Remember stannous goes bad so test it on a known positive to be sure.

If your waste is treated properly with the first step being cementation with copper, you will recover any traces of PM’s in that process from all of your aqua regia wastes.