Welcome to us.I new in this indduusstry, just learning, seeing video on Youtube, and faild 2 times,
I'm here hope to find what I miss, please support
Well you can start reading the links I gave you.Hi,
I'm happy to share my issue:
I have plates with 3 layer: gold, Niken and Copper and I start refining gold step by step as below:
Step 1: Immerse in a solution of nitric acid and water to separate the gold layers. After seeing that the gold layer has completely separated from the plate, I filter it through absorbent paper and obtain the gold-plated layer.
Step 2: I put the filter paper with the gold layer into the aqua regia solution (3HCL + HNO3) with heat, I tried to add as little HNO3 as possible by dropping until the metal was completely dissolved. After the metal was completely dissolved, I filtered the dissolved solution.
Step 3: I add in the same amount of water as the solution and boil until the water level returns to normal then let it cool, my purpose is to remove the HNO3
Step 4: I add SMB the solution, it turn to dark colour
After time, the solution appears precipitate but it stays cloudy and muddy, very soluble, i have attached a picture for you, i tested the water with stannous chloride and it turned black
Should I filter out this precipitate, boil the solution and continue adding SMB until I see a yellow precipitate or is there any other solution? Please advise.
Sure I will read all the link,Well you can start reading the links I gave you.
In Step 3 this do not work at all.
If you are going to do it by evaporation.
You need to evaporate to a thick syrupy consistence.
Then add HCl.
Brown funes should evolve if there still is Nitric in there.
If so do it again.
Whan the Nitric and NOx is driven off.
Add HCl until all is dissolved and filter until crystal clear.
Then add SMB and the Gold should drop just fine. Then test with Stannous.
If it test negative you can set it aside until next day. Test it again then if it is still negative, decant the liquid and collect the powder on the bottom.
If needed refine again.
Have you tested with Stannous?Sure I will read all the link,
But in this case, could you advise me now I should filter the brown precipitate,then start HCL process OR leave them there and start HCL process?
thank you for your respone
Hi,Have you tested with Stannous?
Have you tested the pH?
Stannous will give purple to black if there are Gold, it is our eyes in refining to know if there is still Precious metals in solution.Hi,
I filtered the solution to 2 part:
Part 1 is the brown precipitate: I put to AR and Test Stannous give very black colour
Part 2 is the remain solution in liquid: I test Stannous also give black colour but less than Part 1
So I start solve 2 part as:
Part 1: I add HCL and water and boild to kill HNO3 , then add SMB but precipitate still not hard, i attach picture, please advise me
Part 2: U add HCL and boil to a thick syrupy consistence.
please give me your opinions
Ygg. A Nitric solution decomposes with heat.Stannous will give purple to black if there are Gold, it is our eyes in refining to know if there is still Precious metals in solution.
You need to decompose Nitric NOx before SMB and boiling will not do that.
You need to evaporate to syrup and then add HCl.
After doing this one or more times it is ready to drop it after it is filtered clean.
This should give a clean and complete drop of Gold.
This is how a stannous test look like:
Picture from Lazersteve
View attachment 65231
Enter your email address to join: