Aqua Regia Process:
I will explain two different aqua regia process in this article. You can watch the video that I divide aqua regia solution into two parts. In the first method, I add urea in solution until reaction. Urea neutralized the nitric acid. After that, I added SMB powder directly I gold solution. Immediately, solution color turns into black color. One more special thing happened if you notice that.
Now the bubbles on the solution surface become white. This is a most important thing. If you will become an expert at this point then you will never face difficulty in aqua regia process. You will not need any stannous chloride test for gold. I also never use stannous chloride. If your solution foamy bubbles are yellow then the solution is pregnant and if foamy bubbles are white then gold is not in solution.
2nd Aqua Regia Method:
I did all this to clear your confusion for aqua regia process. You can also use directly SMB powder for gold extraction in aqua regia process. Sometimes, it will work and sometimes it will not work or take a lot of SMB powder. As you can watch in the video, I did not use urea in the second method. I directly added SMB but it did not work. Then, I dissolved SMB in water and added SMB solution in aqua regia. It worked and the solution turned into black color. You can use different methods in aqua regia process as you need. If you have any confusion about gold in solution. Then you can test it with stannous chloride. But first, test your self and examine the solution. This practice will increase your experience and take you to the next level.
I hope, you will learn many things from this article. If you like this or any problem in aqua regia process then comment below. Subscribe my channel Gold Recovery to stay tuned. THANKS