Very quick reaction using SMB

[Shark]

I recently posted on this thread, http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=24229#p256721, about the concentration of the solution. I added 2ml sulfuric to deal with any potential lead and diluted by three times, which should help deal with any silver that may have been present, then filtered.



I then mixed two heaping teaspoons of SMB into a cup of hot water and added it to the solution. It didn't take all of it, but the drop was very fast. I did need to add another 50ml of the SMB solution to get a negative test with stannous. The reaction was so fast had I not been videoing it, I would have missed the initial reaction.

Here is the video:

[youtube]http://www.youtube.com/watch?v=Q9dik2SST2U[/youtube]

Now, to my question, I have used this process to drop other solutions quite a bit so why was the reaction so fast this time? Was it the concentration of the solution? Was this solution cleaner than the others? What is your thoughts on it?

 

[Topher_osAUrus]

Probably concentration and complete initial removal of oxidizer which prevented it from precipitating/dissolving/precipitating until bleach or nitric was used up.

Looks beautiful though. Excellent work!
I hope my solution I am getting prepared to precipitate looks that good. It is just my first refine on the gold, so, i shall soon see.

How much gold do you expect from your drop shark?

 

[Shark]

25.8 grams went in, after redissolving, and one wash cycle, the button is 25.3grams

 

[goldsilverpro]

That's exactly how I do it and how I preach on how to do it. It always seems to drop immediately for me. It's mainly because I use the additions method for nitric. I also think the 3/1 dilution method before filtering lessens the effect of any excess nitric present and that speeds it up. I believe that both the total amount of excess nitric and its concentration are definitely instrumental in the speed or slowness of the drop.

 

[Shark]

GSP, I tried to follow closely the directions you had posted and enjoyed the whole experience of this batch. Next time I have enough material ready to work with, I want to try it again and see if I can get a better calculation on the chemicals I need. This type experience makes all the work involved worth while. Thanks for lending us newer members some proper guidance.