Odd happenings when doing 2nd AR

[yvonbug]

I had a nice bit of gold that I'm going to sell, and I thought I'd give it a 2nd AR to make it even better. I did it in a single batch, and when it came time to drop it out, I did the usual thing I do and thats to only do little amounts at a time. So I poured an inch into the jar, and added REAL hot water to it, till it was 3/4's full, stirred it up and added my Sodium sulfite. Now I do the exact same thing 5 more times, till all the solution is divided up evenly. You would think that they all dropped the same. But this time, one jars result was several shades lighter! Just one jar. All the rest came out the same shade as it went in. My solution started out orange, when I diluted it, it became lighter orange. If I diluted it more it'd be bright yellow. Why did this one batch come out so much lighter than the rest? When everything was done the same? I wish the whole batch had come out this light. That was the plan. But the rest looks the same as when I started, well, maybe a little lighter. I've included pics. I hope these load up in the right order. The bottle on the scale should be first. -Yvonbug-

 

[yvonbug]

Oh well, The pics are in reverse order.

 

[lazersteve]

Yvonne,

The entire batch can be lightened by boiling it in HCl until the solution no longer darkens (usually a yellow color).

Pour off the solution and test it for gold before disposing.

Rinse the gold powder several times with fresh water and slow dry on low-med heat with ample agitation (swirling of the beaker) until all steam vapors and odor of acid is gone.

This should lighten all of the powder in the photo.

As to why your precipitations are different color: My guess is one of the batches was a slightly different concentration than the others. The only color I worry about is the final color of the entire batch before the melt.

Steve

 

[yvonbug]

All I have to use is Muratic . Would that have anything to do with it? And when I boil it, do I use diluted Muratic? Isn't it diluted enough as it is? As it comes in the bottle? Or should I make it 1/2 water, 1/2 Muratic?-Yvonne-

 

[lazersteve]

Straight muriatic is fine for the wash.

Steve

 

[yvonbug]

Just wanted to show how nice it came out. And Thanks for the advice,-yvonbug-

 

[teabone]

Looks really good ! Now its time to melt to metal , thats my favorite part.