Strange memory finger yields

[samuel-a]

Last week i ran a batch of neatly trimmed memory fingers.
Gold yield turned out : 0.83g /lb

Does that figure seems reasonable to you guys?
Memory sticks are all late 90' or younger, even so, seems kinda low yield to me...

 

[Anonymous]

A/P or A/R?

 

[samuel-a]

A/R

any thoughts?

 

[Harold_V]

Last week i ran a batch of neatly trimmed memory fingers.
Gold yield turned out : 0.83 /lb

Might be a good idea to express the yield in the unit of measure. The .83 most likely represents .83 grams, but that may or may not be the case, or clear to those that are not familiar with your thoughts.

I make a point of this because precious metals are generally discussed in terms of troy ounces, not grams.

Harold

 

[glondor]

For a comparison I recovered .91 gram from 12 oz of fingers. This is the amount of fingers from 10 pounds of memory. I thought my return was low as well. A/R method.

 

[samuel-a]

Sure Harold, i agree with your point.
I've added 'g' marking to the original post.

Thanks glondor for comparing note with me. Your numbers equals to: 1.21g /lb

 

[lazersteve]

Last week i ran a batch of neatly trimmed memory fingers.tested your left
Gold yield turned out : 0.83g /lb

Does that figure seems reasonable to you guys?
Memory sticks are all late 90' or younger, even so, seems kinda low yield to me...

Have you tested your leftover solutions for gold using stannous chloride?

Also are you measuring the yield as grams per pound of trimmed fingers or grams per pound of memory sticks?

Steve

 

[samuel-a]

Have you tested your leftover solutions for gold using stannous chloride?

Hi Steve

Sure, it was tested..
While still hot, the first AR leach was indeed positive for gold, for experiment sake i have seperated the 1st AR leach from the fingers while still hot and let it cool back. Upon cooling, gold had been pushed out of solution to settle on the bottom and stannous test turned negative.
For the extra caution, once gold had been filtered out, a flat sheet of copper was hanged in the now (probably) spent AR. No cementation occurred.

The gold from the first leach was combined with the second AR leach.

Also are you measuring the yield as grams per pound of trimmed fingers or grams per pound of memory sticks?

Yes, i probably should have mentioned this, the yield is per pound of trimmed fingers.
I kept statistics of this batch on a note in my lab that i will share later today.

The only 'vriable' that i can think of at the moment and it might be a long shot, if there's really gold missing, it might still be trapped in cavities and between the layers of the fingers board.
Though i doubt it, since the fingers (and gold remains from first AR) was cooked in the second AR enough time and with sufficient nitric and washed thoroughly with water.
I think i'll put them fingers for another round of AR to eliminate (or confirme) this theory.

 

[lazersteve]

Your yields are indeed very low. Perhaps you dissolved some of the gold in your wash cycle or had losses due to splattering.

Steve

 

[dtectr]

An excess of nitric may be keeping your gold in suspension -
Did you use any precipitant besides time & the copper plate?
Was your stannous solution new & fresh?
I've seen strange things with a vital, full & galloping AR solutions. Experience will teach me more, I guess. That is one reason why Hoke's "Familiarization Experiments" are such a revolutionary way to learn reactions.
Keep us posted & good luck!

 

[samuel-a]

Thanks for the suggestions guys.
I have proven (to myself that is) that the first leach didn't contain any values after it had cooled down, by saturating with Cu and repeated filtrations.

The other options i guess is that maybe some values are still left on/in fingers (still on the to do list)
OR
Just accept the fact the the yields are low on most newer kinds of memory sticks...

 

[samuel-a]

The other options i guess is that maybe some values are still left on/in fingers (still on the to do list)

Well.. this one is eliminated too...
Re-leacing of the fingers in dilute AR turned unfurtile.

I'm kinda stumped by that yield...
Seems like all option was covered... oh well... disappointment is part of life... 8)

 

[samuel-a]

The other options i guess is that maybe some values are still left on/in fingers (still on the to do list)

Well.. this one is eliminated too...
Re-leacing of the fingers in dilute AR turned unfurtile.

I'm kinda stumped by that yield...
Seems like all option was covered... oh well... disappointment is part of life... 8)

After sitting unattended in AR for few weeks, a stannous test now show now positive for gold... seems very dilute though...
It's amazing how much more copper dissolved as well from the already AR proccesed fingers...

Anyways... i hope to update soon with numbers.
Hopefully someone will find this data useful.