mass spec components & PM

[dtectr]

My buddy has a 5 gal bucket of these used/junked components - gold-plated brass from mass spectrometers.
diminsions:
the center one:25mm X 7mm X 3mm
end one: 32mm X 10mm X 8mm (center hole is thru & thru, funky shading from scan)
The company, now defunct, would replate their own pieces when it got thin. This is a heavier gold plate, similar in color to the CPU I scanned them next to for color/size comparison. Anyone have any experience with these?

We plan on using a sulfuric cell to strip them. However, for estimating purposes, I was thinking of dissolving a couple hundred grams of each, weighing before & precipitate after, for a guesstimate. Any suggestions on how to procede with analyzing/rough assaying?

any feedback greatly appreciated.
thanks

 

[lazersteve]

Process 100 gram sample with diluted nitric acid, then digest the resulting gold and precipitate. Wash, dry, and melt the precipitated gold powder.

Weigh the resulting clean gold for a rough estimate of pecrcentage of gold in scrap ( 1 gram yield = 1% of gold in scrap).

Steve

 

[dtectr]

would the cold recipe nitric, which if i remember right is approx. 35-38% be suitable or should i dilute it more?

 

[lazersteve]

Check it for chlorides first using a pinch of AgNO3 * dissolved in water, any precipitates that form when added should be filtered out, then use it as is.

Steve

*=Edited to remove calcium nitrate, sorry for the error.

 

[dtectr]

Check it for chlorides first using a pinch of AgNO3 or Ca(NO3)2 dissolved in water, any precipitates that form when added should be filtered out, then use it as is.

Steve

Would the KNO3 I have for Poor Man's AR work for this? I have no nitric made up to produce silver nitrate.

 

[lazersteve]

Yes, just adjust the amount of nitrate you use as listed in the recipes.

Steve

 

[Platdigger]

Actually Steve, I think what he is asking is if he can use potasium nitrate to check his nitric for chlorides.

 

[lazersteve]

Actually Steve, I think what he is asking is if he can use potasium nitrate to check his nitric for chlorides.

If that's what he is asking, the answer is no. Silver nitrate will form an insoluble chloride which can be filtered out, potassium nitrate won't. I checked the solubility chart and found that calcium nitrate would not be a good choice either, so I'm correcting the above post.

Steve