where is my gold? in solution or any where ales.....

[naandesh]

dear friends,
two day ago I received 35g gold from one of my clients for refining. as per XRF result its 85% yellow metal (29g gold and 6 g contamination approx.) . after refining i recover only 11g gold its 99.9% ( use SMB), 7g white powder left in AR. its may be silver.rest of 17g can't dropout from AR solution. I m worry about it cos next batch is above 400g. its happen first time in my refining job. test result is negative for balance solution.

 

[nickvc]

We need more details I think but you could try cementing the solution using copper or try adding a little more HCl to see if more gold will precipitate.

 

[Lino1406]

The 35 grams were nugget?

 

[naandesh]

The 35 grams were nugget?

its old jewelry scrap. melt down in bar then process ...

 

[naandesh]

We need more details I think but you could try cementing the solution using copper or try adding a little more HCl to see if more gold will precipitate.

tomorrow i will plan to add HCl and try to drop down with coppras. I think May be work.

 

[Lino1406]

Was the bar sample to XRF representative?

 

[naandesh]

Was the bar sample to XRF representative?

I personally visit and get the XRF report from my friends testing center.

 

[philddreamer]

Did you stannous test the remaining solution?

 

[jarlowski1]

It could have been a fake bar. The middle of the bar could have been filled with copper or some other metal and then the gold alloy poured around that. Just speculating here of course.

 

[naandesh]

It could have been a fake bar. The middle of the bar could have been filled with copper or some other metal and then the gold alloy poured around that. Just speculating here of course.

meting old jewelry in my own furnace. after turn in to bar then go for testing. Its part of my process flow chart.

 

[naandesh]

Did you stannous test the remaining solution?

its negative, but tomorrow i will be try with fresh one.

 

[Johnny5]

The 35 grams were nugget?

its old jewelry scrap. melt down in bar then process ...

If it was 35 grams of old jewelry, then I would be very surprised if there were 29 grams of gold.

 

[stella polaris]

The 35 grams were nugget?

its old jewelry scrap. melt down in bar then process ...

If it was 35 grams of old jewelry, then I would be very surprised if there were 29 grams of gold.

Asian jewelry is normally containing a high % of gold. You rarely find 8, 12 or 14 carat there.

 

[Johnny5]

The 35 grams were nugget?

its old jewelry scrap. melt down in bar then process ...

If it was 35 grams of old jewelry, then I would be very surprised if there were 29 grams of gold.

Asian jewelry is normally containing a high % of gold. You rarely find 8, 12 or 14 carat there.

Ok, I see now that he/she is in India. That would certainly explain it.

 

[Geo]

Remove the solution from any powders or solids. Heat the solution to where the glass is hot to the touch. There should be small bubbles forming it the solution. Keep the heat going until no more bubbles are forming. Remove from heat and allow the solution to cool completely. Test the solution with stannous chloride. If the test is barren (no color) the gold is hiding somewhere else. If the test looks negative but turns darker over time to nearly black, there is still free nitric acid. Add some more SMB and add a small amount of sodium hydroxide. Less than a gram while stirring. The gold will drop but it will be light and fluffy and not look much like dropped gold. It will need to be further refined.

 

[naandesh]

thanks all of you,
I complete the job, gold lose in process is 1 milligram.........
thanks with regards,

 

[nickvc]

thanks all of you,
I complete the job, gold lose in process is 1 milligram.........
thanks with regards,

Tell us how you solved your problem it may help others.

 

[naandesh]

I m following geo's Suggested method... It's work very well...
Again thanks GEO....

 

[Geo]

Glad I could help you. You are very welcome.