Non-Chemical Cheap scrap mixed with low-grade waste

[golddie]

In the Hoke book on page 67 she writes about
Rolled,Filled and Electroplated Gold, and Gold Scrap, Containing Soft Solder

She says that this cheap stuff can be mixed with low-grade waste from floor sweeps and polishing dust.
To collect the precious metals into a button.
Harold was saying that he had plenty of copper and he could not get rid of it even tough he lived in the same town where they had a big copper refiner.
I was wondering why didn't you mix this copper that was left over from refining when refining low-grade polishing waste.

Also there was a post by Harold that explained how to process low grade waste,if someone know where it is I would like to have that
Thanks

 

[golddie]

Also there was a post by Harold that explained how to process low grade waste,if someone know where it is I would like to have that

I found this link
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=1253&start=20

 

[Harold_V]

I was wondering why didn't you mix this copper that was left over from refining when refining low-grade polishing waste.

For two reasons. One of them is that I didn't use the furnace to process polishing wastes. It was all done chemically, so adding copper would have been the wrong thing to do, simply providing more base metal that had to be dissolved, but providing no benefit. That would not be true if the material was processed by furnace.

My second reason would be that if added metal was required, I would not choose copper, or copper alloys. The reasons are simple. Silver was available to me for such use. It requires a much smaller volume of nitric to dissolve equal amounts of silver as compared to copper, so it was faster and easier to deal with silver than it would have been with copper. It is for that reason that I used silver for inquarting instead of copper, or copper alloys.

Adding brass to your values is never a good idea, nor is adding bronze. By adding brass, you risk introducing lead to the process, which is never a good idea. Bronze, assuming it is bronze as it was once determined (an alloy of copper and tin) presents problems that are better left behind. Tin, in solution, creates filtration problems that are difficult to overcome. Both tin and lead are commonly found in copper alloys, so I avoided their use, in spite of them being recommended by Hoke.

Understand that chemical processing of low grade wastes (polishing wastes, or floor sweeps) generally does not provide a full recovery of values, but it is fast and easy, allowing for a more economical recovery of values in small lots, typical of those that would come from a small operation. Only a very small percentage of values is left behind, so the loss is not of critical importance. Furnace recovery would be better, but slower and more labor intensive. It is for that reason I chose to use the chemical process. All of the waste residues were accumulated for years, which ended up being my retirement plan.

For the record, even furnace recovery is not 100%. There is always some loss, but it can be minimized.

Harold

 

[golddie]

Hi Harold
Thanks very much for that detailed explanation
I really appreciate that