QuestionDear Thomas,
If you refine 20z. of 22kt. would your loss be 5.23g seeing that 22kt is 91.6% pure? The remaining 8.4% is impurities. And if so, is that an absolute rule or, it depends on the impurities. I hope you understand what I am trying to ask. It makes sense in my head but to articulate it is a problem. I hope you can help. Thank you.
AnswerDear Abdul Basir, thanks for this question. I hope the communications is clear enough for both of us. : )
First of all, here are the numbers we are working with, given because my figures are slightly different from yours either from rounding off the numbers differently or the math:
Think of 1 oz. and you can quickly figure results for as many ounces as you want from that. Keep in mind we are using the weight system used for metals, Troy weight. Whereas there are about 28 grams in the normal household ounce, the correct way to work with precious metals is with the Troy system which has 31.1 grams/oz. troy.
When refining a gold alloy down to fine(pure) gold, the difference in recovered metal from the original weight represents the metals in the alloy which were not gold. Those metals are now simply gone from the gold and the refined gold will weigh less by about the weight of the alloy metals. Keep in mind that some refining methods are more efficient than others and there is always the chance of some gold not being recovered and the chance of some alloy metals not being removed completely.
With 22 karat gold, the gold in the mix is 22/24 = 0.9167 or 91.67%. The remainder represents 2 parts out of the 24 parts used to define pure gold or alloys of gold. This 2 parts is 2/24 = 0.083 or 8.3%.
Using these figures for 1 troy ounce which is 31.1 grams, the gold weight in the ounce of 22 karat gold is 0.9167 x 31.1 = 28.509 grams. The remainder to be refined away is
0.083 x 31.1 = 2.581 gm. Adding together to check what we did: 28.509 + 2.581 =
31.09. The result should be 31.1 rounding off other numbers leads to the slight difference.
With 2 oz. troy or 62.2 gm, the refined gold should be right at 57.018 gm and the impurities removed should be at 5.162 gm.
As I mentioned in the third paragraph, the method of refining used may determine how pure your gold results to be. You may have 0.999 pure or possibly 0.990 pure, just to pick a number from the air. If impurities remain, the weights will not be the same as from a purely mathematical result since all is not perfect in this world.
I hope this helps somewhat.
Blessings and Peace. Thomas.
