# Inquartation Knowledge Check.



## sng (Jan 16, 2011)

I have been reading as much as I can and think I'm about ready to put my *knowledge* into practice. Before doing so, I thought it would be a good idea to have my procedure checked by those more knowledgeable than I. Any answers or comments, however small, will be greatly appreciated.


I have recently acquired an amount of jewelery composed of gold (8-22k) and sterling silver. The end product which I wish to achieve is 24k gold bullion. To accomplish this, I plan to use the Inquarting and Parting method. My understanding is that I melt the gold and silver together in a ratio of 1:4 by weight, pour the liquid alloy into cold water, and dissolve the cooled product in 35% nitric acid. After dissolution, the silver (and mostly copper?, please correct if my assumption is wrong, contaminants) should be in solution with the nitric acid while the (presumably pure) gold collects at the bottom of the reacting vessel. 

My first question is regarding the purity of the remaining gold. Given the quality of the source materials I am using, will I need to further process (besides rinsing with distilled water) the gold powder or will it be of acceptable purity for marking as 24k bullion?

To recover the inquarted silver, I will stir the nitric acid solution with a length of copper pipe. This will cause a single displacement reaction to occur in which the copper atoms replace the silver atoms causing them to precipitate out of solution. The reaction is finished when the solution turns blue. If the reaction stops before the solution is blue do I need to add heat or more nitric acid?

Something I was unable to find the answer to elsewhere is whether the copper will replace elements other than the dissolved silver. I am under the impression that the silver, once precipitated, will be of greater purity than the 92.5% at which it started, but this seems too good to be true.

When calculating the weight of the gold used in inquarting, I take the weight of the piece (10g 8k necklace) and multiply it by the percentage ofgold content (ite; 33%). When calculating the appropriate amount of silver to use (4x that of the gold), do I use the measured weight of the sterling pieces or 92.5% (%silver content) of their measured weight?

Lastly, am I wrong to assume that due to the nature of my source material I will be completely free from the great undesirables I've read about such as tin and lead?

Ty in advance.

Edit: PGM's would only be found in white gold, not uncolored gold alloys or silver, correct?


----------



## goldsilverpro (Jan 16, 2011)

The ratio of Au/Ag+other metals should end up 1/3. Three + one = 4 parts. Au is 1/4, one QUARTer of the final alloy. Thus, inQUARTation. Just make the gold about 1/4 of the total final weight. 

Weigh your karat gold in grams (*KGW*) and calculate the total gold (*Au*) in grams. The silver needed: *Ag to be added = 4Au - KGW*. If you have 10 grams of 8KT (33.3% Au), you have 3.33 grams of gold and you would add, from the formula above: (3.33 x 4) - 10 = 13.33 - 10 = 3.33 grams of silver. This gives 10 + 3.33 = 13.33 grams total weight after inquarting. Therefore, 3.33/13.33 = .25 = 25% = 1/4 = a quarter of the total weight after inquarting.

When cementing, the solution will turn blue almost immediately, from Cu dissolving in the displacement reaction. It is no indicator of anything except copper dissolving. The best indicator is to hold an eyedropper containing weak muriatic close to the solution and place one drop gently on the surface. A white cloud is silver chloride and that tells you silver remains in the solution. So, give it a stir and let it work for awhile longer.

Cu will displace some platinum group metals. The other other stuff it will displace does not appear in karat alloys.


----------



## lazersteve (Jan 16, 2011)

Karat gold is marked as parts per 24. Therefore 10kt gold is theoretically :

10 / 24 = 41.7% gold and 58.3% other metals. The other metals can be zinc, copper, nickel, and others depending on who made the gold. Also it's not unusual to find under karat gold, typically by as much as 1/2 karat. 

When inquarting I use 1 part gold to 3 parts base metals and/or silver. When using sterling figure the entire weight towards the base metals needed. 

For 100 g or 10 k you have:

.417 x 100 = 41.7 g pure gold maximum.

Leaving 100 - 41.6 = 58.4g other metals.

The required inquart ratio of 3:1 (Ag:Au) gives:

41.6 x 3 = 125.1 g

Subtract the base metals you have in the karat scrap weight:

125.1 g - 58.3 g = 66.8 g additional sterling scrap required.

When melting the alloy be sure to mix the silver and gold using the torch flame or a fused quartz rod to ensure the alloy is thoroughly mixed. Everything must be fully molten and flow around the dish easily before pouring in the cold water. Pour the alloy into the water in a circular motion to form the cornflakes. Be sure your water is in a tall stainless steel vessel to prevent the alloy from welding to the bottom of the vessel. 

Use heated 35% HNO3 (1 part distilled water to 1 part 70% HNO3) to dissolve the alloy. Add the acid in small increments until no more reaction is seen (small fizzing bubbles). Pour off the blue solution, rinse with distilled water. 

Apply enough 70% HNO3 to cover the gold honeycomb that remains in the beaker, breaking up any clump with a glass rod. Heat again until no more reaction is seen. Cool decant, and rinse with distilled water. 

Combine all solutions and rinses, treat with solid copper buss bar, not wire. With multiple rinses the silver from cementation reactions can approach 99+.

What remains is gold 'honeycomb' of purity in the high 90's (97%+) depending on how well you mix the alloy and perform the extraction plus rinses. Process this gold as typical.

I demonstrate this entire process and more on my upcoming DVD 'Testing and Refining Karat Gold' to be released in a few weeks at my website store:

http://goldrecovery.us/pricing.asp

There are no guarantees that your karat gold is free of lead or tin. It all depends on who owned it before you and if they did any 'shade tree' repairs to the scrap using the wrong solder.

The Guided Tour Link below has more information if you care to read about the required amounts of nitric acid and other details.

Steve


----------



## JOEYL (Jan 19, 2011)

How much 35% nitric is needed to fully dissolve 500g of 25% Au corn flake
is there a simple standard formula for the amount of nitric needed


----------



## sng (Jan 19, 2011)

Cover material in nitric. Wait until reaction slows + add more nitric. Watch Lazersteve's inquartation +separating silver from gold videos. Actually, watch all of his videos .

http://www.goldrecovery.us/site.asp = lazersteve's website.


----------



## goldsilverpro (Jan 19, 2011)

JOEYL said:


> How much 35% nitric is needed to fully dissolve 500g of 25% Au corn flake
> is there a simple standard formula for the amount of nitric needed



If the gold was all 18KT to start with, it will take about 1120 ml of 35% nitric, assuming you used pure silver to inquart with.

If it was all 10KT, it will take about 2410 ml.


----------

