AR Process not completing

[Harold_V]

Hmmm.

You must have normally received about 10k scrap. 110% of scrap gives about 25% gold, if the incoming scrap is close to 10k. But if it averages 14k (admittedly higher grade scrap), then I calc that closer to 190% of scrap weight with Ag is required.

Sorry, you're wrong about everything.

Lets look at it like this:
I'm going to assume that the lot I received was only 14K.
I'm also going to talk about grains, so we can get down to fine details.
I'm going to assume that the 14K I speak of is really not 14K, but likely 13.5 K, which is not unreasonable.

Based on that, I'm going to assume that the gold content is 56%. That means that from the (troy) ounce of gold received, there is contained within 268.8 grains of gold.
That means that it must contain 211.2 grains of silver and base metal.

If I add 110% of the received weight in silver, I'd add 528 grains of silver to the 211 grains already present. That totals 739 grains of silver/base metal. Overall weight would now be 1008 grains. Divide 268 grains by 1008 and you get 26%, which is well within the acceptable parameters of inquartation (Anything up to 35% can work---it's just more fiddly).

Do keep in mind that the metal received was almost never just 14K, therefore my formula worked perfectly well unless there was something mixed with the gold that didn't catch my attention.

Since this is the gold I buy at my scrap biz, I typically separate the various karat gold. I then calculate an "exact" inquartation amount. As I'm pretty sure I'm stirring well enough, I'm probably going to try "infifthing" :mrgreen: instead of inquarting for the next batch. It would be nice if I just didn't have to add another step to my processing.

A decision you may come to regret.

Pay attention to what you're being taught and put your creative thinking on hold. Can you not see that you are ignoring the silver and base metal that is present? Follow my instructions and you will achieve success. Of that I'm pretty sure, considering it served me perfectly well for over 20 years. Why anyone would screw around with this stuff, checking each piece for fineness, escapes me. I had far better things to do with my time, such as process gold for the *12+ hours I spent in the lab each day*.

Harold

*I'm dead serious about that statement. I worked minimum 12 hour days 7 days/week for the last couple years I refined. It took all of my time to keep current with incoming work.

 

[Lobby]

Harold,

I can't tell you how much I appreciate your responses, not only to me, but to entire refining community. You've taught us so much.

One example is your advice on adding a 24k gold button to finish the AR reaction and deplete the nitric acid. Prior to doing that, I'd have left over HNO3, but since I've started that, bingo, no more problems.

I also marvel at the elegant solution you came up with for adding 110% of the scrap's weight in silver. As an extremely busy refiner, I can see how that calculation saved you a bunch of time. That 110% addition works extremely well with real world scrap. Sure, if one only had 10k gold, the resulting inquarted gold concentration would be closer to 20%, but one hardly ever processes only 10k gold. For real world scrap (mixes of 10k and 14k), your 110% rule is about right on.


My main business isn't refining, but scrap gold buying. The reason I segregate my scrap by karat, is so that I can track my yields. As I don't have an XRF, nor an assay oven, math is about the only way I can confirm how much gold I'm selling.

And since I've only processed about 10 batches to date (I just joined the forum in January), gold yield has been of paramount importance to me.

My early batches were troublesome. If one searches for the early threads I started, you'll find some of the silly mistakes I was making. But starting about Batch 5, my yields have been spot on. Between 98% and 103%. (Why 103%? Because there's invariably gold in the silver I'm using to inquart).

This focus on yield (not gold purity) is what's driving me: to not lose gold when I sell it. Thus my posts in this thread (how to get complete dissolution of the gold in AR).

My Batch 9 bar:

99.9% + gold, by two different XRF's, one a refinery

Funny thing: if you follow Harold's gold cleaning procedures, you make pure gold. Imagine that. :mrgreen:

 

[Harold_V]

Lobby and I have been talking behind the scenes, and I offered him my apology for being the curmudgeon I have become (which was reflected in my response), but I believe he now understands that my purpose was to attract his attention in such a way that he would gain a clear understanding that my 110% addition is particularly important for guys that inquart random batches of gold. The time wasted checking each piece becomes troublesome over the long haul. As he alluded, it's rare for a batch to be either all 10K, or 14K, which accounts for the percentage mentioned. In practice, it rarely let me down, and saved me countless hours of time.

I have commented, on several occasions, how important it becomes for the home refiner to become recognized as a (quality) refiner. Because my primary customers were manufacturing jewelers, they were accustomed to the quality of gold I produced, therefore they were willing to buy surplus when it was available. I became the broker for sales---often selling gold that belonged to one customer, to another. I did this free of charge--the only stipulation being that each had to be my customer. I refused sales to others, due in part to the fact that I always sold for spot, normally never available for the buyer, and the best possible return for those hoping to sell. My profit came from having a reliable customer base. Give that some thought.

Harold

 

[CASACEO]

I must say I love this forum. I have been reading articles for hours and have learned so much. I too had little gold beads that were covered in blackness and didn't completely dissolve in AR. I had even previously sanded off the black residue to reveal gold (oops :evil: ) I am new and learning from my mistakes, and now from the mistakes of others. Thanks GRF community!!