99.5%? Is it possible?

Is it possible for a refiner on lots of 4,000 grams or more of clean karat scrap already melted into a bar to pay 99.5% and still make money, while still giving an accurate assay?

(What I mean by clean is the bar will contain nothing else besides Au, Ag, Cu, Ni and Zn.)

I don't think it is possible for a refiner to give a true payout of 99.5% and still make enough money to stay in business without fudging on the assay.

I only bring it up because someone was telling me that xxxxxx Refiner is paying 99.5% and that I should be sending my materiel there. Obviously, I don't get that kind of return now, so I started thinking. And the more I thought about it, the more I came to the conclusion that it's not very likely that the refiner could actually pay out that much on an honest assay. They probably are banking on people not actually knowing exactly what they are shipping off to be refined and picking up the extra profit on a lower assay.

I thought I would run it by you guys to see if you all came to the same conclusion.

I remember a cartoon in an ad, about 20 years, in a recycling magazine where a refiner had his arm around the customer's shoulder and he winked and said, "You're such a great guy, we'll refine your scrap at no charge"

It comes down to a question of scale, aqua regia refining in large enough lot sizes, costs a medium sized refiner about 1/4 of 1% for labor chemicals treatment of waste etc. Assuming your process yields 99.875 accountability on lot by lot basis and the balance is retrieved from residues, slags, baghouse dust, etc. This says nothing of insurance, security and overhead.

So if you process a Pfaudler full of karat you can still make a profit at 1/2%. But there is no room for error. Those rates are for the big refiners and only given on larger lots. So if you're not dealing with JM Branford, Metalor' Republic, or Ohio precious metals, watch your back.

4metals and nickvc,

Thanks for the replies. So, both of you are saying that it is possible, but not likely, unless we're dealing with 100+ oz. lots of recoverable metal and the refiner can sell his bars directly to the bank who sells them to the COMEX?

To be honest unless that was a weekly amount they probably wouldn't offer those sorts of terms, as I said they need to have the plant running 24/7 to make it pay and I dread to think of the volumes the big boys can handle and need to keep the plant near capacity. When you have access to the markets you can sell volumes you don't have but delivery in full is usually required within 28 days, fortunes can be made or lost but no manipulation of the markets ever takes place :roll:

Monte,

The attractive rates are the kind given to those who ship upwards of 5000 ounces fine gold content weekly. With the quantities you're talking you could get rates around 1% if you shop around in NYC and if you can produce it week after week. Make sure you are there to witness or the quoted rate means nothing.

I'm not going to chase the extra 1/2% by switching refiners, I sincerely doubt they would deliver that kind of return on a fair assay. I'm pretty comfortable and fairly confident with the refiner I'm using now, but you guys have given me something to think about.

Thanks for the replies.

You can Miller process your stuff in a few hours for a lot less than 0.5% costs and keep the silver. You'd be delivering 995+ or better material to the refiner/buyer, which would probably pay you very near spot price.

On the other hand, 0.5% is about $6 per ounce...so really all this cost savings, etc. are dwarfed by price risk. If you are already incurring price risk, and only sell and settle when you want, then consider refining yourself with Miller process.

Forget about Wohlwill and 9999, etc., etc. That's extremely expensive to setup and operate properly. But Miller is cheaper and simpler than acid methods for lots above 100 OZ, produces Good Delivery grade (995+), and the silver is yours to keep or sell separately.

If all you have is a one-off batch and/or your time is better spent sourcing material, then ignore everything I typed and go with a refiner you trust and negotiate your terms. It's very hard to operate successfully anything gold related with anyone other than yourself involved, due to fidelity/honesty issues. Even with someone else that is honest, the suspicions will drain your mental resources. Gold brings out the best and the worst in people, if you see what I mean.

I really can't agree with you on the cost of setting up the Miller process , the largest problem is having the proper extraction and fume treatment which is really expensive and will have the Environment Agencies crawling over you to check on the fumes released into the atmosphere, not to mention the toxic chloride waste left over which contains precious metals which will need further treatment to recover them and render the material safe to dispose of. One of our leading lights 4metals was involved in setting up a version of this and I hope he can give us an idea as to cost and the issue of total reclamation of all the precious metals from the process. The wet process can be very effective for large volumes as GSP, Harold and others will bear witness and in the right hands very quick with reasonable accountability and is well documented which the Miller process certainly isn't.

I have been seeing a lot of talk recently about the Miller Chlorine Process on the forum. I have to question whether that those that are recommending it to others have practical experience in using this process themselves. The process is not all that complicated from a technical viewpoint but I have yet to see it as a low cost process for small quantities of gold. With all this talk I would like to see someone come forward with how they are setting up and using it for processing lots of 5 ounces and up and how they can justify the capital investment to do it on that scale.

Theoretical thought processes are fine for discussion but it is a hard sell to advise someone to use a process that they have not used successively themselves. Beyond that one must look at if it is cost effective on the volume they run in a typical week. I would like to hear from someone that is currently doing this for a cost that is less than traditional refining on lots of 5 ounces Au. I chose the 5 ounce mark since it fits with a moderate refiner as a per week through-put (I do not see how one can pay their bills on less than 5 ounces per week). That is also more gold than 95% of our typical forum members will process in a year.

You can't bubble neither air nor chlorine through a 5 Oz melt. I have done it/seen it done in 3 Kg/15 Kg (around 100/400 Oz) of material.

This process is not cost effective for 1-off batches, and I would not use it unless a minimum steady 100 Oz per week of material could be sourced.

I do not professionally refine gold/silver these days.

Properly setup this has less fumes than the equivalent size acid operation. Especially if you use an electric furnace. All the "fumes problem" has been blown out of proportion in the literature, but it is understandable if you use a gas-fired furnace and just start blowing chlorine in an open crucible...all the fumes mix with the flue from the furnace and then you have a huge "fumes problem".

And you are right, I do not currently process even 5 Oz of material per year, and all this is just a hobby/mental exercise to avoid Alzheimer's for me and keep myself busy somehow.

But since I visited the Royal Canadian Mint and also met/spent several hours with Mr. Robert Trepanier (ex Refinery Manager of same) in Caracas in 1988, and setup a small refinery using same process back then, maybe I have a clue or two, but then maybe not. I remember at the time discussing how they were changing all parting furnaces to induction from gas. And how he was very impressed at what we had achieved locally with a normal electric (non-induction) furnace.

Since I was screwed in business from that deal, for one reason or another, I never re-entered the "gold business", till I joined this forum, first as JohnW, but since I lost my password to my email account, I decided to create another without making any noise.

I have read passionately the info in this forum, where I learned a lot, especially from Steve and his ideas of chemical loops, where little/no chemicals are wasted, and the per-sulfuric cell process which was completely new to me.

I have been "advised" to blow myself up once, to shut up because I'm a newbie that knows nothing, and that I am always asking the wrong questions... just for being creative.

Now even my credibility is attacked/questioned/whatever. I have no desire, time or inclination to defend my views or knowledge anymore.

From now on I will just shut up, read, learn whatever is there to learn, and wish you all a happy refining experience using whatever methods you like.

This is an open forum and ideas and discussion of ideas is part of what makes it work. The comments I made are based on what little I could glean from the literature on the Miller process and from some one I know who is at present trying to install it into his new refinery, if I'm wrong please enlighten me, I don't claim to be an expert in any field so I would love to hear how you or anyone else set up and ran the Miller process and at what cost what equipment you used and what problems you encountered and how you over came them .The same I'm sure goes for Oz, we just don't see how you can set up and use this process at reasonable cost and safely so again please tell us your story I'm sure the whole forum will be reading your posts with rapt attention but do expect questions and no doubt some cynicism until the whole story is told. Get typing you have me fascinated already even though I'll never do it now

HAuCl4,

I have seen the Miller process brought up here and in other threads. Perhaps my choice of threads to reply in was poor but it was the most recent I read. I had gathered the impression from these different threads that some might have felt that this might be viable for smaller lots. It is possible that someone here may have experience that shows smaller scale as viable, I am doubtful. You were clear that you were recommending this for 100 ounces and up.

I would think it was reasonable to ask if any that were recommending the process were actually using it, as well as if they are using it if they are able to do so on small lots. To be clear I have no practical experience with it so I was asking for clarification from those that do. I would enjoy any discussion of it but find it helpful to know whether what is being presented is theoretical or from personal experience.

Since you have clarified by saying that you set up and ran the Miller Chlorine Process successfully in a small refinery of your own I would be particularly interested in what you have to say of it. You are the first that I know of on the forum that has instituted this process into their refinery.

Oz I believe there are several but their lips seem sealed, actual hands on experience is really hard to uncover and I'm really looking forward to having a tour round my friends refinery when its up and running, I know that his costs in setting up his refinery is over $750,000, admittedly it covers a furnace that can melt around 100 kilos a time but the cost of the extraction equipment is horrendous apparently due to the fact that the gold chloride is happy to be follow the extracted fumes into the system so recovery is a must to collect the values. I hope our friend HAuCl4 will give us all an insight into what he did and how employing the Miller process, it might well be out of nearly all of our reach on the forum but I for one will be reading every word that he hopefully posts recalling his experiences.

Considering that my equipment setup costs were less than $7,500 complete and that I never lost more than 1/1000th of the gold processed, you probably don't want to hear my story, because it is already unbelievable for most.

$750,000...whew...what a waste. I'm hoping that he spent 95% of that in the vault, the building and other security mechanisms...

I'll type 1 or 2 pages with tips and will try to answer questions to the best of my ability...

My "fumes problem" processing equipment was a state of the art $300.00 vacuum cleaner and 2 drums filled with soda ash and water. We got some silver out of the sludge and insignificant amounts of gold, and no fumes on the exhaust only dry air. I carefully processed this sludge once only to establish the what is what, and then it was just mixed with the low grade slags, sweeps, etc. and smelted once a year.

The gold stayed 97-99% in the crucible charge, in the copper/silver chloride slags 1-3% (recovered as a silver dore cullot inmediately with a sprinkle of soda ash, and re-melt), and maybe a 0.2% as metal in the cracks of the crucible, fully/mostly recovered every 4-5 melts when the crucible was taken out of commission and crushed. The bigger the charge the smaller % that stayed "in transit".

We used AP Green #14 crucibles (Same as the Royal Canadian Mint at the time, why reinvent the wheel right?) at a cost around $15 a piece at the time, and crucible covers for same, in which we drilled a hole for the clay tube used for injecting. If I had to do it again today, I'd try to use state of the art nonporous sintered zirconia crucibles at slightly higher cost, but much higher number of melts per crucible, and a cheap induction furnace.

We built and optimized an electric furnace around that crucible setup. A simple but not trivial cheap furnace setup was reached after a little trial and error.

All the fumes came out from around the injecting clay tube and were promptly sucked in by the vacuum cleaner, and soda ash drum. The biggest amount of fumes occurred when pouring the chlorides slags into another crucible, the vacuum cleaner took care of it, but we also used masks for safety. A couple good electric fans kept the air circulating.

The batches were mainly mine dore at around 90% gold, but sometimes a batch of scrap karat here and there. We injected a little pure air first instead of chlorine to scorify instead of chloridize. The difference in costs was negligible, but I believe it helped on the total removal of copper and other base metals before starting with the chlorine.

9985 was the best we achieved even with extended exposure to chlorine. (And no we did not lose any significant amount of gold as chloride. This is a myth. I can see how one could lose a lot of gold in the flue in a gas fired, open crucible, chlorine splashing operation, but not with this setup.)

Maybe the crucible cover and the mix of glass and borax I used for the flux was a factor in the negligible losses of gold as chloride. There was also a very clear transition when reaching the end of operation, and where chlorine injection had to be slowed down in the elimination of the last remaining silver. If you were paying attention this posed no problems. The purple stain on the clay tube was very distinctive, and marked the near-end of the process. We pushed this point often at a slow chlorine rate in the hopes of ever increasing the fineness of the final product, but after a while it was just a waste of time and chlorine, and negligible gold chloride. Remember all these losses get smaller as a % as the charge gets bigger, and even 1 gram of gold makes A LOT of gold chloride fumes to be detected. And we always had the $300 vacuum cleaner!. :roll:

The silver chloride we recovered using sulphuric and iron, like explained in the literature. We did not refine silver except for a small amount in a thum cell, to be used in the fire assays. This is another story and fully documented in the literature.

Everyone that I have ever met that used Miller to this date (a handful maybe), still regards this process as "secret" and few if any are forthcoming with details. Mr. Trepanier was a notable exception 20+ years ago, and now you are stuck with me, as far as I know... :lol:, but maybe others that have been quiet till now, will share their experience.

There were no platinum group metals present.

Now I love this and you're right the process is clouded in mystery and rumour and hard facts and figures are non existent to anyone outside of the companies using it. I'm shocked that there was so little fume after been led to believe that was the main concern but not surprised as it helps keep the process supposedly beyond the educated amateur. I'm going to read your post over again and try not to be so shocked at the simplicity. Fantastic information, I bet you will not be popular with the big boys in the refining world for sharing this with the forum. I think my friend is installing other refining equipment but until I get a look round I won't know but I do remember him saying he was having trouble getting the clay pipes to use?

Morgan crucible makes and sells clay pipes. Nowadays I know how to make my own, but I don't need to!. Back in that day (there was no internet I remind you!), we obtained tubes made of zirconia that were used in the manufacture of thermocouples for harsh environments. (We got them free at first from the discards!). Each tube would last forever with certain care. There are many internet sources now, just google "clay tubes". So easy now. The hard part is getting the material to refine!. At $1,200 an ounce this is no mystery. Too little gold going around, and too many "refiners".

Re. the "fumes" and the "chlorine": Any pool boy that maintains a medium sized swimming pool at a country club, handles more chlorine per year than most refiners... . He keeps it dilute in water though!. :shock:

Well I have re read your post twice and all I can say is FANTASTIC..... :lol: I never would have believed that a process that is over a century old could still be so little documented until I tried to find out how it worked and what dangerous fumes and by products :roll: were likely to be encountered, now I know why. Thank you for sharing that and for once the information really is gold....I'm pleased you came back onto the forum as an active member, let's see if anyone can fault this who has actually done it!

If clay pipes are hard to find, isn't fused quartz tubing capable of doing this job?