Non-Chemical Refineries

[ME CO]

I know yous like to do your own refinin but I am a gold prospector (first), not a recycler and this subject came up some time ago on another forum I frequent. Basically another member needed some $$$ and sent gold to a refiner with less than desirable results. Here is the link and I know it is a long thread but if Harold, Sue, and GSP could scan it for me and maybe answer some ??? it would help my prospecting buddies and I could look like a HERO (just kidding).
http://www.49ermike.com/dc/dcboard.php?az=show_topic&forum=181&topic_id=57510&mesg_id=&page=&mode=full

I didn't reread the thing before posting this but as I remember the refiner said something about dipping a glass (?) into the molten gold to get a sample for assay- gee wouldn't the glass melt shut real quick and all the impurities be floating on top? There were some good points about melting into a bar and drilling several holes clear through for assay samples but not all have that kind of equipment. I know that it takes a quantity to gear up for a melt (why different percentages are charged for different quantities) but 100 OZT may as well be a ton- what do yous suggest a guy do with 5 or 10 OZT (also a ton I might add haha)?

I would appreciate yous input on this as I am about to embark (one last time) on an expedition to move this from the hobby realm to income realm- I'm only looking for a dwt+/hr. and believe me that will be working ME a$$ off- after all that I wouldn't want to get ripped off by one of you thievin refiners LOL. As a final note- any suggestions on refiners to use for fine flour gold.

That (thievin refiners) bit was a joke- comes from a long standing fued between prospectors and assayers but there are some unscrupulous characters these days. Thanks for any help, Mark

 

[Harold_V]

Mark,

I've read your post, but have yet to read the link you provided. Before I comment, I'd like to do that, but I want you to know that I have a considerable amount of information I'd like to post in answering some of your questions. I won't get to that until late Saturday, or even Sunday.

I have considerable experience refining placer gold----and working with prospectors. The news isn't all good, and it's not always the refiner's fault that a guy is unhappy. I'll discuss that when I post.

Harold

 

[goldsilverpro]

ME CO

The term refiner can be used in 2 different ways.

First, a refiner can be any person that re-fines gold or, makes it Fine again, using chemical, or other means. Using this definition, the re-finer can be anyone, including a hobbyist.

The second definition of a refiner is a person who re-fines gold, as a business, for other people.

Most people on this forum re-fine their own material, for their own entertainment. Some of us have done refining as a business, myself included (40 years), but, no longer. So, we know there are thieving refiners out there. We have known them. In some cases, we have worked for people that have been them.

I have known David Fell, personally, since 1979. He has a good reputation for honesty. He taught me how to drop platinum and palladium, separately, both using the same common chemical. I haven't revealed it because he asked me not to. Dave's retired and I think his son runs the business.

Gold Tutor wrote a fairly popular refining book and should know better than to say some of the things that she says. She diminished herself by (1) She didn't know what a pin sample was. (2) She learned refining from the George Gadja book, which is, without a doubt, the worst, most unknowledgeable, book ever written on refining. If Gadja was her mentor, what can she teach us?

What is a pin sample? Until about 20 or 30 or, whatever, years ago, a refiner would melt the customer's impure gold, cast it into a bar, weigh it, drill it, assay the drillings, and pay the customer. Some small refiners still use this method. This method had problems. When the bar solidified, the impurities stratified into layers. Parts of the bar was richer than other parts. The accuracy of the sample depended on where you drilled the bar and how deep. Old mining books even gave schemes for where and how to make multiple drillings of the bar. One guy I worked for had me drill the bars on opposite corners and the middle on one side and the other corners on the other side. The depth of the drill press was set to drill half way through the bar. The drillings were melted, poured into water, and the resulting shot was assayed. It was a big job to do all this. We still, sometimes, got strange assays.

The invention of the pin sample changed all of this. For quite a few years, pin samples have been the state of the art. Nearly every refinery uses pin samples. They are much simpler to perform. They are much more representative of the entire lot because they are taken on stirred molten metal. It's much easier to stir the melt than it is to stir the bar. Here's what a vacuum tube, which is used to take the pin sample, looks like

http://www.lmine.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=LMS&Product_Code=1829V&Product_Count=&Category_Code=

These are sealed glass tubes with a vacuum in them. On the right hand side of the tubes in the photo, you will notice a small bubble near the end of the tube. This bubble is very thin compared to the rest of the tube. To use this, the slag is preferably removed first, with a carbon rod, and the melt is stirred. Then, with special tongs gripping the sealed pointed end (the left end in the photo), the bubble end is plunged to the center of the melt. The thin bubble immediately melts and the vacuum sucks the molten metal into the tube. The tube is immediately withdrawn. In-Out. If left too long, the tube will soften and sag. The pin solidifies, the glass is broken away with a hammer, pieces are cut off the pin, and the pieces are assayed.

I noticed than one of the refiner links in the thread required that the pins have a 2mm diameter, or less. Also being an assayer, I agree. The smallest dia tubes in the link above are 3.5mm. I don't like these because they are too big to be easy to cut to a proper size. The 2mm ones are much easier.

I might mention another accurate sampling method that is used by some refiners. It is also very simple. The slag is removed with a carbon rod, melt is stirred, some of the melt is removed with a ladle, and shot is made by pouring the metal into water.

REFINERS

You can't assume every refiner is honest, Some are and some aren't. You don't know who. For this reason, you try to eliminate doubt in what you are selling them. Here are some possible things you can do. Take Charge.

(1) Don't send loose gold to them. Melt it into a bar and drill it or pin sample it. Tell them you pulled the samples.

(2) Tell the refiner not to process your material until the assay is complete and he OK's the numbers with you. You will have to pay the assay charge. All the refiner has to do is cupel it and part it and $40-$50 is probably the minimum he'll charge. If he wants more, tell him that all he has to do is cupel it and part it. Know the assay charge before you ship. If you don't like the assay results, have him return it to you.

(3) Split the lot and send half to one refiner and half to another. Tell them both that you are doing this. Don't tell them who the other refiner is.

The motto of many refiner's:"You can shear a sheep many times but, you can only skin him once." Don't put yourself in a position to be skinned.

 

[Harold_V]

Mark,

I followed the link and was somewhat surprised at what I found. In a sense, I was quite impressed with some of the posts from some of the contributors. Some also made me shake my head in wonder. I've rarely seen such stupid comments made in public.

I never got involved in assaying, although it was always something I wanted to pursue. In spite of my lack of exposure, I, too, was aware of pin sampling, which should be considered one of the better ways to extract a viable sample. Anyone that suggests it is not as accurate as drilling a bar is simply misinformed. Not only should it be as precise, it's one hell of a lot faster, and can be accomplished on the fly.

I would like to make one thing clear, and it's sure to raise some conflicting views. The laws of physics that were quoted about metals stratifying upon cooling is nothing short of total BS. The laws of physics dictate that once alloyed, metals tend to form homogenous compounds, and as long as the metals involved will readily alloy (and have), they will not separate when cooled. There are exceptions, but they are not amongst the metals that concern us in this discussion. In other words, if a button or ingot contains silver, gold and copper, if it has been well mixed at the outset, all the settling time in the world won't allow it to stratify-----it simply doesn't do that. The notion that the gold will be sitting at the bottom, with the copper on top is absurd. Various drillings are taken from an ingot not because of stratification, but because of the chance that the heat was not well stirred and mixed properly. Taking samples from various locations on a bar simply verify that you're getting an average of the bar.

Honesty of refiners? They were my best advertising. Virtually all of my customers had had negative experiences with major refiners, as did I. There's was one refiner on the East coast that had a reputation for total dishonesty, and they didn't disappoint. These people pursued jewelers like a dog on a bone.

My most recent bad experience was when I marketed the platinum I had accumulated through the years. Two different refiners reported a variance of over 20% of the purity of the sponge submitted. I knew it wasn't pure, for it was extracted from dirty solutions, and not further refined, but the reports had little to do with the material submitted. The best report, which was altered by a full 10% upon settlement, was close, but still too low. First one returned my sponge when I complained loudly, but at that point you have no idea if they're replaced some with a filler. They reported a platinum content of only 70%. So you'll know, this particular refiner's name is handed about fairly regularly. I wouldn't trust them with anything, for any reason. There is no question in my mind they are dishonest.

My experience with the majority of prospectors left a great deal to be desired, but from reading the posts you referenced, I can see that the net has brought these people along quite nicely. Prior to this kind of exposure, it was evident that many of them had no clue about the makeup of placer gold-----and often expected an ounce for an ounce. The only thing I could say to some of them is "if you think your gold is pure, why are you having it refined?" Many of them were shocked to have me report silver in their gold. Many insisted it was gold------just gold. Uninformed prospectors were the worst people I dealt with----and usually were least likely to trust you, regardless of your efforts. I think, given the reports I've read tonight, I could refine for the majority of these people and gain their trust and respect, for they have reasonable expectations.

I have a real problem with the suggestion that the gold in question had a high percentage of copper. For one, it's more commonly found alloyed with silver, but gold with that high of a percentage would look like copper, not gold. If the gold in question had a yellow cast, especially if it leaned somewhat green, there's no getting around the fact that someone got screwed------the only thing left to determine is was it an accident, or was it on purpose?

Anyone, and I mean anyone that uses Gadja's book for anything aside from fire starter is perfectly uninformed in such a wide area as to be considered dangerous. His book is in direct conflict with much of Hoke's book, a book that lead me from a stupid machinist to a successful gold refiner-----so there's no doubt that she knew of what she wrote. The processes referenced all work exactly as described, should you not know.

One bad example I recall in Gadja's book is his suggestion to use SO2 to precipitate palladium. I've precipitated enough palladium to know that he's wrong------very, very wrong, and if he's wrong about something so elementary, how wrong is he on other things? I used SO2 for years, to precipitate gold. It has almost no effect on palladium. His credibility is shot, as is the credibility of those that support his position. Remember------anyone can write a book----even when they have no clue-----and just because something is in print doesn't make it true.

I do not know the people involved in this mess, not even the refiner in question, but anyone has the potential to be dishonest-----and refining precious metals presents some excellent opportunities.

I don't fit well on this group. My primary interest was to be the best possible refiner. The objective of many here is simply to extract values, and they're not necessarily concerned with the degree of purity. Nothing wrong with that, but at the point where I can be the most help, they are not too interested. That, of course, will likely change as they come to realize that you can market your gold at full spot, if not above, if you become recognized as a good refiner. Most cities of reasonable size have jewelry stores with a benchman. These people will gladly pay spot for gold if the quality is there.

Harold

 

[ME CO]

Double post- sorry, Mark

 

[ME CO]

I thank yous for your time responding GSP and Harold, I will have more questions concerning this I'm sure. If I am successful in my endeavor to catch the gold needed to sustain me I will no doubt find myself needing to send off gold for $$$. After seasons end maybe I will have a couple lbs. left over to play with and learn refining myself. Right now the challenge is to get #100 mesh gold to drop out of the same flow that pushes small cobbles through my dredge sluice. I have been after this for several years and I think this is MY season. Thanks again and anything else you can think of to help me not get skinned please post. Mark

 

[goldsilverpro]

Harold,

We don't disagree often. When we do, it's usually because of our very different experiences. In most cases, both ways work. Concerning our above posts, we agree on everything except the stratification of bars. I don't know if that word is even the right one to use.

Whatever happens when a bar cools, the gold content varies a slight amount in different areas of the bar, no matter how well the melt was stirred before pouring. Since I both drilled and assayed the bars, I could see repeatable differences, especially if the bar cooled slowly. It didn't seem to have anything to do with density. The bars didn't seem to be richer at the bottom. A bar doesn't solidify all at once. It starts on the outside and, the last to become solid is the top center. The differences I saw were in those areas that solidified at different times. I always thought it had something to do the melting points of the alloys formed. It was, though, a chicken and the egg thing. Which came first? It was very hard to pin down. It seemed like, if you could solidify the bar all at once, these assay differences wouldn't show up.

 

[Anonymous]

ME CO

I don't have a lot ot time so I'll be brief. I read that link and came away with different impressions than H and GSP who have responded to you already.

I don't associate with Fell. I don't associate with MidStates, either. There are several other refineries who have fallen off my radar screen for similar reasons, and I'll leave it at that.

You already probably know I do own a copy of Gajda. LOL Looks to me like anyone on this forum who does it differently than Steve or Chris or Harold is in for a hard time. I did do a quick search for anything on the topic of refining by gold refining by Megan Rose that Chris mentioned. I didn't find anything. I found she wrote something about where to look for gold but nothing on refining, so I can't comment there.

I haven't done placer gold refining in ages since my early lab days at Mackay. Good luck to you there.

It appears to me the woman trying to help explain things on that link did a fairly decent job. I have no quarrel with her investigative approach to the problem presented nor the information she presented as the result of her investigation. She seemed pretty thorough and well spoken from what I could read.

The short comings of pin sampling are WELL KNOWN in academia. Since I am a captive employee for my refinery employer, I have no need for any "newer speedier sampling methods. This is especially true with the documented tendency for reporting error which reflect poorly on those who use them under the mistaken impression that faster = better.

I stay with what has been tried and proven over centuries. I suspect when the next "new speedy sampling method" is touted then embraced by the quick buck refiner opportunitists, the currently known but seldom discussed problems of pin sampling will be generally exposed. Then I suspect pin sampling will then be discarded in favor of the newest fad, whatever that turns out to be.

Final purity is our refinery focus, not speed. And we are probably the last to ever embrace a new way of doing things, such as the pin sampling discussed. As an academic, first trained in the old ways, then introduced to the newer methods in the lab in order to apply quantitative comparisons and justify my conclusions to the professors, I'm glad to be working for my current employer. There wouldn't be any room for a Chris or a Harold at this refinery. Maybe at the bar or on the pistol range, but not at this refinery.

It is my opinion the term assay is about as abused a term as anyone can find in this speciality. Harold and his Hoke book and Chris and his globe trotting pursuit of quick buck opportunities during the last gold rush last century, appear to me to use the term, assay very broadly.

Those of us with an academic background don't. When academics use the term assay, we use it in its narrowest definition. When we do an assay, we report on and account for EVERY metal present in a sample, regardless of origin.

If we are looking for one metal like you all look for just the amount of one gold for example, then we call that a test in our circles, not an assay.

If we are testing for purity (fineness) of a single metal, then again, we have to account for the impurities by means of an assay.

I don't know if this helps or not, but that's the words from this employed academic.

a man named Sue

 

[goldsilverpro]

Sue,

What are the shortcomings of pin sampling? What is your tried and true method?

I have an uncle who is the smartest person I know. He has a doctor's degree in Electrical Engineering. Although TV isn't his field, he knows all of the theory concerning it. He can look inside a TV and tell you how everything works. When his TV doesn't work, he calls my brother, who is a TV repairman.

I once was head chemist for a company that was, at the time, the largest supplier of precious metals plating systems in the world. Many of the plating systems used today were patented by this company. A long standing employee of this company was a doctor that was considered, in the industry, to be one of the most knowledgeable people in the world, when it came to the technical aspects of the chemistry of gold plating solutions. He wrote many scholarly papers and gave many lectures. But, he couldn't plate a lick.

The academics provide the theory and many of the innovations. The people in the trenches are the ones who actually know how to do the work. Theory vs tips and tricks. You need both.

Sue wrote:
Looks to me like anyone on this forum who does it differently than Steve or Chris or Harold is in for a hard time.

In reality, it seems like anyone doing it different than Sue is in for a hard time. However, Sue never tells us how he does it. Maybe, he doesn't do it at all. At least, we haven't had any hints that he does.

 

[lazersteve]

Looks to me like anyone on this forum who does it differently than Steve or Chris or Harold is in for a hard time.

Sue,

I've presented many processes to recovery/refine gold. I've also asked, even begged, for others to post their methods of gold recovery/refining to the forum. To the point of giving away gold scrap to get them to post. Unfortunately, I can't personally process gold by every known method and post the results here for obvious reasons. That's why I have been seeking others who have their own ways of doing things to post. You may have noticed that I've started posting contest to help get the forum members posting on the way they do things.

I feel like you are saying that Harold, Chris, and myself are closed minded to other ways of refining and don't want to hear others ways of doing things. I think this statement is far from the truth. I can't speak for Chris or Harold, but I have no agenda here on the forum. I'm here to help where I can and learn as much as possible along the way. I have posted at least five different ways to process gold. I am open to any member that wants to present new and/or improved ways of doing things, including changes to the way I do things. I try to focus on methods that the hobbyist can do at home safely, because that's what I am... a hobbyist.

I'm sorry I've never processed any placers so I can't comment on a technique.

Steve

 

[Harold_V]

Whatever happens when a bar cools, the gold content varies a slight amount in different areas of the bar, no matter how well the melt was stirred before pouring.

That phenomenon is well explained, and has been exploited as another refining procedure. It's called zonal refining, if I recall correctly. It's based on heating an area and keeping it in motion. Impurities are carried in solution, while pure product accumulates behind the liquidus zone. I had completely ignored the fact in my post. How an ingot cools will, indeed, determine how the alloy is distributed, but it is not a function of gravity, so I stand half corrected.

The process in question functions perfectly well when moving horizontally. Think of heating a long object at one end to the molten state, then moving along it's length from one end to the other, eliminating the contaminants by keeping them in the fluid zone as you progress. That's the general idea. Good ice makers work the same way. Only pure water, in theory, accumulates on the frozen plate that creates the ice, with the contaminants kept in suspension by the moving water. Once harvested, the water, now far heavier concentrated with minerals, is discharged and the cycle starts over.

Harold

 

[Harold_V]

I don't know if this helps or not, but that's the words from this employed academic.

a man named Sue

Well, from my perspective, it is a classic post by a man named sue. Cold water tossed on comments by others, with no substance, just negative statements. Instead of telling us that the pin sampling doesn't work to satisfaction, why don't you lend credence to your comments and explain why?

You have failed, at every opportunity, to add anything of substance to a post thus far. I've even encouraged you to comment on simple things-----which you refuse to do. What is your purpose here, to pick at those of us that try to help, lending nothing to the group?

I'm left with the notion that you're nothing short of hot air, with no real experience or knowledge.

Once again, would you like to try to contribute something useful to the group, or are you going to continue to use Gadja's advice and precipitate palladium with SO2? Your credibility is in the balance.

Harold

 

[goldsilverpro]

Harold,

Zone refining has always been an exciting thing to me, although I've never had the opportunity to be around it. I've read whatever I could find about it. I think I read once that they could purify silicon to twelve 9's using this method.

 

[ME CO]

Thanks for the tips. So basically I need to melt the gold into bars, cut the bars in half to send to more than one refiner, pay for multiple assays and hope for the best. If anyone has any good experiences (or bad ones) and would like to recommend (or not) please post- or send me a PM if ya don't want it in public. I'll do the same but I won't be sending off to refiner for awhile- just trying to get my ducks in rows now sos I'm prepared. Thanks again, Mark
Besides gold is going up- don't want to sell short if I don't have too.

 

[goldsilverpro]

ME CO,

Nobody can protect you from a totally dishonest refiner. If they want to take 90% of your gold, they will. You will probably have no recourse. All I can do is tell you things to do to maybe avoid getting taken. Just think of all ways you can get taken and try to do things to prevent them or, at least, minimize them.

Except for the fly-by-nighters, refiners rely on word of mouth and repeat business. If you prepare your lot correctly, they know that you know and will tend not to steal or, to steal less. To most refiners that take a little, the amount taken depends on what the traffic will bear. If you've done things right, they will see this and will take less. If you send them a pile of non-homogeneous material, they will know that you have no idea of it's value and, they will be temped to take more.

Most people that own gold tend to evaluate it on the high side. This can make you unhappy with any refiner's settlement. The guy in the forum thread you gave did no preparation and he overvalued his gold. He also left himself wide open.

There are some refiners out there that quote very low charges, in order to get the business. They intend on stealing a bit to cover their expenses and profit. I remember a cartoon in a recycling magazine, where the refiner told the customer that he was such a good customer that he would do the refining for free. This causes problems for the honest refiner, trying to quote honest charges. If he does, he won't get much business because potential customers compare charges before choosing a refiner. Charges are meaningless with a dishonest refiner.

Just remember, though, that you have to allow the refiner to make a fair profit, whatever that is. I tend to know these things because I've spent a lot of time on both sides of the counter.

 

[ME CO]

Thanks again GSP, I'll try to do what I can to minimize the damage. Hoping to go into new territory going from a hoarding gold dredger to one that actually is making $$$ from this activity. Mark