99.5%? Is it possible?

[4metals]

Johnson Matthey, Metalor, Republic Metals, and Ohio Precious Metals all can either beat or approach that rate in the US. The Royal Canadian Mint for our friends to the north but I hear they're not taking any new customers. Of course we're talking thousands of ounces per week to get that rate, but it is out there.

 

[HAuCl4]

If you make your own 400 OZ 996+ fineness bars (easy, read the forums :lol: ), all the big refiners used to take them from your hands for less than 0.25% refining penalty, and pay you spot bid at the time of your choosing. It used to be that way, maybe it still is. I haven't seen 400 OZ together for a while though. Call all the big guys if you have the bars and negotiate...

 

[Fournines]

Very high rates are possible, but as 4metals said, you have to have the volume to justify it.

Don't forget you'll probably have an assay charge (to the refinery and for your own 3rd party assay) and have to pay interest on any advances you receive.

Suppose you have 400 oz of .995 fine gold (398 troy oz of actual gold). If you get a 90% advance at a price of $1380 = $494,316.00
Assume your advance rate is prime + 0.75 = 4% right now, and a settlement time of 5 business days. That's over $250 in interest.

If you disagree with the assay (and it is not within any negotiated splitting limits), be prepared to go to an umpire lab. If you lose the dispute, you'll also have to pay the umpire charges, which can be several hundred dollars.

 

[HAuCl4]

My next experiment is going to be mixing 2 Oz of finely granulated 18K yellow scrap with 2 Oz of Trichloroisocyanuric acid (C3Cl3N3O3), and 4 Oz of Borax, slowly cook it at 300 C for 15 minutes, then melt at 1,100 C and measure the fineness of the resulting gold. :shock:

I have high hopes. :lol:

How did your sterling atomizing/fluxing experiment to reduce copper go 4metals?. Nitre+Borax or something else?. :?:

 

[HAuCl4]

Very high rates are possible, but as 4metals said, you have to have the volume to justify it.

Don't forget you'll probably have an assay charge (to the refinery and for your own 3rd party assay) and have to pay interest on any advances you receive.

Suppose you have 400 oz of .995 fine gold (398 troy oz of actual gold). If you get a 90% advance at a price of $1380 = $494,316.00
Assume your advance rate is prime + 0.75 = 4% right now, and a settlement time of 5 business days. That's over $250 in interest.

If you disagree with the assay (and it is not within any negotiated splitting limits), be prepared to go to an umpire lab. If you lose the dispute, you'll also have to pay the umpire charges, which can be several hundred dollars.

The 7 commandments of gold trading/refining:

1-Weight everything accurately multiple times.
2-Buy low and sell high. (Buy at discount, sell at premium, etc.)
3-Collect early and pay late.
4-Borrow sub-libor and lend plus-prime. :shock:
5-Long physical, short paper.
6-Do it faster!. 8)
7-The "golden rule": He who holds the gold, makes the rules.

:lol:

 

[4metals]

How did your sterling atomizing/fluxing experiment to reduce copper go 4metals?.

Fluxing in a reverberatory furnace won out over atomizing and leaching.

Trouble is the fluxing method yields slag with copper in it and not payable. The leaching requires a lot of extra work for 290 pounds of copper a week. Plus waste treatment.

 

[HAuCl4]

How did your sterling atomizing/fluxing experiment to reduce copper go 4metals?.

Fluxing in a reverberatory furnace won out over atomizing and leaching.

Trouble is the fluxing method yields slag with copper in it and not payable. The leaching requires a lot of extra work for 290 pounds of copper a week. Plus waste treatment.

I thought your plan was to atomize sterling, mix it with an oxidizing flux, and melt it, slagging most of the copper oxides off, and putting the silver through a cell afterwards, and I was asking about that. Now I'm more confused. :?: :roll:

Copper oxides dissolve well in diluted sulphuric acid without supervision, and the copper cements well with iron without supervision. The iron sulphate solution can be evaporated to a crust. Not sure if it is economical, but for $1,000+ a week it may be. Or maybe you can find another use for the cemented copper, with... another client. :idea: (i.e.: Buy from one client, sell to the other.)

 

[4metals]

With a good reverberatory furnace and the right temperature and fluxing the copper (or most of it) and lead, tin, and a few other problem metals can be removed by melting and exposing the molten charge to an oxidizing environment.

I originally thought that by atomizing the sterling and fluxing I could get the same result in a standard furnace by using fluxes. Well you can but it may take a few passes. The reverb is better.

Along the way GSP suggested leaching the copper from the atomized sterling and recovering the copper from the solution. Also a viable option. The tremendous surface area of atomized metal opens up many avenues to refining.

When copper prices get to the point that it is sold by the ounce, leaching may pay off.

 

[Oz]

When copper prices get to the point that it is sold by the ounce, leaching may pay off.

Copper is $0.305 per troy ounce this morning.

 

[4metals]

Both of the copper removal methods require follow up in the silver cell, the goal is to get a low copper feedstock so the electrolyte does not have to be changed as often.

The atomized sterling was roasted to oxidize the copper which was exposed to the air due to the huge surface area of the atomized material, then the oxide was leached off in dilute sulfuric to produce a silver alloy with a much reduced copper content.

You are right the leaching and copper dropping with iron require little effort but the waste treatment on between 300 and 500 gallons of waste a week is costly to deal with and monitor.

My goal is always keeping it simple, I try to set up places so I don't have to go back to hold hands very often.

 

[HAuCl4]

Both of the copper removal methods require follow up in the silver cell, the goal is to get a low copper feedstock so the electrolyte does not have to be changed as often.

The atomized sterling was roasted to oxidize the copper which was exposed to the air due to the huge surface area of the atomized material, then the oxide was leached off in dilute sulfuric to produce a silver alloy with a much reduced copper content.

You are right the leaching and copper dropping with iron require little effort but the waste treatment on between 300 and 500 gallons of waste a week is costly to deal with and monitor.

My goal is always keeping it simple, I try to set up places so I don't have to go back to hold hands very often.

May I suggest grinding/mixing the copper slags with charcoal once a week (or a month, or a quarter or yearly) and selling the resulting copper ingot?. I think that's the cleanest path if you have the crusher and the furnace with exhaust control. :idea: Approx. $75 k in metal a year at current copper prices. :shock:

 

[4metals]

Copper is $0.305 per troy ounce this morning.

The lowest silver price I worked with was $3.00 an ounce, at that price it was often thought to be more of a pain than it was worth. I guess if copper goes to $3/oz we can all complain about recovering it as well.

 

[4metals]

Melting 50,000 ounces of silver a week generates about 600 pounds of slag, I've never tried grinding slags with charcoal before, it would require a pretty big crusher, but say some more about this approach.

 

[HAuCl4]

Melting 50,000 ounces of silver a week generates about 600 pounds of slag, I've never tried grinding slags with charcoal before, it would require a pretty big crusher, but say some more about this approach.

http://en.wikipedia.org/wiki/Cupola_furnace

A modernized approach to the oldest smelting procedure, I think. The charcoal burns and reduces the oxides to metal when you limit the air going in, but need to watch the gases exhausted which may be simple CO2 or harsher if any sulphur is in there or other metals.

 

[4metals]

OK grinding and mixing just turned into firing in a cupola. A bit more complicated. I would guess I could try grinding some of the slag with charcoal and firing it in a crucible furnace so the O2 would be limited. Pouring may be a bit of a challenge as the reduced metal is on the bottom with a ton of flux on top. I could let it freeze in and old crucible and just bust it out to see how much copper actually reduced.

 

[HAuCl4]

if you have the crusher and the furnace with exhaust control.

Yeah, sorry for the confusion, sometimes I think faster than I type. I thought it was clear. :lol:

Good thing is a cupola for that size costs a lot less than $75K, and may have other uses.

Your suggestion of using a crucible is great, and cheaper, if you transform the crucible into a tundish first!. Thanks!. 8)

With enough charcoal and good grind/mix all the copper should reduce to metal.

 

[4metals]

Guess I didn't connect all the dots, can't remember ever mixing 2 solids in a mill and opening it up to find an ingot.

 

[Lou]

Cone mold, anyone?

 

[4metals]

That would work, and they make them pretty large as well. Another option could be to use the cascading ingot molds and the flux would just overflow to the next mold leaving metal in the shape of the ingot mold. I'm definitely going to see if the charcoal reduction will work but whether or not it's worth the large furnace or cupola needed, as well as the space to do it, is up to the owner.

A lot depends on how much additional flux, if any, has to be added to make the whole mass fluid enough to settle the metal in the pour. With the rising costs of flux and fuel, that may be a deal breaker. Still worth the experiment because if copper keeps going up in price, it may be feasible some day.

 

[HAuCl4]

It has worked for several thousand years. I don't think the metal gods are going to play a joke on you at this point in time!. :lol: