GRF Search!

GOLD SMELTING FLUX

<<

mic

Active Member

Posts: 1800

Joined: July 16th, 2010, 7:47 am

Location: Cocoa Beach,Florida

Post October 10th, 2011, 11:41 am

Re: GOLD SMELTING FLUX

As I stated before,this method will work.I have performed it many times using various insulation materials,and fluxes.The success depends mostly on the microwave.A cheap wal-mart one will not get the job done.We have a commercial unit that came from a restaurant,and had no problems melting copper,and have had no problems with the mcrowave since my experiments, a year ago.
<<

bswartzwelder

Active Member

Posts: 499

Joined: October 24th, 2011, 1:19 am

Post October 26th, 2011, 12:06 pm

Re: GOLD SMELTING FLUX

HELP! Does anybody know what formula would make a good gold smelting flux? I am planning on buying a kiln in the near future and the only formula for flux I have found is: 30 grams of ground sample + 30 grams soda (Na2CO3) + 30 grams lead oxide (PbO) + 2 grams flour + 10 grams silica sand. The problem with this is that any gold in the sample will end up as a button on the bottom of the crucible with the lead which came from the lead oxide. You then have to separate the lead by reheating it with the kiln door open slightly. This allow enough oxygen in to form lead oxide and leave any other metals in the sample behind.

I see that with the microwave method, once the melted mess is poured into a mold and allowed to cool, all that seems to be left is the gold and whatever else is in the glass mixture. I understand the glass mixture came from sand in the flux.
<<

4metals

User avatar

Active Member

Posts: 2108

Joined: April 5th, 2009, 7:05 pm

Location: northeast USA

Post October 26th, 2011, 2:12 pm

Re: GOLD SMELTING FLUX

There is a world of difference between a fusion which you are talking about and smelting. The lead from your fusion is removed by cupellation in a cupel placed in an assay kiln.

What is your material that you are trying to smelt? I suggest you do some reading on the forum, all of the answers are here but it takes some commitment on your part to see it through.
<<

bswartzwelder

Active Member

Posts: 499

Joined: October 24th, 2011, 1:19 am

Post October 26th, 2011, 10:52 pm

Re: GOLD SMELTING FLUX

I have been doing a lot of reading, but I seem to be more confused than ever. I wanted to see how much gold there is in various samples of black sand that I have accumulated. I suspect some of them migh be very rich in gold content. Also, if it is possible to separate the gold from the black sand by smelting, then that process just might be the answer to my questions. I am new to this and may not be using the right terms to properly phrase what I am trying to do. At some point, I want to refine what gold I have and pour it into ingots.
<<

butcher

Active Member

Posts: 7204

Joined: January 6th, 2008, 2:09 pm

Location: Pacific NW

Post October 29th, 2011, 1:37 am

Re: GOLD SMELTING FLUX

The problem I see with black sands is they are very high in Iron, magnetite and hematite, smelting, may just make a blob of Iron mixed with what little gold the had in them, that is if you were able to convert them to metals without them oxidizing in the melt making a slag of iron and tiny bits of gold locked up in them, Limestone (caco3), coal (coke), quartz (SiO2) are used to convert these iron oxides to metal in blast furnaces, not something easily done in your backyard.

just maybe with a flux very high in carbon (sodium carbonate) (or other carbon source like limestone) (coal and coke)to convert oxides of Iron and sand, borax to help make sand or quartz a glass slag for base metals to gather, something like fluorspar to help dissolve and make liquid, and a metal collector like lead, you may get a small bead, like they would in an assay, but by the time you wasted all of that time experimenting failing and wasting of furnace gas and dissolving good crucibles to find a mix that may yield tiny minimum amounts of gold, you would probably still find yourself in the hole as far as cost.

My thinking is if you can not classify it and pan it out is most likely not worth fooling with unless you had many tons of this, then sell it to china.

Sluicing, blue bowl or shaker tables if you have more than you care to pan.

Trouble with leaching is getting rid of all that iron; it wastes all your money on acids and oxidizers trying to get the iron out.

This is just my uneducated answer to your problem
<<

4metals

User avatar

Active Member

Posts: 2108

Joined: April 5th, 2009, 7:05 pm

Location: northeast USA

Post October 29th, 2011, 10:29 am

Re: GOLD SMELTING FLUX

I agree with Butcher, the iron is your problem here. Have you tried an amalgamation test? That will give you an idea of how much gold can be recovered from the ore by amalgamation. If it is substantial then you know you have something.

The amalgamation test is not considered as a method of assay capable of telling you the total gold content of the ore, only the gold recoverable by amalgamation.

If you want to fire assay the material you need to make up a flux like this;

sample size 1/2 assay ton (an assay ton is 29.166 grams)
sodium carbonate 20 g
borax glass 15 g
litharge 35 g
Flour 4 g
Flourospar 5 g
silica 20 grams

If the ore contains silica you can reduce the silica in the charge.

This will produce a bead containing all of the precious metals after cupellation in a bone ash cupel.
<<

solar_plasma

User avatar

Active Member

Posts: 1647

Joined: February 27th, 2013, 12:37 pm

Location: Germany

Post March 31st, 2013, 10:01 am

Re: GOLD SMELTING FLUX

In this thread you discussed about microwave...

Here are links of a german institute for further education on the field of chemistry, that show how to find the hot spots in a normal microwave and how to build a diy crucible that uses a layer of graphite spray to gain temperatures above 1000 degrees celsius. They form brass alloy with that project:

finding hot spot with thermo fax paper: http://www.chf.de/eduthek/mikrowelle-experiment07.html
crucible with graphite layer: http://www.chf.de/eduthek/mikrowelle-experiment09.html
brass alloy: http://www.chf.de/eduthek/mikrowelle-experiment10.html

...kinda ingenious!

When I sooner or later have obtained experiences with it and if it will be usable for our subjects of interest, I will write a description in english.
Disclaimer
Everything I write on the forum regardless the wording and formulation may contain false and/or incomplete statements and is a matter of theoretical exchange of insights and assumptions for a educational purpose. I do not advise to use anything of it in practice, and if you use it anyway in whatever way, you do it on your own risk and responseblity, only if you have professional knowledge to do it safely and only if permitted to you by the laws and regulations of your country.
<<

butcher

Active Member

Posts: 7204

Joined: January 6th, 2008, 2:09 pm

Location: Pacific NW

Post March 31st, 2013, 12:04 pm

Re: GOLD SMELTING FLUX

The graphite is the microwave susceptor material, there are several materials that can act as microwave susceptor material, that can absorb heat from the microwave energy to help give the heat needed to melt the metals.
http://www.google.com/#hl=en&sclient=ps ... 24&bih=594
<<

vyper

User avatar

Member

Posts: 46

Joined: April 13th, 2012, 8:16 pm

Post June 8th, 2013, 1:05 pm

Re: GOLD SMELTING FLUX

Would a process like this be feasible for cons derived from incinerated flatpacks, IC's etc. Not worried about the microwave portion of it just if there's a flux one could use to remove most of the junk from the cons? Then refining from there once you had a good amount of conical buttons to do so.
Refining Precious Metal Wastes C.M.Hoke http://tinyurl.com/mfnyhs
Get it, read it, read it, and read it again. Oh did I say read it.

The proof is in the button.
<<

bswartzwelder

Active Member

Posts: 499

Joined: October 24th, 2011, 1:19 am

Post June 9th, 2013, 9:37 am

Re: GOLD SMELTING FLUX

A lot of the iron in the black sands can be removed with an ingenious new device called a magnet. Drop a magnet into black sands and the hematite wil be attracted to it leaving the non magnetic portion of the black sand behind. WOW technology never ceases to amaze me. One caveat, I don't know if the gold is alloyed with the hematite or not. If it is, throw the magnet away. Also, from what I've read, a ton of black sand only yields an ounce or maybe two of gold. Usually gold is found with black sand, but not all black sand contains gold.
<<

vyper

User avatar

Member

Posts: 46

Joined: April 13th, 2012, 8:16 pm

Post June 16th, 2013, 9:24 am

Re: GOLD SMELTING FLUX

Take it that's a no?
Refining Precious Metal Wastes C.M.Hoke http://tinyurl.com/mfnyhs
Get it, read it, read it, and read it again. Oh did I say read it.

The proof is in the button.
Previous

Return to Other Processes

Who is online

Users browsing this forum: No registered users and 1 guest

[Most Recent Quotes from www.kitco.com]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by Vjacheslav Trushkin for Free Forums/DivisionCore.