Has anyone actually smelted their black sands?

[Martijn]

Some comments:

Instructions are best understood with clearly written instructions and punctuality. Small mistakes can destroy lives. Especially in chemistry.
Was it test it with stannous or taste it with stannous? Hmmm, just choose one and find out yourself...

E.g.:
" I'm giving up drinking strong booze for one month"
Or: "I'm giving up. Drinking strong booze for one month."

To quote another members plead: "Paragraphs, PLEASE!!!!"

Whsnare has not been online since 2011. He might not read it anytime soon.

Time for a cup of coffee.

 

[jphayesjr]

I wet tumble black sand in a rubber rock polisher drum with tungsten grains until it is finely pulverized. I sift out the tungsten using an appropriate sized classifier screen. I then mix the black sand powder in an old cast iron dutch oven with borax and oxalic acid. I let it sit in the sun until completely dry. In a very well ventilated area, with very good regulator, back flame suppressor, and a foam fire extinguisher, I then smelt with acetylene, until molten, toss in more borax and oxalic, use an old iron ladle to carefully skim off foaming slag waste. If you worry this contains gold or other pm's, put it aside to cool, smash. classify. The end product in the pot will be a glowing glassy sheet on top of gold. You can carefully break it off. The gold should be 22 to 23.x K. You can further purify using methods in Hoke. My sands contain a high percentage of microcrystalline gold, some silver, and significant PGMs. The pm's often are visible in the larger black granules, both magnetic and other. You be the judge of yours, though. My yield usually is 2 to 3% from black sands. Sometimes higher if I'm working old tailings. Do clean out the tumbler occasionally with an absorbent paper towel, and SAVE them. Once you've got a nice bucket full, You can burn them, and wash out the ashes, hold and evaporate the filtrate, and then repeat the above procedure. Please avoid using toxic heavy metals such as Pb and Hg, always wear PPE including effective gloves and a fire retardant apron. Stuff happens, stay safe.

 

[stoneware]

The Clarkson Rod Mill for reducing black sand to enable the recovery of fine gold.

Black sand from an inland gold producing area under the microscope.

Flux's used in smelting and their purpose.

The maganese dioxide in Chapmans flux is there to reduce the sulfides.

 

[stoneware]

A more detailed use of the various flux's.

 

[stoneware]

Black sand from two different areas.

 

[marvelousdanes]

eeTHr

I can assure you that there is black nuggets. It is not what lots
of people envision, or a myth,just a simple act of nature. We
have found several on our claims. Most are found in black iron
schist outcrops. They are just iron crusted gold ,and most are
shaped like pumpkin seeds or are flat.

Also I have played with black sand quite a lot. Black sand can be
made up of lots of different types of minerals or rock. Most is
magnetite ,but not all. In some areas some of the black sand is
actually smokey quartz,or other rock.

In an epithermal type deposit there can be all kinds of salts,
minerals,clay,acids,chemicals,than can act as binding agents.
Native gold is rough ,right down to micro size. Imagine a rough
nugget or grain of gold laying trapped at the bottom of a wash
in a soup of micro powdered iron,magnetite,and other black
minerals. A black crust will form over time in the right conditions.
Throw in a few grains of smokey quartz with native gold grains
actually in the quartz,plus some free micro size gold ,and you
can see why the black sand thing gets so much attention.

A few black sand areas are worth looking at,most are just
magnetite,and not worth fooling with,unless there is a lot of
free small grains or flakes of gold in the mix. Also gold found
in the roots of live oaks and other desert plants in a wash can
be discolored by the acids in the roots. Some large nuggets will
come out of the ground black as the ace of spades in these places.

I darn near threw away a bunch of black nuggets while panning
concentrates once. They were mixed in with some course chunks
of magnetite. They just had a real thin coat of black stain,darn
near like they had been spray painted flat black. Gold can come
out of the ground looking like anything but gold. It can be coated
in all kinds of crap,depending on where it came from.

There is also places that you can load a train with black sand and
not find one trace of gold. Quartz is the same,some has gold but
most of it doesn't. Gold is found where you find it,and it can be in
some weird places too. Lots of people have too many preconceived
notions ,and read too many books to actually find gold.

There is lots of simple tests for gold in black sand,or coated in
oxides,and various other crap. No use to get anal about mining
black sand ,when a simple test or two will tell you if it is worth
fooling with or not. :lol:

What are the simple tests?

 

[Yggdrasil]

What are the simple tests?

Welcome.
The simple tests comes further down in his next post.

If you plan to stay here and learn we prefer people to study a bit.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library