Gold Powder Density

[realTCPL]

Hello all! I searched for this question and didn't find an answer, so if this is a duplicate, my apologies.

My question is: has anyone taken a measurement of the density of powdered gold after precipitation, but before smelting?

I know the intrinsic density of solid gold but for storage purposes, I'd like to know what the powder density is too.

Thanks!

 

[Yggdrasil]

Hello all! I searched for this question and didn't find an answer, so if this is a duplicate, my apologies.

My question is: has anyone taken a measurement of the density of powdered gold after precipitation, but before smelting?

I know the intrinsic density of solid gold but for storage purposes, I'd like to know what the powder density is too.

Thanks!

The density of Gold powder is per definition the same as a Gold bar.
But I believe you are pointing at apparent density, which is the amount of space the powder will occupy divided by its weight.

This number will never be correct or exact unless all the powder has the exact size and form and the same packing.
So for all practical purposes it will always just be a guesstimate.

So why do you want such a number?

 

[realTCPL]

The density of Gold powder is per definition the same as a Gold bar.
But I believe you are pointing at apparent density, which is the amount of space the powder will occupy divided by its weight.

This number will never be correct or exact unless all the powder has the exact size and form and the same packing.
So for all practical purposes it will always just be a guesstimate.

So why do you want such a number?

I figured if I'm chemically separating gold from solution, the precipitate will generally be the same size every time if the same process is used.

I'm asking because I think I might store my gold in powder form until a customer has ordered some, then smelt and cast it on demand. It seems that storing it as powder is more secure against theft because who would steal a jar of dirt? Lol. Gold powder just looks like light colored clay.

 

[Shark]

My great niece described it to her aunt as “he melts dirt and it turns into gold”.

I kept mine in powder form a lot just because no one knew what it was. Often I kept it covered in small jar with a lid on it in plain site. No one ever knew what it was.

 

[Yggdrasil]

I figured if I'm chemically separating gold from solution, the precipitate will generally be the same size every time if the same process is used.

I'm asking because I think I might store my gold in powder form until a customer has ordered some, then smelt and cast it on demand. It seems that storing it as powder is more secure against theft because who would steal a jar of dirt? Lol. Gold powder just looks like light colored clay.

No, size will depend on concentration, pH, temperature and the dinner that day.

But no need for this complicated thing, just weigh it, one TOz of Gold will always be the same volume

You are going to sell on weight anyway, right? So why mix volume into it at all?

Edited for clarity

 

[orvi]

Depends on particle size. I sometimes use 2mL HPLC vials for storage of separate lots from separate small-volume material customers. Sometimes you can pack like 5g of gold into 2 mL vial, sometimes less than 2g. If gold was dropped nicely using SMB and from clean solution, density is usually bigger. If it is dirty and from low-concentrated solution, it can be very light.

 

[goldshark]

To answer your question, here is the mechanism you are dealing with. As Orvi stated, the volume per weight will vary with the particle size(s). For instance, if you had two - 1/2 oz. irregular shaped nuggets, regardless of fineness, and tried to fit them in a bottle, it would take a fairly large bottle/vial, something like a 2 oz. container. On the other side of the equation, take some all 100 mesh screen size Au. That would take up another, smaller volume of the same size vial. If they all were 100 mesh, but round, that would take up a greater volume than very flat pieces. This because of the open area between grains, called the interstices. Now combine some 200 mesh to the 100 mesh, shake a little to settle the 200 mech into the interstices, and you will end up with little increase in volume, but a fairly good increase in weight.
The only way you could ever get a consistent result, is if you could figure a way to precipitate out into perfect cubes. Then take your tweezers and a microscope, and stack them very carefully in your container, so there is no open space . It is easier to melt and cast to get a certain repeatable volume per weight. I hope this answers your question adequately.

 

[Yggdrasil]

Just to avoid confusion.

SG of Gold is 19.3
This means one CC of Gold weighs 19.3 grams.
It can take up a lot more space though, but it will always weigh 19.3 grams.
Apparent volume may be significant larger even if the actual volume is only 1 CC

 

[miroman]

You can try something like:

1. take a measuring tube and fill it with exact (as example) 5 ml. water.
2. put exact (as example) 1 gr. precipitated dry gold powder in the tube and see how much the water level will rise up (i.e. how ml. is the increased volume)
3. now you have the volume and the weight of the powder, so you can calculate the density.

 

[Yggdrasil]

You can try something like:

1. take a measuring tube and fill it with exact (as example) 5 ml. water.
2. put exact (as example) 1 gr. precipitated dry gold powder in the tube and see how much the water level will rise up (i.e. how ml. is the increased volume)
3. now you have the volume and the weight of the powder, so you can calculate the density.

Density of gold is 19.3

Edit to add.
The OP wished to know if it was possible to know the volume a said amont if Gold power would occupy.
That is for all practical purposes not possible, because the size and shape of the grains will vary.

One of his reasoning was that he then would know how much to melt before making a bar for a potential customer.
I can’t see why, he still have to weigh it, he can’t sell in volume.

Edit for spelling

 

[goldshark]

One other way to get a known volume to weight relationship, is to say put it in a cylinder, compress under a couple thousand pounds, and cold weld the particles into a cylinder. It is still easier to just melt, and cast into a known weight unit.

 

[realTCPL]

Density of gold is 19.3

Edit to add.
The OP wished to know if it was possible to know the volume a said amont if Gold power would occupy.
That is for all practical purposes not possible, because the size and shape of the grains will vary.

One of his reasoning was that he then would know how much to melt before making a bar for a potential customer.
I can’t see why, he still gave to weigh it, he can’t sell in volume.

Yeah I had no plans to sell it in volume. Was simply a transport/storage security question. I'd either melt before sale to customer or bring my furnace to the customer and melt on the spot. Probably the former, given possible logistical issues

 

[cejohnsonsr1]

I don’t see the problem. As long as your gold is in a simple shape, a given weight will will equate to a certain volume. Volume can be determined by the calculator on any phone. So the easiest thing to do is just weigh out your powder, melt and pour into a a common shape (like a bar) and then measure the dimensions of the bar to determine the volume.

 

[goldshark]

I can see where you are going with this. He is afraid of getting ripped off by some unscrupulous customer, or thugs in general. Like Shark said,"keep it in powdered form, nobody knows what it is". Smart idea, unless you have a lot of refining friends. I would weigh out what the customer orders, add some Borax, then hardly anybody knows what it is. Put in vials, and maybe even make up a dummy bunch of vials, with similar looking composition. Keep the good separate from the bad vials. Offer them freely telling the crooks that there is no amount of Gold worth dying over. Maybe even create some fake bullion, just for this purpose. It' amazing how fast crooks will scatter, once they think they got the goods.