Cheap clay crucibles

[Ayham Hafez]

I noticed many Indonesian E-waste recyclers use smelting process with cheap clay crucibles, they use this kind of crucibles only one time, then they break it to get metal button for further processing.

I found this video talking about same crucibles producing.



I tried to understand what they exactly use for the crucible recipe by YouTube translator, I noticed that they only use clay from agriculture rices fields (as read by YouTube translator)

Anybody have any idea about what they exactly use to make this kind of crucibles? Can we just smelt E-waste using normal pottery clay?

Here another video I shared before for e-waste smelting using same crucibles.

 

[Ultrax]

Anybody have any idea about what they exactly use to make this kind of crucibles? Can we just smelt E-waste using normal pottery clay?

Their method is faster and doesn't require a furnace: the higher the rate of sedimentation of gold particles through the molten slag, the faster drops coagulate into a bead.
A usual pot crucible needs to be heated longer in the furnace and takes longer to sediment and coagulate the small metal particles through a much thicker layer of relatively viscous slag.

P. S. Very clever: two cheap dishes are equal to a furnace, crucible, and cover
And it’s important that they have almost no losses due to metal evaporation!

 

[Yggdrasil]

Their method is faster and doesn't require a furnace: the higher the rate of sedimentation of gold particles through the molten slag, the faster drops coagulate into a bead.
A usual pot crucible needs to be heated longer in the furnace and takes longer to sediment and coagulate the small metal particles through a much thicker layer of relatively viscous slag.

P. S. Very clever: two cheap dishes are equal to a furnace, crucible, and cover

Another clever thing is that the charge is heated directly and not the crucibles.

 

[Ayham Hafez]

Their method is faster and doesn't require a furnace: the higher the rate of sedimentation of gold particles through the molten slag, the faster drops coagulate into a bead.
A usual pot crucible needs to be heated longer in the furnace and takes longer to sediment and coagulate the small metal particles through a much thicker layer of relatively viscous slag.

P. S. Very clever: two cheap dishes are equal to a furnace, crucible, and cover
And it’s important that they have almost no losses due to metal evaporation!

I think you impressed by their method like me, almost smelting cost is zero!

 

[Ayham Hafez]

Another clever thing is that the charge is heated directly and not the crucibles.

Yes, oxidizing base metals will increase since air hit directly the ash

 

[Ultrax]

What kind of burner do they use? Looks like gasoline +compressed air.

 

[Ayham Hafez]

What kind of burner do they use? Looks like gasoline +compressed air.

Yes I think its gasoline with air compressor, I have an idea to make waste oil nozzle with same design to keep smelting cost equal zero

 

[Ayham Hafez]

Here another impressed video



They smelt active carbon without any collector metal, the flux recipe mentioned in the comments

They mix soda ash, flour, borax and diesel with the active carbon ash

 

[Yggdrasil]

Here another impressed video



They smelt active carbon without any collector metal, the flux recipe mentioned in the comments

They mix soda ash, flour, borax and diesel with the active carbon ash

I would expect heavy losses during these operations.

 

[Ultrax]

What is the relative level of gold in their activated carbon?

 

[Ayham Hafez]

I would expect heavy losses during these operations.

Before couple years I was in gold mines area in Sudan, they use same process but they only use borax, also use graphite crucible, after finished smelting they wait about 2 to 3 minutes till gold button be metallic and take it from the bottom of the graphite crucible, they use the graphite crucible couple times before they crush and mill it and put it with gold ore to be procesesed again with gold ore in Cyanide.

 

[Ayham Hafez]

What is the relative level of gold in their activated carbon?

It's hard to know, video has more than one year on YouTube, I doubt if I ask them will give me right answer

 

[Ayham Hafez]

What kind of burner do they use? Looks like gasoline +compressed air.

I think we can mix gasoline with waste oil to get same quick firing 50/50

 

[Ayham Hafez]

Anyone has an experience with using sodium silicate solution instead of water to make clay crucibles? Will it gives the ability for clay to resist the high smelting temperature? I think the main challenge of using pottery clay in smelting is to give it the ability to be stretched without cracked.

 

[Ayham Hafez]

They said they use diesel for smelting

What kind of burner do they use? Looks like gasoline +compressed air.

 

[Ultrax]

Anyone has an experience with using sodium silicate solution instead of water to make clay crucibles? Will it gives the ability for clay to resist the high smelting temperature? I think the main challenge of using pottery clay in smelting is to give it the ability to be stretched without cracked

You will need to replace (Na) ions in silicate mass (after forming) with (Ca) using CaCl₂ solution. Soak the finished crucible after pressing in the solution for several hours. And you will receive a metasilicate crucible with good 1200-1400C resistance after drying.

 

[Ultrax]

I think we can mix gasoline with waste oil to get same quick firing 50/50

A reductive flame is not always required.
And if there is oil in the fuel mixture, the flame is only reductive (carbon).

 

[Ayham Hafez]

You will need to replace (Na) ions in silicate mass (after forming) with (Ca) using CaCl₂ solution. Soak the finished crucible after pressing in the solution for several hours. And you will receive a metasilicate crucible with good 1200-1400C resistance after drying.

Can I use calcium carbonate instead? I remember that I see a video for tempering graphite crucible by soaking it in calcium carbonate dissolved in water

 

[Ultrax]

Can I use calcium carbonate instead? I remember that I see a video for tempering graphite crucible by soaking it in calcium carbonate dissolved in water

No. Calcium chloride only.
Use replacement reaction: Calcium carbonate or Calcium oxide + HCl.

Updated: Calcium hypochlorite - incorrect. Use HCl.

 

[Ayham Hafez]

No. Calcium chloride only.
Use replacement reaction: Calcium carbonate or Calcium oxide + HCl.

Updated: Calcium hypochlorite - incorrect. Use HCl.

Incase I dissolved calcium carbonate in 1 liter HCl till it stopped fizzing, then filtrate the calcium chloride solution, how much water I can add to the filtered solution to make the proper concentration to soak crucibles into it? And how much time needed for soaking? Can I use similar solution different times for soaking different crucibles?