Smelting,melting and incinerating

[HAuCl4]

Interesting photos and tips guys. 8)

 

[4metals]

Years ago I used one of these to burn in http://www.small-incinerators.com/portableincinerators/smartash/gallery/ they were called burn down cans. For e-scrap you would need kerosene or some fuel to get it going, or possibly balled up newspaper with circuits in the middle.

 

[Oz]

Now that is real interesting! Do these meet EPA requirements when burning circuit boards? If they will take diesel as a fuel I would bet waste oil or used vegetable oil would also work.

 

[Anonymous]

Not so sure I would use one for pcb's oz,theres an aweful lot of air transfer there.Maybe a partially sealed container inside the drum would work well,that would slowly introduce the smoke to the fire.I am thinking that would work pretty well.

I am sure that model "Drug Terminator" will end up angering some members on the forum though.....

 

[4metals]

I used them for burning Kim Wipes which had gold paste on them from hybrid manufacturers. I've seen them used for some nasty stuff though.

 

[goldsilverpro]

I used them for burning Kim Wipes which had gold paste on them from hybrid manufacturers. I've seen them used for some nasty stuff though.

That is very interesting. What is the cost?

 

[4metals]

I bought them in the '80's and they were about $400 for the unit, you supply the drum. They used to be called trash aways but I can't find any listings now under that name.

 

[glondor]

I just priced one of these, Smart ash. They wanted 5 grand and would not sell me one because I live in Ontario. Way too much money and bullsh1t. http://www.small-incinerators.com/portableincinerators/smartash/gallery/

I really want to be able to incinerate this stuff. I was thinking of an 8 inch steel tube inside one of these barrel burners with a smallish vent hole in a lid on the tube. Almost a roasting. Would this be a reducing atmosphere? If so would this be an asset or a drawback? Any one know?

 

[skippy]

I'm not an expert, but I would say reducing atmosphere is a drawback. You'd have a much greater quantity of nasty complex chemicals making it through. Polycyclic aromatic hydrocarbons, halogenated hydrocarbons, dioxins etc. A reducing atmosphere would be ok in a first chamber, if followed by reburning the carbon rich exhaust in an afterburner. Even post afterburner the dioxins can reform unless the gasses drop a certain temperature range very quickly.
Then there is still HCl and HBr in the exhaust from burning the PVC and brominated flame retardants. This needs to be scrubbed out.

Making your own incinerator to match the function of a commercial one capable of handling e-scrap withing emissions regulations is no small design challenge.

 

[waltsplaza]

I was just wondering if graphite gold ingot molds require any pre-heating before making a pour?
Thanks, Walt

 

[Harold_V]

I was just wondering if graphite gold ingot molds require any pre-heating before making a pour?
Thanks, Walt

Gold should NEVER be poured to a cold mold, regardless of its construction. Should the mold have any moisture, you risk a steam explosion. Hot flying gold can prove quite hazardous, to say nothing of being costly. A good rule of thumb is to blacken a mold and heat it just below the point where carbon combusts, then make the pour. You can improve surface finish of the ingot by proper blackening of the mold, but it's very important when pouring to an iron mold, which I recommend over graphite.

Harold

Edit: Moisture in a mold isn't always obvious. A mold can appear dry and still have enough moisture to cause the explosion. Be certain to preheat your molds.

 

[bubba]

The biggest cost of building an incinerator is the burners and controls but for a small one I would think it could be done using manual temperature control by turning on and off the burner. The home made burners I've seen on the backyard casting website should work.

Incineration is never done in a crucible, it is either done on the surface of the incinerator refractory floor (which is fine if it's your incinerator) or in steel trays. The material has to be burned in thin layers and usually it has to be raked.

I think an ideal body for the incinerator could be a vogelzang double barrel stove kit. The kits are cheap and made to use 55 or 30 gallon drums. This is a single drum kit http://www.2kstore.com/stove/stv6.htm if you start with a 30 gallon steel drum and pour a 3 inch refractory cement layer at the bottom, when it dries cut the hole for the exhaust to come out of, usually a 6" hole. Now insert a 14" or so sonitube as a form to pour the refractory wall and add small section of 6" sonitube to connect the hold you made to the inside chamber of the incinerator. Pour this with refractory cement and add some needles which are sold to stiffen the cement in incinerators and act as rebar. When it dries you will have the body of an incinerator. the door from the kit has to be installed into the front section which should also be refractory cement. Set the door so when it opens the bottom is flush with the refractory so you can rake out the burnt material.

Now all you need to do is install one of those backyard casting burners in the door or even through a hole in the side so the flame hits on the material we are trying to burn. A thermometer sticking into the chamber can give you an idea of the inside temps.

Now the second drum is for an afterburner, it goes on top of the first (both laying horizontally) and has a solid bottom as before, the same sides, and a solid top with a hole for another burner. The afterburner should run at 1500 to 1700 degrees to burn the smoke. Add a stack and you'll have a mini incinerator.

Now controls and forced air feed burners are possible, and some on the forum may be able to advise us as to how to install these.

This should produce burnt e-scrap, ready for crushing and sifting and melting the oversize with copper. The quantity of material you can load it up with is learned by trial and error.

The products of this process should be homogeneous and easily assayable.

This thread is quite interesting, has anyone who has done this know how much the e-scrap (boards,etc.) is reduced by incineration? I am talking by weight.....30% ?, 50 % ?, maybe more?.......

 

[goldsilverpro]

This thread is quite interesting, has anyone who has done this know how much the e-scrap (boards,etc.) is reduced by incineration? I am talking by weight.....30% ?, 50 % ?, maybe more?.......

It's been a long time and I really didn't worry about those kind of numbers when I did circuit boards - what it was was what it was. Also, the material has changed, somewhat. Before burning, we removed most of the big stuff, like transformers, aluminum heat sinks, and steel (and, often, the larger electrolytic tantalum capacitors, if there were a lot of them - in the 80s, you might find 1/2# of them on a board - they were heavy and fairly valuable and added up quick - if we had burned them, we would have lost all their value). Then, from what was left, I think about 65-75% of the weight, on average, was eliminated by burning to white ash.

 

[bubba]

This thread is quite interesting, has anyone who has done this know how much the e-scrap (boards,etc.) is reduced by incineration? I am talking by weight.....30% ?, 50 % ?, maybe more?.......

It's been a long time and I really didn't worry about those kind of numbers when I did circuit boards - what it was was what it was. Also, the material has changed, somewhat. Before burning, we removed most of the big stuff, like transformers, aluminum heat sinks, and steel (and, often, the larger electrolytic tantalum capacitors, if there were a lot of them - in the 80s, you might find 1/2# of them on a board - they were heavy and fairly valuable and added up quick - if we had burned them, we would have lost all their value). Then, from what was left, I think about 65-75% of the weight, on average, was eliminated by burning to white ash.

thanks. I have been trying to find the time to go through your book,just got it last week, lots of good info. thanks again. andrew.