Info on building electric furnace ?

[Proffshuggarn]

I picked up a bunch of heating elements [ these are coiled wires in-beaded in aobut 1/2" thick fire brick with groves for the coils

Exciting project! What are these heating threads used for in "normal cases"? I mean the ones seen in the picture?
I'm also going to build a new/better furnace, after the heating thread burned off on my cheap China melting furnace on the second heating.

But I've saved the PID unit and relay etc. However, I haven't decided if I'm going to build a propane or electric furnace yet.
In my world:
-A properly engineered propane furnace feels more efficient and trouble-free.
-As well as a well-designed electric oven with optimized PID settings should be more flexible, but both electricity and propane have their pros and cons and with my "Chinese oven" fresh in my mind, an electric oven feels like my second choice.

Although you will be building with stronger dimensions and then it might work better.
Hmm.. hard choice for me anyway.

But if you're good with electricity, you'll probably build a really nice and durable oven. Sorry for my long post. Will follow this thread. Good luck
/Dennis

 

[goldshark]

Exciting project! What are these heating threads used for in "normal cases"? I mean the ones seen in the picture?
I'm also going to build a new/better furnace, after the heating thread burned off on my cheap China melting furnace on the second heating.

But I've saved the PID unit and relay etc. However, I haven't decided if I'm going to build a propane or electric furnace yet.
In my world:
-A properly engineered propane furnace feels more efficient and trouble-free.
-As well as a well-designed electric oven with optimized PID settings should be more flexible, but both electricity and propane have their pros and cons and with my "Chinese oven" fresh in my mind, an electric oven feels like my second choice.

Although you will be building with stronger dimensions and then it might work better.
Hmm.. hard choice for me anyway.

But if you're good with electricity, you'll probably build a really nice and durable oven. Sorry for my long post. Will follow this thread. Good luck
/Dennis

Maybe somebody on this forum, can shed some light onto why some heating elements last longer then others. I was using an electric ceramics kiln ( I got it free ) for assaying. It worked for melting metals only, a fairly long time. When the elements were exposed to CO2, they quit working. It seems they became super brittle, as they had broken in several places. Any body knowledgable about heating resistance wires, their composition, and which to avoid for certain environments?

 

[Proffshuggarn]

Maybe somebody on this forum, can shed some light onto why some heating elements last longer then others. I was using an electric ceramics kiln ( I got it free ) for assaying. It worked for melting metals only, a fairly long time. When the elements were exposed to CO2, they quit working. It seems they became super brittle, as they had broken in several places. Any body knowledgable about heating resistance wires, their composition, and which to avoid for certain environments?

@goldshark, an excellent suggestion. The heating wire in my china oven that was wound on the outside of the ceramic interior melted apart in two different places. It was supposed to handle temperatures up to 1300 degrees Celcius, but I only ran the oven at about 950 C. When I disassembled the oven and found the faults and examined the heating thread, I noted that it was very brittle and was easy to break off. I'll see if I can find it and post some pictures.
/Dennis

 

[Yggdrasil]

Not sure yet , any suggestions are welcome .
Maybe some type of fuelled exhaust pipe much less need for controlling heat / vs. not blending all the metal in the IC's .

Please reply to a text if you comment or ask questions.
Now it is an open question without reference.

 

[Yggdrasil]

Maybe somebody on this forum, can shed some light onto why some heating elements last longer then others. I was using an electric ceramics kiln ( I got it free ) for assaying. It worked for melting metals only, a fairly long time. When the elements were exposed to CO2, they quit working. It seems they became super brittle, as they had broken in several places. Any body knowledgable about heating resistance wires, their composition, and which to avoid for certain environments?

It has to do by a combination of heat and chemistry.
There was a discussion at Orchid were the conclusion was that Kanthal “older” handled heat better than NiChrome “new and cheaper”.
But this was purely melting/fusing ovens.
I am certain the chemistry in our use play a significant role too.
So if one of our members are masters in this, we’d be happy to read

Edit for typing error.

 

[kurtak]

I have some thought on making this project even a bigger deal - doing volume , starting with a 5 gal bucket of IC's and to get them ashed in one load

Not a good idea

What do you plan to do with the smoke coming from pyrolizing the chips?
You'll need an afterburner to completely burn all smoke.

As pointed out by Martijn

Not sure yet , any suggestions are welcome .
Maybe some type of fuelled exhaust pipe much less need for controlling heat / vs. not blending all the metal in the IC's .

Incineration of plastics (epoxy chips) is a VERY NASTY & TOXIC process if not properly done

Incineration of plastics creates TOXIC gases (dioxins & furans) as well as acidic fumes (& other nasties) & those gases/fumes need to be destroyed through proper incineration so that you are not poisoning your self & others living near you

I have posted much about this so here are some things for you to read to better understand the toxic nature of incineration & what is required for proper incineration in order to deal with those toxic gases/fumes

https://goldrefiningforum.com/threads/what-about-beryllium-in-ic-chips.27671/page-2
https://goldrefiningforum.com/threa...s-from-carbon-and-organics.28551/#post-301413
https://goldrefiningforum.com/threads/pyrolysis-reactor.22581/#p237092

Same with another 5 gal bucket of memory cards - low heat to get IC's to drop off boards

Even this - which will not produce actual smoke like incineration does will still produces the very same toxic gases/fumes as incineration does --- it takes very little heat to release the dioxins, furans & acidic fumes from the epoxy resins that make up the fiberglass circuit board - so heating the boards enough to cause the chips & other components to fall off the boards still creates the same toxic gases/fume - that need to be dealt with

Kurt

 

[snoman701]

Trying to incinerate with electric resistance coiled wire heating elements is a lesson in frustration and short element life.

NiChrome, Kanthal, etc all are made for oxidizing environments only. It heats up and forms a passivation layer. Once you have a reducing environment, you lose that passivation layer and the element shorts out.

 

[goldshark]

Thanks for that info. What wire is recommended for reducing environments? Are you going to make me google it?

 

[Darkthirty]

Trying to incinerate with electric resistance coiled wire heating elements is a lesson in frustration and short element life.

NiChrome, Kanthal, etc all are made for oxidizing environments only. It heats up and forms a passivation layer. Once you have a reducing environment, you lose that passivation layer and the element shorts out.

What would be the downside of mounting electric stove elements instead of bare Ni Chrome wire?

 

[Mech]

Waiting

 

[Yggdrasil]

Waiting

Waiting for what?
Are you out of inputs and questions regarding your own situation?

 

[Mech]

I clicked on goldshark's post --- but it did not show in my " Waiting " post ?

 

[Brett Novak]

why are you burning PCB's? A simple hot water and lye solution takes damn near everything off including the green crap and usually leaves most of the traces behind.

for IC's - if they are ceramic, an old wok pan and a propane torch do the job.

for plastic, goodwill cheap blenders do the trick. but you have to filter and AP, then AR the slurry

 

[Mech]

Have some old blenders

 

[kurtak]

for plastic, goodwill cheap blenders do the trick.

I tried that one time

The impact of IC chips hitting against the walls of the blender at a high rate of spinning speed shattered the blender !!! --- granted - some of the chips were the LARGER thicker PROMs & QUADs --- the blender literally exploded (& it happened within 10 -15 seconds of turning on the blender)

Might work (to a point) on smaller & thinner chips - but - with large thick chips it is an accident waiting to happen !!!

Also - ALL of the epoxy needs to be milled/ground down to a FINE powder of "at least" 80 mesh or some gold bond wire will remain incased in epoxy particles that are larger then 80 mesh in size - which means the acid can't get to the gold to leach it out of the epoxy - meaning though you may get some of the gold - but - not all of the gold

Good luck getting ALL the epoxy to mill/grind to 80 mesh & smaller --- maybe with small thin chips - but - certainly not with large thick chips

Kurt

 

[andu]

First of all, be carefull when incinerating electronics stuff because some might blow up, same for the blender, you hit a lithium capacitor with hit or cut thru it and it can burn or explode.
Second, there's plenty of videos on youtube on how to make different kinds of furnaces.
And third, the wires that heat up are really sensitive, there are some that are better but are hard to find and still not indestructible, not cheap either so temp/power controller for them is a must if you want them to last longer. It mostly depends on material they are made of.