Zinc Removal with Steam and Flirting with Tinsel Fairy

[wimms]

OK...sounds like you have yourself convinced that you can pull this off...just remember to video it...I wanna see what you look like 'before & after'...

I believe so yes. But I take your input seriously. Why do you think it will blow up?

[JimB..]

3 feet? Why do you think so much is necessary? I'd think 1-2 rings around the pot would suffice.

This is simple. p = 0.0981 * h * SG where h is head(m) and SG is specific gravity. For lead, SG=11 thus
p = 0.0981 * 0.1 * 11 = 0.11 bar above atmospheric pressure. Pressure cookers work at 1-1.2 bar.

3’ was a swag at what a full lining of the pot would be, no real reason but more can’t hurt I don’t think.

Pressure is fluid density times depth times gravity, so
11 gm/cm3 x 10cm x 980cm/sec2 = 107,800 gm/cm2
Or 100bar

Although my units seem to be a mess so maybe I’m wrong. Looks like you and I moved the decimal in different directions converting gravity from meters per sec sq to cams per sec sq.

[popper]

You test turbine input (live) steam with a LARGE cardboard sheet.

[JimB..]

I am very concerned about pressure at the bottom of the pot. It will not be possible to keep the steam dry if the pressure is too high. Of course you could inject it just below or even at the surface. Slower effect, but perhaps safer.

[wimms]

Pressure is fluid density times depth times gravity, so
11 gm/cm3 x 10cm x 980cm/sec2 = 107,800 gm/cm2
Or 100bar

11 g/cm^3 x 10cm x 980cm/sec^2 to bar

0.1078 bar

[OS OK]

I believe so yes. But I take your input seriously. Why do you think it will blow up?

Because when the steam looses temperature it condenses. Also, when first starting up the process, steam will loose temperature until all the tubing involved is as hot or hotter than the steam within...the result is condensation in the steam delivery line and eventually it's going to find it's way into the melt. Condensate doesn't necessarily mean droplets of H2O...it begins as superheated H2O and deposits like a film along the interior of the piping and accumulates into droplets eventually...it's appearance is like a shiny Clear Coat PC...Steam piping is a one way system and the steam will push the accumulating film/condensate with it.
I just can't see how you can avoid the condensate...condensate is H2O & that will return to steam in the melt...can't see how you can avoid it.

Possibly if you were to bring the steam system up to temp before the melt is started in the pot and maintain the steam, it seems that the steam in direct contact with the melt would be encouraged to remain as steam because of the Pb temp...I really dunnoh? This is the first I've ever heard of such a process...I'm hung up on the physics of condensate being introduced into the melt.

If I were looking at 1,000 lbs. or so of Pb I could recover then that would be tempting but I would for sure talk to someone who has done it before...all of us keyboard jockeys around here will only help you get burned or worse!

[lightman]

While the science behind this is interesting, I believe I would either dilute the contaminated alloy until it would cast well or just scrap it.

[MaryB]

The above! Add more alloy until the zinc is below 1%

[vzerone]

The above! Add more alloy until the zinc is below 1%

That's what I said earlier. A little bit of zinc doesn't hurt, other then it may make the alloy a little harder.

[JimB..]

11 g/cm^3 x 10cm x 980cm/sec^2 to bar

0.1078 bar

107,800 g/cm^2 x 0.000980665 = 105.7bar

This agrees with the website https://www.convertunits.com/from/g/cm%5E2/to/bar

I’m happy to understand where I’m wrong, but our math is in agreement until the conversion to bar which is a black box.

[OldBearHair]

Ten inch sections of Stainless Steel wire .020 dia. packed into the 3/16 brake line until no more will fit in and then coiled to fit the application might help with delivering the needed amount of steam to the bottom of the mix. Or however long the submerged coiled tubing is would work instead of the 10" sections. SS fishing leader line can be used.

[OldBearHair]

Ten inch sections of Stainless Steel wire .020 dia. packed into the 3/16 brake line until no more will fit in and then coiled to fit the application might help with delivering the needed amount of steam to the bottom of the mix. Or cut wires to however long the submerged coiled tubing is would work instead of the 10" sections. SS fishing leader line can be used.

[runfiverun]

the melted alloy alone would provide enough heat to insure the steam stays steam.
[that extreme heat is what causes the tinsel fairy to visit]
it's between the pot and the coils I would be most concerned about condensation occurring.

I wonder if you couldn't just pull zinc out by boiling water on top of the alloy.
it would be a fairly tedious process of stir boil stir boil skim stir boil.

[vzerone]

the melted alloy alone would provide enough heat to insure the steam stays steam.
[that extreme heat is what causes the tinsel fairy to visit]
it's between the pot and the coils I would be most concerned about condensation occurring.

I wonder if you couldn't just pull zinc out by boiling water on top of the alloy.
it would be a fairly tedious process of stir boil stir boil skim stir boil.

I was waiting to see if anyone caught that the heat of alloy would insure the steam stayed superheated steam. By golly you knew runfiverun!!

[john.k]

Ay caramba.Have you met the grim reaper,yet?This is the craziest thing I have ever read on a forum,any forum.And its so easy to do.What could possibly go wrong?

[rondog]

Wow, there's NWIH I'd go through all that expense and hassle! I'd just scrap it and buy fresh alloy from Rotometals.

[wimms]

107,800 g/cm^2 x 0.000980665 = 105.7bar

This agrees with the website https://www.convertunits.com/from/g/cm%5E2/to/bar

I’m happy to understand where I’m wrong, but our math is in agreement until the conversion to bar which is a black box.

Your mistake is in units. Pressure is in units of force per area, N/m^2, and your final units is g/(cm*s^2) not g/(cm^2)

Simpler approach: you know that 9.8m of water head is 1 bar pressure. Lead is 11 times more dense, thus 9.8/11=0.9m of lead head is 1bar. 0.1m of lead is 0.1 bar.

[JimB..]

Your mistake is in units. Pressure is in units of force per area, N/m^2, and your final units is g/(cm*s^2) not g/(cm^2)

Simpler approach: you know that 9.8m of water head is 1 bar pressure. Lead is 11 times more dense, thus 9.8/11=0.9m of lead head is 1bar. 0.1m of lead is 0.1 bar.

Thanks, that makes sense.

[wimms]

Because when the steam looses temperature it condenses. Also, when first starting up the process, steam will loose temperature until all the tubing involved is as hot or hotter than the steam within...the result is condensation in the steam delivery line and eventually it's going to find it's way into the melt. Condensate doesn't necessarily mean droplets of H2O...it begins as superheated H2O and deposits like a film along the interior of the piping and accumulates into droplets eventually...it's appearance is like a shiny Clear Coat PC...Steam piping is a one way system and the steam will push the accumulating film/condensate with it.
I just can't see how you can avoid the condensate...condensate is H2O & that will return to steam in the melt...can't see how you can avoid it.

Check out properties of superheated steam. Condensate can occur only when steam is cooled down to temp of saturation, which is around 130C at 2bar abs pressure. When you add heat to the steam, it has to be released before it can fall down to that. And we do add lots of heat to raise it to 400C. Sure, the whole tubing must be at higher temp than 130C for condensate to not occur, by a safe margin, but it is doable, and superheated steam will do it.

Possibly if you were to bring the steam system up to temp before the melt is started in the pot and maintain the steam, it seems that the steam in direct contact with the melt would be encouraged to remain as steam because of the Pb temp...I really dunnoh?

But of course, you startup the steam and bring it to working temperature before you submerge the coil into the melt, or use some valve to purge the tubing before redirecting steam into the melt. Superheated steam will dry out any moisture in the tubing and any little that gets carried along is turned into steam by the tube section that is in the melt and at the melt temperature.

This is the first I've ever heard of such a process...I'm hung up on the physics of condensate being introduced into the melt.

This is actually quite interesting. This process of using steam for lead refining was first used Cordurié in 1867 and has been used in lead industry for over 100 years, yet it is still quite difficult to find description of it on internet. But not one book on lead metallurgy exists that doesn't mention it.

It exists, it's not my invention by any stretch, I just try to apply it on a small scale.

If I were looking at 1,000 lbs. or so of Pb I could recover then that would be tempting but I would for sure talk to someone who has done it before...all of us keyboard jockeys around here will only help you get burned or worse!

I'm aware of the dangers as should anyone be who wants to try it.

I'm not even so much interested in removing zinc. This process is more than just for zinc, it removes many impurities, fluxes, stirrs, and is completely clean. In industry they don't even use mechanical stirring anymore, they use steam stirring.

It is easy to add CO2 to the steam, or even by adding charcoal on the path of the superheated steam to generate CO inside the tubing which works as lead and tin oxide reducer, and can be burned on the surface of the melt. Heck, you could even inject propane into the pressure cooker. It will self-ignite after coming out of the melt, leave some carbon and reduce surface oxides. It can't burn inside the melt as there is insufficient oxygen there. Pure steam removes carbon by gasification of it into CO2.

It looks like it is possible to do lead refining without needing any of the traditional fluxes that burn, stink and leave ash behind, using only gaseous matter. It's fascinating.

And I am well aware how crazy it sounds. But we are all crazy here right? It's just a new level of crazy I guess..

I'm telling you, seriously, some refineries don't even bother with steam, they route tap water under the kettle, use tap water pressure to force water into the melt and let the melt do all the steam generation. Boiler is tubing inside the melt and uses the heat of the melt to generate steam before it is released into it. Kettle loads in tens of tons at a time..

[OS OK]

Like I said before...make a video. Not so much now for the explosion but I'd just like to see the process.

Have you thought about how to keep the splatter down to a minimum? You know though...the superheated steam shouldn't expand any more physically when it hits the bottom of the pot so...it oughta just bubble in the pot like boiling water bubbles?

right...?