Zinc Removal with Steam and Flirting with Tinsel Fairy

[john.k]

There are any number of industrial processes that work perfectly every day,but to attempt them in a Lee 20lb pot and a pressure cooker would be more than a bit risky.

[wimms]

There are any number of industrial processes that work perfectly every day,but to attempt them in a Lee 20lb pot and a pressure cooker would be more than a bit risky.

Oh no, this is not for a lee pot. It's a smelting job outside and with propane burners.

[wimms]

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

I will. But this will have to wait for spring. It's cold winter season here.

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...?

Yeah, I expect it to look like boiling water. My plan is to make orifices small so that they work as restrictors. The steam would probably still expand as I don't think I can control the superheater output temperature very accurately, and the melt temp could be anywhere between 500-800C. That's really my main concern - I need high btu heater to heat up steam fast, and have to make sure I do not overheat the copper tubing vs underheat the steam. In addition to that pressure cooker regulating valve is pulsating type thus the steam pressure and flow will also be pulsating. I also need to find a way to regulate the steam flow rate. And, I'd need to rebuilt my smelting station before I dive in with those experiments.

[William Yanda]

In your op you specified "copper tubing like brake line" or words to that effect. Brake line is steel, and probably cheaper than copper. The trade-off is that it is more reactive with water and even more reactive at elevated temperatures. And there are always trade-offs.

[OS OK]

https://www.youtube.com/watch?v=6HhdkkdsvTM >An old film of lead mining in the US. Very interesting.

https://energy.gov/sites/prod/files/...esscontrol.pdf > Starting on page 9 there is info in controlling steam...looks expensive.

[Bent Ramrod]

There are steam traps (actually condensate traps) that are used to keep steam lines dry.

All the ones I’ve seen are pretty good-sized, used on well insulated steam lines running from the boiler house to outbuildings. You’d have to consult a catalog to see if they make small ones.

They would trap the condensate and hold it until enough had built up to open a valve at the bottom, then the steam pressure would blow it out. When the trap was empty, the valve would seal again.

They saw hard service where I worked and were constantly sticking open and had to be maintained. But better than having condensate in the lines at the operating end.

[alamogunr]

I knew I should have paid more attention in beginning thermodynamics classes in college. I still wouldn't have been able to add anything intelligent to this conversation but I might have understood it better.

[wimms]

Brake line is steel, and probably cheaper than copper. The trade-off is that it is more reactive with water and even more reactive at elevated temperatures. And there are always trade-offs.

There are several types, steel, braided, copper, and copper-nickel. The latter one is best suited. We might use even plumbing copper tubing, but the brake line tubing has a kind of its own fittings universe that is convenient to use I hope.

There are steam traps (actually condensate traps) that are used to keep steam lines dry.

They saw hard service where I worked and were constantly sticking open and had to be maintained. But better than having condensate in the lines at the operating end.

The whole point of superheating is to 1) avoid the need for traps, and 2) prep the steam volumetric density so that it does not explosively expand inside the melt. Thus I want to preheat it up to at least 400C.

[gwpercle]

hey Ma watch this

I know what happens when you say that !

Please make a video of this.....it's going to be a humdinger !

[runfiverun]

about 15 seconds in.

[McFred]

Wimms, I like the way you think. If you have mostly pure lead contaminated with zinc then you can heat the melt up to any temperature over a propane burner. Dribble distilled water via an IV bag on a stand, for example, through some copper "refrigeration tubing" or "capillary tubing" coiled up in the propane burner flame under the pot for a 'dry steam' source and rig a mechanical agitator and percolate the steam through to generate your zinc oxide for skimming. It'd be quite easy with some 20lb propane bottles cut open and organized to skim the impurities and later pour off the result. I wouldn't regulate the steam, just the flow rate of water into the capillary coil. Once the lead is up to temperature it shouldn't take much heat to keep it liquid, use the spare BTUs to boil the water instead. Think about how liquid-fuel rockets work: liquid fuel is evaporated in the exhaust before the gaseous fuel's injected into the jet nozzle...

I'm surprised that the other users are such closed-minded safety nazis that they can't conceive of a safe way to accomplish the goal. Shame on them for crapping on your proposal. I too want a video or a report on the success; not for an explosion.

Some people don't realize that the process is often as fun as the end result. I say go for it.

[OS OK]

So...now we are calling each other... 'NAZI's' ...that's a new low!

[McFred]

Sorry, what's the internet-lingo equivalent of someone putting down another person's idea for fear of injury? Mother hen? Nanny? Babysitter? OSHA rep? In my defense I did use a lower-case "n" for the nazi word.

[OS OK]

I'm glad you didn't mean it in a mean spirited way...but...I've heard that term applied to the Conservative Right for so long now that it just took me back hearing it come from within our brotherhood!

[runfiverun]

he I'm sure meant it more like grammar or spelling nazi.
it's more a grrr grmble thing than a pointing fingers hey look thing.

check out that video that I posted, it shows them doing exactly what is proposed here.

[john.k]

The video shows a common method of removing dross from a melt,by bubbling an inert gas thru,the bubbles carry the impurities to the surface for skimming.This method is commonly used prior to pouring aluminium alloys.A ceramic sponge disperses the gas,which is argon or helium.Bubbling steam is a bit different,in that a violent reaction may occur.Without elaborate precaution steam in a long tube will be accompanied by slugs of superheated water.Where is the tower,Bulgaria,Romania? dont seem to be any EPA or WHS.