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Smelting and melting


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I see these terms used almost interchangeably as of late. In my mind "smelting" is a chemical reduction of ore. "Melting" is just that, the heating of a material till it turns liquid. I don't believe that just because the word "smelt" contains the word "melt" that they are interchangeable terms. We don't smelt bars of iron in a hearth, we melt them, likewise we don't really melt the ore in a stack (or crucible) we smelt it, its a chemical reaction that happens at a certain temp.

These are my thoughts on the subject, I'd like to hear what others thought. I hate to bring up terminology again, but I feel that it is important.

 

Thanks

Zeb

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I am almost certainly a culprit of this,and I've been trying to avoid it. Would it be a smelt if I were to refine something and remove the impurities by fully liquefying it, or is that still melting? Also, what about melting two materials together to alloy them? As I enter the world of casting, I have a feeling I'll be around these terms more often, and I would rather use them correctly.

 

John

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Zeb is correct. If it is not converting ore to metal it is not a "smelt." For instance, the Aristotle furnace, while nifty, is a remelting furnace, not a smelting furnace. Same thing with Mark's hearth he uses for his Evenstad experiments (well, I guess technically that could be called "fining"). Making tamahagane is smelting, making oroshigane is melting.

 

On the other hand, a smelt is also a type of small fish with no use in the reduction of ores...although smelt roe ( ore? roe? see what I did there? :P ) is excellent on maki roll-type sushi. ;)

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John, this isn't really about "culprits" and finding them :) I've heard the term smelting refered to quite a bit in the backyard casting hangouts, and I've probably used it wrong before as well, that damn s in the begining makes it sound so much cooler :)

Lee, I'm pretty sure if it weren't for you I'd probably never have known what a real smelt is.

Alan, I used to go smelt dipping when I was a kid, I was raised eating so much fish, I can't hardly even stand the smell of it cooking anymore. Were not fining furnaces used for decarbing pig iron as well?

 

Zeb

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I agree with above and propose to ban the term melting or remelting from our vocabulary. This term is confusing and simply suggest to me that a metal has turned into liquid which occurs during smelting too. I rather do malting than melting. (Malting: Processing grain to make beer.)

 

Smelting: Reduction of any form of iron oxide (ore) to metal. Usually associated with the image of a stack furnace but as Jeff has repeatedly shown us, a crucible would do. I would further divide this into two processes. One for making iron (less than 0.1% carbon) or steel or a mix of both (kera-oshi) and the second to make cast iron (zuku-oshi) since there are some differences in the procedure. I am aware that sometimes you can make all three, iron, steel and cast iron in one run but defining something is trying to simplify it to have a common vocubulary to be able to further the conversation.

Refining: Modifying carbon content in already reduced metal. Usually associated with a hearth or forge (kajiba). And I would further divide this into two as well. Carburazing (cementation or oroshigane) iron into steel or cast iron or by decarburizing (finery or sageba) cast iron into steel or iron. It could also be used to describe the process of improving the quality of the metal (fining): iron to better iron, steel to better steel. In this regard, the term fining or refining could be used interchangeably.

 

This situation is akin to using the term "damascus" for pattern-welded steel. It's a matter or educating people by repeating the terminology.

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Unfortunately, the term "refining" already has a specific metallurgical meaning, referring to removing silicon from pig iron, so could lead to confusion again. "Fining" also has a specific meaning, referring to decarburizing pig, and doesn't even cover all decarbing processes, just a couple of specific ones.

 

Probably we end up in the same place we did last time we had this discussion, which is to use "smelt" only for reduction from ore, and then take the time to be specific when we;re talking about any of the subsequent processes.

 

I tend to use "remelt" because it's accurate, and implies that it is a process subsequent to smelting, and doesn't already have a specific metallurgical meaning. And I try to be specific, as in "remelt to make steel", or "remelt to decarburize", or "remelt to remove slag".

 

No easy way around this one, is there?

 

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I think it´s allready quite like all are saying...

 

We however need to consider the fact that we are from all over the world...diffenent countries.

In all of these we have very different terms/slang word to all these prosses..

Smelting..guite wide range

Melting....quite wide range too...

 

I however think that smelting is eng word for reduction prosses for any metal that is driven from ore...Iron,direct reduction to steel...cast...copper...

Melting too eng word...and I would keep this for any prosses that is done after smelting..

 

After smelting there is lots we can do...in spesific furnace, forge or in crucibel...

But even in smelting...there is different states of prosses in side during time of prosses...even we turn ore to iron, iron to steel..steel to cast..its still just smelting.( even there is japanese terms to make two different materials...but other hand there is lots of side product in it )..

 

I think over all terminology is ok, when we use it in "right" contens. Japanese terms for japanese methods, "viking" terms ( if we only could know more than stackfurnace ) for viking...German for german....list goes one and one...

 

But Im not consider any of these too much of an issue as long as just this smelting and melting goes about right...Even im not sure have I used it right...maby not :D


We use eng as over all language here...so thats why smelting and melting goes just fine.

If one wants to point out prosses what he or she is using to make material thats really cool plus and gives pit more inside what is selected

method giving and what is prosses history too.

 

...Me thinks

 

BR

Niko

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All very good points! My specific concern I guess was because I see the term "smelt" refered to in crucible steel making quite a bit. While there are people smelting in a crucible (direct reduction from ore) most of the time the term smelt is used for something that should be refered to as a melt.

The hearth processes after the bloomery process, is probably best termed using the japanese terms, as Jesus pointed out, they are specific to each process, but there are some folk who get all bent out of shape because we aren't really using a tatara to produce tamahagane, because only the "real" stuff comes from Japan, or something thereabouts :blink: but likewise, we aren't making "real" viking swords either :lol:

Let me try and get the japanese terms figured out in my head, tell me if there's something I got backwards.

 

Kera-oshi basicly the bloomery process as we know it?

Zuku-oshi a furnace similar to a cupola, except we are aiming for cast iron from ore?

Orishigane a hearth made product starting with a lower carbon content and adding carbon?

Sageba A hearth product starting with cast iron and decarburizing it?

 

no wonder there are there are aisi definitions for modern steels :lol:

 

Zeb

Edited by ZebDeming
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That's pretty much it, Zeb. And to make it a bit easier (or not)...

Kera = bloom.

Zuku = cast iron.

-gane = metal.

Sageba is also the term for the hearth/forge itself where the decarb process takes place.

Kajiba is also a term for the general smithing hearth/forge and even for the smithy/shop.

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I agree with above and propose to ban the term melting or remelting from our vocabulary. This term is confusing and simply suggest to me that a metal has turned into liquid which occurs during smelting too. I rather do malting than melting. (Malting: Processing grain to make beer.)

 

Jesus, you're speaking my language!!

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