Ethnographic Arms & Armour
 

Go Back   Ethnographic Arms & Armour > Discussion Forums > Ethnographic Weapons
User Name
Password
FAQ Members List Calendar Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
Old 20th December 2017, 09:10 PM   #61
Timo Nieminen
Member
 
Timo Nieminen's Avatar
 
Join Date: Mar 2012
Posts: 408
Default

Quote:
Originally Posted by A. G. Maisey
Terrestrial iron ores need to be reduced to turn them into usable material. Iron rusts, which means it combines with moisture, so before terrestrial iron ores can be worked they need to have the moisture removed from the ore, this is what the smelting process does, it removes moisture and produces a solid lump of material called a bloom. This bloom can then be worked in a forge.
Smelting can be used with any ferric raw material, including meteoritic material.
However, in the case of meteoritic material, and also limonite, forge processing is also possible, which is not the case with haematite. Haematite is probably the most prolific source of iron. I doubt that haematite is found in combination with nickel, but limonite is found in combination with nickel, and also with cobalt, however the nickel percentage in limonite is far less than is usual in an iron-nickel meteorite.

This brings us back to the KT dagger:- if the nickel in that blade is 10% it is almost certainly meteoritic.


Jambon doesn't analyse the dagger; he uses the measurements by Comelli et al. 2016, (10.8% Ni, 0.58% Co, and also quotes the measurement given by Ströbele et al. 2016 (ref at end), 12.9% Ni.

A few comments on smelting etc.:

"Smelting" is the conversion of ore to metal. For iron, this is typically done by using carbon to bond to the oxygen in an iron oxide, giving CO or CO2 and metallic iron. For a metallic meteoric, there is no need for smelting, because it's already metallic. For any ore, you smelt, by definition, to obtain metal. For iron, the temperature required is well below the melting point of iron, and the chemistry can be made to happen in the solid state, giving a bloom. The is some conflation of "smelting" and "melting" in non-technical usage. You can melt with smelting (just start with metal instead of ore) and smelt without melting (as possible with iron).

When an ore is heated to remove moisture, the process is "roasting", not smelting. Some ores (like limonite) are hydrated, and some are not. Roasting can also be used to make other changes in the ore, such as converting sulphides to oxides. The difference between smelting and roasting is that smelting produces metal and roasting produces a different type of ore. When limonite is roasted, it's converted to haematite, which is then smelting as usual.

The usual early traditional method to smelt limonite (e.g., bog iron) was to roast and then smelt in a bloomery furnace.

For details of the chemistry of smelting and roasting:
https://www.tf.uni-kiel.de/matwis/a...one/ra_2_2.html
or the version with frames if you want to navigate to elsewhere in the document:
https://www.tf.uni-kiel.de/matwis/amat/iss/index.html

I haven't heard of limonite with significant amounts of nickel. The common high-nickel iron ore is laterite. Jambon gives some data for nickel and cobalt content of various laterites.

Other refs:

Comelli et al. 2016: https://doi.org/10.1111/maps.12664

Jambon: https://doi.org/10.1016/j.jas.2017.09.008

Ströbele et al., 2016:
F. Ströbele, K. Broschat, C. Koeberl, J. Zipfel, H. Hassan, Ch Eckmann
The iron objects of tutanchamun. Metalla
Archäometrie und Denkmalpflege 2016, Göttingen
Sonderheft, 8 (2016), pp. 186-189
Timo Nieminen is offline   Reply With Quote
Old 20th December 2017, 10:45 PM   #62
A. G. Maisey
Member
 
Join Date: May 2006
Posts: 4,667
Default

I spoke too soon.

Good stuff Timo, and clearly more advanced than my own knowledge, especially so in your use of terminology, my own terminology is that used by people who actually work with the materials.

For instance, there used to be a gentleman named Mike Peterson who did a smelt once a year. Mike has passed on now but he lived on the South Coast of NSW. In technical terms he probably did not really smelt, what he did was to collect a lot of various kinds of iron and steel, stack with charcoal and produce a bloom. Or maybe Mike did "melt with smelting", as you have noted. I have a piece of one of the blooms he produced, and have worked with this material. It requires quite gentle initial welding, not dissimilar to welding meteorite. It makes very good blades.

My understanding is that limonite comes in various forms and that the solid forms of limonite were forge worked in early times by smiths in sub-Saharan Africa. I actually have a few pieces of limonite, identified as such by a metallurgist, I picked it up at Bungonia and had it for years before I knew what it was. I have not worked with it, but from the look and feel of it, it seems as if it could be worked in a forge.

Yes, I understand that limonite was worked in later times by heating to remove moisture, and then to use smelting, but in early times my understanding was that it was worked in the forge by gradually increasing temperatures, first removing the moisture then welding and folding.

Yes when limonite does carry nickel, the content is quite low, I think something like 1%-2% ?

I know nothing about laterite ores, I've heard the name, but only in connection with soil and with building materials.

Last edited by A. G. Maisey : 20th December 2017 at 11:06 PM.
A. G. Maisey is offline   Reply With Quote
Old 20th December 2017, 11:39 PM   #63
Timo Nieminen
Member
 
Timo Nieminen's Avatar
 
Join Date: Mar 2012
Posts: 408
Default

Quote:
Originally Posted by A. G. Maisey
For instance, there used to be a gentleman named Mike Peterson who did a smelt once a year. Mike has passed on now but he lived on the South Coast of NSW. In technical terms he probably did not really smelt, what he did was to collect a lot of various kinds of iron and steel, stack with charcoal and produce a bloom. Or maybe Mike did "melt with smelting", as you have noted. I have a piece of one of the blooms he produced, and have worked with this material. It requires quite gentle initial welding, not dissimilar to welding meteorite. It makes very good blades.


Yes, technically not smelting. This is a traditional process for steel-making, starting with iron. It's one of the 4 ancient steel-making methods (make steel directly in a bloomery furnace during the smelting process, make iron in a smelter and then carburise in a second step, make cast iron in a smelter (a blast furnace rather than a bloomery) and decarburise the cast iron, and crucible steel).

The goal is to carburise the iron to produce steel, and done right it can make excellent steel. The diffusion of the carbon into the iron is the same as what happens when you make steel directly in a bloomery. You don't want it to melt, since you want high-carbon steel, not cast iron, so you get a bloom. I guess (but it's only a guess) that the bloom would be much cleaner than the bloom from a bloomery smelter, since if you just put in iron and charcoal, you should get a bloom full of slag.

Steel made this way is called oroshigane by the Japanese, and it's still done for swordmaking.

For those interested, video showing this kind of thing: https://www.youtube.com/watch?v=n5Zyf8svLKI

I've heard of people doing similar things with forge scale, which is smelting (since it's an oxide).

Quote:
Originally Posted by A. G. Maisey
Yes when limonite does carry nickel, the content is quite low, I think something like 1%-2% ?

I know nothing about laterite ores, I've heard the name, but only in connection with soil and with building materials.


The only limonite I know anything of the chemistry of is bog iron, which AFAIK has only trace amounts of nickel. So time to learn more.

[A pause, to go away and learn more.]

OK, the deal with laterites is that "laterite" is a very broad category, and includes rocks that are iron ores and rocks that aren't iron ores. If they are iron ores, the iron is usually in the form of limonite. 70% of laterites contain limonite.

Anatolian laterites have a Nickel:Iron ratio of about 1:30. If you made nickel-iron from them with 100% efficiency, you'd get about 3-4% nickel in the iron. Some laterites have more nickel than that, which is why (a) 8% (rather than 4%) is often considered a good rule of thumb to distinguish between ancient smelted nickel-iron and meteoric iron, and (b) people look at the nickel:cobalt ratio because that tends to be different for terrestrial vs meteoric (and Jambon has some nice graphs showing this (but his data doesn't include Anatolian ores)).
Timo Nieminen is offline   Reply With Quote
Old 21st December 2017, 02:05 AM   #64
A. G. Maisey
Member
 
Join Date: May 2006
Posts: 4,667
Default

This is very interesting technical information Timo, it is something that for the most part I do not know, in fact something I have not needed to know, my knowledge in this area deals with forge work, and I --- and I believe most other people involved with forge work --- tend to look at all the processes that produce the material with which we work, as "smelting". Obviously technically incorrect.

I had intended to stop posting to this thread, but your posts gave it a new life, well, at least for me they did.

However we've still got King Tut's dagger sitting in front of us, and if we can now accept that it is indeed meteoritic material, which it must be if the nickel content is as high as it is reported to be, then we really only have one question:-

prior to 1323BC who had the technology that could forge weld iron or could cast iron?

welding depends on heat and pressure, but in the absence of a massive power hammer, the heat needed to weld iron is around 2500F - 2600F

nickel will weld at a slightly lower temperature than iron

casting depends upon having liquid metal, iron will melt at about 2800F

Prior to 1323BC, when King Tutankhamen died, what people, anywhere in the world, had the technology that would provide temperatures in excess of 2500F?

If that question can be answered we will know where the King Tut dagger came from, if it cannot be answered all we can do is to speculate.

--- or maybe Erik von Daniken had the answer after all????
A. G. Maisey is offline   Reply With Quote
Old 21st December 2017, 03:06 AM   #65
Battara
EAAF Staff
 
Battara's Avatar
 
Join Date: Dec 2004
Location: Louisville, KY
Posts: 5,837
Default

I am fascinated that this thread got this technical and went on so long. Great info, and it seems now that it has come full circle.

Thank you for sharing your knowledge. Alan, I especially thank you for your forging insights. In fact, I thank every one of you for your insights and thoughts.
Battara is offline   Reply With Quote
Old 21st December 2017, 09:06 AM   #66
mariusgmioc
Member
 
mariusgmioc's Avatar
 
Join Date: Sep 2014
Location: Netherlands
Posts: 1,083
Default

Quote:
Originally Posted by A. G. Maisey
or maybe Erik von Daniken had the answer after all????


Very often, what appear to be very complicated and misterious problems have very simple and straight forward solutions... that however might elude us...

However, as long as all we have is very little factual evidence, any theory might be the valid one.

In this context, maybe Roland's hypothesis may be closer to reality than we will ever know...

Meanwhile... MERRY CHRISTMAS!
mariusgmioc is offline   Reply With Quote
Old 22nd December 2017, 02:36 AM   #67
Timo Nieminen
Member
 
Timo Nieminen's Avatar
 
Join Date: Mar 2012
Posts: 408
Default

Quote:
Originally Posted by A. G. Maisey
prior to 1323BC who had the technology that could forge weld iron or could cast iron?


"Who?" is the difficult question.

As you noted, while it takes high temperatures to forge weld iron, it's otherwise low-tech:
Quote:
Originally Posted by A. G. Maisey
Meteoritic material was used in Sub-Saharan Africa, and it was worked in primitive forges; the original Javanese/Balinese forges were not much more than a depression in the ground with air delivered to the fire through bambu tubes from feather bellows. You do not need high technology to weld iron. In fact, the traditional type of "hole in the ground" forge is still in use in some parts of Jawa, and probably is still in use in some parts of Bali.

A hole in the ground, charcoal, a blower, a rock as an anvil and a rock as a hammer: https://www.youtube.com/watch?v=v94aAEMZMIQ

Casting (low-carbon) iron or steel is much more technologically demanding, and I know of nobody doing it before the Industrial Evolution. The Chinese were casting cast iron about 2000 years ago, but "cast iron" has a quite low melting point (about 1200C/2200F) since it's a saturated carbon solution (typically 3%-4% carbon).

Iron forging/welding technology might have preceding iron smelting technology. First, it allows small pieces of meteoric or telluric iron (native iron, i.e., naturally occurring metallic iron of terrestrial origin) to be used to make larger objects than would be possible without welding. Second, it appears that there was occasional accidental smelting of iron in the copper industry, when iron oxide was used a flux in copper smelting (and temperature got a little higher than needed for copper smelting).

So there was motivation for forge welding iron. Forge welding of copper alloys and gold was already known, so the basic idea was there. Judging by the history of the techniques, forge welding iron is much easier than casting (low carbon) iron.

But "Who?" is a difficult question to answer.
Timo Nieminen is offline   Reply With Quote
Old 22nd December 2017, 05:27 AM   #68
A. G. Maisey
Member
 
Join Date: May 2006
Posts: 4,667
Default

Yes, correct Timo.

I threw the idea of casting into the mix because of two things:- some suggestions that it might have been cast as a continuation of bronze casting, and the fact that I cannot find any authoritative opinions of the KT dagger being forged.

On my monitor I cannot see any evidence of it being forged, but I'm certain that in the hand that evidence would be obvious. What I'd like to see is somebody who has handled it and who knows exactly what he is looking at to have published that it is forged.

I personally think it was.

There seems to be good evidence that iron working technology appeared in India before anywhere else. The Vedic Peoples had Aryan roots, the Hittites and Mitanni were also from Aryan roots.They worshipped the same Gods. I wonder if there was contact between the New Hittite Kingdom and the Vedic Peoples of India?

It seems that the formation of the New Hittite Kingdom coincides with the beginning of iron working technology in India. We know that in the early 17th century BC Indo-Aryans were moving from the East to the west and through the Middle East.

I tend to think that when the requisite research has been carried out, and from my enquiries it appears to be something that is still ongoing with as yet no definite conclusions, we might find that Hittite iron technology has its roots in Indo-Vedic or Indo-Aryan culture, which in effect can push the beginning of Hittite iron age technology back to 1500BC, which just happens to coincide with the time by which the Hittites had developed viable iron weapons.

My personal opinion remains the same as it has been from the beginning of this thread, and in fact for a very long time before this thread began, and that is that the King Tut Dagger was a product of Hittite technology.

Incidentally, I have finished reading the papers that were so generously bestowed upon me, and I now have no doubt at all that the material of the King Tut Dagger is of meteoritic origin.

Facts seem to have a half-life of about 45 years (Arbesman) so this meteoritic origin might not be a fact forever, but as at right now it seems to be a pretty good imitation of a fact.
A. G. Maisey is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT. The time now is 10:43 AM.


Powered by: vBulletin Version 3.0.3
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Posts are regarded as being copyrighted by their authors and the act of posting material is deemed to be a granting of an irrevocable nonexclusive license for display here.