IRON CORRECTION

Geez

I've been poking web stuff since 7:30 this morning. Not much to show for it. Made some changes to the first two splash pages on the Wareham Forge site. Mainly to keep it vaguely up to date and to clean it up a bit. Added a link over to this stuff, so we shall see.

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One major addition on the Iron Smelting front. I got a return comment from Lee Sauder, pointing up a major error in use of terms on the posted Adventures in Iron Smelting paper:

" Howdy Darrell-

The paper looks good, clearly written. I only see one major thing I think you should fix.

You seem to be a bit confused about slag terminology. You're calling nasty slag fayalite, good slag wustite. Not right.

Fayalite is Fe2SiO4. It is black and fluid, not green and gooey. Think of fayalite as your optimal final slag. It has the lowest melting point of all the slags on the FeO to SiO2 gradient. If there's more FeO (wustite) than that, the melting temperature of the slag rises gradually. If there's less FeO than fayalite, the melting temp of the slag goes up dramatically.

So fayalite slag is perfect slag. Slag that is higher in silica (and alumina) than fayalite is the gooey nasty stuff. Slag higher in iron than fayalite is strongly decarburizing (reducing), and is a good candidate for recycling.

Another way to look at it. Fayalite is composed of wustite (FeO) and silica (SiO2). It is often written as 2(FeO)SiO2 (that is, 2 wustites and one silica) rather than Fe2SiO4. More wustite than that proportion makes an active, decarburizing/reducing, and reasonably fluid slag. More silica than the wustite proportion than the fayalite proportion makes an unreactive, gooey slag that doesn't contribute to reduction and allows carburization.

So to call high silica slag fayalite, and high iron slag wusite is inaccurate and confusing. Probably the best way to fix it is just to remove the referneces to those things, since you've got to cut everything down for publication anyway,

Hope that's not too confusing! It makes more sense looking at the phase diagram...."

I'm copying over Lee's clear discription of the chemistry here mainly for completeness. I have just gone in and changed the use of terms and a bit of the surrounding text on the posted paper.

I've also found out that the paper is in fact to be published! Mind you, the text has to be drasticly shortened - down to 15 pages total. I will be cutting out most of the 'towards a sucessful smelt' section. Reduce the 'experimental overview' to a simple table with the main measurements. Likely reducing the descriptions of the various raw materials to simplify. I DO want to leave the section on air systems and most of 'implications for the Viking Age'.

its getting close to lunch and I should get outside...

Darrell