Slag is at least as important as debitage, cores, and preforms are on  
a prehistoric site. Until the advent of modern metallurgy the slag  
(late 1800s) was the only way most metallurgical processes could be  
controlled. Most of the "ore" ended up in the slag, with only the  
primary metal and some other elements making it into the finished  
product. This is  especially true before hot blast was introduced in  
the US around 1840 (iron industry). Most of the information available  
about a metallurgical process is in the slag rather than the metal.  
Which is why most archaeologists don't do slag analysis... ?

After 1900 the controls on furnaces become increasingly complex and  
more and more real time. Now the computer controls and sensors allow  
real time information on exactly what is going on inside a furnace. I  
doubt that there are very many people alive that can tell you much  
about slag that worked in the industry on the floor (but I could be  
wrong). Starting in the late 19C most iron/steel firms hired  
metallurgists and established labs.

If you haven't read Bob Gordon's American Iron you should. If you  
don't have a copy of John Percy (1864) you need to find one. And if  
you really want to understand what is going on at your site you  
probably ought to hire an archaeometallurgist to do some analysis  
(Tim probably knows some good ones in the US, I worked primarily with  
English universities, they did the analysis for my MA for free).  
There are some references on slag including:

Verein Deutscher Eisenhüttenleute (ed.)
     1981               Schlackenatlas. Verlag Stahleisen MBH.,  
Düsseldorf.

Tim and others that have dealt with newer plants can probably suggest  
other references. My study has been primarily with the colonial iron  
industry.

James Brothers, RPA
[log in to unmask]



On Sep 7, 2006, at 10:20, Timothy Mancl wrote:

> Melissa,
>
> There is not a single written source to which you can refer. I  
> agree with the others
> that talking to a steel worker, especially someone familiar with  
> the various
> elements of operations, is a good idea. Also, Ron Hatt has run  
> workshops on coal
> and slag at past SHA conferences (see past conference programs).  
> Perhaps he
> could lend a hand?
>
> However, as an Industrial Archaeologist, I have some concerns about  
> your work,
> especially since you stated that in the past you've tended to  
> simply classify some
> materials as slag. This might be fine for most historic period  
> sites, although, again,
> I have reservations about this approach, but for an industrial  
> site, I'd recommend
> hiring a historian or archaeologist familiar with the steel  
> industry. Have you
> considered hiring an industrial archaeologist, even if on a  
> consulting basis only?
> There are people in your area with the expertise.
>
> Tim Mancl, RPA
> Heite Consulting, Inc.
>
> ---------- Original Message ----------------------------------
> From: HISTARCH automatic digest system <[log in to unmask]>
> Reply-To: HISTORICAL ARCHAEOLOGY <[log in to unmask]>
> Date:  Thu, 07 Sep 2006 00:00:56 -0700
>
>> Date:    Wed, 6 Sep 2006 15:43:46 -0400
>> From:    Meli Diamanti <[log in to unmask]>
>> Subject: Industrial byproducts & waste products
>>
>> I'm looking for information to help me identify industrial waste and
>> byproducts.
>> In the past, I've had either glassy/bubbly or more metallic material
>> that I have simply classified as slag.  But I now have a crew  
>> doing work
>> in a steel town in western Pennsylvania (Braddock) and want to know
>> whether there are distinctions I should be making within slag.  Also
>> what does coke look like (made from coal for steel plant fuel)?  What
>> about other coal waste ("clinkers")?  or other products that I  
>> would be
>> likely to encounter in that setting.  I've seen everything from  
>> black to
>> ashy beige materials, to a very blue-ish gray; some dense, some very
>> light and full of air bubbles like pumice.  I can see that they are
>> different materials, but don't know where to look, to learn how to
>> better classify them.  So any descriptions, pictures, or  
>> directions to
>> an informative website would be greatly appreciated.
>> Melissa Diamanti
>> Archaeological & Historical Consultants, Inc.
>
>
>
>
>
>