CanIRON 8 A - November 6, 2010
Preparing for a demonstration using the Econo Norse system

Smelt by Neil Peterson and Richard Schwietzer,
with assistance by Darrell Markewitz and Laurier University archaeology students

The DARC team would like to thank
McDonald's Home Hardware in Dundalk Ontario.
who assisted in the purchase of the charcoal.

the Econo Norse is is a simple and easy to build furnace using standard construction materials. Basically three octangal rings of standard fireplace lining bricks are stacked up to form the cylindrical shaft. A piece of sheet metal is placed around the stack, with packing made of ash and sand mix filling the spaces.

The demonstration for CanIRON 8 (the Canadian National Blacksmith Conference at Fergus Ontario) will mark a shift for the DARC team from recent focus on archaeological protoypes. For this demo on (Thursday July 28, 2011) the stress is on a production smelt using simple and easy to duplicate methods for the auidence of blacksmiths.

This proved to be a text book smelt, although this was the first time Neil and Richard had conducted the entire furnace build to extration process on their own. Darrell primarily kept detailed notes of tools and supplies utilized - and did his best to keep on the side lines.

Furnace Layout
Plinth with Fines
First brick layer
Second brick layer
with tuyere block
Third brick layer
with support wires
Fitting the metal collar
Cutting tuyere slot
Fitting the tuyere
Completed furnace
Wood split pre-heat
Errosion at tuyere
latter in smelt
Adding ore charge
Scooping out remaining charcoal
Using the 'Thumper'
Metal collar removed
Hooking under the bloom
Pulling the bloom
Bloom as extracted
Thomas & Katie as strikers
Checking for quality

Finished Bloom

24 kg of ganular hematite ore

8.5 kg of high carbon bloom

Yield at 35%

Spark test = High Carbon

YouTube Video - showing the extraction sequence

A total of 24 kg of granular haemitite ore was used. In the past the haemitite has proved somewhat 'dry' and does have a tendancy to absorb considerable carbon in the reaction column. This lack of silica is balanced by the Econo Norse furnace 'leaking' its packing material between the component bricks. As the packing is a mix of sand and ash, (the components of glass), any slag present comes from this - or from the melting of the inner brick surfaces. As in past uses of this ore, there was an amount of 'white cast iron' produced as well as the desired bloom.

Experimental Sequence
Conduct of the smelt as recorded by Katie Thorton.

Furnace Details Interior Diameter 28 cm (approximate)
Stack Height 55 cm (above tuyere)
  Tuyere Height 21 cm (above base)
  Tuyere Angle 23 degrees down
  Tuyere Insert 4 cm
  Tuyere Type 2.5 cm ceramic tube
Smelt Details Total Ore 24 kg
  Bloom Weight 8.5 kg 'high carbon'
  Secondary Production 2.7 kg 'white' cast iron
  Bloom Yield 35 %
  Total Yield 45 %

Additional Photographs (indicated by GREEN boxes) Steve Budge - used with permission.
Text and photography © 2010, Darrell Markewitz