Adventures in Early Iron Production


An overview of experimental iron smelts, 2001 - 2005.


Darrell Markewitz
Interpretive Program Designer
The Wareham Forge - Ontario CDN

Appendix 1 - Experimental Overview

Date: June 2001 - 1
Location: L'Anse Aux Meadows NF
Team: Parks Canada consultants (1)
Furnace: Norse boxed bowl
stone slab sides, clay sealed, sod backed
no tap arch
Size: 35 cm x 30 x 50 H
Source: based on LAM (theoretical)
Tuyere: 25 mm ID steel pipe
Placement: 5 cm above floor
3 cm in from wall
angle slightly up
Bellows: standard Norse double chamber
Air: (E) 2 L per stroke
(E) 120 L per minute
Charcoal 8 kg broken hardwood
Consumption:
Ore: LAM bog ore
5 kg (roasted)
Sequence: ore added as one large charge
Duration: about 2 hours (plus preheat)
Result: small slag mass
small iron 'prills' (total 100 gm)
high carbon (cast iron)
Yield:
Notes: a number of basic errors, consider equipment test:
- charcoal allowed to burn down to half way
- ore placed on raft of bark
- air flow not constant (cyles temperature)
- low pressure / poor penetration of air
- sequence too short

Date: May 2002 - 2/D1
Location: Wareham ON
Team: DARC (2) + Dr. Kevin Smith
Furnace: Norse boxed bowl
stone slab sides, clay sealed, sod backed
no tap arch
Size: 30 cm x 30 x 40 H
Source: based on LAM (theoretical)
Tuyere: 25 mm ID steel pipe
Placement: angle slightly up
Bellows: standard Norse double chamber
Air: (EE) 1.2 L per stroke
(EE) 120 - 72 L per minute
Charcoal 22 kg broken hardwood
Consumption:
Ore: St Lunaire bog ore
6 kg (roasted)
mix of 2.8 ore / 2.5 scale / .7 sand
Sequence: ore added as three large charges
Duration: about 8 hours (plus preheat)
Result: 2 kg slag mass
total 4.3 kg magnetic slag recovered
Yield:
Notes: a number of basic errors:
- use of large amount forge scale
- extremely low air volume
- low pressure / poor penetration of air
- air flow not constant (cyles temperature)
Date: June 2003 - 3/D2
Location: Wareham ON
Team: DARC
Furnace: Romano British Medium Shaft
cylindrical cob with refractory liner
tap arch
fire brick base
Size: 27 cm taper to 24 x 90 H
Source: suggested by Sauder & Williams
Tuyere: 25 mm ID steel pipe
Placement: (E) about 20 cm from base
about 5 cm in from wall
angle at 15 down
Bellows: electric blower (vacumn)
Air:
Charcoal: (E) 50 kg broken hardwood
Consumption: about 1.5 kg charcoal every 12-15 minutes
Ore: Virginia rock ore
8 kg (roasted)
Sequence: ore added as 6 x 1.5 kg charges
Duration: about 4 1/2 hours (plus preheat)
Result: - initial liquid slag (faylite) tapped
- burn through crashes sequence
Yield:
Notes: Generally sequence is closer to correct
Slag bowl forms too high
- slightly reduced air volume
- incorrect tuyere angle
Date: June 2004 - 4/D3
Location: Wareham ON
Team: DARC + Mike McCarthy, Mark Pilgrim
Furnace: Norse Boxed Short Shaft
cylindrical cob backed with stone slab and sand
no tap arch
Size: 25 cm tapers to 20 x 50 H
Source: suggested by Crew
Tuyere: 25 mm ID steel pipe
Placement: 2 cm from base
about 5 cm in from wall
angle at 15 down
Bellows: initial Norse double bag / various
Air: initial 2.2 per stroke
at 130 per minute
/ various
Charcoal: (E) 19 kg broken hardwood
Consumption: about 1.5 kg charcoal every 12-15 minutes
Ore: Virginia rock ore
7 kg (roasted)
Sequence: ore added as 7 x 1 kg charges
Duration: about 6 hours (plus preheat)
Result: slag masses only
Yield:
Notes: - Clay slumps during smelter construction and moves tuyere to incorrect possition - too close to floor and shallow angle. This 'drowns' air flow.
- Air system failures leads to fluctuating temperatures
- Attempt to cut new tuyere unsucsessful
Date: October 2004 - 5
Location: Cooperstown NY (Early Iron 1)
Team: Michael Mahoney / Millard Wyman /
Paul Burdon / Elizabeth Hendrix
Furnace: Norse Short Shaft
cylindrical cob set in earth trench
no tap arch
Size: 28 cm x 60 H
Source: suggested by eariler experiments
Tuyere: 25 mm ID steel pipe
Placement: 15 cm from base
about 3 cm in from wall
angle at 15 down
Bellows: Norse double bag
Air: 2.2 L per stroke
at 130 L per minute
Charcoal: 100 L broken hardwood
Consumption: about 6 L charcoal every 15 minutes
Ore: Virginia rock ore
8 kg (roasted)
Sequence: ore added as 5 x 1.5 kg charges + .5 reduction
Duration: about 4 hours (plus preheat)
Result: 'pre bloom mass'
Yield:
Notes: - Air cut during operator changes and short
repairs to body of smelter only
- Generally structure sucessfull
- Air flow still low
- Longer sequence required to develop larger bloom
Date: October 2004 - 6/D4
Location: Wareham ON
Team: DARC
Furnace: Econo Norse (first prototype)
firebrick backed with sand set in earth trench
no tap arch
Size: 30 cm x 70 H
Source: suggested by eariler experiments
Tuyere: 25 mm ID steel pipe
Placement: 20 cm from base
about 3 cm in from wall
angle at 20 down
Bellows: electric blower
Air: 550 L per minute
Charcoal: 110 L broken hardwood
Consumption: about 6 L charcoal every 12 - 15 minutes
Ore: Virginia rock ore
(EE) 8 kg (roasted)
Sequence: ore added as 8 x 1 kg (E) charges
Duration: about 5 1/2 hours (10 hours total)
Result: 2 kg bloom - high carbon (cast iron)
Yield: EE 25%
Notes: - Air cut (electrical problems) at pre-heat only
- Sucessfull creation of small bloom
- Air flow still a bit low
- Longer sequence required to develop larger bloom
Date: February 2005 - 7
Location: Lexiton VA (Smeltfest 05)
Team: Gangue aux Fer (3)
Furnace: Econo Norse
firebrick backed with sand set on plinth
tap arch
Size: 25 cm x 60 H
Source: DARC 10/04
Tuyere: 25 mm ID 1/8" formed copper
Placement: 18 cm from base
about 5 cm in from wall
angle at 20 down
Bellows: electric blower
Air: 815 L per minute
Charcoal: 85 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
Ore: Virginia rock ore
about 35 kg (roasted)
Sequence: ore added about every 10 minutes
as small charges .5 - 2 kg
Duration: about 7 hours (not including preheat)
Result: 6.5 kg bloom - (not tested)
Yield: 18 %
Notes: - Sucessfull creation of mid sized bloom
- tap slag recycled
Date: February 2005 - 8
Location: Lexiton VA (Smeltfest 05)
Team: Vince Petty / Vandy Simpson
Furnace: Econo Norse
firebrick backed with sand set on plinth
tap arch
Size: 25 cm x 60 H
Source: DARC 10/04
Tuyere: 25 mm ID 1/8" formed copper
Placement: 18 cm from base
about 5 cm in from wall
angle at 20 down
Bellows: electric blower
Air: 815 L per minute
Charcoal: 85 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
Ore: Virginia rock ore
28 kg (roasted)
Sequence: ore added about every 10 minutes
as small charges .5 - 2 kg
Duration: about 7 hours (not including preheat)
Result: 7.5 kg bloom - (not tested)
Yeild: 27 %
Notes: - Sucessfull creation of mid sized bloom
- tap slag recycled
Date: May 2005 - 9
Location: Wareham, ON
Team: OABA / Neil Peterson / John Burton
Furnace: Econo Norse
firebrick backed with sand set on plinth
tap arch
Size: 25 cm x 60 H
Source: DARC 10/04
Tuyere: 25 mm ID schedule 40 pipe
Placement: 20 cm from base
about 5 cm in from wall
angle at 20 down
Bellows: electric blowers / rotary hand
Air: inconsistant flow
Charcoal: 67 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
Ore: Stelco takenite
3 kg (roasted)
Sequence: ore added about every 12 minutes
as small charges .75 - 3 lbs
Duration: about 7 1/2 hours (not including preheat)
Result: 9.5 kg bloom - (estimated)
Yield: 45 % E
Notes: - Sucessfull creation of mid sized bloom
- tap slag recycled
- problems with melting of pipe tuyeres
- packing of ash / sand / wood shavings
proves a poor choice
Date: June 2005 -10/D5
Location: Wareham, ON
Team: DARC demo team
Furnace: Norse Short Shaft
clay cob with stone slab support
tap arch
Size: 25 cm x 60 H
Source: suggested by earlier experiments
Tuyere: 25 mm ID schedule 40 pipe
Placement: 16 cm from base
about 5 cm in from wall
angle at 20 down
Bellows: large double bellows / electric blower
Air: 600 l / min (estimated)
Charcoal: 38 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
Ore: Stelco tacenite
9 kg (roasted)
Sequence: ore added in variable sequence (10 - 20 min)
as small charges .75 - 2.25 lbs
shift to forced air at 2:30
Duration: about 5 1/2 hours (not including preheat)
Result: 3 kg bloom - (estimated)
Yield: 28 % E
Notes: - Sucessfull creation of historic sized bloom
- extreme hot weather limits use of bellows
Date: September 2005 -11/D6
Location: Annapolois Royal NS
Team: DARC demo team + Mark Pilgrim
Furnace: Norse Short Shaft
commercial clay cob with stone slab support
tap arch
Size: 25 cm x 60 H
Source: suggested by earlier experiments
Tuyere: 25 mm ID schedule 40 pipe
Placement: 24 cm from base
about 5 cm in from wall
angle at 20 down
Bellows: large double bellows / electric blower
Air: no data
Charcoal: 47 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
Ore: Stelco tacenite
9 kg (roasted)
Sequence: ore added in variable sequence (10 - 20 min)
as small charges .75 - 2.25 lbs
shift to forced air at 6:45
Duration: about 9 hours (not including preheat)
Result: cast iron mass
2 kg? no data available on size
Notes: use of high purity tacenite means no silica
use of high temperature clay means no silica
no silica means no carbon control
exit valves required on bellows ??
Date: September 2005 - 12
Location: Copperstown NY (Early Iron 2)
Team: Elizabeth Hendrix / Toby Bashaw
Furnace: Flue Tyle
commercial tile reinforced with wire
tap arch
Size: 25 cm square x 60 H
Source: developed by Sauder & Williams
Tuyere: 25 mm ID forged copper
Placement: about 24 cm from base
5 cm in from wall
angle at 20 down
Bellows: electric blower
Air: plus 1000 L/min (estimated)
Charcoal: 110 lbs primary sequene / no data for balance*
Consumption: about 4 kg charcoal every 10 minutes
Ore: Virginia Rock Ore
about 16 kg *
Sequence: ore added in variable sequence (8 - 12 min)
as small charges .75 - 2.25 lbs
Duration: about 7 1/2 hours * (not including preheat)
Result: Two bloom masses
Secondary at 3.4 KG
Notes: Main smelt sequence abandonded at 6 1/2 hours
Smelt assumed, produced secondary 'salvage bloom'
* no clear records kept for secondary sequence
Date: October 2005 -13/D7
Location: Wareham, ON
Team: DARC
Furnace: Norse Short Shaft
clay cob with stone slab support
tap arch
Note - reuse of furnace from June 05
Size: 25 cm x 60 H
Source: suggested by earlier experiments
Tuyere: 25 mm ID ceramic kiln support
Placement: 16 cm from base
about 5 cm in from wall
angle at 20 down
Bellows: electric blower
Air: 600 l / min (estimated)
Charcoal: 79.5 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
Ore: Stelco tacenite (unroasted) +
Virginia Rock Ore (roasted)
7 kg total
Sequence: ore added in variable sequence (7 - 10 min)
as small charges .75 - 2.25 lbs
Duration: about 6 1/4 hours (not including preheat)
Result: 4.3 kg bloom
Yield: 22 %
Notes: - Sucessfull creation of historic sized bloom
- Sucess in patching and re-firing smelt
TEAM PARTICIPANTS

(1) Parks Canada / L'Anse aux Meadows
Mark Pilgrim
Birgitta Wallace Arne Espelund

(2) Dark Ages Re-creation Company
Core (demo) Team:
Kevin Jarbeau Dave Cox
Neil Peterson
Assisting:
Ken Cook Marcus Burnham
Karen Peterson Vandy Simpson
Gus Gissing David Robertson

(3) Gangue aux Fer
Lee Sauder Skip Williams
Mike McCarthy
Assisting:
Elisabeth Sauder