IRON SMELT Experiment Overview

2006

V3 / 2021

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CONSUMPTION / SEQUENCE rates (at m/kg) are from first ore to last ore additions

Date: February 2006
Experiment: 14
Location: Black Rock Forge, Traverse City MN
Team: (demonstration) Brent Cole, Ken Chambers
Furnace: Econo Norse
firebrick backed with sand set on plinth
tap arch (disassemble to extract)
Size: 25 cm x 60 H
Source: DARC 10/04
Tuyere: 25 mm ceramic tube
Placement: 20 cm from base
about 5 cm in from wall
angle at 22.5 down
Bellows: electric blower
Air: 775 L per minute
Charcoal: 107 kg broken hardwood
Consumption: about 2 kg charcoal every 9 minutes
3.8 m/kg
Ore: Michigan taconite
30 kg (roasted)
Sequence: ore added about every 9 minutes
charges range from .45 to 2.2 kg each
10.5 m/kg
Duration: about 7 1/4 hours (not including preheat)
Result: 13.5 kg bloom - good workable iron
Yield = 45 %
Notes: - Successful creation of mid sized bloom
- small amount of tap slag recycled
Date: March 2006
Experiment: 15
Location: Smeltfest - Lexington VI
Team: Dick Sargent (Gangue aux Fer)
Furnace: Norse Medium Shaft - "Yormungand'
clay cob set on plinth
tap arch (bottom extraction)
Size: 35 to 30 cm x 85 H
Source: ongoing research, details suggested by Williams
Tuyere: 25 mm ID ceramic tube
Placement: 15 cm from base
about 6 cm in from wall (wall is angled)
angle at 22.5 down
Bellows: electric blower
Air: 740 l/m
Charcoal: 84 kg broken hardwood
Consumption: about 2 kg charcoal every 7 minutes
2.9 kg/m
Ore: hematite grit (commercial) @ 68 % Fe
45.5 kg
Sequence: ore added about every 7 minutes
increasing from .5 to 2.8 kg
4,2 m/kg
Duration: about 4 3/4 hours (not including preheat)
Result: 22 kg bloom - high carbon 'steel'
Yield = 48 %
Notes: - Successful creation of large carbon rich bloom
- test of spit wood form
- test of commercial hematite blasting grit ore
Date: March 2006
Experiment: 16
Location: Smeltfest - Lexington VI
Team: Dick Sargent (Gangue aux Fer)
Furnace: Norse Short Shaft - "Yormungand'
clay cob set on plinth
tap arch (bottom extraction)
second firing of furnace
Size: 35 to 30 cm x 60 H
Source: ongoing research, details suggested by Williams
Tuyere: 25 mm ID ceramic tube
Placement: 15 cm from base
about 6 cm in from wall (wall is angled)
angle at 22.5 down
Bellows: electric blower
Air: 740 l/m
Charcoal: 68 kg broken hardwood
Consumption: about 2 kg charcoal every 7 minutes
3.4 m/kg
Ore: hematite grit (commercial) @ 68 % Fe
45.5 kg
Sequence: ore added about every 7 minutes
increasing from .5 to 2.8 kg
4.7 m/kg
Duration: about 4 3/4 hours (not including preheat)
Result: 20 kg bloom - high carbon 'steel'
Yield = 44 %
Notes: - Successful creation of large carbon rich bloom
- damaged top of previous smelter removed
- clear duplication of earlier sequence
Date: June 2005
Experiment: 17 / D8
Location: Wareham, ON
Team: DARC - Leaders Dave Cox & Kevin Jarbeau
Furnace: Norse Short Shaft
clay cob half dug into earth bank
small tap arch (top extraction)
Size: 25 cm x 65 H
Source: suggested by earlier experiments
Tuyere: 25 mm ID ceramic tube
Placement: 7 cm from base
about 5 cm in from wall
angle at 22.5 down
Bellows: electric blower
Air: 970* l / min (re-calculated)
Charcoal: 87 kg broken hardwood
Consumption: about 2 kg charcoal every 10 minutes
5 m/kg
Ore: Virginia rock ore + gromps
18 kg (roasted)
Sequence: ore added in smaller charges for most of smelt
considerable re-cycle of tap slag
21.1 m/kg
Duration: about 8 hours (not including preheat)
Result: 1.5 kg bloom - cast iron
Yield (main) = 8 %
Notes: - first smelt controlled by Dave and Kevin
- slow addition of ore resulted in excess carbon
Date: September 2006
Experiment: 18 / D9
Location: Bonfield ON (Baron's Howe SCA)
Team: DARC - Nick West (with labour from observers)
Furnace: Norse Short Shaft
clay cob with stone slab support
small tap arch
Size: 28 to 18 cm x 60 H
Source: suggested by earlier experiments
Tuyere: 25 mm ID ceramic tube
Placement: no information on base
about 5 cm in from wall
angle at 22.5 down
Bellows: large double bellows
Air: no data
Charcoal: 59 kg broken hardwood
Consumption: about 2 kg charcoal every 15 minutes
6.7 m/kg
Ore: Virginia rock ore @ 66 % Fe
10.5 kg (roasted)
Sequence: ore added in variable sequence (10 - 20 min)
as small charges .75 - 2.25 lbs
22.8 m/kg
Duration: about 6 1/4 hours (not including preheat)
Result: small cast iron mass about 1.5 kg
Yield = 16 %
Notes: demonstration smelt with high audience content
Irregular bellows control from many operators
smelter set up to replicate LAM arrangement
Date: October 2006
Experiment: 19
Location: Peter's Valley NJ - Early Iron 3
Team: none (demonstration smelt)
Furnace: Small diameter Norse short shaft - "Loki'
clay cob set
small tap arch (top extraction)
Size: 20 cm x 65 H
Source: ongoing research
Tuyere: 25 mm ID ceramic tube
Placement: 7 cm from base
about 5 cm in from wall
angle at 22.5 down
Bellows: electric blower
Air: 700 * l/m (based on recalculated rates)
Charcoal: 36 kg broken hardwood
Consumption: about 2 kg charcoal every 14 minutes
considerable variation (from 9 - 20 min)
20.9 m/kg
Ore: Minden Bog
8.9 kg
Sequence: ore added about every 14 minutes (see above)
increasing from .5 to 1 kg
7.4 m/kg
Duration: about 4 3/4 hours (not including preheat)
Result: .7 kg small lumps of clean cast iron
Notes: - Successful test of small diameter furnace
- test of (questionable) Minden 'ooze'
Date: October 2006
Experiment: 20
Location: Peter's Valley NJ - Early Iron 3
Team: Dick Sargent (Gangue aux Fer)
Furnace: Flue Tyle
standard clay tile set on block plinth
bottom extraction
Size: 28 cm x 60 H
Source: Developed by Sauder & Williams
Tuyere: 25 mm ID ceramic tube
Placement: 15 cm from base (?)
about 3 cm in from wall
angle at 20 down
Bellows: Rock Bridge blower
Air: approx 1000 l/m E
Charcoal: 60 kg broken charcoal
Consumption: about 2 kg charcoal every 8 minutes
4.8 m/kg
Ore: Virginia rock ore @ 66 % Fe
45.5 kg (roasted)
Sequence: started at 1.7 increasing to 2.4 kg
3.8 m/kg
Duration: about 5 hours (plus preheat)
Result: 8.2 (E) kg dense bloom of workable iron
Yield = 18 %
Notes: - use of large charges suggested by McCarthy
- furnace ran hot and predictably
- 1/3 forged into Norse reproduction anvil
Date: November 2006
Experiment: 21/ D10
Location: Wareham, ON
Team: DARC
Furnace: Norse Short / Medium Shaft
clay cob half dug into earth bank (reuse of 6/06)
small tap arch (top extraction)
Size: 25 cm x 65 H
metal cylinder extends top 30 cm
Source: suggested by earlier experiments
Tuyere: 25 mm ID ceramic tube
Placement: 10 cm from base (light ash only)
about 5 cm in from wall
angle at 22.5 down
Bellows: electric blower
Air: 1060* l / min (re-calculated)
Charcoal: 29 kg broken hardwood
Consumption: about 2 kg charcoal every 6 minutes
3.0 m/kg
Ore: Virginia rock ore @ 66 % Fe
21 kg (roasted)
Sequence: all charges at 2 kg each
2.9 m/kg
Duration: about 2.3 hours (not including preheat)
Result: large volume of high iron content slag
no recognizable bloom
Notes: - attempt to duplicate 'fast charge' method
- reuse of earlier cobb smelter
- no solid base lowers material below sinter zone
Date: November 2006
Experiment: 22
Location: Wareham, ON
Team: none
Furnace: Norse Short / Medium Shaft
clay cob half dug into earth bank (reuse of 6/06)
small tap arch (top planned, bottom used)
Size: 25 cm x 65 H
metal cylinder extends top 30 cm
Source: suggested by earlier experiments
Tuyere: 25 mm ID ceramic tube
Placement: 10 cm from base
about 5 cm in from wall
angle at 22.5 down
Bellows: electric blower
Air: 1060* l / min (re-calculated)
Charcoal: 51 kg broken hardwood
Consumption: about 2 kg charcoal every 6 minutes
5.1 m/kg
Ore: Virginia rock ore plus gangue from previous smelt
8.8 kg (roasted) plus 10.2 kg
Sequence: ore added first as 1.4 kg each 6 minutes
gangue added last as 1.1 kg each 7 minutes
9.7 m/kg
Duration: about 2.3 hours (not including preheat)
Result: 6.8 kg dense workable iron
Yield = 35 % (likely effected by use of gromps)
Notes: - 'Redemption Smelt' to re-smelt gangue material
- attempt to duplicate 'fast charge' method
- reuse of earlier cobb smelter
CONTINUE - for the 2007 Experiments

TEAM PARTICIPANTS


Dark Ages Re-creation Company
Core Team:
Kevin Jarbeau / Dave Cox
Neil Peterson
Assisting:
Ken Cook / Marcus Burnham
Karen Peterson / Vandy Simpson
Gus Gissing

Gangue aux Fer
Lee Sauder / Skip Williams
Mike McCarthy
Dick Sargent
Assisting:
Elisabeth Sauder & Vandy Simpson

Photo by Elisabeth Sauder
IRON SMELT LINKS

Lee Sauder
Mike McCarthy
DARC - Iron Experiments



Unless indicated, All text and photographs © 2005 - 2006 Darrell Markewitz - the Wareham Forge