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May 30, 2009
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Oct 12, 2008
Jun 14, 2008
Apr 13, 2008
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Oct 8, 2007
Jun 10, 2007 - Excav.
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Jun 9, 2007 - First
Nov 5, 2006
Sep 1-2, 2006
Jun 10, 2006
Jun 10, 2006 - Tools
Nov 4, 2005
Sep 1, 2005 - CanIron V
Jun 11, 2005
May 14, 2005 - OABA
Jan 14, 2005 - Consolid.
Oct 24, 2004
Jun 3, 2004
Jun 3, 2004 - Design
Jun 3, 2004 - Questions
May, 2003 - Analysis
May 2003
May 2002

Iron Smelting Experiment - 14 May 2005

This experiment was not performed by DARC but is a part of the sequence of experiements.  Please contact Darrell Markewitz for more details about this experiment.

Date: May 14, 2005
Location: Wareham, ON
Team:

Leader Darrell Markewitz
Staff Neil Peterson
John Burton
Recorder Neil Peterson
Vandy Simpson
Charcoal Monkeys Gus Gissing
Ken Cook
Sam Falzone
Smelt_cd Reports of all of our iron smelting efforts along with more articles and information are available on the "Iron Smelting in the Viking Age" CD from the Wareham Forge.  Copies of the CD can be purchased here.
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 above floor, 5 cm in from wall, angle 20 deg down
    Bellows: electric blower / rotary blower
        Air: inconstant flow
Charcoal: 150 lbs broken hardwood
Consumption: approx 2Kg per10 minutes
Ore: Stelco Taconite - 38 lbs (roasted)

Sequence: ore added about every 12 minutes as small charges .75 - 3 lbs
Duration
: about 7 hours (plus preheat)
Result: 21 lb bloom - (not tested)
This represents 45 % yield from roasted ore weight

Notes:
- Sucessfull creation of mid sized bloom
- tap slag recycled

Bloom was significantly 'trough' shaped - this a result from changes in the tuyere angle during the smelt. Weight estimate is for the main bloom only, and does not include smaller (walnut sized) fragments. Roughly one third of the mass was cut off while still hot from the smelt. The remaining section weighs 14 lbs.

Considerable trouble was experienced during the early part of the sequence with air delivery. Although checked before storage, the main blower did not work at first attempt. A smaller (less volume) vacumn blower was initially employed. Concern developed that it was not producing enough air volume, so a second hand cranked blower was added in conjunction. The main blower was checked and re-installed to the smelter about hour three.

The use of a packing mixure of roughly 50 / 50 beach sand and rough saw dust proved a mixed blessing. First, gaps in the brick structure were not sealed with clay. During firing, the sawdust element burned, and the heated sand ran like a fluid through the cracks. Continual addition of replacement packing proved necessary.

As it turned out, the pure taconite ore lacked the silica content to provide for the required slag. Normally this would have been a major problem, as the firebrick adds little silica (through melting). In this smelt, the sand from the packing actually added the required silica content to create plentiful slag - required to control the carbon content of the bloom.

One third of the bloom was given to Llyod Johnson. He later consolidated and finished the mass into a workable bar. He reports that the material created was 'nice soft workable iron'.

Time Event Measures
Relative Absolute Total
Relative Elapsed Charcoal Ore
-00 00 start preheat with wood splits        
-35 35 addition rough charcoal, gentle air blast        
-45 45 fill with rough charcoal        
12:00 00 timer reset - smelt begins        
12:10 10 first measured charcoal 1 4 lbs* 4 lbs  
12:20 10 charcoal 2 4 lbs 8 lbs  
12:40 20 charcoal 3 4 lbs 12 lbs  
12:51 11 seed charge 1 .75 lbs   .75 lbs
charcoal 4 4 lbs 16 lbs  
1:06 15 seed charge 2 .75 lbs   1.5 lbs
1:09 18 charcoal 5 4 lbs 20 lbs  
1:32 23 charcoal 6 4 lbs 24 lbs  
26 seed charge 3 .75 lbs   2.25 lbs
1:40   addition of second hand crank blower        
1:45   tuyere replaced with copper        
***
2:02 30 charcoal 7 4 lbs 28 lbs  
seed charge 4 .75 lbs   3 lbs
2:12 10 charcoal 8 4 lbs 32 lbs  
2:17 15 seed charge 5 .75 lbs   3.75 lbs
2:29 17 charcoal 9 4 lbs 36 lbs  
12 seed charge 6 .75 lbs   4.5 lbs
2:44 15 charcoal 10 4 lbs 40 lbs  
15 seed charge 7 .75 lbs   5.25 lbs
2:49 5 charcoal 11 4 lbs 44 lbs  
5 seed charge 8 .75 lbs   6 lbs
2:53 4 charcoal 12 4 lbs 48 lbs  
4 full charge 9 1.5 lbs   7.5 lbs
3:00 7 charcoal 13 4 lbs 52 lbs  
3:10 17 half charge 10 .75 lbs   8.25 lbs
3:12 12 charcoal 14 4 lbs 56 lbs  
2 full charge 11 1.5 lbs   9.75 lbs
***
3:23 11 charcoal 15 4 lbs 60 lbs  
full charge 12 1.5 lbs   11.25 lbs
3:31 12 charcoal 16 4 lbs 64 lbs  
full charge 13 1.5 lbs   12.75 lbs
3:38 7 charcoal 17 4 lbs 68 lbs  
full charge 14 3 lbs   15.75 lbs
3:50 12 charcoal 18 4 lbs 72 lbs  
full charge 15 3 lbs   18.75 lbs
3.58 8 charcoal 19 4 lbs 76 lbs  
full charge 16 3 lbs   21.75 lbs
4:11 13 charcoal 20 4 lbs 80 lbs  
full charge 17 2.25 lbs   24 lbs
4:21   first tapping attempt        
4:23 12 charcoal 21 4 lbs 84 lbs  
half charge 18 .75 lbs   24.75 lbs
4:26 3 charcoal 22 4 lbs 88 lbs  
full charge 19 3.75 lbs   28.5 lbs
4:36 10 charcoal 23 4 lbs 92 lbs  
full charge 20 2.25 lbs   30.75 lbs
second tapping attempt        
4:44 12 charcoal 24 4 lbs 96 lbs  
full charge 21 2.25 lbs   33 lbs
4:52 12 charcoal 25 4 lbs 100 lbs  
full charge 22 2.25 lbs   35.25 lbs
5:02 10 charcoal 26 4 lbs 104 lbs  
full charge 23 3 lbs   38.25 lbs
5:15 13 charcoal 27 4 lbs 108 lbs  
full charge 24 2.25 lbs   40.5 lbs
5:22 7 charcoal 28 4 lbs 112 lbs  
full charge 25 3 lbs   43.5 lbs
5:32 10 charcoal 29 4 lbs 116 lbs  
full charge 26 3.75 lbs   47.25 lbs
5:43 11 charcoal 30 4 lbs 120 lbs  
full charge 27 3 lbs   50.25 lbs
5:54 11 charcoal 31 4 lbs 124 lbs  
full charge 28 3 lbs   53.25 lbs
6:08 12 charcoal 32 4 lbs 128 lbs  
full charge 29 3.75   57 lbs
6:29   tap slag and recycle   3 lbs    
(one charcoal addition may be missing here)
6:34 26 charcoal 31 4 lbs 132 lbs  
6:43 11 charcoal 32 4 lbs 136 lbs  
6:52 11 charcoal 33 4 lbs 140 lbs  
6:59 7 charcoal 34 4 lbs 144 lbs  
7:06 7 charcoal 35 4 lbs 148 lbs  
7:13   start to dismantle smelter        
7:26   bloom removed        

NOTES:

All ore charges are based on a 'standard scoop' - taconite weight of .75 lbs
* All charcoal charges are based on a 'standard pail' - weight of 4 lbs
This is estimated weight only, not added into charge total

*** Marks areas were records are suspect


      Updated: 4 Dec, 2007
Text © Darrell Markewitz, Neil Peterson, 2006   Photographs © Individual artists   Copyright details
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