Continuing the descriptions of the work under my OAC Project Grant...
The third smelt undertaken as part of Turf to Tools 2 was an extra one.
Eden Jolly and Uist Corrigan (SSW staff) did most all the work on this. My contribution was some helpfull advice, breaking ore, and as striker at the end.
|Eden (sitting) and Uist - at the start of the sequence|
|Slag running as part of 'constant tap' process|
- Initial charges of 3 kg iron rich slag (Nissen)
- Continuous slag tapping (Sauder)
- Addition of partially sintered gromps (Sauder & Williams)
|Resulting 9 kg bloom, partially compacted and cut|
Build : standard clay / sand / manure mix (repair from smelt B)
Size : Tapered 25 to 20 cm ID, 68 cm total with 50 cm stack and 30 cm to hard base
Tuyere : tapered copper, 5 cm proud, 20 degree down angle
Ore : Industrial Taconite (22 kg) + Lecht Mine (6 kg) + smelt 2 gromps (6 kg) - total 34 kg
Fuel : hardwood charcoal broken to standard size
Method : 3 kg iron rich slag added as first charges
BLOOM : 9 kg, fragmented - yield 26 %
|Larger piece, after cutting and breaking|
Enlarging the image above may prove interesting. Note the large size of the broken crystals, and the very white colour of the metal there. Both are visual indicators of a higher than normal carbon content to this bloom. Spark testing confirmed that the iron produced was 'steely' - consistent with a roughly 0.50 % carbon content (similar to a modern spring steel). When fully compacted, this should prove a good tool making material!
|Furnace just after extraction|