|The dry powders were mixed roughly by hand, then enough water added to make a dough like paste. This required the addition of about 50 % by weight of water. The paste was dried before it was then broken up for addition to the smelter.|
|The June 14 smelt was undertaken with the assistance of Ken
Cook and Sam Falazone. It proved quite unusual,
in that there was extremely little effect on the structure of the smelter
itself. The image shows the inside surface of the smelter, with the area
around the tuyere in the upper right.
First, there is very little erosion of the wall material. The area above the tuyere, normally sustains damage, but in this case you can see that the wall has hardly been effected. Curiously, what erosion that took place was just bellow the tuyere. The tuyere itself was also only slightly effected, and other than a slight rounding of the square tip, still remains the same distance proud of the wall surface as at the start of the smelt.
Second, very little material, either slag or partially sintered ore, can be seen remaining attached to the inner wall surface. In many past smelts, a considerable build up of these two materials can be seen.
|A magnet was passed through the screened debris, extracting any pieces containing enough iron to allow attraction. These 'gromps' were measured separately.|
Considerable slag material remained both inside and scattered around the smelter after the bottom extraction of the bloom through the tap arch. This material would have formed the bulk of the slag bowl. These pieces are also a dull medium grey, and often include some imbedded charcoal and ash. Generally the pieces are quite irregular and range around 'walnut' sized.
|This smelt had a major 'self tapping' event occur late in the sequence, during the last stages of the burn down phase. This tap slag was fluid, dark olive / black and proved to have no magnetic quality.|
|As the bloom was extracted, a mass of hard slag remained attached. This material (we call 'mother') cools much more quickly than the iron bloom. It is also brittle, and is shattered off the bloom under the effect of hammering on a wooden stub during the initial consolidation step. Generally this material is quite dense, and a medium matte grey in colour. Some portions of it may prove magnetic (fragments broken off the bloom). Most of the pieces are walnut to fist sized. As this work station is a grassed area just to the side of the smelter platform, any fragments smaller than about 3 cm were surely not recovered.|
|The bloom itself for this experiment is somewhat smaller than our usual.
One factor here is that the weight was taken at a later step in the consolidation
process than what is normally the case. (Standard practice is to make a
single consolidation heat, striking off the majority of slag 'mother'. In
this case, the bloom was subjected to two additional heat / hammer sequences.)
The bloom reacted well to hammering, but was somewhat 'lumpy' in texture.
Through spark testing, it appears to have some low carbon content (roughly
equal to a mild steel).
Weight of Bloom - 1.8 kg