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ON THE USE OF LIGNITE IN THE BLAST FURNACE. 155 
others, included the Professor of Metallurgy in the School of 
Mines, Herr Franz Kupelwieser. 
From this committee, up to the present time, only one state- 
ment has emanated, that being an article from Professer Kupel- 
wieser, entitled “Studies on the Application of Brown Coal to 
the Production of Pig Iron,” which is contained in the last num- 
ber of the “ Journal of the Mining and Metallurgical Association 
of Styria and Carinthia,” pages 260-271.* The author himself 
* In this paper Professor Kupelwieser, after reviewing the various experiments 
made to utilise brown coal in the blast furnace, remarks that it appears to him to be 
necessary in order to the production of pig iron with brown coal, to consider care- 
fully the effect of temperature on that description of fuel in the blast furnace. Brown 
coal and lignite contain so much water and so many elements which escape in gase- 
ous form, that the quantity of heat remaining is thereby substantia]ly diminished, 
The single particles of this diminished volume not being adequate, explosions 
(sprunge) occur, which cause the larger pieces to disintegrate. When the brown 
coal is dense and of conchoidal fracture, it generally remains in pieces of a parallelo- 
piped form, sharp-edged and hard, the external appearance being very similar to 
anthracite. These pieces, generally but a few cubic centimetres in size (I cubic 
centimetre = 0°061 English cubic inch) are hard, solid, and somewhat friable. For 
successful working, such pieces should be kept somewhat larger, whereby a great 
adyantage would be gained, Lignite, which shows a woody texture, separates in 
blisters in consequence of the heat, and then gives off thin, hard and dense slices, 
which are also much smaller in size. This tendency to split into bits is less apparent 
in knotty pieces, because in them the fibres are so folded together that when they 
explode the component parts mechanically hold themselves better together. 
On a closer consideration of their action in the blast furnace it appears doubtful, 
according to Professor Kupelwieser, whether the smelting column becomes so much 
the more dense as the materials of the charge are more finely granulated. Ifa given 
furnace is worked with coked fuel, the height of the furnace and the pressure of blast 
continuing the same, the size of the grain of the material of the charge becomes 
gradually smaller, and the expansion of the gases in the furnace in a similiar ratio 
becomes greater and greater. But if the other conditions remain the same, with the 
rising of the expanding gases, the quantity of blast carried into the furnace would 
continually become smaller, and the production would go down till it reached the 
limit at which the burning of the fuel would altogether cease, and would appear to 
be completely stopped. 
This phenomenon will always appear as soon as the size of the grain of the fuel, 
the ore, and the slag is so small that the blast appears unable to effect a uniform 
distribution through the smelting column. In these conditions it appears to be a 
matter of indifference whether charcoal, coke, or coked brown coal in small pieces 
be applied as fuel to powder-like ore and slags. 
The difficulty in working a blast furnace with brown coal consists, therefore, in 
the right selection of the coal to be used; the difficulty is not in respect of the 
change in the condition of the fuel brought about by the chemical composition of 
the charge, but is to be sought in the size of the grain and in the density produced 
in the strata of the smelting column. 
It thus appears very clearly that the working of the blast furnace with brown coal 
alone, or with coke produced from brown coal, would be found practicable if by 
some means the smelting column could be kept sufficiently loose, if the dense com- 
pression of the smelting column could be prevented; or if in the coking of brown 
coal means were found of producing pieces of cohesive coke of larger size, or of 
making the small pieces of coked brown coal into briquettes, in such a way that the 
briquettes would not split into pieces in the heat. é 
As means which appear under these conditions calculated to give the greatest 
possible production of pig iron with brown coal as fuel, or the coke produced from 
it, the Professor specifies the following as prominent :— 
Ist. In order to keep the smelting column less dense, a stronger pressure of 
blast should be applied. There would be of course, under circumstances in other 
respects alike, an increased expansion along with the pressure of the blast, whereby 
apart of the smelting column would be supported, and be consequently loosened. 
2nd. Another way of lessening the density of the smelting column might be 
sought by changing, in part at least, the size of the grain of the material charged, 
3rd, The formation of the blast furnace would have a great influence on the 
possibility of using much brown coal. 
