Calculation of the Ore Mixture or Burden for a Blast Furnace. [Volume: 8, Issue: 3, 1889, pp. 130-143]

140

UNITED STATES ASSOCIATION OF

[VOL. 8,

A12lO CaOMgO
0.2 equivalents lias ore,.. 10.52 parts with 0.68
1.8 equivalents bog ore,... 54.54 parts with 0.54 0.65
2 equivalents.
1 equivalents limestone,. 7.02 parts with.. 3.63
72.08 1.22 4.28
and this ratio will be diminished to 1: 3.5. The amount of iron
in the last mixture would be:
10.52 parts lias ore contain of iron,. 4.50 parts.
54.54 parts bog ore contain of iron,..21.97 parts.
7.02 parts limestone contain of iron,... parts.
72.08 parts contain of iron,...... 26.47 = 36.7 per cent.
With regard to the percentage of carbon, an ottput of about
38 per cent. of iron is to be expected, and the mixture in this
respect would be worth smelting, without requiring an increase in
the amount of iron by substituting spathic ore for limestone.
Another occasion for this might arise from the fact that both
lias ore and bog ore are high in phosphorus, and a smaller
amount of phosphorus would appear to be necessary or desirable
Lias ore contains 0.5 per cent. of phosphorus, and bog ore 1.02.
If we suppose that this is all taken up by the iron, which is at
least approximately the case, the amount of phosphorus in the
iron would be
10.52 parts lias ore contain of phosphorus,.......052 parts.
54.54 parts bog ore contain of phosphorus,.......654 parts..706 parts.
These.706 parts phosphorus would be taken up by 26.47
parts of iron, which the above calculation shows to be contained
in the ores. The amount of phosphorus in the iron would
therefore be about 2.6 per cent. The spathic ore is free from
phosphorus. Replacing experimentally the entire amount of
limestone flux by an equivalent quantity of spathic ore, the
amount of iron inthe burden is increased, and in this way the
amount of phosphorus in the iron produced is diminished. We
then obtain the followirg new'mixture: