The Blast-furnace Theory

FERROUS metallurgy today, defined as the art of extracting money from iron ores, appears to suffer from a complex of inherited theory. In so far as pig iron costs contribute to inadequate profit margins, this symptom may be diagnosed as due to persistence, despite disproval, of Sir Lowthian Bell's theories of reduction. An attempt to meet the economic situation by reducing costs through improving blast-furnace metallurgy would be inconsistent with Bell's theories. These theories, though refutable on the facts of practice, still prevail and today's metallurgy, as measured by its fuel economy or smelting efficiency ranging between 30 and 40 per cent. is no better than Bell's, showing a specific efficiency of 36 per cent.1 If fair to neglect dry-blast operations, it appears that the advance in furnace practice since Bell's day, as shown by a tenfold increase in individual furnace capacity, has been largely mechanical and that the metallurgy of the process has not been changed materially, since the introduction of blast heat, patented in 1828. It seems fair to attribute, this lack of progress on the strictly metallurgical side to a domination of the industry by false ideas first expressed by Lowthian Bell. What the furnace seems to need first, in the interest of lower costs and of better iron, is some destructive criticism of these ideas, in moderate doses, to be followed by a constructive theoretical treatment; then, research and still more research.