Nouveau procédé pour affiner le fer brut
In the manufacture of iron, chemical reagents have been sometimes used with more or less success in the puddling process, and they recently have found application in the refining process, but until now they have not to the best of my belief been used for the manufacture of malleable steel and iron, which is the object of the present process. The effect of chemical reagents is very imperfect, however, in its use for the puddling process, as the separation of earthy and other deleterious matter cannot take place in any complete way, and my improvements relate to manufacturing malleable products from crude fluid iron directly by means of chemical reagents.
Pig (crude) iron running out from the blast furnace or from a remelting common cupola or reverberatory furnace is introduced in sufficient large mass into a basin or basins established near the blast or other furnaces. It will be useful to protect such basins by fireproof matter as usual, and to surround them by sand, cinders, or other materials, to avoid the escape of heat. Also before the introduction of fluid metal, the basins may be heated to a degree sufficient to prevent irregularities and failures, whilst the mass of metal is entering in a fluid state no further heat will be wanted, because the process by means of chemical reactions produces a quantity of heat sufficient to keep the metal in a fluid state until the chemical actions have ceased.
All crude fluid iron running from the blast furnace must be considered as a combination of iron, carbon, and other earthy and deleterious matter, and it is impossible to manufacture it into malleable products without removing such extraneous alloy, which until the present time has only been performed by systems of manufacturing, which are very expensive, besides material faults and imperfections in point of quality being connected therewith.
It is therefore a discovery of the greatest importance, to make malleable products directly out of crude fluid iron, simply by the introduction of chemical reagents (as alum, sulphate of iron, manganese, etc. etc.), which by their decomposition and combination with the deleterious matter or alloy, remove such deleterious matter as well as a large quantity of carbon, as much as may be required. These reagents by being decomposed in close contact with the fluid metal, supply a convenient quantity of oxygen, etc.