US311159A - Method of removing silicon from wrought - Google Patents

Description

UNITE WV. A. OTTO WU'IH, OF PITTSBURG, PENNSYLVANIA.

METHOD OF REMOVING SILICON FROM WROUGHT-lRON.

SPECIFICATION forming part of Letters Patent No. 311,159, dated January 20, 1885.

Application filed June 2, 1884. (No specimens.)

To aZZ whom it may concern:

Be it known that I, W. A. OTTO WUTH, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Methods of Removing Silicon from \Vrought-Iron; and I do hereby declare the following to be a full, clear, and exact description thereof.

It is of great importance that the iron used in the manufacture of crucible and the better grades of open-hearth steel should be as free as possible from silicon, whether chemically cent., and sometimes ashigh as four per cent.

One per cent. of slag contains about .12 per cent. of silicon, and 2.50 per cent. of slag .30 per cent. of silicon.

The iron as it comes from the furnace to be hammered into blooms or billets, no matter by what process produced-the Catalan forge or puddling-furnaceconsists of a spongy, pasty mass of iron the interstices of which are filled with a fluid slag or cinder, (silicate of iron.) The separation of the slag from iron is accomplished by mechanical means. For the lower grades of iron, not suitable for making steel, it is done by passing the balls through a squeezer, and in other cases by hammering. If, when the balls are at a white heat, so that the cinder is limpidlike water, the full force of the hammer could be applied immediately, all or nearly all of the cinder could be driven out, leaving the iron comparatively free from slag. But in practice this cannot be done, as it would cause the iron to scatter in all directions, which would be both dangerous and wasteful. The practice, therefore, is to begin with light blows, delivered on all sides of the ball, which is frequently turned, until the iron becomes gradually solid enough to allow the full force of the hammer to be applied. Nearly one-half of the time necessary to reduce the ball to a solid billet or bloom is occupied in getting it solid enough to allow of the full force of the hammer. During this process of hammering the slag becomes too pasty to be completely separated from the iron. Just in proportion as the temperature of the ball is allowed to become lower and the slag more pasty will the bloom or billet contain more or less slag, the silicon of which in contact with the carbon in the crucible, reduced from silicic acid in the slag'to silicon, combines with the iron, and the result is steel with varying percentages of silicon. One hammer is provided for several furnaces, and as the balls, after being formed, cannot be kept in the furnace without oxidizing part of the iron, they often have to be taken out and kept in the air when the hammer is occupied. This allows them to cool before reaching the hammer, so that the iron is too solid and the slag too pasty to permit the latter to be driven out, no matter how perfectly the hammering is'done.

My improved process of freeing the ball from the slag, and thereby obtaining a better and more regular product, is asfollows: I take the ball as soon as it comes from the furnace and pass it through the squeezer, by preference the rotary one, which makes it sufficiently solid-to receive the full force of the hammer. Itis now too cold to enable the slag to be eliminated by hammering. I therefore take it after it comes from the squeezer, and with or without passing it through the so-called lllllClQlOllS, by preference without, to a reverberatory furnace, and submit it to aneutral or but slightly-oxidizing flame, and, after bringing it to a white heat, remove it from the furnace and hammer the now liquid Y cinder out of the porous mass of iron.

In testimony whereof I have hereunto set my hand this 29th day of May, A. D. 1884.

V. A. OTTO WVUTH.

WVhat I do claim as my invention, and desire to secure by Letters Patent, is

The improved method of removing silicate of iron from wrought-iron, which consists in passing the heated ball as it comes from the furnace through the squeezer, then reheating, and finally hammering it, substantially as described.

Vitnesses:

Jos. H. JAooBs, J. K. SMITH.