US779037A - Method of smelting ore. - Google Patents

Description

UNITED STATES Iatented January 3, 1905.

PATENT OFFICE.

METHOD OF SMELTING ORE.

SPECIFICATION forming part of Letters Patent No. 779,037, dated January 3, 1905.

Application filed October 25, 1904. Serial No. 229,895.

To all whom it may concern.-

Be it known that I, J AMEs GAYLEY, of New York city, county of New York, and State of New York, have invented a new and useful Method of Smelting Ore, of which the following is a full, clear, and exact description.

In the smelting of iron ore when the air supplied to the blast-furnace is first dried and the moisture lessened to a small and'uniform percentage, as described in my United States Patent No. 527,844, it is theoretically possible to reduce the percentage of the coke employed in the charge by an amount equal to that which would have been required to dissipate the moisture extracted from the air. The saving of fuel thus calculated amounts to about five or seven per cent. of the total fuel consumed per ton of iron.

I have discovered that important advantages can be secured by lessening the percentage ofthe saving of fuel calculated from the heat re quired to dissipate the 4.5 grains of elimininated moisture is about seven per cent. but I have discovered that by lessening the proportion of fuel in the charge to a point considerably below that which is theoretically required to keep the furnace in running conditionsay, from sixteen to twenty per cent. less than the proportion of fuel normally required when undried atmospheric air is employedI not only save the cost of the fuel, but I also improve the quality of iron by lessening the extent to which it is contaminated with sulfur and phosphorus, obtain greater uniformity of work, prevent waste of ore carried away from the furnace by the gases, reduce the temperature of the gases leaving the throat of the furnace, and increase the output of metal about twenty per cent. At

the same time I maintain in the furnace with such greatly-reduced percentage of coke a suflicient degree of heat to carry on perfectly all the desired reactions of smelting. I attribute these results, in part at least, to the increased reducing power imparted to the furnace-gases by the removal of the moisture from the air-blast; but it may be due in part to other causes, and I state this cause merely as the one which now seems most apt to explain the new and important results which I have secured.

For thepurpose of giving to those skilled in the art a concrete example of the process in its preferable form I will state that in ordinary practice in an iron blast-furnace using atmospheric air containing six grains of moistureper cubic foot of air ten thousand two hundred pounds of coke to twenty thousand pounds of ore are employed. The saving of fuel that could be calculated from the extraction of 4.5 grains of moisture would have made a burden of twenty-one thousand four hundred pounds of ore, the burden of fuel remaining as before. I have-discovered that with a burden of twenty-four thousand pounds of ore to ten thousand two hundred pounds of coke I obtain the results mentioned above.

Without limiting myself precisely to the proportions which I have stated as most suitable, What I claim is The method herein described of smelting ore, which consists in subjecting the ore with carbonaceous fuel to a blast of dried air, the burden of fuel being less than the normal burden by an amount materially greater than that which would be required to dissipatethe eliminated moisture; substantially as described.

In testimony whereof I have hereunto set my hand.

JAMES GAYLEY. Witnesses:

J. W. ALLEN, W. S. REED.