- Email: [email protected]
Production of steel direct from ore
Sept., I914.]
CURRENT TOPICS.
379
various constituents of the ash and the fusing temperature. Hence a chemical analysis is of no value for arriving at a judgment as to the clinkering quality of a coal. The fusion temperature of the ash ought, therefore, in the future to displace the sulphur determination in coals used for steaming purposes, and this change will readily show the fallacy of buying and selling coal on an analysis basis, where specifications are used containing sulphur tables penalizing beyond a certain guaranteed amount of sulphur. It has been quite a common practice to place I. 5 per cent. of sulphur as a limit, and to penalize the seller as much as 4 cents per ton for every o.25 per cent. of sulphur above 1.5o per cent. The injustice of this practice is evident, as it often happens that coals with a high sulphur-content are extremely high in heat value, and do not clinker readily. Since the sulphur has no appreciable effect upon the metallic parts of the furnace, it need not be considered in the selection of a coal for steaming purposes. To arrive at the value of a coal for this purpose it is therefore just as essential to make the fusion test of the ash, as it is to make the calorimetric determination. If these two determinations are made, an explanation is readily found as to why two coals of apparently like proximate analyses give entirely different evaporation when fired under like conditions. Production of Steel Direct from Ore. E. HUMBERT and A. HETHEG. (Iron and Steel Inzt., May, I914.)--Tests were made with Swedish and Brazilian iron ores in a H6roult electric furnace of six tons capacity, using coke as fuel. The conclusions reached are: that the economic manufacture of steel from ore is practicable; that the product, on account of its comparative freedom from hydrogen, nitrogen, and other impurities, is superior, especially in toughness, to steel obtained by present methods; that the electric furnace employed should be of a type permitting violent ebullition of the bath without overflowing; that either charcoal, coke or anthracite may be used as fuel; and that anthracite electrodes will probably be most economical. Demolition of the First Skyscraper. ANON'. (SCi. Amer., cx, No. 18, 359.)--To make way for a larger structure, there has recently been demolished a ten-story tower building at 6o Broadway, New York City. The building was erected in 1889 and has been in service about 25 years. Naturally the condition of its framework was of considerable interest to architects and engineers. The frame consisted of cast-iron columns and wrought-iron floor beams. The floors were of flat arch terra cotta construction. The framework was found in excellent condition, the wrought-iron beams showing a practical absence of rust, and the cast-iron columns, with a three-inch cast-iron shell around them for fire prote.ction, showing only a few localized patches of rust, and heavy rusting only at a few special points.
CURRENT TOPICS.
379
various constituents of the ash and the fusing temperature. Hence a chemical analysis is of no value for arriving at a judgment as to the clinkering quality of a coal. The fusion temperature of the ash ought, therefore, in the future to displace the sulphur determination in coals used for steaming purposes, and this change will readily show the fallacy of buying and selling coal on an analysis basis, where specifications are used containing sulphur tables penalizing beyond a certain guaranteed amount of sulphur. It has been quite a common practice to place I. 5 per cent. of sulphur as a limit, and to penalize the seller as much as 4 cents per ton for every o.25 per cent. of sulphur above 1.5o per cent. The injustice of this practice is evident, as it often happens that coals with a high sulphur-content are extremely high in heat value, and do not clinker readily. Since the sulphur has no appreciable effect upon the metallic parts of the furnace, it need not be considered in the selection of a coal for steaming purposes. To arrive at the value of a coal for this purpose it is therefore just as essential to make the fusion test of the ash, as it is to make the calorimetric determination. If these two determinations are made, an explanation is readily found as to why two coals of apparently like proximate analyses give entirely different evaporation when fired under like conditions. Production of Steel Direct from Ore. E. HUMBERT and A. HETHEG. (Iron and Steel Inzt., May, I914.)--Tests were made with Swedish and Brazilian iron ores in a H6roult electric furnace of six tons capacity, using coke as fuel. The conclusions reached are: that the economic manufacture of steel from ore is practicable; that the product, on account of its comparative freedom from hydrogen, nitrogen, and other impurities, is superior, especially in toughness, to steel obtained by present methods; that the electric furnace employed should be of a type permitting violent ebullition of the bath without overflowing; that either charcoal, coke or anthracite may be used as fuel; and that anthracite electrodes will probably be most economical. Demolition of the First Skyscraper. ANON'. (SCi. Amer., cx, No. 18, 359.)--To make way for a larger structure, there has recently been demolished a ten-story tower building at 6o Broadway, New York City. The building was erected in 1889 and has been in service about 25 years. Naturally the condition of its framework was of considerable interest to architects and engineers. The frame consisted of cast-iron columns and wrought-iron floor beams. The floors were of flat arch terra cotta construction. The framework was found in excellent condition, the wrought-iron beams showing a practical absence of rust, and the cast-iron columns, with a three-inch cast-iron shell around them for fire prote.ction, showing only a few localized patches of rust, and heavy rusting only at a few special points.