534 



IRON AND STEEL. 



composed of iron from oxidation, we find the 

 following especially worthy of record. 



Manufacture of Iron and Steel from the Cin- 

 ders of Furnaces, Prof. A. L. Fleury, of Troy, 

 N". Y., read before the Franklin Institute, Aug. 

 20th, 1863, a paper on the subject indicated in 

 the title. Hitherto, thousands of tons of cinders, 

 drawn from the puddling and reheating fur- 

 naces, have been thrown away as useless, or 

 have been mixed with iron ores in blast fur- 

 naces, to increase the yield not to improve 

 the quality of the iron. Analysis shows that 

 these cinders contain from 25 to 50 per cent, 

 of metallic iron, combined and intermixed with 

 sulphur, silica, lime, and alumina. From this 

 material, which had hitherto proved intractable, 

 Prof. Fleury has succeeded in extracting good 

 cast, as well as wrought iron, and even in pro- 

 ducing a good cast steel. The two chief diffi- 

 culties to be overcome, were: 1, that the com- 

 bination of the iron metallic and in oxides 

 with the other materials of the cinders, is such 

 as mainly to withstand the application of heat, 

 even the high heat in a steel crucible ; 2, that 

 upon reworking the cinder with lime, either 

 alone or mixed with charcoal and clay, the sul- 

 phur, silicium and phosphorus remain in com- 

 bination with the iron, and the latter is " red- 

 short," or " red " and " cold-short." 



These difficulties Prof. Fleury has been able 

 to overcome by availing himself of the fact 

 that, when unslacked burnt lime is caused to 

 undergo hydration (slacking) in contact with 

 or while intermixed through sand, the lime 

 will, where in contact with the sand, combine 

 with silica, and to this end will even decom- 

 pose silicates. Accordingly, having ground the 

 cinders to be treated fine, and mixed with them 

 a proper percentage of powdered burnt but 

 unslacked lime, he then wet the mass through 

 with water, and exposed it in the air to dry. In 

 his first trials, the dry mixture having been 

 heated in a common puddling furnace, and treat- 

 ed in the same mode as pig iron, yielded 50 per 

 cent, [see statement in the succeeding para- 

 graph] of wrought iron, but which, from remain- 

 ing traces of sulphur, was somewhat red-short. 

 Later, he succeeded in removing this, by pre- 

 viously dissolving in the water to be used for 

 slacking a small percentage of a chlorine salt. 

 The author stated that this process for which 

 he had patents both in this country and 

 Europe is also applicable to the working of 

 silicious ores, and can be performed in the pud- 

 dling, cupola, or blast furnace. The cost of prep- 

 aration and materials for the process is slight ; 

 and, properly worked, the result is invariably 

 a good quality of iron. 



At a meeting of the Polytechnic Association, 

 of New York, March 31st, 1864, Prof. Fleury, 

 after speaking in regard to certain other pro- 

 cesses of manufacture of steel and iron, stated, 

 in reference to that above described, that he 

 had made more than a hundred experiments 

 for the purpose of ascertaining the best mode 

 of abstracting the metal; and that he had 



found a feasible plan to be that of blowing the 

 cinders into the furnace, along with the air- 

 blast. By this method, he had obtained 50 per 

 cent, of the iron in them. 



The Bessemer Process for Steel and Iron. 

 For converting the purer varieties of pig iron 

 into bar iron and steel, this method, it is stat- 

 ed, is among European ironmasters constantly 

 increasing in favor. In a recent communication 

 to the " Berggeist," Prof. Tunner states that 

 thousands of cwt. of Bessemer steel and iron 

 are now annually produced in England and 

 Sweden ; that the steel is already an article of 

 commerce in Germany ; and that large works for 

 this method are in course of erection in France. 



The loss in converting pig iron into steel 

 by this method, is 12 to 15 per cent. ; in 

 making bar iron, 18 to 22 per cent. In 5 to 

 10 minutes, 15 to 20 cwt. of pig iron are con- 

 verted into steel or bar iron, with very little 

 cost of fuel, and without hand labor. The 

 pressure of blast used is from ^ to li atmos- 

 pheres, and the amount is 800"to 1,200 cubic 

 feet of cold air of the ordinary atmospheric 

 density. When the proper raw material is used, 

 the steel and iron resulting equal in quality 

 the best of cast steel and of forge iron. The 

 failure of the earlier experiments is now said 

 to be due to the employment in them of an 

 inferior iron. Only good charcoal iron is now 

 adopted for conversion by this method. In 

 some new iron works, it has been attempted to 

 improve English pig iron carried to the point 

 of conversion by the addition of melted 

 Swedish pig iron ; and for a like purpose, man- 

 ganese compounds have been used. The sepa- 

 ration, however, of the deleterious materials 

 associated in pig iron with carbon, would appear 

 to remain still an unsolved problem. A high 

 temperature is also indispensable ; and this can 

 be attained when large quantities of iron are 

 converted at a single operation : as incidental 

 advantages, the cost is diminished, and the 

 product is more uniform. In Sweden, the 

 minimum charge is 15 cwt. ; and with 60 to 100 

 cwt. the result would be more favorable. That 

 so much larger quantities of the material can be 

 operated upon at one charge is, indeed, one great 

 advantage of the process. For producing the 

 proper temperature, the relative amount of 

 blast to the iron should be carefully regulated : 

 with too little blast, the process is slow, and 

 heat is lost by radiation ; with too much, the 

 heat is too largely carried off by the air, and 

 the desired decomposition in the iron is not 

 effected. But in order that the whole mass of 

 molten iron shall be thoroughly penetrated 

 and set in agitation, the pressure of the blast 

 must at least exceed that of the column of iron 

 in the furnace. 



Mr. Tunner lays great stress on the employ- 

 ment of a high pressure with hot blast. He 

 believes the conversion would proceed with 

 great regularity and completeness, and that 

 many of the practical difficulties would 

 be overcome, if the blast were heated to 200- 



