NATURE 



333 



THURSDAY, FEBRUARY 12, 1885 



/AW AND STEEL 

 Principles of the Manufacture of Iron and Steel. By 

 Lowthian Bell, F.R.S. 



r rHE work before us, as its title indicates, does not 

 I attempt to describe the plant or the manipulation 

 involved in the successful conduct of the several processes 

 pursued in the manufacture of iron, but is confined to a 

 scientific discourse upon the reactions and economics of 

 the production of iron, and more especially upon the 

 question of the economical consumption of fuel in the 

 blast furnace, as based upon the author's long practical 

 experience as a Cleveland ironmaster, fortified by the 

 results of, and deductions drawn from, the numerous and 

 carefully-conducted experiments which he has made upon 

 the chemistry and physics of iron-making. These results 

 have been previously largely published at different periods 

 in the Transactions of the Iron and Steel Institute ; but, 

 as the author says in his introductory chapter, they " were 

 described in the language of the laboratory," and it is his 

 desire in the present volume to present the general results 

 at which he had "arrived in a more consecutive and less 

 attractive form than that necessarily adopted under such 

 circumstances, and to correct any opinion therein stated 

 which further observation had shown to require modifica- 

 tion." The book also contains some valuable considera- 

 tions of a more commercial character than those usually 

 found in scientific or technical works. 



After an introductory chapter, Mr. Bell devotes a sec- 

 tion to an interesting historical sketch, arranged in 

 chronological order, of the progress and improvements 

 effected in the iron manufacture, commencing with the 

 primitive forge found in the interior of Africa and closing 

 with the introduction of the basic process for the 

 manufacture of steel. Then follows a chapter upon 

 the direct processes for making malleable iron, in which 

 the economic results of these processes, as against the 

 indirect methods (where the blast and puddling furnaces 

 are conjointly employed), are discussed adversely to the 

 direct processes. Mr. Bell considers that, owing to their 

 simplicity and the partially oxidising tendency of the 

 operations of direct smelting, whereby the phosphorus in 

 the ores is largely left in the slags, these processes have 

 received during the past thirty years more attention than 

 they merit. The author's ideal is a well-appointed blast 

 furnace which expels oxygen from the ore, intercepts the 

 escaping heat, and raises the product to the desired tem- 

 perature in one apparatus. Owing to an erroneous 

 assumption, viz. that the cost for melting steel [in' the 

 open hearth furnace is the same whether pig iron and 

 iron ore, or pig iron and scrap, are the materials 

 employed, the author is led to compare somewhat un- 

 fairly, on p. 39, the cost for fuel and labour of the product 

 of the Siemens rotary furnace with pig iron produced 

 in the blast furnace. The comparison is made as though 

 the two products were the same, whereas the rotator- 

 blooms are used in the open-hearth steel process in lieu 

 of malleable iron, and not as a substitute for "iron in 

 the form of pig," and hence the comparison should 

 VOL. xxxi. — No. 798 



fairly be made as between rotator-balls or blooms and 

 balls or blooms of suitable quality as made by the in- 

 direct process of puddling the product of the blast 

 furnace. 



Section IV. is devoted to a brief consideration of the 

 preliminary treatment of materials for the blast furnace, 

 such as coking, charcoal-burning, and the calcination of 

 ores; and with Section V., at page 61, the author com- 

 mences his discussion of blast furnace phenomena, which 

 he continues through Sections VI., VII., VIII., IX., X., 

 and XL, devoting altogether a space of 282 pages to this 

 division of the subject ; whilst Chapters XII. and XIII., 

 occupying only forty-eight pages, suffice for the discussion 

 of the phenomena and economic results attending the 

 production of malleable iron from pig iron in low hearths, 

 together with considerations upon the action of the refinery, 

 and of the various forms of puddling furnace, from that 

 of Cort to the Danks, and other mechanical puddling 

 appliances. 



Section IX. gives much information of a speculative 

 character, bearing upon the causes of the observed alter- 

 ations in the relative proportion of carbon, oxygen, and 

 nitrogen to each other in the gases withdrawn at differ- 

 ent levels below the furnace throat. A like remark ap- 

 plies to the theories propounded to account for the origin 

 and behaviour of cyanogen compounds in the blast 

 furnace, and likewise to the explanations offered for the 

 appearance of bodies, such as silica, lime, alumina, mag- 

 nesia, oxide of zinc, and oxide of lead in varying relative 

 proportions in the fume withdrawn with the gases taken 

 at different depths in the furnace. 



In Section X. the author maintains the conclusions 

 previously arrived at in his " Chemical Phenomena of 

 the Blast Furnace," viz. that in practice, when smelting 

 Cleveland stone in well-appointed and well-managed 

 blastfurnaces of 80 feet in height and from 11,000 to 

 25,000 cubic feet capacity, driven by a blast heated 

 in p_ipe-stoves to a temperature of from 500 C. to 

 6oo° C, that a ton of pig iron can be produced 

 with the consumption of 2C4 cwt. of coke, which the 

 author calculates is within l '26 cwt. of the minimum con- 

 sumption of coke required by theory to smelt a ton of 

 pig iron from the ore in question. He maintains that 

 such furnaces are, and must be as economical in fuel as 

 larger furnaces driven by blast heated in brick stoves to a 

 temperature of Soo 3 C. ; but he does not directly venture 

 to dispute the advantage of an increased make per 1000 

 cubic feet of capacity effected by the larger furnaces and 

 the higher temperatures of blast employed in them. 



Mr. Bell dismisses, in the sixty pages of Chapter 

 XIV., the consideration of the manufacture of steel by 

 the Bessemer, the dephosphorisation or basic process, 

 the open-hearth processes, known as the Siemens-Martin, 

 and the ore process. The manufacture of steel in 

 the Pernot furnace, by the cementation and the puddling 

 process, are here also discussed, and in the same chapter 

 are also described the reactions and investigations which 

 resulted in the author's purifying or pig-washing process 

 for the dephosphorisation of pig iron by means of molten 

 oxide of iron added to the charge of phosphoric pig iron 

 contained in a rotating furnace. Further, there is in Chapter 

 XIV. an important sheet of six diagrams, graphically 



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