hot and cold blast iron, 150. Composition of pig iron before and
after reaching the tuyeres of blast furnace, 154. Kish, 155. Carbon
in pig iron, 157. Graphitic and combined carbon, 158. Conversion
of combined into graphitic carbon, 158. Conversion of graphitic into
combined carbon, 159. Cementation process, 160. Transference of
carbon from cast to wrought iron, 160. Case of absence of carbon
in iron in the blast furnace, 161. Silicon in pig iron, 161. Glazed
iron, 162. Sulphur in pig iron, 163. Phosphorus, 165. Manganese,
165. Other metals in pig iron, 167. Slag or cinder from the blast
furnace, 168. Furnace fume, 174.
CHEMICAL CHANGES AS THEY TAKE PLACE IN THE BLAST FURNACE ... 176
Order of changes ascertained by composition of gas in the furnace, 176.
Change in content of carbonic
Cooling effects of different
Temperatures of escaping gases, 178.
acid effected by charges of coke, 179.
materials in charging, 179. Increase of temperature of gases on
ceasing to charge, 181. Temperature at which ore commences to lose
oxygen, 182. Rate at which reduction goes on at different tempera-
tures, 183. Effect of rapid currents of reducing gas, 183. Carbonic
acid decomposed by metallic iron, 184. Action of mixtures of car-
bonic oxide and carbonic acid at different temperatures, 185. Five
reactions of carbonic oxide on oxide of iron, 186. Carbon de-
position from carbonic oxide, 187. Caron and Schinz on carbon
deposition, 189. Carbon deposition affected by quality of oxide of
iron, 189. Presence of carbonic acid reduces amount of carbon
deposited, 190. Temperature at which reduction of Cleveland ore
commences, 191. No necessary correspondence between rate of
reduction and of carbon deposition, 192. Presence of metallic iron not
indispensable for carbon deposition, 193. Dissociation of carbonic
oxide by other metals and their oxides, 193. Power of carbon to
split up carbonic acid, 194. Effect of dissociation of carbonic acid,
195. Power of soft coke to split up carbonic acid, 196. Power of
solid carbon to reduce ore, 197. Dissociation of carbonic acid of the
limestone used, 198. Generation of carbonic oxide on the hearth of
the blast furnace, 199. Carbonic acid in the gases of the Styrian
furnaces, 201. Change of composition of gases as they ascend through
materials filling the furnace, 201. Disadvantages of a low furnace,
202. Composition and temperature of gases from furnaces of 80 and
48 feet in height, 203. Irregularities in composition of gases taken
at different levels of the furnace, 212. Potassium and sodium cyanides
in gases, 216. Contribution of dissociation of carbonic oxide to
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Value of the fuel dependent on fixed carbon it contains, 234. Heating
power of fuel, how modified, 235. By quantity and nature of foreign
matter, 235. By temperature and condition of air, 238. By state of
oxidation, 238. By quantity of heat which escapes in gases, 240.
Effect of imperfectly calcined ironstone, 240. Intricacy of heat
estimates, 241. Equivalents of heat and of coke to each function in
the furnace, 241. Causes which affect oxidation of carbon, 247.
Heat carried off in the escaping gases, 248.
additions to the temperature of the blast, 249.
to heating the blast, 251. Quantity of heat
burnt with air at a given temperature, 251. Use of superheated air
at the Ormesby furnaces, 252. Effect of superheated air on furnaces
under 25,000 cubic feet, 255. Use of superheated air in the manu-
facture of Bessemer iron, 256. In furnaces of sufficient capacity
oxidation of carbon and loss of heat in gases are independent of
temperatures of the blast, 260. Heat contributed by blast at different
temperatures and by carbon in different stages of oxidation, 260.
Calculations showing equivalents of coke required per ton of iron
according to temperature of blast and state of oxidation of carbon, 262.
Waste of fuel in a furnace of insufficient size, 263. Limit to which
air can be heated, 264. Further observations on saving of fuel by
successive increments of temperature of the blast, 265. Superheated
blast supposed cause of reducing quantity of carbonic acid in gases, 267.
Influence of shape of the blast furnace in economizing fuel, 268.
Possible errors in stating the quantity of coke consumed per ton of
iron, 269. Mode of checking this by analyzing escaping gases, 269.
Heat equivalent of charcoal, 274. Heat equivalent of coke and
charcoal compared, 282. Moderate temperature of blast used at
charcoal furnaces, 283. Experiments on charcoal furnaces by M.
Frederici, 284. Reduction of ores used in Styria by carbonic oxide,
285. Effect of hard coke, soft coke and of charcoal on carbonic acid,
287. Reducing power of carbonic oxide on mixtures of Styrian ore
and charcoal and Cleveland ore and coke, 287. Similar experiments
by M. Åkerman in Sweden, 288. Ratio of carbonic acid and carbonic
oxide in charcoal furnaces, 289. Portion of ore always escaping
reduction, 291. Quantity of carbonic acid in gases of charcoal
furnaces less than that in Cleveland furnaces per ton of iron made,
291. Difference of composition of gases at different heights of the
furnace between coke and charcoal furnaces, 292. Increase of tempera-
ture at different depths in charcoal furnaces, 295. Zone of reduction
in charcoal furnaces different from that in Cleveland furnaces, 296.
Supposed effect of using superheated air in charcoal furnaces, 299.
American experience with superheated air in charcoal furnaces, 300.
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Hydrogen produced by water, 305. Quantity of hydrogen in the gases
of a coke furnace, 306. Quantity of hydrogen in gases at different
depths of the furnace, 308. Value of hydrogen as a reducing agent
doubtful, 309. Experiments to ascertain reducing power of pure
hydrogen, 310. Mixtures of hydrogen and carbonic oxide as reducing
agents, 310. Effect of hydrogen on carbonic acid, 312. Condensation
of tar and ammonia from furnace gases where raw coal is used, 314.
Use of raw coal in smelting iron, 315. Composition of escaping gases
when using coal, 315. Heat absorbed and evolved in raw coal furnace,
319. Effect of a mixture of vapour of water and hydrogen on metallic
iron at high temperatures, 321. Deficiency of carbonic acid in gases
of furnaces using raw coal, 322. Use of raw coal in smelting Bilbao
ore, 323. Raw coal in smelting Oolitic ores of Midland Counties, 324.
Raw coal and coke compared, 325. Ammonia from furnaces using
coke, 326. Ammonia from furnaces using raw coal, 327. Collection
of ammonia, tar and oil from coke ovens, 327. Proposed injection of
hydrogen at tuyeres, 329. Proposal to inject water-gas at tuyeres, 329.
Experiment of use of coke and water-gas in smelting iron, 340. Use
of petroleum in smelting iron, 342.
ON THE REFINING AND PUDDLING FURNACE...
Cort's invention of the puddling furnace, 351. Puddling on sand bottom,
351. S. B. Rogers' improved furnace, 351. Continued use of refinery
to oxidise the silicon, &c., 352. Amount of oxygen required, compared
with air used, 353. Change effected in pig iron by the process of re-
fining, 354. Slags produced in manufacture of malleable iron returned
to the blast furnace, 356. Proportion of phosphorus and sulphur
which accumulates in slags, 357. Gradual change of composition of
iron during process of refining, 359. Change of composition in pudd-
ling refined metal, 360. Composition of refinery cinders, 361. Use of
unrefined pig iron in the puddling furnace, 362. Impurities of pig
removed by oxide of iron, 362. Loss of weight and coal used in
puddling pig iron, 363. Quantity of the metalloids left in iron
obtained from puddling Cleveland pig iron, 365. Mechanical puddling
furnaces, 365. Quality of iron produced by mechanical puddling,
366. Presence of slag in iron made in puddling furnace, 368. Relative
cost of puddling by hand and by mechanical means, 372. Redshort-
ness in iron made in mechanical puddling furnaces, 373. Use of
mechanical furnaces for making iron by direct process, 374. Use of
chemicals in puddling, 376. Prospect of ingot iron and steel dis-
placing the puddling furnace, 376.
BY IRON DURING ITS PASSAGE THROUGH THE BLAST FURNACES 381
Bessemer's invention, 381. Phosphorus, an obstacle to its success, 383.
Mushet's discovery of value of Spiegel iron to correct red-shortness, 383.
Henderson makes ferro manganese, 383. Rapid advance of Bessemer
steel industry, 384. Its economy compared with the manufacture of
iron, 385. Superiority of strength as compared with iron, 385. Pro-
gress of the manufacture of steel, 386. Consequent advance in value
of hematite pig iron, 387. Diagrams showing rates of separations of
metalloids from pig iron by different processes, 388. Conditions which
influence their separation, 389. Slags from Bessemer converter, 393.
M. Grüner's explanation of silica in slags as the cause of phosphorus
being retained by iron in the converter, 394. Removal of phosphorus
by oxide of iron, 395. Influence of temperature in dephosphorising,
396. Influence of temperature in removal of other metalloids from
pig iron, 400. Removal of carbon, silicon, and phosphorus in different
processes, 402. Experiments at Essen to dephosphorise pig iron, 404.
Mr. Snelus' trials of lining converter with lime, 406. Basic process,
406. Waste of iron in basic process, 410. Absorption of oxygen by
iron and steel in manufacture, 413. Composition of rails made by
acid and basic processes, 414. Addition of phosphorus to pig intended
for basic treatment, 416. Composition of pig iron and basic-made
steel, 417. Estimates of heat evolved during basic blows, 418. Heat
evolved in an acid blow, 421. Expense of basic process, 425. Quality
of steel by basic process, 425. J. M. Heath's mode of making steel,
426. Siemens-Martin's steel process, 426. Composition of iron rails,
428. "Ore process" for making steel, 430. Increase in make of
Bessemer and open hearth steels, 432. Use of steam in open hearth
process, 432.
Pernot furnace for steel making, 433. Quality of
Bessemer and open hearth steels, 434. Other methods of making
steel, 435. Steel by cementation process, 436. Wootz, 436. German
steel, 436. Puddled steel, 437. Soaking pits of Mr. Gjers, 440.
International exhibitions, 441. Progress of iron trade in Great Britain,
443. Increase of iron trade in some other countries, 444. Supremacy
of British iron trade threatened, 446. Effect of protective duties
levied in foreign countries, 446. Alteration in cost of labour in
Great Britain, 447. Effect of duties on British exports of iron, 447.
Statistics of coal production in Great Britain, Germany, France,
Belgium, and in the United States, 448. Statistics of iron ore pro-
duction, 449. Quality of ore required for acid process in making steel,
450. Ore for basic process, 451. Ore obtained in five above named
countries, 451. Imports and exports of ore, 452. Increase of Besse-
mer steel made, 453.
Different kinds of ore produced in Great
Britain, 454. British ores raised and pig iron produced there-
from, 456. Effect of increased make of steel on manufacture
of malleable iron, 459. Sources of limestone required in smelting
iron, 461. Effect of abolition of duties by foreign governments, 461.
Large investments of capital in iron manufacture, 463. Iron trade
in Germany, 463. Belgian iron trade, 464. French iron trade, 466.
Russian iron trade, 467. Iron trade in United States, 467. Con-
sumption of iron per head by different nations, 470. Shipbuilding as
a source of consumption of iron, 471. Power of United States in pro-
ducing and exporting iron, 472. Export of iron from Germany, 474.
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