IRON 



991 



Forge cinders thrown Cinder run out of 



into the refinery the refinery 



Sulphur 1-34 . . . 0-16 



Phosphoric acid .... 2'06 . . . OT29 



A ton of grey iron may be refined by steam in half an hour, using seven jets of 

 steam fths of an inch in diameter, and with a pressure of from 30 to 40 Ibs. ; the tem- 

 perature of the steam being from 600 to 700 F., the orifices of the tuyeres being 

 2 or 3 inches above the surface of the iron. As the fluidity of the metal depends 

 upon the heat which it is receiving from the combustion of the fuel in the grate, and not 

 on any generated in it by the action of the steam, it is evident that the supply of the 

 latter in a given time must not exceed a certain limit, or the temperature of the fluid 

 iron will become reduced below that of the furnace. This, however, partly regulates 

 itself, and does not require much nicety in the management, for, if too much steam be 

 given the ebullition becomes so violent, as to cause the cinders to flow over the 

 bridges, giving notice to the refiner to slack his blast. The ' forge cinders ' used in 

 the steam refinery contain 66 per cent, of iron ; the ' run out ' cinder contains only 

 26 ; 40 per cent, of iron, or thereabouts, have therefore been converted into refined 

 metal, and the resulting cinder is as pure as the ordinary Welsh mine, with its yield 

 of 25 per cent, of iron. The following is the result of one week's work of the steam 

 refinery : 



cwts. qrs. Ibs. 



Pigs used .. ; . , | : .'V ,...*.>. 396 15 

 Metal made , 393 3 1 



Loss 

 Yield 



1 14 



20 14 



The quantity of cinder (puddling) used was 3| cwts. per ton of pig. When 1| cwt. 

 of cinders were used to 1 ton of pig, the yield was invariably 20 cwts. over a make of 

 about 100 tons. 



Refining by Gas (German method). The most simple form of gas reverberatory 

 furnace is that known as Eck's furnace (figs. 1251 to 1256), which is employed at the 

 government works of Gleiwitz and Konigshiitte, for refining iron made on the spot. The 

 following description and plan of this furnace are extracted from a report to the 

 Secretary of State for War, from the superintendent of the Royal G-un Factories, 

 Colonel Wilmot, R. A., and the chemist of the War Department, Professor Abel. 



The gas-generator (which replaces the fire-place of the ordinary reverberatory 

 furnace) is an oblong chamber, the width of which is 3 feet 9 inches, and the height 

 from the sole to the commencement of the sloping bridge 6 

 feet 4 inches. It tapers slightly towards the top, so as to 

 facilitate the descent of the fuel, which is introduced through 

 1246 i a lateral opening near the top of the generator. Its cubical 



contents are about 44 feet. 



1248 |] jjg 1; j ^ The air necessary for the produc- 

 tion of the gas is supplied by a feeble 

 blast, and enters the generator from 

 the two openings or tuyeres of a long 

 air-chest of iron plate (figs. 1246, 

 1247, 1248) fixed at the back of the 

 chamber, near the bottom. The space 

 between the air-chest and the sole of 

 the chamber serves as a receptable 

 for the slag and ash from the fuel. 

 There are openings on the other side 

 1247 f the cnam ber, opposite the tuyeres, 

 l^i which are generally closed by iron 



1 U plugs, but are required when the 



tuyeres have to be cleaned out. 

 There is an opening below the air-chest, through which fire is introduced into the 

 chamber, when the furnace is set to work, and which is then bricked up, until at the 

 expiration of about 14 days it becomes necessary to let the fire die out, when the slag 

 and ash which have accumulated on the sole of the chamber are removed through 

 this opening. 



The hearth of the furnace is constructed of a somewhat loamy sand ; its general 



thickness is about 6 inches, its form is that of a shallow dish, with a slight incline 



towards the tap-hole ; the iron is prevented from penetrating through the hearth by 



the rapid circulation of cold air below the fire-bridge and the plate of the hearth. 



Figs. 1249 and 1250 represent the upper oblong air-chest provided with a series of 



1250 



