990 IRON 



furnace, the preliminary refining being thus avoided. In October 1855, Mr. Bessemer 

 patented for a somewhat similar process for the conversion of iron into steel : the steam 

 highly heated, or a mixture of air and steam, being forced through the liquid iron 

 run from the furnace into skittle-pots, steam being used only at an early stage of the 

 process, and the treatment finished with heated air. In the early part of the same year 

 Mr. Martien of New Jersey obtained a patent for a partial purification of crude iron, 

 by causing air or steam to pass up through the liquid metal, as it flows along gutters 

 from the top-hole of the furnace or finery forge ; and he subsequently proposed to include 

 with the air or steam, other purifying agents, such as chlorine, hydrogen, and coal-gas, 

 oxides of manganese, and zinc, &c. Other methods of treating crude iron with air :ml 

 steam were made the subjects of patents by Mr. Bessemer in December 185;') ami 

 January 1856. In October a patent for the employment of steam in .admixture wit h 

 cold blast in the smelting furnace and fining forge, was obtained by Messrs. ArmitaL'n 

 and Lee, of Leeds, and in August a patent was obtained by Mr. George Parry, of tlu> 

 Ebbw Vale Iron Works, for the purification of iron by means of highly-heated 

 The fluid iron is allowed to run into a reverberatory furnace previously heated, and tin; 

 steam is made to impinge upon it from several tuyeres, or to pass through the metal. St <.! 

 is to be obtained by treating highly carburetted iron with the steam, and then running 

 it into water, and fusing it with the addition of purifying agents, or adding to it in 

 the furnace a small quantity of clay, and afterwards about 10 or 15 percent, of calcined 

 spathose ore. Mr. Parry observing that when steam was sent through the molten 

 iron, as in Mr. Nasmyth's process, the iron quickly solidified, conceived the idea of 

 communicating a high degree of heat to the steam by raising the steam-pipe a couple 

 of inches above the surface of the metal, so that it might be exposed to the intensely- 

 heated atmosphere of the furnace ; and also of inclining the jet at an angle of 45, so 

 as to give the molten mass a motion round the furnace while the pipe was maintained 

 in the same position at a little distance beyond the centre : when this was done, in a 

 few minutes the iron began to boil violently, the rotatory motion of the fluid bringing 

 every part of it successively into contact with the highly-heated mixture of steam and 

 atmospheric air, and no solidification taking place. Having thus ascertained the pro- 

 per way of using steam as a refining agent, it occurred to Mr. Parry that, as the pre- 

 sence of silicon in the pigs for puddling affects in a remarkable degree the yield of 

 iron, as well as its strength, it is a matter of consequence that this element should be 

 removed as completely as possible previous to the puddling operation ; the steaming 

 of the iron would probably therefore be more profitably applied in the refinery than in 

 the puddling furnace. Pig-iron containing 3 per cent, of silicon gives 6 per cent, of 

 silica, which, to form a cinder sufficiently fluid to allow the balling-up of the iron, 

 would require from 10 to 12 per cent, of iron ; and this can, of course, only be obtained 

 by burning that amount of iron in the puddling furnace, after the expulsion of the 

 carbon, and while the mass is in a powdery state. The superheated steam is injected 

 on the surface of the iron in the refinery by water tuyeres, similar to those used for 

 hot blast at smelting furnaces ; they are inclined at an angle of about 45 ; some are 

 inserted at each side of the door of the furnace, and are pointed so as to cross each 

 other, and give the iron a circulating motion in the furnace. The tuyeres are from 

 f ths to | an inch in diameter ; a little oxide of iron or silicate in a state of fusion on tho 

 surface of the iron accelerates the action, as in common refineries, and increases tho 

 yield of metal, but to a much greater extent than when blasts of air are used. The 

 bteam having been turned on, the mass of iron commences circulating around the in- 

 clined tuyeres, and soon begins to boil, and the action is kept uniform by regu- 

 lating the flow of the steam. The most impure oxides of iron may be used in this 

 process, such as tap cinder or hammer slag from puddling furnaces, without injury 

 to the quality of the refined metal made ; the large quantities of sulphur and 

 phosphorus which they contain being effectually removed by the detergent action of 

 tho heated steam. When 4 cwts. of cinders are used to the ton of pig, 20 cwts. <>f 

 metal may be drawn, the impurities in the pig being replaced by refined iron from the 

 cinders. 



Dr. Noad had several opportunities of witnessing this refining process at tho Ebbw 

 Vale Iron Works, and made the following analysis of the cinders and metal, which 

 fully bear out the above statements : 



Pitf-iron Refined metal 



Graphite 2'40 . . 0'30 



Silicon 2-68 . . 0'32 



Slag 0-68 . . O'OO 



Sulphur 0-22 . . 0-18 



Phosphorus 0'13 . 0'09 



Manganese . . . . 0'86 



0-24 



