.SYA 1 WILLIAM .S7A.1//-W.V, l-.R.S. 30! 



In the rotative furnace streams of carbonic oxide are set up 

 within the mass under reaction ; and this carbonic oxide on 

 reaching the surface meets the current of intensely heated air 

 proceeding from the regenerators, and completes with it perfect 

 ci.iiilnistion within the free space of the chamber. The carbonic 

 acid thus generated comes in no further contact with carbon or 

 metal, consequently it cannot split up, but is drawn away un- 

 changed into the chimney, while the evolved heat is taken up by 

 the sides of the chamber and transmitted by reverberation and 

 conduction to the mixture of ore, fluxes, and coal. 



In this process we have, therefore, to accomplish two things, 

 viz., the deoxidation of the ore, and the fusion of the earthy 

 matter mixed with it. If we take (say) hematite ore, consisting 

 of peroxide of iron with 10 per cent, of silica, we shall determine 

 the quantity of carbon necessary for its reduction from the 

 formula Fe a 3 + 3C, which gives 2Fe + 3CO ; and according to 

 which the consumption of carbon (taking its atomic weight at 12 



Q x 1 9 



and that of iron at 56) amounts to ' = *32 Ibs. per Ib. of iron 



2x56 



reduced. 



The heat absorbed in this reaction amounts, according to Dr. 

 Debus, to 892 units * per Ib. of iron produced, but on the other 

 hand the further combustion of '32 Ib. of carbon from the condi- 

 tion of carbonic oxide to carbonic acid (CO to C0 a ), by means of 

 the free oxygen introduced into the rotative chamber from the 

 regenerator yields "32 x 5600= 1792 units of heat, leaving 1792 - 

 892 = 900 units available for heating the materials and for melting 

 the slag. 



The quantity of materials to be heated per Ib. of iron produced 

 would amount to ore, 1'59 ; lime or other fluxing materials, '16 ; 

 making a total of 1'75 ; and taking the specific heat of Fe 2 3 at 

 154 as determined by Herman Kopp, and the temperature to 

 which the materials have to be raised at 1500 C., the heat 

 required for this purpose would not exceed 1'75 x '154 x 1500 

 = 404'25 units. To this consumption would have to be added 

 the latent heat absorbed in liquefying the slag. The slag would 

 amount to '16 Ib. silica + -16 Ib. lime = '32 Ib. per pound of iron 



* Dr. A. W. Williamson gives 885 '3 units as the result of his calculation, which 

 two figures agree sufficiently for my present purpose. 



