.s/A' WILLIAM SIE.MEXS, I'.R.S. 287 



Tin- sulphur and phosphorus are oxidised to a considerable 

 extent; a circumstance which enables us to use pig metal con- 

 taining a certain small percentage of these admixtures, which are 

 not absolutely objectionable unless they occur in excessive propor- 

 tions, the quantity admissible of both phosphorus and sulphur 

 bt ing about '08 per cent. 



The decarburising agent employed being ferric oxide, no cast- 

 iron can possibly be oxidised, and a ton of pig metal with its 

 quota of spiegel, containing from 9 to 10 per cent, of foreign 

 substances, yields fully 21 cwt. of steel ingots. In this process 

 the addition of spiegeleisen at the end of the operation is an abso- 

 lute necessity, however much manganese may have been contained 

 in the pig metal employed, because the manganese is rapidly oxi- 

 dised, as can be seen from the foregoing table. 



The reason of the different reaction in the Bessemer process is, 

 in my opinion, that the silica liberated from the beginning of the 

 operation requires a base for its saturation, and that its great 

 affinity to protoxide of iron determines the oxidation of this metal 

 (free oxygen from the blast being present) in preference to man- 

 ganese. 



A characteristic difference between the two metals, in their fluid 

 condition, is that Bessemer metal on cooling in the moulds sets up 

 a violent ebullition, probably resulting from a reaction between 

 occluded oxygen and carbon, which is counteracted by stoppering 

 the moulds. The ore process metal, if it has been made with care, 

 on the contrary, contains no occluded oxygen, and sinks in the 

 moulds on cooling in the same way as " dead melted " steel does, 

 produced by the old Sheffield process. 



It has been an open question between metallurgical chemists 

 whether manganese is really required to be present in malleable 

 steel, some maintaining that its beneficial action is confined to the 

 elimination of sulphur during the process of production. Such, 

 however, is not the case, as may be seen from the following extract 

 from Messrs. Hackney and Willis's report : 



" Our observation, based on five years' experience, is that no 

 chemical reaction takes place between the manganese of the 

 spiegeleisen and the other elements of the steel, but that it acts 

 simply as an alloy. With regard to manganese not removing any 

 sulphur in a bath of steel, it is a curious fact that the reverse 



