50 JOURNAL AND PROCEEDINGS 



of material of unsuitable quality. At the present time it is 

 almost universall)^ the custom to regulate the composition of 

 the charge by means of chemical analysis, and the composi- 

 tion of the Pig Iron and Foundry Scrap are kept within 

 fairly well defined limits. The elements that are present in 

 commercial iron, and that are kept under special control are 

 Silicon, Sulphur, Phosphorus, Manganese and Carbon, and 

 although it is beyond the scope of this article to enter 

 minutely into the question of the influence of these elements 

 upon the quality of the metal, the general specifications for 

 Pig Iron tliat are given in Table 2, indicate the customery 

 limits that are set for this material. 



Table No. 2. 



Silicon 1.00 to 2.00% 



Sulphur Not above .05% 



Phosphorus Not above .20% 



Manganese 40 to .60% 



Total Carbon 3.25 to 4.00% 



The furnace charge is ordinarily made up of 50 to 60 per 

 cent, of Pig Iron and 40 to 50 per cent, of foundry scrap, con- 

 sisting of sprues, gates and defective castings. A small 

 percentage of steel, also, is frequently used for the purpose of 

 increasing the strength of the iron, or to bring the carbon of 

 a tardy heat to the proper state of combination. The chem- 

 ical composition of the various pig irons and of tlie foundry 

 scrap being known, the composition of the charge is estimated 

 upon the basis of the weights of each iron entering the 

 charge. In Table 3 are given the weights of various materials 

 making up a one ton charge, together with the calculated 

 analysis of the mixture and tlie actual analysis of the 



product. 



Tabic No. 3. 



Quantity ANAI^YSIS. 



Iron. Per Ton. Silicon. Sulphur. Phosphorus. Manganese 



Pig Iron-Car $56,474 100 lbs. 1.56 .022 .26 .64 



5,225 200 " 1,70 .035 .08 .42 



9,378 200 " 1.86 .035 .16 .69 



1,656 200 " 2.24 .082 .14 .72 



17,530 350 " 1.05 ,049 .16 .61 



Sprue and Scrap 9-50 " 1.00 .066 .16 .25 



2,000 lbs. 



