[stansfield] smelting OF IRON ORE 219 



various reducing reagents. We have the information needed for calcu- 

 lating the equilibrium curves of the reduction, but there is not enough 

 information available to show at what rate the reduction can practi- 

 cally be effected. 



Several years ago when designing an electric furnace process for 

 the production of steel from iron ore, I made experiments on the 

 reduction of titaniferous magnetites, which were crushed, mixed with 

 charcoal and briquetted with pitch and tar. I found that these 

 briquettes must be heated to a temperature of at least 900°C. before 

 any large proportion of the iron was reduced to the metallic state, 

 and this circumstance made it very difficult to secure the efficient 

 reduction of the ore in any practicable kind of preheating apparatus. 

 Those who are familiar with furnace construction will recognize that 

 a difference of as little as 100° C. in the operating temperature of such 

 an appliance may make the difference between commercial success 

 and failure. 



In view of the lack of exact knowledge of this subject, I applied 

 to the Advisory Research Council in March, 1918, for a grant to 

 assist me in making a series of experiments to secure the needed in- 

 formation. Owing, however, to the extreme difficulty, during the war, 

 of securing skilled assistance, I was unable to begin work until Janu- 

 ary, 1919, when I obtained the help of Mr. G. R. Kendall, B.Sc, 

 who has carried on the work up to the present time. It seems in- 

 advisable to state our results in any detail in their present incomplete 

 condition; but I may say that we have aimed at obtaining definite 

 information of a scientific character that would be useful in designing 

 a process and have resisted fairly well the temptation to make guesses 

 at a process before we had the information needed for designing it. 



In my earlier process for the production of steel from iron ores^ 

 I depended on the gases from the electric smelting furnace for heating 

 and partly reducing the ore. The reduction of the ore, in this appli- 

 ance, could never be complete because it was carried out by the gases 

 arising from the reduction of the unreduced portion. Another difficulty 

 was met with in view of the relatively large size of the reduction part 

 of the furnace which prevented a satisfactory design of the smelting 

 portion. 



In view of these difficulties, I came to the conclusion that the 

 reduction of the ore and the fusion of the reduced ore should be 

 carried out in separate appliances, and that the first thing to do was 

 to study practically the conditions essential for the reduction, in the 

 solid condition, of hematite and magnetite ores. 



1 Stansfield, "The Electric Furnace." 1914 Ed. p. 258. 



