The Smelting of Titaniferous Iron Ores 47 



Approximate Temperatures of the Runs 



Temp, on Stream Temp, on Furnace 

 Run of Slag. Lining Nature of Slag 



Gland 2 2380°F=1304°C. 2480°F=1360°C. Fluid 



G 3 and 4 2200°F= 1204°C. 2400°F= 1315°C. Fluid 



G 5 and 6 *2600°F= 1426°C. 2420°F= 1326°C. Very liuid 

 G 7 and 8 2530°F = 1388°C. 2480°F = 1360°C. Slag fluid. 



Most of iron 

 "frozen" on 

 bottom. 

 *Reading taken on bubbling slag round electrode before pouring. 



These temperatures from 1315°C. to 1360°C. are well below the tempera- 

 ture at which the average iron blast-furnace slag runs from the furnace, 

 namely 1450°C.i 



It has been realised by some investigators who have gone fully into 

 the subject, that temperatures determined in the ways noted above are, 

 at the best, approximations'. The ordinary determinations of slag as 

 "sticky," "free-running," "fluid," and so on, are likewise rather vague. 

 Hence any conclusions on the question of the temperature-viscosity 

 relations of slags based upon such data is bound to be inconclusive, and 

 of a rather un-scientific character. The United States Bureau of Mines 

 has in the course of an investigation of blast-furnace slags gone fully 

 into the question of their temperature-viscosity relations. The work 

 of Feild & Royster on this problem^ is impressive in its completeness, 

 and seems to be founded on sound scientific principles. The procuring 

 of similar information with regard to this new titania slag might afford 

 a sound basis on which to make it useful in smelting on an industrial 

 scale, and might also save the years of time that would in all probability 

 be consumed in gaining the necessary information in an empirical way. 



To determine temperature-viscosity relations with the precision 

 necessary to make the results useful, a machine was devised in which the 

 drag or torsion was measured between an inner stationary spindle and 

 an outer rotating crucible filled with molten slag, the latter being kept 

 in the fluid condition by an electric furnace that enclosed the apparatus. 

 The viscosities of actual blast-furnace slags of varying compositions 



^Johnson, J. E., as above, p. 32. 



Feild & Royster. — ^"Slag Viscosity Tables for Blast Furnace Work," p. 23. 

 ^Johnson, J. E., Jr., as above, p. 50 and (quoting A. L. Feild), p. 228. 

 'Feild, A. L., and Royster, P. H. Tech Papers Nos. 157, 187, and 189, U. S. Bureau 

 of Mines. 



