president's address^section e. 95 



of iron scorified and of the temperature and heat units evolved — its 

 afSnity for iron should be kept unhampered by the presence of alumina, 

 or other bases, in the lining. 



In view of the importance of this question of the lining material, 

 attempts were not long in being made having for their object the intro- 

 duction of siliceous material from the outside duiing the blow, so as 

 to conserve the lining. Efforts towards blowing sand thiough the 

 tuyeres were undertaken very early, but have not been successful. 

 Aside from the nuisance caused by the sand's blowing out of the wind- 

 box when the. tuyeres were being punched, this fine material did not 

 properly assimilate with the iron in the bath, and the bulk of it sped 

 out through the nose. The feeding in of siliceous material in lump 

 form also had not altogether the looked-for effect. It floated on top of 

 the matte, and the paucity of oxygen there, due to its absorption in lower 

 regions of the bath, impeded the union of iron and silica in the higher 

 portions. Nevertheless, the question is not yet given up as hopeless, and 

 it is still receiving a good deal of attention. Meanwhile siliceous ores are 

 frequently added before or during the blow, or worked into the lining of 

 the converter body as a convenient and advantageous half measure. 



Basic Lininqs. — In connection with this subject, the old question 

 of basic linings is being revived. This, as remarked, was at first taken 

 up in direct disregard of the fundamental chemistry of the process, 

 which is inexorably bound to the formation of a silicate rf iron for the 

 removal of the latter element, and, needless to say, the results were 

 absolutely negative. Of late years the use of basic linings has. how- 

 ever, again been brought to the front with the special intention of 

 employing a lining which shall be indifferent to the chemical action 

 going on in the converter, while the latter is simultaneously supported 

 by the systematic introduction of siliceous substances from the out- 

 side, principally ores. Special constructions and special manipulations 

 are resorted to for the purpose of overcoming the obstacles experienced 

 in the earlier attempts, and briefly indicated above, and some measure 

 of success has been achieved. It must be clear at the outset, however, 

 that, even at the best, the above strictures on the treatment of low- 

 grade mattes in a Bessemer vessel continue to apply and must be ob- 

 served, for otherwise the apparatus simply becomes a hybrid pneumatic 

 appliance, halfway between an inadequately devised and conducted 

 p}Tite smelting furnace and an overburdened copper-converter. In 

 any case the basicity of the lining plays no part whatever in these 

 particular schemes, and the magnesite used might as well be replaced 

 by a proper thickness of any other substance indifferent co oxvgen, 

 sulphur, and silica. In this connection the designation of " basic " 

 is misleading. What is striven for is an indifferent, neutral behaviour, 

 and, as regards this chemical attitude, Vautin's suggestion to use carbon 

 blocks is worthy of renewed attention, though possibly their wearing 

 qualities would be unsatisfactory. 



The latest embodiment (t) of the so-called " basic " idea makes 

 use of a horizontal converter 20ft. long inside by 8ft. diameter, with 



(<) Process of Baggaley et al., 1905. 



