"94 president's address — section b. 



the converter should at least not be held accountable for the expense 

 of any work of smelting which properly should have been done in the 

 blast furnace or reverberatory furnace beforehand. An intermittently 

 working apparatus like the converter — which is furthermore marred by 

 an imperfect contraposition of the substances forming the slag, ^.'•., the 

 iron in the mass of matte and the silica merely on the superficial surface 

 ■of the lining enclosing that mass — is not a judicious means for the 

 scorification of large amounts of iron. The eoiiy attempts to work up 

 very low grade mattes, which led to the alarmed feeling here referred 

 to, weie irrational, and demanded too much. The endeavor should 

 be to work up as high grade mattes as the local economic conditions 

 will at all allow. The copper converter should be regarded from the 

 :standpoint of a refining apparatus, and not of a smelting apparatus, 

 and this point of view will not only conduce to a betterment of the pre- 

 ceding smelting, but will also place the consumption of lining on the 

 most rational basis possible u.nder the local conditions. That the 

 consumption of lining will have to be patiently suffered until certain 

 radical improvements in the general practice of the pneumatic method 

 •shall have been established, which can at the momeut only be im- 

 perfectly apprehended, is an unavoidable necessity inherent in the 

 present state of things. 



Given a proper, comfortable grade of matte, the operatives — if not 

 the wTiters — have, however, long ago accustomed themselves to accept 

 the expense of the linings as a matter of course. And when we recollect 

 that the difficulty of providing suitable refractory material in sufficient 

 quantity is said to have led to the early condemnation of the process 

 in England (Vivian's, 1884-5), we are but painfully reminded of the 

 ingrained conservatism of the practising metallurgist, shying at trifles 

 because they are new. With respect to the composition of the linings, 

 experience has very greatly narrowed down the demands once made on 

 the "refiactory" qualities of the material used. In fact it is now patent 

 that, as far as the metal bath is concerned, the lining should not be 

 actually chemically refractory at all, but should afiord a suitable 

 facility of scorification if the blows are not to be needlessly and un- 

 economically protracted. The mechanical, rather than the chemical, 

 properties of the lining have required study, for the former decide its 

 lasting qualities quite as much as the latter ; and for this reason we 

 occasionally find the most chemically ordinarv silicas and clays in use, 

 as the outcome of the empirical search for the cheapest, while, at the 

 same time, most enduring, materials which the respective locality 

 affords. The chemical composition of the lining is necessarily as acid 

 as possible, from the nature of the chemical work expected of it, and 

 should consist of the maximum amount of free silica which it is possible 

 to get into the mixture, consistent with the presence of an amount of 

 clayey substance supplying the cohesive qualities which the siliceous 

 material lacks. The presence of a maximum of uncombined, free 

 silica is a .nne qua non for the development of a proper amount of heat 

 to conduct the operation to a suc(iessful finish, and, since the silica acts 

 as the chief determining agent — both in respect of the relative amount 



