THE BAUXITE DEPOSITS OF ARKANSAS 28 1 



4. Refractory wares, such as furnace linings. 



5. It is also available for increasing the refractoriness of 

 fire clays used in the manufacture of fire bricks, furnace linings 

 and the like. 



I shall say nothing of the methods employed in the utiliza- 

 tion of the raw material. Some of them are described in the 

 works mentioned at the end of this paper, others are guarded 

 as trade secrets, or are covered by patents. 



There is one use, however, for which bauxite is available to 

 which I wish to direct especial attention, and that is as a 

 refractory material in the manufacture of iron and steel. 



Bauxite as a refractory material. — Bauxite is one of the 

 most refractory materials used in the arts. It is especially val- 

 uable for lining blast furnaces where it outlasts the best artificial 

 fire bricks. It is used alone and also as an ingredient for increas- 

 ing the percentage of alumina in other refactory materials. 



In his " Feuerfesten Thone," Bischof speaks as follows of 

 bauxite:^ "This natural aluminium hydrate which has as yet 

 been found only in a few places, .... when not impure on 

 account of the admixture of foreign substances, especially of iron, 

 which generally occurs in considerable quantities in compounds 

 of alumina, is extremely refractory. . . . The addition of the 

 varieties free from iron, or the white ones, to other refractory 

 cla^'S offers the only importafii means k?iozv7i of increasing their 

 percentage of alumina, and at the same time their refractoriness. 

 On account of a large percentage of chemically combined water 

 this material shrinks considerably in burning, a fact to be noted 

 in using it." In another place Bischof says:' "Bricks made 

 from calcined bauxite are especially useful in the production of 

 iron and steel in the Siemens revolving furnace. "3 



Bruno Kerl, an excellent authority on this subject, says :* 

 " Bauxite bricks and crucibles of bauxite, recommended by 



'Die Feuerfesten Thone, C. Bischof, pp. 193-4, 

 = 0p. cit., p. 277. 



3See also Dingler's Polytechnisches Journal, Vol. CXCVIII., p. 156; ibidem, Vol. 

 CCX., p. 109. 



•t Thonwaarenindustrie, p. 526. 



