146 DETAILED REPORT ON ALABAMA CLAYS. 



Analysis of Bauxite, Rock Run, Cherokee Co., No. 4. 



Silica '... ;<: 3 - 30 



Alumina 66.70 



Ferric oxide .10 



Water 31,30. 



101.40 



49. (No. 5.) Mixtures made were: 

 a. 35 per cent. 10-20 mesh and 65 per cent, under 

 20 mesh. Required 18 per cent, of water to work up. 



b. under 30-mesh. Required 20 per cent, of water. 



c. under 20-mesli. Required 25 per cent, of water. 

 The air shrinkage of all was 1 to 2 per ceno. 



At 2550 F. the shrinkage was 20 per cent. 



The bauxite when heated to cone 30 in the Deville 

 furnace, preserved its form and sharp edges, and 

 showed the faintest trace of incipient fusion. It is 

 therefore highly refractory. 



Analysis of Bauxite, Rock Run, Cherokee Co., No. 5. 



Silica 28 



Alumina 68.14 



Ferric oxide trace 



Water.. 32.60 



101.02 



73. (No. 6.) A whitish, claylike bauxite. Thte 

 took 46 per cent, of water to work it up and gave a 

 fairly plastic mass, but had very little tensile 

 strength. 



At 2400 F. the shrinkage was 10 per cent., brick- 

 let still soft enough to be scratched by the nail. 



At 2550 F. shrinkage 27 per cent. 



At 2600 F. shrinkage 30 per cent., brick resisted 

 scratching by a knife. 



At 3100 F. bauxite dense, gray in color, but form 

 perfectly sharp. 



