320 



CLAYS AND CLAY INDUSTRY. 



Analyses of some foreign fire clays. 





can 

 Sen 

 '5 



a 



= < 

 < 



V 



'x 

 So 



to 



uO 

 i4 



.3 



§ 



Alkalies, 



3 

 



> c 

 w 



'v 

 u 



'3 



d 



3 



M-. 

 O 

 V 



a 

 

 



HI 

 3 







CI 



C 



M ■ 



<u 





u 



HI 



& 



B 

 s 





q 



O 





Sand 5.15 

 4°-53 

 44.76 



51.45 



59-15 



56-03 



43-93 

 8.99 



65-77 

 3-72 



38.54 

 39-25 



45 23 

 3564 



37-22 



39-i6 

 33 20 



0.90 

 0.4S 

 0-55 



1.04 

 3.10 



2.57 

 1. 12 



00S 

 0.26 

 0.30 



0.36 

 tr. 



0.18 



0.25 



0.38 

 0.36 

 41 



0-33 

 0.30 



124 

 0.70 



0.66 



i-55 

 1.78 







13.00 

 13-41 



35 



In bu 



2.28 



rned 

 tion 



0.49 



condi- 

 0.76 









3 



35 



32-33 

 33 



30 

 32-33 



3-04 



5-19 

 6.72 



754 



4-5° 



0.71 



0.69 

 0.30 



1.42 

 095 



1.78 



, 







4 

 5 



6 

 7 



3 46 

 3-32 



3-55 



2 43 



3-46 

 3-32 



3-55 



2-43 









10.51 



'9-99) 



i. Washed kaolin Zettlitz, Bohemia. 



2. Clay, green, from Buessen. 



3. Clay, burned, from Buessen. 



4. Burned clay from Ebernhahn, Westerwald district. 



analyst. 



5. Hettenleidelheim. Seger & Cramer, analyst. 



6. Griinstadt, Ger., clay. 



7. Griinstadt, Ger., Pipe clay. 



Seger 



Cramer, 



In looking over the fusibility tests of fire clays, given above, 

 it is observable that the clays listed range in fusibility from cones 

 2 7 to 35. The question, therefore, arises as to what the standard 

 of refractoriness of a fire clay should be, for none has been 

 adopted by fire-brick manufacturers in this country. In Europe 

 a clay is not considered refractory unless it becomes viscous above 

 cone 27, although it may vitrify at a lower cone, and there has 

 been some discussion among foreign fire-brick producers regard- 

 ing the advisability of raising this standard. It is certainly 

 reasonable to set cone 27 as the lower limit of refractoriness, and 

 in the case of No. 1 fire clays it would seem desirable to demand 

 that they have a fusing point above cone 33. Unfortunately, 

 many clays are put on the market as fire clays which have abso- 

 lutely no claim to the name, and the same is sometimes true of 



