CLAYS OF NEW TOEK 783 



The following figures indicate tlie fusibility of several well 

 known American fire clays, the fusion points being expressed in 

 terms of Seger's cones. For comparative purposes tlie refractori- 

 ness of several standard European clays are given. -^ 



1 Kreiscfierville, IST. Y. wliite clay 35+ 



2 St Louis, Mo. C'kristie raw clay 31-30 



3 Golden, Col '..... 32-31 



4 Mineralpoint, O 33 



5 Mt Savage, Md. (hard) 34-35 



6 Sayreville, IT. J 35 



Refractory clay products 



Fire bricks. These are the commonest fire clay products, since 

 most of the refractory clay mined is used for this purpose. They 

 are utilized in many different ways; consequently not only the 

 shape but also' the quality varies. In certain cases the brick has 

 to withstand high temperature, in others corrosion by molten ma- 

 terials, while again in other situations resistance to abrasion is 

 required. 



The bricks set in the upper part of a blast furnace must resist 

 abrasion, those in the boshes must resist corrosion, and the same 

 condition must be complied with in glass pots. 



An idea of the number of shapes and sizes of fire brick manu- 

 factured can be gained from the statement that one large steel 

 company in this country uses 200 different ones. 



Many fire bricka are used for lining coke ovens. For such ser- 

 vice it is highly essential that they be able to withstand sudden 

 changes of temperature and not crack when the coke oven is 

 watered down after burning. The degree of heat which such 

 brick are subjected to is not very high. None are made in ITew 

 York state. 



1 No. 1 tested by the writer. The others by H. O. Hofman. Trans. Amer. 

 inat. min. eng. 25: 14. 



