222 



cox. 



Suppose that we recompcse clay number 1 with schi.st number 9 so that, 



alumina (resp. iron oxide) 1 „, , , ^. . , „ 



TV. = -K The calculation is as follows: 



silica 6' 



(102 2\ 

 4.66Xf?7ro) =25.63 P^''*^ alumina equivalent to 

 159. o/ 



alumina and iron o-xide in 100 parts clay. 



^^■^"^ a oAa silica „ „ .. 



„E-^,=2.346 or .— =2.346. 



25.0.5 alumina 



(102 2\ 

 l.lSX i-^ n I =13.30 parts alumina equivalent to 

 lo9.8/ 



alumina and iron oxide in 100 parts schist. 



80.12 silica . .., 



f5~o?v=6-025 or-j r— =6.025. 



13.30 alumina 



For any given intermediate ratio, parts of each must be combined, inversely 

 in proportion as the found ratio varies from that given. For a ratio of 3 to 1 

 therefore, 0.654 (i. e., 3 — 2.346) part of schist would need to be combined with 



(3 0^5 \ 

 ' " I 



o. 025 -f-0. 654/ 



clay nuniher 1 and 17.75 per cent I ' — | schist number 9 would be 



required. 



Accordingly, a new siliceous material would be obtained as follows: 



Table IX. 



[The numbers give parts of the materials by weight.] 



3.025 (i. e., 0.025- 



Material. 



Individual constituents. 



SiOo. 



AI.O3. 



FeaO,,. 



CaO. 



MgO. 



1 

 Loss on 

 ignition. 



82.25 clay (No. 1).. _ 



49.50 

 14.23 



18.62 

 2.23 



3.84 

 0.20 



0.26 

 0.02 



1.52 

 0.09 



5.23 

 0.38 



17. 75 schist (No. 9) 



100 



63.73 1 20.85 



4.04 



0.28 



1.61 



5.61 



1 









The formula requires 3.475 parts of limestone number 7 to every part of the 

 above material to give the maximum of lime which should be present in the 

 cement mixture as follows: 



Table X. 



[The numbers give parts of the materials by weight.] 





Total. 



Individual constituents. 



Silica 

 (SiOj). 



Alu- 

 mina 

 (AKOa) 



Iron 



oxide 



(FeoOs). 



Cal- 

 cium 

 oxide 

 (CaO). 



Magne- 

 sia 

 (MgO). 



Volatile 



(CO0+ 



H.O-h, 



etc.) 



Clay (No. 1) 



Schist (No. 9) 



Limestone (No. 7)... 



82.25 



17.75 



347.50 



49.50 



14.23 



1.32 



18.62 

 2.23 

 0.62 



3.84 

 0.20 



0.26 



0.02 



193.50 



1.52 

 0.09 







5.23 



0.38 

 1.52.00 



447.50 

 157.6 



65.05 



21.47 



4.04 



193.8 



1.61 



157.6 



Volatile 





289.9 



22.48 



7.40 



1.39 



66.8 



0.55 









