Estimation of major phases

From the CaO content, deduct free lime and any CaO present as sulphate or CaCOj. In the absence of more detailed data, assume that 67% of the insoluble residue is Si02 and that 33% is AI2O3, and deduct accordingly. This gives AI2O3, 5.6% Si02, 21.5% CaO, 65.3%. 

Assume that the four major phases have the compositions given in Table 1.2, that of alite being adjusted in accordance with the MgO and Fe20j contents of the clinker as indicated in Note 1 to that table. 

Set up four linear, simultaneous equations represented in matrix form as A.X = B, where fljj is the weight fraction of oxide component i in phase j,. Vj is the weight percentage of phase j in the clinker, and Aj is the corrected weight percentage of oxide component i in the clinker  

The solution to these equations, obtained by inverting the matrix A, is 

The calculated percentages of alite, belite, aluminate and ferrite are given by. v,-.V4, respectively. The Bogue calculation gives 60.3%, 16.1%, 9.4% and 9.7%, assuming that the Si02 and AI2O3 contents have been corrected for insoluble residue. 

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