Evaluation of Mineral Composition of the Cement Clinker with Composite Mineralizers and Crystal Forms of Alite in That Wang ChenghuaIn the present paper, the changes in the mineral composition of the cement clinker caused by addition of fiuorite and gypsum to raw materials as mineral- izers were studied. It was shown that the alite content in the clinker with min- eralizers was higher than that calculated by Jinde formula and the flouroalum- inate C_(11)A_7 CaF_2 and the anhydrous calcium the sulphoaluminate C_4A_3S have been found in the clinker. Experiments show a linear relationship between the content of C_(11)A_7 C_(?)F_2 and C_4A_3S and the molar ratio of CaF_2/SO_3 in the clinker. A set of formulae for evaluating the mineral composition have also been derived, by which the calculated content of alite is more than that by usually used Jinde formula by 10％ more. The morphology of alite has been observed by SEM. Alite obtained under different burnt condition exists in different forms: overburnt alite does in the form of cylinders and hexagonal flakes with the size of 60μ and move while well-burnt one does in more regular crystals. The crystals of alite in the clin- ker burnt in the reducing atmosphere are small and thin. XRD analyses of the clinkers of different litre weights have also been made. The aluminoferrite phase in the normal clinker can be considered as the average composition of C_4 AF.