Samples 	RN-7	RN-9	RN-10	RN-11	RN-12	
wt%						
SiO2	44.33	42.26	42.64	45.11	46.62	
TiO2	3.82	3.725	3.76	2.78	2.83	
Al2O3	12.18	11.86	12.89	11.86	12.39	
Fe2O3 T	14.32	13.72	12.34	12.57	12.55	
MnO	0.18	0.175	0.17	0.16	0.16	
MgO	8.31	9.47	8.01	8.29	9.02	
CaO	10.84	11.6	10.69	11.58	9.59	
Na2O	3.04	2.87	2.82	3.03	2.78	
K2O	1.33	1.675	1.96	1.14	1.09	
P2O5	1.01	0.86	0.95	0.54	0.54	
LOI	0.68	1.88	2.76	1.77	1.16	
 Total	100.04	100.10	98.99	98.83	98.73	
Major oxides (wt%) and LOI values of the studied samples