Table 4.

Stage I: orthogonal design test.

Sample No.	SS1	SS2	SS3	SS4	SS5	SS6	SS7	SS8
BFS/%	10				20
Alkali/%	16	18	20	22	16	18	20	22
Modulus	0.4	0.6	0.8	1.0	0.6	0.4	1.0	0.8
Sample No.	SS9	SS10	SS11	SS12	SS13	SS14	SS15	SS16
BFS/%	30				40
Alkali/%	16	18	20	22	16	18	20	22
Modulus	0.8	1.0	0.4	0.6	1.0	0.8	0.6	0.4