ratio lower than 2 7 low temperature nitrogen sorption isotherms in fig6 7 clearly show that the porosity of skeletonc increases with decreasing ratio of c tio 2 in stage c of carbide making sorption isotherms presented in fig8 9 confirm that there is an optimum carbide making temperature in stage c u02dc 1500 u00b0 c that produces the skeletonc of highest porosity finally the quantitative relationships between stage c parameters and skeletonc properties were assumed as shown in fig1 12 the c tio 2 ratios between 2 5 and 3 3 in stage c relate linearly to the several porosity characteristics such as specific surface total pore volume benzene adsorption apparent density etc of skeletonc carbon chlorinated at u02dc 800 u00b0 c in stage d if the carbide making temperature in stage c is chosen 1600 u00b0 c the following equation describes the relationship between specific surface bet of skeletonc and the c tio 2 ratio x bet u2212 1 47 x 5 64 u00b7 1000 whereby the square of correlation coefficient r 2 0 989 if the carbide making temperature in stage c is chosen e g 1530 u00b0 c the following equation describes the relationship between specific surface bet of skeletonc and the c tio 2 ratio x bet u2212 1 71 x 6 49 u00b7 1000 whereby the square of correlation coefficient r 2 0 991 if the carbide making temperature in stage c is chosen e g 1450 u00b0 c the following equation describes the relationship between specific surface bet of skeletonc and the c tio 2 ratio x bet u2212 1 93 x.