COMPLEXOMETRIC DETERMINATION OF MAGNESIUM-OXIDE IN FLY-ASH BLENDED CEMENT

A complexometric titration method is proposed to determine magnesium o xide in flyash blended cement. A 0.50 g of sample was heated with hydr ochloric acid for 10 min. The solution was diluted to 500 ml, and 50 m l was pipetted and heated to boiling with 2.5 ml of 5% ammonium oxalat e solution. The solution was then made alkaline by ammonium hydroxide. The suspension was cooled and filtered. The filtrate was titrated by standard 0.002M EDTA solution. The concentration of MgO in sample was calculated. The flyash content of the sample was determined by British Standard method and the recovery factor (f) was calculated by the equ ation of f = 100/(99 - 0.315 x %FA). Concentration of MgO in sample wa s corrected by multiplying the recovery factor with concentration init ially found by EDTA titration. The precision of the method is better w ith more time saving than the official methods.