This SOPs covers a method for determination of loss on ignition in alumino silicate refractory materials.

Loss on ignition of the material is determined on ignited in a muffle furnace at 1025 ± 20°C.

• Platinum crucibles
• Muffle Furnace (1025 ± 20°C)
• Balance

It is prepared for the purpose of chemical analysis by drying a sufficient quantity of the laboratory sample in a glass weighing bottle in air oven at 105 to 110°C.

• Weigh 1.0 g of sample into a previously weighed platinum crucible. 
• Introduce it into a muffle furnace and slowly raise the temperature to 1025 ± 20°C. Ignite le mass at this temperature for 1 hour. 
• Remove the crucible and cool in a desiccator containing preferably magnesium perchlorate and weigh. Repeat the heating till constant weight.

Where,

A = initial mass in g of the crucible with sample, 

B = final mass in g of the crucible with residue after ignition, and 

C = mass in g of the sample taken.