Grease ash is the burning of a batch of grease and the calcination of solid residues into ash, expressed in mass percent. Determination of ash content index usually has no great practical significance, but to a certain extent, it explains the characteristics of grease components, and plays a certain role in controlling the components and preparation process of grease. See SH/T0327 "Determination of Grease Ash Content" for the test method, some methods are equivalent to TOCT6474-53.

   Analytical equipment and materials: 30mL porcelain crucible with lid; crucible tongs; desiccator; 500mL beaker; Distilled water is made into a 1:4 volume ratio of dilute hydrochloric acid and acid into a 10% ammonium nitrate aqueous solution, etc.

   Experimental steps: Weigh 2~5g of the sample into a crucible with constant weight, soak the sample with filter paper rolled into a cone (cut off the tip), and then ignite and burn; put the crucible containing the carbonized residue after burning Move it into a high temperature electric furnace at 600℃±20℃ and burn for 1.5H until the residue is completely turned into ash; if the carbonized residue is difficult to burn into ashes, drop a few drops of ammonium nitrate aqueous solution after the crucible is cooled to wet the residue and wait for it to evaporate After drying, continue calcining; after the residue is completely ash, take it out and cool it in the air for 3 minutes, then move it into a desiccator to cool for 30-40 minutes, then weigh it, and repeat the calcination, cooling and weighing until the constant weight is reached.

   The ash content X (%) of the sample is calculated as follows:

                           X=[( m1- m2)/m]x100

    where m1——the mass of sample ash and filter ash, g;

        m2——the mass of filter paper ash, g;

         m——the mass of the sample, g.