Grease ash is a batch of grease burned and solid residue calcined to ash, expressed as a mass percentage. The determination of the ash index is usually not of great practical significance, but to a certain extent, it explains the characteristics of the grease component, and has a certain effect on the control of the grease component and the preparation process. For the test method, see SH/T0327 "Determination of Ash Content of Lubricating Grease". These methods are equivalent to TOCT6474-53.

   Analytical instruments and materials: 30mL porcelain crucible with lid; crucible tongs; dryer; 500mL beaker; high temperature electric furnace or crucible furnace with constant temperature of 600℃±20℃ and 800℃±20℃; quantitative filter paper with a diameter of 9cm; and Distilled water is mixed into dilute hydrochloric acid and acid with a volume ratio of 1:4 to 10% ammonium nitrate aqueous solution.

   Experimental procedure: Weigh 2~5g of the sample into a crucible with constant weight, the surface is impregnated with filter paper rolled into a cone (the tip part is cut off), and then ignited and burned; the crucible filled with carbonized residue is finally burned Move to 600℃±20℃ high-temperature electric furnace and burn for 1.5H until the residue is completely ashed; if the carbonized residue is difficult to burn into ash, drop a few drops of ammonium nitrate aqueous solution after the crucible is cooled to make the residue soaked and wait for it to evaporate Continue to calcinate after drying; after the residue is completely ashed, take out and cool in the air for 3min, then move to a desiccator to cool for 30~40min, and then weigh, then repeat the calcining, cooling and weighing until constant weight.

   The ash 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 quality of filter paper ash, g;

         m——The quality of the sample, g.