Determination of % Ash

Apparatus

  1. MUFFLE FURNACE
  2. PORCELAIN CRUCIBLES

Procedure

  1. Weigh crucible and record weight to 4 decimal places.
  2. Weigh approximately 2 g into crucible.
  3. Record weight to 4 decimal places.
  4. Ash sample at 600oC for 2 h.  (Bring temperature rapidly to 600)
  5. Cool in desiccator and weigh within 1 h after reaching room temperature.
  6. Weigh ashed sample and record weight to 4 decimal places.
  7. Calculate % Ash and record value with one decimal.

Calculation

  1. % ASH = ((ashed wt.) - (crucible wt.)) x 100/((crucible and sample wt.) - (crucible wt.))

Reference

  1. St. John (1939), JOACI,XXII, 630.