PAPTAC - G.10
ASH IN WOOD, PULP, PAPER AND PAPERBOARD BY IGNITION AT 525°C
|Publication Date:||1 May 2013|
This Standard describes the determination of the ash content in wood and all types of pulp, paper and paperboard by ignition at 525oC (Note 1). The ash may consist of:
a) mineral matter in wood or pulp and various residues from chemicals used in pulp and paper manufacture
b) metallic matter from piping and machinery
c) fillers, pigments, coatings or residues from various additives
In samples containing calcium carbonate, there is minimal decomposition of carbonate by ashing at 525oC. Some pigments, such as titanium dioxide, are also unaffected by ashing at 525oC. Accordingly, the ash content as determined by this Standard provides a good estimate of the total inorganic matter in the sample, provided that the sample does not contain other minerals or fillers which decompose at or below this temperature. For example, clay and magnesium carbonate may, at least partly, decompose at temperatures below 525oC. Thus, the amount of mineral constituents in these samples can only be calculated if the loss on ignition of the particular mineral or pigment used is known.
For the determination of ash by ignition at 900oC, refer to PAPTAC Standard G.11.