BS ISO 1762 pdf free download
BS ISO 1762-2015 pdf free download.Paper, board and pulps – Determination of residue (ash) on ignition at 525 °C.
BS ISO 1762 describes the determination of the residue (ash) on ignition of paper. board and pulp at 525 °C. It is applicable to all types of paper, board, and pulp samples. The ash may consist of a) mineral matter in the pulp and various residues from chemicals used in its manufacture,
b) metallic matter from piping and machinery, and
c) fillers, pigments, coatings, or residues from various additives.
In samples containing calcium carbonate, there is practically no decomposition of carbonate by ashing at 525 °C. Other fillers and pigments such as clay and titanium dioxide are also unaffected by ashing at 525 °C. Accordingly, the residue on Ignition as determined by this International Standard provides a good estimate of the total inorganic matter in the sample, provided that the sample does not contain other minerals which decompose at or below this temperature. For example, magnesium carbonate and calcium sulfate may, at least partly, decompose at temperatures below 525 °C.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition oithe referenced document (including any amendments) applies.
ISO 186, Paper and board — Sampling to determine average quality
ISO 287, Paper and board — Determination of moisture content of a lot — Oven-drying method
ISO 638, Paper, board and puips — Determination of dry matter content — Oven-drying method
ISO 7213, Pulps — Sampling for testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 residue on Ignition
ash on ignition
mass of the residue remaining after a test specimen of paper, board, or pulp is ignited in a furnace at
525 °C ± 25 °C as specified in this International Standard
4 Principle
A test specimen is weighed in a heat-resistant crucible and ignited in a muffle furnace at 525 °C ± 25 °C. The moisture content of a separate test specimen is also measured, The percentage ash is then determined, on a moisture-free basis, from the weight of residue after ignition and the moisture content of the sample.
5 Apparatus
5.1 Heat-resistant crucibles, made of platinum, porcelain, or silica, with a capacity of 50 ml to 100 ml.
5.2 Muffle furnace, capable of maintaining a temperature of 525°C ± 25°C. It is recommended to place
the furnace in a hood or to provide means for evacuating smoke and fumes.
5.3 Analytical balance, accurate to 0,1 mg.
5.4 Desiccator.
6 Sampling and preparation of test specimen
If the analysis is being done to evaluate a lot, obtain a representative sample of paper, board, or pulp as described in ISO 186 or ISO 7213, as relevant. Sufficient sample must be collected to allow for at least duplicate determinations and for determination of moisture content. Take a test specimen consisting of small pieces, not larger than 1 cm2, taken from various parts of the sample in such a manner as to be thoroughly representative of it. The total mass shall be at least I g moisture free and shall yield a weight of ash not less than 10 mg and preferably over 20 mg (See the Note in Clause 7). In a similar manner, obtain a moisture specimen from the sample.
7 Procedure
Carry out the procedure in duplicate.
Air-dry the test and moisture specimens in the laboratory atmosphere until they reach equilibrium moisture.
Determine the moisture content on the moisture specimen as described in ISO 287 or ISO 638, as relevant. Weigh this specimen at the same time as the specimen used for ash determination.
Heat the empty crucible (5.1) for 30 mm to 60 mm in the muffle furnace (5.2) at 525 °C ± 25 °C. Cool it to room temperature in a desiccator.
Weigh the empty crucible to the nearest 0,1 mg. Add the test specimen and immediately weigh again.
Place the crucible containing the test specimen in the furnace at room temperature and gradually raise the temperature to 525 °C (about 200 °C/h) in order to burn the sample without it bursting into flames, and to ensure that no material is lost in the form of flying particles.
Maintain the ignition temperature of 525 °C for at least 2 h in the case of pulp and board samples and at least 3 h for paper samples. The specimen shall be completely charred as indicated by the absence of black particles.
Remove the crucible from the furnace, and cool it to room temperature in a desiccator. Weigh the crucible and content to the nearest 0,1 mg.
NOTE lithe sample has a very low residue on ignition (for example in the case of so-called ashless grades), it may be necessary to use several portions of the sample which are then ignited consecutively in the same crucible, in order to obtain a total residue of at least 10 mg.BS ISO 01762 pdf download.
