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IS0
I NT ER NAT1 ON AL ORGAN I ZATl O N FOR STANDARD I ZATl ON
I S O R E C O M M E N D AT1 O N
R 602
DETERMINATION OF MINERAL MATTER IN COAL
1 st EDITION
July 1967
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The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRIEF HISTORY
The IS0 Recommendation R 602, Determination of Mineral Matter in Coal, was drawn
up by Technical Committee ISO/TC 27, Solid Mineral Fuels, the Secretariat of which is held by
the British Standards Institution (BSI).
Work on this question by the Technical Committee began in 1955 and led, in 1961, to the
adoption of a Draft IS0 Recommendation.
In March 1964, this Draft IS0 Recommendation (No.679) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial nature,
by the following Member Bodies:
Australia Germany Switzerland
Austria India Turkey
Belgium Italy U.A.R.
Brazil Korea, Rep. of United Kingdom
Netherlands U.S.A.
Canada
Chile New Zealand U.S.S.R.
Colombia Poland
Czechoslovakia Republic
Denmark of South Africa
France Romania
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0
Council, which decided, in July 1967, to accept it as an IS0 RECOMMENDATION.
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ISO/R 602 - 1967 (E)
IS0 Recommendation R 602 July 1967
DETERMINATION OF MINERAL MATTER IN COAL
1. SCOPE
I
This IS0 Recommendation describes a method of determining the amount of mineral matter
in coal.
2. PRINCIPLE
A sample of the coal is partially demineralized by treatment with hydrochloric and hydrofluoric
acids under such conditions that the coal substance remains unaffected. The loss in mass of the coal
due to the acid treatment is recorded and the insoluble part of the mineral matter determined by
ashing the partially demineralized coal. In addition, the iron content of the ash is determined so
that the pyrites present in the extracted coal can be calculated. The amount of hydrochloric acid
absorbed by the coal substance is also determined.
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3. REAGENTS
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All reagents should be of analytical reagent quality and distilled water should be used throughout.
3.1 Hydrochloric acid, d 1.18 or 1.19.
3.2 Hydrochloric acid, 5 N.
3.3 Hydrofluoric acid, d 1.13 or 1.14.
4. APPARATUS
I
All the apparatus listed below should be resistant to acids, especially hydrofluoric acid. A suitable
material is polyvinyl chloride (P.V.C.). The balance used should be sensitive to 0.1 mg.
4.1 Beaker. A 200 ml beaker with a cover slip.
4.2 Thermometer pocket. A tube, sealed at one end, to carry a thermometer.
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4.3 Stirrer.
4.4 Wash-bottle.
4.5 Filter, with a sintered alumina filter plate, as shown for example in the Figure, page 4.
4.6 Filter flask.
5. PROCEDURE
I
Before commencing the determination, mix the air-dried analysis sample of coal (see Note 1),
ground to pass a sieve of 0.2 mm aperture, thoroughly for at least one minute, preferably by
mechanical means.
Weigh accurately about 6 g of the sample into the beaker and add 40 ml of the hydrochloric acid
(3.2) (see Note 2). Insert the stirrer and the tube carrying the thermometer and place the cover
slip over the beaker. Place the beaker in a water bath, maintained at 55 to 60 OC. Stir the contents
at 5 minute intervals, remove the beaker after 45 minutes and allow the coal suspension to settle
for 10 minutes. Decant the solution through the filter (4.5) under suction.
Wash any coal on the filter with water, drain and transfer the coal back to the beaker with the
aid of not more than 5 ml of water. Care is required to avoid loss of coal by splashing (see Note 3).
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ISO/R 602 - 1967 (E)
a: paper filter, connected to the
upper cylinder with an adhesive
substance
b : plate of sintered alumina
c: rubber ring
d : cylinder of acid resistant material
(e.g. polyvinyl chloride)
FIGURE. - Filtering device (Left half shown in section)
Add 40 ml of the hydrofluoric acid (3.3) to the beaker and repeat the heat treatment and filtration
as previously described. Rinse any coal on the filter back into the beaker with not more than
5 ml water. Add 50 ml of hydrochloric acid (3.1) to the beaker, replace it in the water bath and
repeat the heat treatment previously described. Decant the solution through the prepared filtering
device and wash the coal with water three times, decanting eac
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