GB/T 216-2003Determination of phosphorus in coal (English PDF)

1 Scope

This Standard specifies the abstract of methods, reagents, instruments and equipment, determination procedure, result expression and precision of determination of phosphorus content in coal.

This Standard is applicable to determination of phosphorus content in lignite, bituminous coal, anthracite and coking coal.

2 Normative references

The articles contained in the following documents have become part of this Standard when they are quoted herein. For the dated documents so quoted, all the modifications (excluding corrections) or revisions made thereafter shall not be applicable to this Standard.

For the undated documents so quoted, the latest editions shall be applicable to this

Standard.

GB/T 212 Proximate analysis of coal (GB/T 212-2001, eqv ISO 1171:1997)

3 Abstract of methods

After ashing of the coal sample, decompose it with hydrofluoric acid-sulfuric acid. Remove silicon dioxide. Then add ammonium molybdate and ascorbic acid to generate phosphorus molybdenum blue. Determine the absorbance with spectrophotometer.

4 Reagents

4.1 Hydrofluoric acid (GB/T 620): 40% (mass fraction).

7 Precision

The precision of determination of phosphorus is specified in Table 1:

Table 1 Precision of determination of phosphorus

Mass fraction of phosphorus/% Repeatability limit (P ad)/%

Critical difference of reproducibility (P d )/%

<0.02 0.002 (absolute) 0.004 (absolute)

>=0.02 10% (relative) 20% (relative)

8 Test report

The test report shall include the following information:

a) Sample No.;

b) Test Standards;

c) Methods used;

d) Result calculation;

e) Deviation from standard;

f) Abnormalities observed in test;

g) Test date.

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