Moisture, as determined by the instrumental test method, is used for calculating other analytical results to a moisture-free basis using procedures in Practice D 3180. Moisture percent determined by this test method may be used in conjunction with the air-dry moisture loss determined in Method D 2013 and Test Method D 3302 to determine total moisture in coal. Total moisture is used for calculating other analytical results to an as-received basis using Practice D 3180.

Ash yield, as determined by this test method, is the residue remaining after burning the coal and coke samples.

Volatile matter yield, when determined as herein described, may be used to (1) establish the rank of coals, (2) indicate coke yield on carbonization, (3) provide the basis for purchasing and selling, or (4) establish burning characteristics.

Fixed carbon is a calculated value. It is the difference between 100 and the sum of the percent moisture, ash, and volatile matter. All percents shall be on the moisture reference base.

Moisture, ash, volatile matter, and fixed carbon percents constitute the proximate analysis of coal and coke.

Note 1—The ash obtained differs in composition and amount from the mineral constituents present in the original coal. Incineration causes an expulsion of all water, the loss of carbon dioxide from carbonates, the conversion of iron pyrite into iron oxides and sulfur oxides, and other chemical reactions. Ash yield, as determined by this test method, can differ from the amount of ash produced in furnace operations or other combustion systems because incineration conditions influence the chemistry and amount of ash.

1.1 These instrumental test methods cover the determination of moisture, volatile matter, and ash, and the calculation of fixed carbon in the analysis of coal and coke samples prepared in accordance with Method D 2013 and Practice D 346. Results obtained through the use of the instrumental tests have been shown to differ from those obtained with Test Methods D 3173, D 3174, and D 3175 on some coals and cokes. Where a relative bias between the instrumental methods and Test Methods D 3173, D 3174, and D 3175 for proximate analysis of coal and coke are shown to exist, the instrumental results shall be corrected or the instrument calibrated using samples of known proximate analysis. Test Methods D 3173, D 3174, and D 3175 shall be considered the referee test methods. The instrumental test methods are not applicable to thermogravimetric analyzers using microgram size samples.

1.2 The moisture value determined is used for calculating other analytical results to a dry basis. When used in conjunction with the air dry loss moisture, as determined in accordance with Method D 2013, Test Method D 3302, or Practice D 346, the calculated total moisture can be used to convert dry basis analytical results to the as-received basis.

1.3 The result of the ash determinations can be applied in the ultimate analysis, Practice D 3176.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.