5.1 Free Moisture, as determined by this instrumental test method, is used for calculating other analytical results to a dry basis using procedures in Practice D3180.

5.2 Gypsum is the primary product used to assess the quality of the FGD-Solids for industrial purposes, especially construction wallboard. FGD solids are also used in mining applications, cement manufacturing, and for agricultural purposes.

5.3 Calcium Sulfite Hemihydrate is used to assess the suitability of some FGD-Solids for industrial uses.

1.1 This instrumental test method covers the determination of free moisture, gypsum (CaSO₄•2H₂O), calcium sulfite hemihydrate (CaSO₃•¹/₂H2O), calcium hydroxide (Ca(OH)₂), calcium carbonate (CaCO₃), and ash in flue gas desulfurization solids using a macro thermogravimetric analyzer.

1.2 This instrumental test method is not applicable to thermogravimetric analyzers using microgram size samples.

1.3 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.