ASTM C25-19 PDF Download

The ASTM C25-19 standard provides accurate and reliable analytical procedures for determining the chemical constituents of limestone, quicklime, and hydrated lime. These test methods are important for assessing the quality and fitness for use of these materials. The results obtained from these tests can be used to determine if the material meets specified requirements.

It is important to note that precision and bias in the analysis of quicklime and hydrated lime are highly dependent on precautions taken during sample preparation and analysis to minimize exposure to water and carbon dioxide in the air. The standard test methods may also be applicable to other calcareous materials, provided that compensations are made for known interferences.

The standard test methods are classified as either preferred or optional. The preferred methods employ classical gravimetric or volumetric analytical procedures and are typically required for referee analyses where chemical specifications are essential for contractual agreements. On the other hand, optional test methods are provided for routine determinations of certain constituents and may be shorter or more convenient. However, the use of optional methods may require expensive instrumentation that may not be accessible to all laboratories, and therefore their use is at the discretion of each laboratory.

The test methods outlined in the standard cover a wide range of chemical constituents, including aluminum oxide, calcium and magnesium oxide, carbon dioxide, iron and aluminum oxides, free moisture, free silica, insoluble matter, magnesium oxide, manganese, phosphorus, silicon dioxide, strontium oxide, sulfur trioxide, total carbon, total iron, and total sulfur. The list also includes alternative methods for calcium and magnesium oxide determination. These methods are presented in a specific order, supported by appendices and notes to facilitate accurate and efficient chemical analysis.