ASTM C400-19 PDF Download

Standard Test Methods for Quicklime and Hydrated Lime for Neutralization of Waste Acid, ASTM C400-19, provides guidelines for testing the effectiveness of quicklime and hydrated lime in treating waste acid solutions. The standard emphasizes the importance of evaluating the relative quantity of a specific lime required for neutralizing a given quantity of acid, considering that different limes and waste acid solutions may vary in their composition.

The basicity factor of liming materials is used to assess their relative neutralizing power. This factor represents the amount of calcium oxide equivalents per kilogram of the liming material and enables comparisons without relying solely on chemical analysis. Similarly, the acid value of specific waste acids, expressed as grams of hydrochloric acid equivalent per litre, is used to determine the lime neutralization requirements for a liquid acid waste, based on stoichiometry.

The scope of the standard encompasses the characterization of the liming material and the acid waste. It also provides a note indicating that the method can be adapted to evaluate lime requirements for a plant waste acid, with adjustments made to treatment conditions according to plant practice. Another note highlights that, in certain test conditions, the lime requirement may deviate significantly from what could be predicted based on ultimate chemical analysis or the determination of available alkalinity using titration.