Hydrated Lime & Testing Methods

IS 1514 : 1990 also known as Sugar method is the most rightful and authentic method to check the purity of hydrated lime, which takes about 2-3 hours to check.

Additional method used is Iodine Method.
Other routinely, common used method by various ETP and CETP Plant and few industries is HCL method , which basically  checks  acid in-soluble and impurities.

In this method , there is mix of HCL and distilled water , and few gms of hydrated lime is mixed in the same , after few minutes the insoluble/impurities  matters settle down , and based on % of matter settled down , purity is determined.

However , this just checks the acid insoluble, and not actual purity of hydrated lime , which can vary , thereby affecting other factors. Its possible lower purity too have low % acid insoluble.

Spectrum Industries , however recommends Sugar Method to determine actual purity of the material.