HYDRATED LIME

Hydrated lime, also known as calcium hydroxide, is an alkaline inorganic compound with the chemical formula Ca(OH)₂ and CAS number 1305-62-0. Manufacturers produce it by adding a controlled amount of water to quicklime, which results in a fine, white powder with strong neutralising properties. Consequently, industries use it in water treatment, construction, wastewater management, soil stabilisation and various chemical processes.

In water treatment, it raises pH and adjusts alkalinity. Moreover, it helps soften hard water by promoting the precipitation of certain dissolved minerals. Wastewater treatment plants also use it to neutralise acidic streams and support contaminant removal. In addition, industrial facilities apply suitable grades to control acidic gases and reduce sulphur emissions. However, operators must select the correct grade and dosage according to the treatment process and required water quality.

In construction, it improves the workability and water retention of compatible mortar and plaster mixtures. It also supports masonry applications and selected soil stabilisation processes. Furthermore, manufacturers use it in certain mineral processing operations and chemical formulations. Its performance depends on purity, particle size, moisture content and the specific application. Therefore, buyers should check the product’s technical data sheet before selecting a suitable grade.

Hydrated lime has a molecular weight of approximately 74.09 g/mol and a specific gravity of about 2.2–2.4. It is only slightly soluble in water, although its alkaline reaction can produce a saturated solution with a pH of approximately 12.4. Additionally, the powder absorbs moisture and reacts with carbon dioxide in the air, gradually forming calcium carbonate. For this reason, users should store it in tightly sealed packaging in a cool, dry and well-ventilated area.

Finally, hydrated lime requires careful handling because its alkaline nature can irritate or burn the skin and eyes. Workers should wear suitable gloves, protective clothing and chemical safety goggles. They should also minimise dust generation and use appropriate respiratory protection where necessary. Always follow the supplier’s safety data sheet and application instructions.