Description
Hydrated Lime, also known as Calcium Hydroxide (Ca(OH)₂), is a fine, white alkaline powder produced by adding water to quick lime (Calcium Oxide). It is widely used in water treatment, mining, construction, chemical manufacturing, agriculture, and various industrial processes. Its ability to neutralize acids, adjust pH, and react with impurities makes it a valuable product across multiple industries.
Chemical Analysis
- Calcium Hydroxide (Ca(OH)₂): Commercial hydrated lime typically contains approximately 90% to 98% calcium hydroxide, depending on the grade and source.
- Available Calcium Oxide (CaO): Typically equivalent to approximately 68% to 74% of the product mass for high-purity hydrated lime, depending on its calcium hydroxide content.
- Magnesium Content (MgO): Varies depending on the limestone source and manufacturing process; it may range from less than 1% to several percent.
- Moisture Content: Generally low in properly manufactured and stored hydrated lime, with actual levels depending on product specifications and storage conditions.
- Impurities: May include small amounts of silica, alumina, iron oxides, unreacted limestone, and other mineral residues.
Note: Actual chemical composition varies by supplier and grade. Refer to the product’s Certificate of Analysis (COA) for confirmed specifications.
Key Characteristics
- High Alkalinity: Neutralizes acidic substances and raises pH in water, soil, and industrial processes.
- Low Water Solubility: Dissolves only slightly in water, forming an alkaline solution known as limewater.
- Fine Particle Size: Fine powder allows effective contact with acidic materials and supports efficient reactions.
- Moisture Sensitivity: Reacts with carbon dioxide in the air to form calcium carbonate over time, so proper storage is essential.
- Calcium Supply: Provides calcium for selected industrial, agricultural, and processing applications.
- Chemical Reactivity: Reacts with acids and can help precipitate certain dissolved metals and impurities under suitable treatment conditions.
Major Uses & Applications
- Water and Wastewater Treatment: Used to adjust pH, neutralize acidic water, assist in removing impurities, and support sludge treatment.
- Mining and Mineral Processing: Used for pH control, neutralization of acidic process streams, and selected mineral-processing applications, including gold recovery circuits where specified by the process.
- Agriculture and Soil Treatment: Used to neutralize acidic soils and raise soil pH where recommended by soil analysis and agronomic assessment.
- Construction Industry: Used in mortar, plaster, lime-based building materials, and selected soil stabilization applications.
- Chemical Manufacturing: Serves as a raw material in the production of calcium-based compounds and other industrial chemicals.
- Sugar Processing: Used in sugar clarification and purification to help remove impurities.
- Industrial Effluent Treatment: Helps neutralize acidic wastewater and supports the treatment of certain industrial residues.
- Paints and Building Materials: Used in selected formulations and manufacturing processes, depending on the required product specifications.
Handling and Storage
Hydrated Lime is an alkaline material that can cause skin irritation, serious eye damage, and respiratory irritation from airborne dust. Avoid direct contact and inhalation. Use suitable gloves, protective clothing, safety goggles, and appropriate respiratory protection where necessary. Store in a dry, well-ventilated area in tightly sealed, moisture-resistant packaging.
