- Other name: Calcium Oxide, Burnt Lime, Calcined Lime, Unslaked Lime
- Chemical Formula: CaO
- Manufacturer: Vietnam Technology Mineral JSC
- Quicklime is created by heating limestone (which is calcium carbonate or CaCO3) to high temperatures in a kiln, causing it to undergo calcination
- The chemical reaction during calcination can be written as CaCO3 → CaO + CO2
- When water is added or mixed into quicklime, it undergoes hydration and develops intense heat. This reaction is called slaking of lime
- It has a very high alkaline pH of around 12.5, making it strongly caustic and able to damage skin, eyes, and respiratory tract on contact. Proper precautions must be taken when handling it
- Calcium oxide (CaO) content – The highest quality quicklime will be at least 90% pure calcium oxide
- Particle size – Finer particles (<1mm) offer a larger surface area and faster reactivity
- Moisture content – Quicklime picks up moisture easily which decreases reactivity. High-quality lime will have less than 1-2% moisture content
- Chemical impurities – Minerals like magnesia (MgO) are common but desirably under 2.5%. Trace heavy metals like lead or arsenic should be virtually nonexistent
- Consistency – Well-burnt, high-density quicklime will be uniform in particle size, density, and reactivity across batches
- Reactivity – Faster, more exothermic reactions when slaked indicate purer, livelier lime that mixes/sets quicker. 24 hours is ideal setting time
- Storage stability – Long shelf life with no detectable decline in properties over 6-12 months stored properly demonstrates consistent burning
- Source traceability – Knowing limestone source and kiln conditions results in more predictable, reliable quicklime quality batch to batch
- Proper burning is key – Quicklime from modern rotary kilns tends to offer the best, most consistent quality versus older fixed-grate kilns