Calcium Oxide, Calcium Hydroxide, Quicklime, Burnt Lime, Calcium Monoxid, Slaked Lime, Hydrated Lime, Lime Water, Calcium Hydrate, 1305-78-8, 1305-62-0

CALCIUM OXIDE (CaO) AND CALCIUM HYDROXIDE (Ca(OH)₂)

PRODUCT IDENTIFICATION INFORMATION

CHEMICAL STRUCTURE

    Calcium Oxide (CaO)              Calcium Hydroxide (Ca(OH)₂)
    
        O²⁻                            OH⁻
         |                              |
    Ca²⁺ — O²⁻ — Ca²⁺              Ca²⁺ — OH⁻

    Ionic Structure                 Ionic Structure

Calcium Oxide Molecular Formula: CaO
Calcium Hydroxide Molecular Formula: Ca(OH)₂
SMILES (CaO): O=[Ca]
SMILES (Ca(OH)₂): [Ca+2].[OH-].[OH-]
Crystal System: Cubic (CaO); Hexagonal (Ca(OH)₂)

SECTION 1: CHEMICAL IDENTITY AND DEFINITION

SECTION 2: PHYSICAL AND CHEMICAL PROPERTIES

SECTION 3: CHEMICAL PROPERTIES AND REACTIVITY

SECTION 4: COMPARISON OF CALCIUM COMPOUNDS

SECTION 5: PRODUCTION METHODS

Calcium Oxide (CaO) Production

Method 1: Calcination of Limestone (Main Industrial Method)

• Reaction: CaCO₃ → CaO + CO₂ (at 900-1,200°C)

• Description: Calcium carbonate (limestone) is heated at high temperatures; Calcium oxide and carbon dioxide are formed; Most common industrial production method; Rotary kiln or shaft kiln used

Method 2: Rotary Kiln Calcination

• Process: Limestone → Crushing → Rotary kiln (900-1,200°C) → CaO

• Description: Limestone is continuously calcined in a rotary kiln; High-purity calcium oxide is produced; Large-scale industrial production

Method 3: Shaft Kiln Calcination

• Process: Limestone → Shaft kiln (900-1,200°C) → CaO

• Description: Limestone is calcined in a shaft kiln; Lower energy consumption; Medium-scale production

Calcium Hydroxide (Ca(OH)₂) Production

Method 1: Slaking (Quicklime + Water)

• Reaction: CaO + H₂O → Ca(OH)₂ + Heat (violent exothermic)

• Description: Calcium oxide (quicklime) is reacted with water; Calcium hydroxide (slaked lime) is formed; Controlled water addition yields powder or suspension

Method 2: Controlled Hydration Slaking

• Process: CaO + Water (controlled amount) → Ca(OH)₂ powder

• Description: Controlled amount of water is added to quicklime; Fine powder form of calcium hydroxide is obtained; Used in agriculture and construction applications

Method 3: Lime Milk Production (Suspension)

• Process: CaO + Excess water → Ca(OH)₂ suspension

• Description: Quicklime is reacted with excess water; Lime milk suspension is obtained; Used in water treatment and industrial applications

SECTION 6: FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION

Calcium Oxide (CaO)

Calcium Hydroxide (Ca(OH)₂)

SECTION 7: MAIN APPLICATION AREAS

SECTION 8: QUALITY SPECIFICATIONS

Calcium Oxide (CaO) Specifications

Calcium Hydroxide (Ca(OH)₂) Specifications

SECTION 9: TOXICOLOGICAL PROFILE

SECTION 10: GHS CLASSIFICATION AND LABELING

Calcium Oxide (CaO) - GHS Classification

Signal Word: DANGER
Hazard Pictograms: GHS05 (Corrosion), GHS07 (Exclamation Mark)

Calcium Hydroxide (Ca(OH)₂) - GHS Classification

Signal Word: DANGER
Hazard Pictograms: GHS05 (Corrosion), GHS07 (Exclamation Mark)

Hazard Statements (H-Codes) - Both Compounds:

NFPA 704 Hazard Classification:

SECTION 11: PRECAUTIONARY STATEMENTS (P-CODES)

SECTION 12: FIRST AID MEASURES

SECTION 13: FIREFIGHTING MEASURES

SECTION 14: STORAGE AND SHELF LIFE

SECTION 15: PACKAGING OPTIONS

SECTION 16: TRANSPORT INFORMATION

SECTION 17: REGULATORY STATUS

SECTION 18: OTHER NAMES AND SYNONYMS

SECTION 19: SUMMARY TABLE

SECTION 20: CRITICAL WARNINGS AND BEST PRACTICES

CRITICAL WARNINGS (CALCIUM OXIDE - CaO):

• Causes severe skin burns and eye damage (H314/H318). Corrosive substance. Avoid skin and eye contact.

• Reacts violently with water (exothermic). Releases heat causing splashing and burns. NEVER add water to dry CaO.

• For skin contact with dry CaO, DO NOT wash with water immediately. Brush off dry material first, then rinse with water.

• Hygroscopic. Absorbs moisture from air. Store in airtight containers.

• Absorbs CO₂. Carbonation causes quality loss. Store in airtight containers.

• Avoid inhalation of dust. Severe respiratory tract irritation.

• Non-combustible but reacts violently with water. DO NOT USE WATER for firefighting.

CRITICAL WARNINGS (CALCIUM HYDROXIDE - Ca(OH)₂):

• Causes severe skin burns and eye damage (H314/H318). Corrosive substance. Avoid skin and eye contact.

• Avoid inhalation of dust. Respiratory tract irritation.

• Absorbs CO₂. Carbonation causes quality loss. Store in airtight containers.

• Non-combustible.

• Food additive (E526): Only food grade should be used. Industrial grade must NOT be used for food.

• More stable and less corrosive than CaO but still requires protective equipment.

BEST PRACTICE RECOMMENDATIONS:

• Construction and Cement Sector: Use CaO in clinker production; 60-70% in cement production; Use Ca(OH)₂ in mortar and plaster applications; Carbonation provides hardening.

• Agriculture Applications: Use Ca(OH)₂ as soil pH regulator (200-500 kg/ha); Neutralize acidic soils; Use as calcium source; Improve soil structure.

• Water Treatment: Use Ca(OH)₂ in wastewater treatment; pH adjustment; Heavy metal precipitation; Drinking water softening.

• Metallurgy: Use CaO as flux in steel production; Sulfur and phosphorus removal; Remove impurities from molten metal.

• Food and Pharmaceutical: Use ONLY food grade CaO (E529) or Ca(OH)₂ (E526); Comply with FDA/EFSA/Turkish Food Codex regulations.

• Handling (CaO): Use in well-ventilated areas; AVOID CONTACT WITH WATER; Wear protective gloves, goggles, face shield, and respiratory protection; Avoid dust generation.

• Handling (Ca(OH)₂): Use in well-ventilated areas; Wear protective gloves, goggles, and respiratory protection; Avoid dust generation.

• Personal Protective Equipment: Wear impermeable gloves (nitrile, neoprene, butyl), chemical safety goggles, full-face shield, protective clothing, and NIOSH-approved dust mask/respirator.

• Storage (CaO): Store in airtight, tightly closed containers in dry conditions; Protect from moisture and CO₂; AVOID CONTACT WITH WATER; Store separately from acids.

• Storage (Ca(OH)₂): Store in tightly closed containers in dry conditions; Protect from CO₂; Store separately from acids.

• Spill Response (CaO): DO NOT USE WATER; Clean up dry; Place in closed containers; Do not allow to enter drains or waterways.

• Spill Response (Ca(OH)₂): Avoid dust generation; Vacuum or sweep; Place in closed containers.

• Disposal: Dispose of in accordance with local, regional, and national regulations; Do not discharge into sewers or water sources; Lime is regulated as hazardous waste.

SPECIAL NOTE ON SLAKING REACTION (CALCIUM OXIDE + WATER):

• Reaction: CaO + H₂O → Ca(OH)₂ + Heat (violent exothermic)

• Heat Released: ~1,120 kJ/kg (very high)

• Temperature Rise: Can exceed 100°C

• Hazard: Splashing and severe burns

• Precaution: NEVER add water to dry CaO; Perform controlled slaking; Use appropriate PPE

SPECIAL NOTE ON CARBONATION:

Both compounds absorb CO₂ from air:

• Reaction (CaO): CaO + CO₂ → CaCO₃

• Reaction (Ca(OH)₂): Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

• Effect: Purity decreases; Reactivity decreases; Quality loss

• Precaution: Store in airtight containers; Perform periodic analysis for long-term storage

LEGAL DISCLAIMER:

The information provided in this document is based on our current knowledge and experience and is presented in good faith. However, as all conditions of use are beyond our control, this document does not constitute a binding specification or warranty. This Technical Data Sheet is for informational purposes only. Users are responsible for testing suitability for their own applications. For complete safety, storage, handling, transportation, waste, and regulatory compliance information, please refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier.