Calcium Hydroxide Ca(OH)₂ 96% — Technical Specifications, Applications & Price Quote
Table of contents
- Ca(OH)₂ 96% — CAS 1305-62-0, fine white powder, sparingly soluble in water (1.73 g/L at 20°C), saturated pH ~12.4
- Applications in water treatment, construction, agriculture, aquaculture, flue gas treatment, chemicals
- Save 60–70% on chemical costs compared to NaOH 32% for the same pH neutralization level
- Packed in 25kg PE-lined PP bags — store in dry conditions, avoid moisture
- Call 0979 891 929 — quote within 15 minutes, COA per batch, nationwide delivery
1. What Is Calcium Hydroxide Ca(OH)₂?
Calcium hydroxide — Ca(OH)₂ — is an alkaline compound produced by the lime slaking reaction: reacting calcium oxide (CaO — quicklime) with water in a strongly exothermic process:
The resulting product is a fine white powder, sparingly soluble in water (1.73 g/L at 20°C). The dissolved portion forms limewater with a pH of ~12.4 — sufficiently alkaline to neutralize acids, precipitate heavy metals, and disinfect.
1.1 Technical Specifications — Ca(OH)₂ 96% from Loc Thien
| Parameter | Value |
|---|---|
| Trade name | Calcium Hydroxide / Hydrated Lime / Slaked Lime |
| Chemical formula | Ca(OH)₂ |
| CAS number | 1305-62-0 |
| Content | ≥ 96% |
| MgO impurity | ≤ 1.5% |
| Fe₂O₃ impurity | Per batch COA |
| Insoluble residue | ≤ 1% |
| Form | Fine white powder |
| Solubility in water (20°C) | 1.73 g/L |
| Saturated solution pH | ~12.4 |
| Packing specification | 25 kg/PE-lined PP bag |
| Origin | Vietnam |
1.2 Common Names
In industry and daily use, Ca(OH)₂ is known by several names:
- Slaked lime (slaked lime) — the most common name in construction
- Hydrated lime / Slaked lime — international terminology
- Limewater — filtered saturated Ca(OH)₂ solution
- Milk of lime — Ca(OH)₂ suspension in water, dosed into treatment systems
2. 6 Main Applications of Ca(OH)₂
2.1 Industrial Wastewater Treatment
The largest application of Ca(OH)₂ in industry is wastewater treatment. Hydrated lime performs three functions simultaneously:
a) pH adjustment: Industrial wastewater often has a low pH (2–5) due to residual acids from electroplating, descaling, and manufacturing. Ca(OH)₂ neutralizes acids effectively:
Ca(OH)₂ + 2HCl → CaCl₂ + 2H₂O
b) Heavy metal precipitation: At pH 8.5–10, most heavy metals (Cr³⁺, Cu²⁺, Zn²⁺, Ni²⁺, Fe³⁺) precipitate as insoluble hydroxides:
Cu²⁺ + 2OH⁻ → Cu(OH)₂↓
c) Phosphate removal: Ca²⁺ from Ca(OH)₂ reacts with PO₄³⁻ to form Ca₃(PO₄)₂ precipitate, reducing phosphate to <1 mg/L — meeting QCVN 40:2025/BTNMT (replacing QCVN 40:2011, effective September 1, 2025) Column A standards.
Reference dosage: 100–300 g Ca(OH)₂/m³ of wastewater, depending on inlet pH and metal loading. A Jar Test should be performed to determine the optimal dosage for each plant.
2.2 Potable Water Treatment
Ca(OH)₂ 96% meets TCVN standards for potable water treatment with strict impurity limits (MgO ≤ 1.5%; Fe₂O₃ as stated on the batch COA). Applications in water treatment plants:
- pH elevation and water stabilization after RO filtration or soft water
- Iron and manganese removal through precipitation at high pH
- Water softening — removal of temporary Ca²⁺/Mg²⁺ via CaCO₃ precipitation
- Corrosion control in distribution pipelines
Suitable for water treatment plants meeting QCVN 01:2009/BYT standards. Loc Thien supplies Ca(OH)₂ with COA per batch — ensuring full traceability for compliance documentation.
2.3 Construction & Building Materials
In construction, Ca(OH)₂ is an essential component:
- Mortar & plaster: Ca(OH)₂ + sand + water → mortar with high plasticity and good adhesion. Upon drying, Ca(OH)₂ absorbs atmospheric CO₂ to form hard CaCO₃: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O
- Whitewash: Lime milk brushed onto walls — natural antimicrobial, low cost
- Soil stabilization: Mixing Ca(OH)₂ into clay soil reduces swelling and increases compressive strength for road foundations
- Silicate brick production: Ca(OH)₂ + SiO₂ (sand) → hydrothermal reaction producing calcium silicate hydrate — high strength
2.4 Agriculture & Soil Improvement
- Acidic soil pH correction: Tropical soils in Vietnam typically have pH 4.5–5.5 due to heavy rainfall leaching bases. Applying Ca(OH)₂ lime raises pH to 6.0–7.0 — optimal for NPK uptake by crops. Dosage: 500–1,500 kg/ha depending on soil pH
- Calcium supplementation: Ca²⁺ is a secondary macronutrient — essential for cell wall structure, cell division, and root development
- Soil disinfection: High pH from lime kills fungal pathogens and nematodes in soil before planting season
2.5 Aquaculture
Ca(OH)₂ is a standard chemical in pond preparation for shrimp and fish farming:
- Pond bottom treatment: Apply 100–150 kg/1,000 m² of pond bottom, dry for 7–10 days. High pH (>11) eliminates pathogens, harmful bacteria, and snail eggs
- Water pH elevation: When pond pH drops below 7 (after heavy rain or algal die-off), dissolve Ca(OH)₂ into lime milk and spray evenly over the pond surface: 10–20 kg/1,000 m³ water
- H₂S toxic gas treatment: Ca(OH)₂ raises pH → H₂S converts to HS⁻ (less toxic) → reduces shrimp/fish mortality
- Suspended solids settling: Ca²⁺ flocculates clay colloids → clearer water, better algal photosynthesis
For export aquaculture (GlobalGAP, ASC), choose Ca(OH)₂ 96% with low heavy metal impurities — meeting food safety standards.
2.6 Industrial Flue Gas Treatment
Ca(OH)₂ is used in SO₂ removal systems for boiler and incinerator flue gas:
Ca(OH)₂ + CO₂ → CaCO₃ + H₂O
Dry method (injecting Ca(OH)₂ powder into the gas stream) or wet method (bubbling gas through lime milk) — SO₂ removal efficiency reaches 85–95%. Applied in thermal power plants, cement factories, and metallurgy.
Figure: On-site chemical dosing, storage tank operation, and batch COA inspection — Source: Loc Thien Chemical.
3. Ca(OH)₂ vs NaOH Comparison — Which Is More Cost-Effective?
Every wastewater treatment plant asks the same practical question: Ca(OH)₂ or NaOH? Both are alkaline chemicals, but their cost structures differ significantly:
| Criteria | Ca(OH)₂ 96% | NaOH 32% |
|---|---|---|
| Unit price level per kg | Significantly lower | Higher |
| Neutralization equivalent | 1 mol Ca(OH)₂ ↔ 2 mol H⁺ | 1 mol NaOH ↔ 1 mol H⁺ |
| Molecular weight | 74 g/mol | 40 g/mol |
| Chemical cost/m³ wastewater (pH 2→7) | Roughly 60–70% lower | Baseline |
| Savings | — | Save 60–70% |
| Additional equipment required | Lime milk mixing tank + diaphragm pump | Standard dosing pump |
| Post-treatment residue | Yes (CaSO₄, CaCO₃) — clean every 3–6 months | Minimal residue |
| Best suited for | Plants ≥200 m³/day | Small plants, simple operation |
Practical conclusion: For a 500 m³/day plant, switching from NaOH to Ca(OH)₂ cuts neutralization chemical costs by roughly 60–70%; the lime milk mixing tank investment is recovered quickly through these recurring chemical savings. Actual unit prices for both chemicals depend on volume, delivery region and packaging — call 0979 891 929 for a quote within 15 minutes.
4. Safe Handling Guide for Ca(OH)₂
4.1 Personal Protective Equipment (PPE)
- Tight-fitting safety goggles — prevent lime dust from entering eyes
- N95 dust mask — Ca(OH)₂ is a fine powder that causes respiratory irritation
- Rubber/nitrile gloves — avoid skin contact (alkaline burns)
- Long-sleeved shirt and long pants — cover skin completely
4.2 Lime Milk Preparation Procedure
- Add water to the tank first, then slowly add Ca(OH)₂ powder — do NOT reverse the order (prevents clumping)
- Stir continuously for 15–20 minutes using a mechanical agitator (60–100 RPM)
- Lime milk concentration: 5–10% (50–100 g Ca(OH)₂ / liter of water) is optimal for dosing pump injection
- Piping: HDPE, PP, or PVC — avoid metal pipes (mild corrosion over time)
- Periodic cleaning: Drain tank bottom and flush pipelines every 3–6 months to prevent CaCO₃ scaling blockage
4.3 First Aid for Exposure
- Eye contact: Rinse immediately under running water for 15 minutes, seek medical attention
- Skin contact: Remove contaminated clothing, wash with clean water and soap
- Inhalation: Move to fresh air, drink warm water
- Ingestion: Drink plenty of water, do NOT induce vomiting, seek immediate medical attention
5. Where to Buy Ca(OH)₂ 96% — Pricing from Loc Thien
Hoa Chat Loc Thien is a specialized supplier of Calcium Hydroxide Ca(OH)₂ 96% for factories nationwide:
- Standard content ≥96%, Vietnamese origin — consistent batch quality
- COA with each shipment — transparent traceability
- Packed in 25kg PE-lined PP bags — good protection, easy transport and dosing
- Delivered from 6 strategic warehouses: Ba Ria – Vung Tau, Dong Nai, Binh Duong, Da Nang, Can Tho, Bac Ninh
- Technical support: dosage consultation, Jar Testing, lime milk dosing system design
Call now 0979 891 929 — price quote within 15 minutes, nationwide delivery.
Need a Ca(OH)₂ 96% quote for your plant?
Call 0979 891 929 — Quote within 15 minutes
COA per batch · 6 nationwide warehouses · 24/7 technical support
Technical Support & B2B Procurement Hotline
Loc Thien Chemical specializes in direct manufacturing of FeCl₂ / FeCl₃ and direct industrial supply of basic chemicals (NaOH, HCl, H₂SO₄, PAC, NaOCl, H₂O₂, FeSO₄) with direct B2B pricing and dedicated 5–30-ton tanker delivery across Vietnam.
- Hotline / Zalo: +84 979 891 929
- Official Email: [email protected]
- Direct Manufacturer: Ferrous Chloride (FeCl₂ 30%) & Ferric Chloride (FeCl₃ 38–40%)
- Primary Supplier: NaOH 32%/45%/50%/99%, HCl 32%, H₂SO₄ 98%, PAC 30–31%, NaOCl 10–12%, H₂O₂ 35%/50%
- Compliance & Quality: FeCl₂ ZDHC MRSL v3.1 test report (Smart testing, 5 substance groups, TUV Rheinland Vietnam), ISO 9001:2015, Quatest 3, Full COA & GHS SDS
Industrial Field Operation & Batch Quality Verification
1. Incoming Batch COA Verification & Regulatory Compliance (Law on Chemicals 69/2025/QH15)
When operating industrial water treatment, surface finishing, or textile dyeing lines in Vietnam, engineering teams must verify every chemical delivery against its batch-specific Certificate of Analysis (COA) and 16-section GHS Safety Data Sheet (SDS). Under the Vietnam Law on Chemicals No. 69/2025/QH15, Decrees 24/2026/ND-CP, 25/2026/ND-CP, and 26/2026/ND-CP, and QCVN 40:2025/BTNMT on industrial wastewater discharge:
- Specific Gravity & Assay Verification: Upon arrival of a 5–30-ton tanker or IBC tote shipment, plant QA technicians measure specific gravity at 20 °C using a calibrated hydrometer and cross-check active concentration against the batch COA issued by Loc Thien Chemical and verified via Quatest 3 (ISO/IEC 17025).
- Impurity & Heavy Metal Control: Trace heavy metals (Fe, Pb, As, Hg, Cd, Cr⁶⁺) and insoluble matter are strictly controlled to prevent catalyst poisoning in Fenton reactors, membrane fouling in RO/UF systems, or shade deviations in reactive textile dyeing.
- ZDHC MRSL v3.1 Level 1 Portfolio Boundary: For export-oriented textile and footwear FDI factories, Loc Thien Chemical maintains official ZDHC MRSL v3.1 Conformance Level 1 documentation for exactly 9 core products: four products certified by TUV SUD Product Service GmbH (
NaOH,H2O2,Na2SO4,Na2CO3) and five products verified via Conformance Summary Report (CSR) and Analytical Test Report by TUV Rheinland Vietnam (H2SO4,FeCl2,HCl,Javel/NaOCl,PAC 31%).
| Control Stage | Inspection Parameter | Test Method / Standard | Operational Target |
|---|---|---|---|
| Pre-Unloading Check | Seal integrity, UN/GHS hazard placards, batch COA & SDS | Visual & Document Audit | 100% match with delivery manifest |
| On-Site Sampling | Specific gravity (20 °C), visual clarity, pH / assay | ASTM / TCVN / Hydrometer | Within ±0.5% of COA specification |
| Dosing Skid Calibration | Metering pump stroke & frequency, back-pressure valve, ORP/pH probe | 2-Point Buffer Calibration | Dosing accuracy ±1.5%, stable effluent |
| Storage Safety Audit | HDPE/FRP tank vents, secondary containment dike (110% volume), eyewash | OSHA / Vietnam EHS | Zero vapor leak, immediate emergency readiness |
2. Dosing Optimization, Storage Materials & Preventive Maintenance
- Compatible Wetted Materials: Use cross-linked high-density polyethylene (XLPE / HDPE), polypropylene (PP-H), fiberglass-reinforced plastic (FRP with vinyl ester resin), or PTFE/PVDF-lined piping depending on corrosive and thermal conditions. Avoid unlined carbon steel or incompatible elastomers.
- Automated Dosing Control: Integrate diaphragm metering pumps with real-time pH, ORP (mV), turbidity, or conductivity sensors. Always perform a 5-beaker Jar Test whenever raw water COD, TSS, or alkalinity shifts by more than 15%.
- Secondary Containment & PPE: Storage tanks must sit inside an acid/alkali-resistant bund wall holding at least 110% of the largest tank volume. Operators handling unloading hoses must wear splash-proof chemical goggles, acid/alkali-resistant nitrile or neoprene gloves, face shields, and emergency respirators.
3. Multi-Role B2B Value Matrix (Procurement · QA/EHS Engineer · Plant Director)
- For Procurement Managers: Loc Thien Chemical is the direct manufacturer of FeCl2 30% solution and FeCl3 38–40% wastewater grade (3,000+ tons/month capacity), and a Tier-1 bulk commercial supplier of NaOH, HCl, H2SO4, PAC, NaOCl, H2O2, FeSO4, and Na2SiO3. Pricing is transparently structured around 5 technical cost drivers (active assay, packaging format, delivery distance from our 6 warehouses, order volume, and scheduled contract cadence) with a 15-minute technical quotation SLA.
- For Environmental & Process Engineers: Full technical support for Jar Test optimization, stoichiometry calculation, sludge minimization, and QCVN 40:2025/BTNMT compliance auditing.
- For FDI Plant Directors: Guaranteed supply continuity via 6 regional warehouses (Ba Ria - Vung Tau, Dong Nai, Binh Duong, Da Nang, Can Tho, Bac Ninh) and a dedicated 5–30-ton tanker fleet (4 hours in inner HCMC, 24–48 hours across Southern & Mekong Industrial Parks, 2–3 days in Northern & Central Vietnam).
4. Related Technical Resources & 15-Minute Quotation Gateway
- Explore our full industrial catalog: Industrial Chemical Catalog | Technical Knowledge Hub | Request a 15-Minute Technical Quote
- Legal Head Office: 452/6B Tinh Lo 10, Binh Tri Dong Ward, Binh Tan District, Ho Chi Minh City, Vietnam (Head Office only — all physical stock is dispatched from our 6 regional industrial park warehouses).
- 24/7 Technical Hotline: 0979 891 929 (Please contact hotline 0979 891 929 for detailed delivery procedures) | Official Email: [email protected]