
Calcium Hydroxide for Water Treatment – Uses, Benefits & Applications
Calcium Hydroxide, commonly known as Hydrated Lime or Slaked Lime, is an important chemical widely used in water and wastewater treatment processes. Its chemical formula is Ca(OH)₂, and it is produced when calcium oxide (quicklime) reacts with water in a process called slaking.
Calcium hydroxide appears as a fine white free-flowing powder and has strong alkaline properties. Because of its high pH value, it is widely used to neutralize acidic water, remove impurities, and improve overall water quality.
Due to its effectiveness and low cost, calcium hydroxide is widely used in municipal water treatment plants, industrial wastewater treatment systems, and environmental treatment processes.
Calcium Hydroxide (Food Grade)
What is Calcium Hydroxide?
Calcium hydroxide is an inorganic alkaline compound that plays a major role in many purification and chemical treatment processes.
Chemical Information
| Property | Details |
|---|---|
| Chemical Name | Calcium Hydroxide |
| Other Names | Hydrated Lime, Slaked Lime |
| Chemical Formula | Ca(OH)₂ |
| CAS Number | 1305-62-0 |
| Physical Form | Powder |
| Appearance | Fine Snow White Powder |
| Solubility | Slightly soluble in water |
Product Specifications
| Parameter | Specification |
|---|---|
| Grade | Filler Grade |
| Physical Form | Powder |
| Packaging | Packet / Bags |
| Packaging Size | 40 kg Bags |
| Shelf Life | 3–6 months |
| Appearance | Fine white powder |
Why Calcium Hydroxide is Used in Water Treatment
Calcium hydroxide is widely used in water treatment because it can raise pH levels and remove harmful contaminants.
Key Benefits
✔ Neutralizes acidic water
✔ Removes heavy metals and impurities
✔ Improves water clarity
✔ Helps in sludge stabilization
✔ Cost-effective water treatment chemical
Because of these advantages, calcium hydroxide is an essential chemical used in water purification systems around the world.
Major Applications in Water Treatment
1. Drinking Water Treatment
Calcium hydroxide helps adjust the pH level of drinking water, making it safe for consumption.
2. Wastewater Treatment
It is widely used to neutralize industrial wastewater and sewage treatment plants.
3. Heavy Metal Removal
Hydrated lime helps remove heavy metals such as:
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Lead
-
Copper
-
Zinc
-
Nickel
from wastewater.
4. Sludge Stabilization
Calcium hydroxide helps reduce harmful microorganisms and stabilize sludge produced during wastewater treatment.
5. Industrial Water Purification
Industries use hydrated lime to treat water before discharge or reuse.
Hydrated Lime in Construction

Industrial Applications of Calcium Hydroxide
Apart from water treatment, calcium hydroxide is also widely used in many industries.
Industrial Uses
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Asphalt manufacturing
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Metallurgy
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Construction materials
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Iron and steel production
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Ore concentration
Environmental Uses
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Effluent treatment
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Flue gas treatment
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Hazardous waste treatment
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Bio-solid treatment
Chemical Uses
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Production of citrates and nitrates
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Silicates and acetates manufacturing
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Plastic stabilizers
-
Paints and lubricants
Packaging & Storage
Packaging Options
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40 kg bags
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HDPE bags
-
Industrial packaging options
Storage Conditions
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Store in a dry, ventilated area
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Protect from moisture
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Keep bags tightly sealed
Proper storage helps maintain product quality and shelf life.
Key Features of Calcium Hydroxide for Water Treatment
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Fine free-flowing powder
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Strong alkaline properties
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Effective impurity removal
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Cost-efficient treatment chemical
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Suitable for industrial and municipal water treatment
Frequently Asked Questions (FAQs)
What is calcium hydroxide used for in water treatment?
It is used to neutralize acidic water, remove impurities, and improve water quality.
Is hydrated lime the same as calcium hydroxide?
Yes, hydrated lime and slaked lime are different names for calcium hydroxide (Ca(OH)₂).
Why is calcium hydroxide effective for wastewater treatment?
Because of its strong alkalinity, it can neutralize acids and precipitate heavy metals.
What industries use calcium hydroxide for water treatment?
Industries such as municipal water plants, chemical factories, mining operations, and manufacturing industries use calcium hydroxide.