Water Treatment Industry
IS 712 certified Ca(OH)₂ in Premium & Ultra grades — trusted by municipal water plants, ETPs, and STPs across India for consistent pH control and heavy metal removal.
Hydrated lime (calcium hydroxide, Ca(OH)₂) is the most widely used chemical in water and wastewater treatment in India. It is cost-effective, safe to handle, and highly effective across a wide range of treatment processes — from municipal drinking water plants to industrial effluent treatment plants (ETPs) and sewage treatment plants (STPs).
Unlike quick lime, hydrated lime dissolves directly in water to form a stable lime slurry or lime water solution, making dosing precise and controllable without the need for on-site slaking equipment. This simplicity, combined with its high alkalinity and reactivity, makes it the preferred choice for most water treatment applications in India.
Hydrated lime is the most economical chemical for raising the pH of acidic water or industrial effluent. It neutralises acids, raises pH to the required level (typically 7–9 for discharge compliance), and reduces corrosivity. Used in ETPs treating acidic wastewater from textile, chemical, electroplating, and battery industries.
In the lime-soda softening process, hydrated lime reacts with dissolved calcium bicarbonate and magnesium salts to precipitate them as insoluble carbonates and hydroxides. This reduces water hardness for boiler feed water, cooling tower water, and process water applications in industries.
Raising pH with hydrated lime precipitates dissolved heavy metals — lead, zinc, copper, chromium, cadmium, nickel — as insoluble metal hydroxides that settle out in clarifiers. This is the standard method for meeting CPCB/SPCB discharge norms for heavy metal-bearing industrial effluents.
In sewage treatment plants (STPs), hydrated lime is used for chemical phosphorus removal. Lime reacts with dissolved phosphates to form insoluble calcium phosphate, which is removed in the sedimentation stage. This prevents eutrophication of receiving water bodies.
Hydrated lime is used alongside coagulants (alum, ferric chloride) to optimise the pH for coagulation. Proper pH control improves floc formation, settling rates, and turbidity removal in drinking water treatment plants.
Lime is added to sewage sludge to raise pH above 12, killing pathogens and stabilising the sludge for safe disposal or land application. This process — called lime stabilisation — is used in STPs and industrial ETPs to meet CPCB biosolids standards.
| Application | Recommended Grade |
|---|---|
| Municipal drinking water treatment | Premium (88–92%) |
| Industrial ETP — pH correction | Industrial (80–85%) |
| Heavy metal precipitation | Premium (88–92%) or Ultra (93–95%) |
| Boiler feed water softening | Ultra (93–95%) |
| STP sludge stabilisation | Industrial (80–85%) |
Every batch of hydrated lime is tested and certified to IS 712 (BIS) standards. Test certificates provided with each shipment.
In-house laboratory tests every batch before dispatch. Moisture content controlled below 2% to prevent clumping and ensure accurate dosing.
Our hydrated lime meets IS 712 fineness requirements — maximum residue on 212-micron and 90-micron sieves — ensuring fast dissolution and complete reaction.
15 MT minimum order. Pan-India delivery to Rajasthan, Gujarat, Maharashtra, MP, UP, Punjab, and more. Consistent supply for monthly procurement contracts.
Documented quality management system ensures batch-to-batch consistency — critical for water treatment plants with strict process control requirements.
Request a free sample before placing your first bulk order. Test our quality in your process before committing.
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