Calcium Hydroxide Supplier Salalah: Water pH and Hold Washing

Most buyers in Salalah need calcium hydroxide for one of two jobs: correcting the pH of water or effluent, or lime washing a ship's hold before it loads sulphur. As a calcium hydroxide supplier Salalah plants and ship agents can order from, we supply hydrated lime powder (part number RXSOL-22-2207-025, Ca(OH)2 98.0 % min) and a liquid calcium hydroxide (RXSOL-40-2207-030). Both are delivered from our Barka warehouse to Salalah and Dhofar.

For water work, plants usually dose calcium hydroxide as a 1 to 5% slurry. The dose is set by a jar test and typically falls between 5 and 500 mg/L. For hold washing, the usual mix is about 60 kg of lime to 200 litres of fresh water, and the wash must dry before loading starts. The sections below cover grades, dosing, the hold wash method, storage through the khareef and safe handling.

Calcium hydroxide in Salalah: what buyers ask for

Calcium hydroxide, Ca(OH)2, CAS 1305-62-0, is a white, odourless powder. It is made by slaking quicklime with water, then drying and milling it. You will also see it called hydrated lime, slaked lime, caustic lime or pickling lime, and our records list it as Lime Powder.

Buyers usually want it for three jobs. Water and wastewater operators use it to raise pH and alkalinity. Plants with acidic effluent use it for neutralisation. Ship agents and crews use it to lime wash holds before sulphur and other corrosive bulk cargoes. This page is for buyers who need to order and dose it.

Hydrated lime, quicklime and liquid lime compared

Quicklime is calcium oxide. It reacts with water and gives off heat, and a high-calcium quicklime plant in the Salalah Free Zone uses local limestone and exports through the Port of Salalah. Hydrated lime is the product of that reaction after drying. It is easier and safer to handle on site because the heat of slaking has already been released.

Dry calcium hydroxide powder suits hold washing and plants that already run a slurry make-up tank. Our liquid calcium hydroxide suits buyers who would rather not handle dust or run a slurry mixer. Its data sheet lists calcium hydroxide at 30% W/W. We list it for water treatment, waste water treatment, acid neutralisation and as a substitute in many liquid caustic applications.

Grades, purity and specifications

Commercial hydrated lime usually contains 80 to 96% calcium hydroxide, and a typical grade for plant use sits between 85 and 98% Ca(OH)2. Our powder is specified at 98.0 % min by ASTM C-25. Pure hydrated lime has a specific gravity of 2.3 to 2.4 and a typical bulk density of 450 to 560 kg/m3, so a bag of lime takes up more space than its weight suggests. Hydrated lime is only sparingly soluble: 0.165 g per 100 g of saturated solution at 20°C.

A 25 kg bag is a common pack size for hydrated lime powder across the trade. Tell us the quantity and the pack you need, and we will confirm the packing available for your order on the quote.

Hydrated lime for water treatment and pH correction

In water treatment, calcium hydroxide raises pH and alkalinity. Operators use it to get the best out of coagulation, for final pH correction to reduce corrosion in the distribution network, for lime softening and for sludge dewatering. Lime softening works by forming calcium carbonate and magnesium hydroxide, which settle out. In natural water, each 1 mg/L of calcium hydroxide that dissolves raises total alkalinity by about 1.35 mg/L (as CaCO3). That gives you a starting figure before the jar test.

Run a jar test on your own water first, because typical doses range from 5 to 500 mg/L. Dose lime as a solution or as a milk of lime slurry of up to 10% strength. A 1 to 5% slurry is the most common. Because the lime barely dissolves, the slurry tank needs continuous agitation. Dosing tanks and lines can be rubber-lined, FRP, polyethylene, PVC, cast iron or steel, but abrasion can damage FRP slurry tanks. Flush blocked lines with water or weak acid.

For wastewater neutralisation with lime at Dhofar plants, the same slurry corrects acidic effluent. In factory and plant wastewater it also helps precipitate metals such as lead, copper and zinc. Fish processors and cold stores with acidic wash water should start with a jar test on a composite sample from a full shift.

Lime washing cargo holds at Salalah port before sulphur

Lime wash on cargo hold steel works as a physical barrier and an alkaline neutralising layer between wet sulphur and steel. It slows corrosion but does not stop it, and it works best over sound paint. A single coat gives about 30 to 40 days of protection. Hydrated or slaked lime is the preferred choice for hold lime wash.

Crew checklist before loading:

• Bring the hold to grain clean condition: remove residues and loose scale, wash fully with seawater, then wash with fresh water. For oil, soot or coal stain, pre-clean with AquaaTuff Ship Hold Cleaner by circulation at 0.1-1% in the wash water, supplied in 25, 50, 210 Ltrs drums.
• Mix about 60 kg of lime to 200 litres of fresh water. For spraying with a portable submersible pump, hose and nozzle, a thinner mix of 2 parts water to 1 part lime works better.
• Let the wash dry before loading, or the protective glaze may not form. Holds must be fully dry before loading.
• Cover bilge strainers with hessian during the voyage. Bilges can be partly filled with lime.

After discharging sulphur, remove all residues and wash the holds with seawater and then fresh water. For hardened lime and mineral deposits, our Rock Phosphate Ship Hold Cleaner is used as a 50% solution with water where accumulation is not heavy. Our full ship hold cleaner range covers other hold cleaning jobs.

Storage in khareef humidity and safe handling

From June to September the khareef brings damp air to Salalah, and open lime takes up moisture and CO2 from the air, turning into calcium carbonate. Store bags in a dry, well-ventilated place, off the floor and away from water, and keep each container tightly closed. Do not leave a part-used bag open. Aluminium is unsuitable for packaging. The product is non-combustible.

Hydrated lime carries the signal word Danger: Skin Irrit. 2 (H315), Eye Dam. 1 (H318, causes serious eye damage) and STOT SE 3 (H335, may cause respiratory irritation). Avoid dust and contact with skin and eyes. Wear gloves and eye or face protection, do not wear contact lenses, and keep eyewash facilities on hand. For eye contact, flush with plenty of water for at least 15 minutes and get medical advice. In the EU the exposure limit for the respirable dust is 1 mg/m3 (8 h) and 4 mg/m3 short-term. Our own handling note adds: Do not breathe dust. In case of insufficient ventilation, wear suitable respiratory equipment. Keep away from incompatibles such as acids.

Calcium hydroxide supplier Salalah: delivery from Barka and how to order

Salalah Chemical (RXSOL group, Oman) ships calcium hydroxide from our Barka warehouse, with deliveries to Salalah and Dhofar. Give us the delivery point when you ask, whether that is a plant in the free zone, a treatment site inland or a vessel through its agent at Salalah port, and we confirm timing on the quote. Call +968 77333599, message us on WhatsApp, or email muscatchem@gmail.com.

If your plant is in the north, the same liquid lime is also listed on our sister sites for Sohar port and Batinah deliveries and for Muscat and Ruwi sites. You can browse all our products for the other water and hold chemicals you need on the same order.

To request a quote, send the product, quantity and delivery point on WhatsApp to +968 77333599 or use our quote request page.

Frequently asked questions

Where can I buy calcium hydroxide (hydrated lime) in Salalah?

Salalah Chemical supplies hydrated lime powder (RXSOL-22-2207-025) and liquid calcium hydroxide (RXSOL-40-2207-030) from its Barka warehouse, with deliveries to Salalah and Dhofar. Call or WhatsApp +968 77333599 for a quote.

What is the difference between quicklime and hydrated lime?

Quicklime is calcium oxide and gives off heat when it reacts with water. Hydrated lime is calcium hydroxide, the dried product of that reaction, so it is easier to handle and is the usual choice for water dosing and hold lime wash.

How much hydrated lime is needed to raise the pH of water?

Typical lime doses in water treatment range from 5 to 500 mg/L, depending on the water, so run a jar test first. In natural water, each 1 mg/L of calcium hydroxide that dissolves raises total alkalinity by about 1.35 mg/L as CaCO3. Most plants dose a 1 to 5% slurry.

How do you mix lime wash for a cargo hold before loading sulphur, and does it need to dry?

Bring the hold to grain clean condition, then mix about 60 kg of lime to 200 litres of fresh water, or 2 parts water to 1 part lime for spraying. Let the wash dry before loading, or the protective glaze may not form. A single coat gives about 30 to 40 days of protection.

Is calcium hydroxide dangerous to the eyes and skin?

Yes. It causes serious eye damage (H318) and skin irritation (H315), and the dust may cause respiratory irritation (H335). Wear gloves and eye or face protection, keep eyewash on hand, and flush eyes with plenty of water for at least 15 minutes after contact, then get medical advice.