Quicklime (Calcium Oxide)

Quicklime is calcium oxide (CaO, CAS 1305-78-8) made by calcining limestone, supplied by Global Chemicals LLC at 90–95% CaO as 10–50 mm lumps, pebbles or powder, in 25 kg bags, big bags and bulk from stock in Muscat and Rusayl. It is the most concentrated and cheapest source of alkalinity per tonne, which is why water plants, steelworks, contractors and chemical plants buy it in preference to hydrated lime whenever they can slake it on site.

Slaking is the first step for most users. Quicklime reacts with water to form calcium hydroxide and releases a great deal of heat, enough to boil the water and crack the lumps; a slaker or a lime-milk tank with controlled water addition turns one tonne of quicklime into about 1.3 tonnes of hydrated lime or into milk of lime for dosing. A highly reactive lime slakes in minutes, and the reactivity test on the certificate tells the operator what to expect. For users who want to skip the slaker, see our hydrated lime page.

Uses in Oman: pH adjustment and neutralisation of acidic effluent, lime softening to remove carbonate hardness, precipitation of heavy metals and phosphate, and conditioning of sewage sludge in water and wastewater treatment; soil stabilisation, where 2–6% by weight of quicklime dries wet clay subgrades and raises their bearing strength on road and infrastructure projects in the interior; a flux and desulphurising agent in steel and metallurgy; flue-gas desulphurisation; purification of sugar juice and the causticising cycle of pulp mills; mortars, plasters and lime binders in construction; and a raw material for calcium chemicals.

Handling and storage: quicklime is corrosive to skin and eyes and reacts violently with water, so keep bags sealed, dry and off the floor, well away from any water or damp; it also absorbs moisture and carbon dioxide from the air and loses strength if left open. Wear gloves, goggles and a dust mask, and add lime to water slowly in a vessel that can take the heat. Every lot ships with a certificate of analysis giving CaO content, reactivity and sizing, and a GHS safety data sheet.

Delivery is same day within Muscat, next day to Sohar, Salalah and Duqm, and by road across the GCC with a certificate of origin. Request a quote with the form, sizing, tonnage and delivery point.