Limestone (Food Grade)

Ground limestone is natural calcium carbonate (CaCO3, CAS 471-34-1); the standard grade runs 95–98% CaCO3, giving 38–39% calcium, and material for food use (E170) must reach at least 98% CaCO3 on a dried basis, so ask for the food-grade certificate where it will reach food. It comes with low heavy metals, at least 85% whiteness and particle sizes from 50 to 200 mesh, supplied by Global Chemicals LLC in 25 kg and 50 kg bags and bulk from stock in Muscat. A 10% slurry reads about pH 9, so it neutralises acidity gently and without the overshoot of lime or caustic.

Food, feed and agriculture. Feed mills use it as the main calcium source in poultry and livestock rations: layer hens need coarse particles of 2–4 mm for strong eggshells, a different size from the 50–200 mesh powder listed here, so specify the layer grade when ordering; broiler and ruminant feeds take the fine grades. Food processors use it as a calcium fortificant and acidity regulator (E170) and as a neutralising agent for acidic process streams and wastes. Beet sugar factories and sugar refineries burn limestone to make the quicklime and carbon dioxide used to purify juice by carbonatation. In agriculture it is the standard liming material for acidic soils and growing media, and a calcium source where gypsum is not wanted.

Industrial uses. Water-treatment plants use limestone contactors and dosing to remineralise and stabilise desalinated water, and to neutralise acidic effluent; flue-gas desulphurisation scrubbers use limestone slurry to capture sulphur dioxide; and construction uses the coarser grades as filler and aggregate. For high-brightness industrial grades in plastics, paint and paper, see the calcium carbonate page.

Choosing the grade: ask for food or feed grade where the product will reach food or animal feed, and specify the particle size for the job, because reaction speed and handling depend on fineness. The powder is non-hazardous; avoid breathing dust, wear a dust mask when tipping bags, and keep bags dry, as damp limestone cakes and flows poorly. Every lot carries a certificate of analysis giving CaCO3 content, particle size, moisture and heavy metals, and a safety data sheet.

Delivery is same day within Muscat and Rusayl Industrial Area, next day to Sohar, Salalah and Duqm, and by road to the UAE, Saudi Arabia, Qatar, Kuwait and Bahrain with a certificate of origin. Request a quote with the grade, particle size, tonnage and delivery point.