Calcium carbonate

Raw materials

1. Calcium oxide

2. Water

3. Carbon dioxide

Process

1. Calcium carbonate is prepared by calcining crude calcium oxide.

2. Water is added to give calcium hydroxide.

3. Carbon dioxide is passed through this solution to precipitate the desired calcium carbonate, referred to in the industry as precipitated calcium carbonate (PCC):

CaCO₃ → CaO + CO₂

CaO + H₂O → Ca(OH)₂

Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

Note: Calcium carbonate used in industry is extracted by mining or quarrying. Pure calcium carbonate (e.g. for food or pharmaceutical use), can be produced from a pure quarried source (usually marble).

Product

Calcium carbonate

Used for/as

Construction industry, either as a building material or limestone aggregate for road building or as an ingredient of cement or as the starting material for the preparation of builder's lime by burning in a kiln; purification of iron from iron ore in a blast furnace; added to drilling fluids in the oil industry as a formation-bridging and filtercake-sealing agent and as weighting material which increases the density of drilling fluids to control the downhole pressure; pH corrector in swimming pools for maintaining alkalinity and offsetting the acidic properties of the disinfectant agent; major component of blackboard chalk;  filler material for latex gloves; filler in paper (cheaper than wood fiber); extender in paints; inexpensive dietary calcium supplement or gastric antacid; phosphate binder for the treatment of hyperphosphatemia (primarily in patients with chronic renal failure); inert filler in pharmaceutical industry for tablets and other pharmaceuticals; sufferers to help reduce diarrhea in irritable bowel syndrome sufferers; production of toothpaste; food preservative; color retainer; neutralize the effects of acid rain in river ecosystems; neutralize acidic conditions in both soil and water

Production facility

Gladstone, QLD

Export
Phnom Penh, Cambodia