• Precipitated Calcium Carbonate
• Activated Calcium Carbonate

These two forms of calcium carbonate differ in respect of coating which the former does not have and later has. Both the forms of calcium carbonate are being used in various industries as filler or extender, thus assumes crucial importance in chemical and allied industries. PVC Rubber, denitrifice, cigarette paper, printing ink, pharmaceutical are some of the calcium carbonate using industries.

In this offer we have considered the product mix of Precipitated Grade which could cover very wide range of grades in terms of Particle Size, Shape and Distribution. It will be possible to vary any of the three physical properties alongwith other physical properties, such as Bulk Density, Flow Point, Viscosity, as required by individual customers as per their need. We have also considered 40 Tons per day capacity Activated Calcium Carbonate with different coating arrangement as well as sophisticated Pressure Filtration and Drying System to ensure the quality product.

PROCESS

High Grade Lime stone containing more than 90% CaO is calcined in a lime kiln fired by coal to obtain burnt lime (CaO).

For manufacture of Precipitated Calcium Carbonate, the burnt lime is converted into a thin slurry containing 15-20% of calcium hydroxide by adding required quantity of water and stirring in a mixing tank. The solution is passed through a cyclone separator for removing impurities like sand. The clean slurry is transferred into a carbonating tower.

The flue gases from the lime kiln containing 20-30% carbon-dioxide are collected and scrubbed with water in a scrubbing tower to remove dust and other impurities. The clean gas in compressed with the help of compressor and bubbled through the lime slurry solution in the carbonating tower. The calcium hydroxide in the solution reacts with carbon di oxide in the gas to form calcium carbonates. The contents of the carbonator are kept under circulation with the help of a pump to prevent settlement of the product. After completing the carbonation, the slurry is passed through a vacuum rotary filter to obtain precipitated calcium carbonate in the form of wet cake containing 40-50% moisture. The filtered water is collected and recycled for making lime slurry. The wet cake of calcium carbonate is dried in a tray drier and pulverised to the required mesh in a micro pulveriser. The product after testing is packed in polythene bags of 50% kgs. Each for marketing.

Activated calcium carbonate is produced by adding stearic acid to the calcium carbonate slurry obtained from the carbonating tower and heating to 80o C for one hour with recirculation.