METHOD OF HYDROPHOBIC FILLER OBTAINMENT FOR POLYMERS BY CHEMICAL DEPOSIT CALCIUM CARBONATE MODIFICATION BY STEARIC ACID Russian patent published in 2015 - IPC C09C1/02 C09C3/08 C08K3/26 C01F11/18 

FIELD: construction.

SUBSTANCE: to obtain hydrophobic carbonate filler for polymers, by-product of mineral nitrogen fertiliser production, chemical deposit chalk, is dried in fluidised-bed dryer for 2 hours at 200°C to reduce humidity to 0.2% or less. Then the dried chalk is fed by pneumatic pipeline to vibration screens 014 and 0045 to remove silica and silicate inclusions. Screened calcium carbonate is fed to ball grinder for reduction during 5 hours. Then calcium carbonate proceeds to separation in magnetic separator. Fine-dispersed calcium carbonate obtained is passed to vortex grinder where it undergoes hydrophobisation by stearic acid used in amount of 0.8% of the calcium carbonate weight at 100°C. Hydrophobic calcium carbonate is cooled by cold air and packed up.

EFFECT: possible utilisation of mineral nitrogen fertiliser production waste with obtainment of high-quality hydrophobic carbonate filler for polymers.

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