Heavy (Ground) Calcium Carbonate is widely used as filler and improver. Purity: 98%min. Appearance: ... ) Calcium Carbonate is widely used as filler and improver in plastic, paint, paper-making, rubber, pharmacy, feed, daily chemical, ceramics, adhesives ... ) Calcium Carbonate is widely used as filler and improver in plastic, paint, paper-making, rubber, pharmacy, feed, daily chemical, ceramics, adhesives ...