Heavy calcium carbonate , calcium carbonate white powder, ground calcium carbonate, widely used. Heavy calcium carbonate white powder of high white, brightness and purity.Used in Paint, Dope, Rubber, PVC pipe, Paper making etc as stuff materials. Heavy calcium carbonate specificationMW: 100.09CaCO3 contents: 98.5%Fe2O3 contents: 0.03%SiO2 contents: 0.02%Al 2O3 contents: 0.01%Size: 325mesh, ...