Usage:
In paper making,it's used as stuffing
 As stuffing agent and strengthening agent for rubber and plastics
 As dye agent for coating materials
Specifications(HG2226-91)
     item                top grade  first grade  qualified product testing result 
                                                                    of products
content of calcium carbonate(CaCO₃)
    (base on dry sulfuryl ),%        98.0        97.0             96.0              98.68
content of volatile below 105 ,%     0.40        0.70              1.00              0.40
pH value (10% soliquoid )           9.0-10.0     9.0-10.5          9.0-11.           0 7-9.7
insoluble liquid of hydrochloric acid % 0.10     0.20              0.30              0.10
settling volume ml/g                 2.8         2.6               2.4               2.8
content of ferrum (Fe),%             0.08        0.10              0.12              0.08
content of mangan (Mn),%             0.006       0.008             0.010             0.006
residue on sieve  125um testing sieve ,% 0.005   0.010             0.015             0.005
 45um testing sieve ,%               0.30        0.40              0.50              0.08
white content,content                90.0        90.0              -                 94.5
average particle diameter ( m)        -          -                 -                 3.6-4