Item

       TH-2

      TH-4

Purity counted as Ca(OH) 2    %≥

95.0

95.0

Loss of Drying             %≤

1.0

1.0

Hcl-insoluble matter         %≤

0.05

0.20

Fe                       %≤

0.03

0.05

Heavy metals              %≤

0.002

0.002

Magnesium and Alkali Salts    %≤

2.0

2.0

As                       %≤

0.0003

0.0003

Pb                       %≤

0.0003

0.0003

sulfate                    %≤

0.5

0.5

Residue     %≤

0.4 (325mesh)

0.01(200mesh)

chloride                   %≤

0.05

0.05

whiteness                   ≥

92.0

90.0