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