Item

Index

superior product

top grade product

qualified product

barium sulfate content (in dry basis), ω/% ≥

98.5

98

98

105°C volatile matter, ω/% ≤

0.1

0.2

0.2

water solubles, ω/% ≤

0.15

0.2

0.25

ferrum (Fe), ω/% ≤

0.001

0.001

0.001

whiteness ≥

97

96

96

oil absorption/(g/100g)

10-20

10-20

10-30

PH value (100g/L suspension liquid)

6.5-7.5

6.5-8.5

6.5-8.5

fineness(45μm residue on sieve)/% ≤

0.1

0.15

0.2

particle size distribution

＜10μm, % ≥

98

98

97

＜5μm, % ≥

97

97

96

＜2μm, % ≥

90

90

80