Item

Type I

Type II

Premium product

Premium product

First-class product

Qualified product

appearance

Light sodium carbonate is a white crystalline powder

Heavy sodium carbonate is white fine particles

Total alkalinity（Based on the mass fraction of Na2CO3 on a dry basis）/ω/% ≥

99.4

99.2

98.8

98.0

Total alkalinity（Based on the mass fraction of Na2CO3 on a wet basis )a/ω/% ≥

98.1

97.9

97.5

96.7

Chloride (calculated as the mass fraction of NaCl on a dry basis)/ω/% ≤

0.30

0.70

0.90

1.20

Mass fraction of iron (on a dry basis) content/ω/% ≤

0.0025

0.0035

0.0055

0.0085

Sulfate (calculated as the mass fraction of SO4 on a dry basis)/ω/% ≤

0.03

—

—

—

Mass fraction of water-insoluble matter/ω/% ≤

0.02

0.03

0.10

0.15

bulk density b/g/mL ≥

0.85

0.90

0.90

0.90

granularity b

Residue on sieve

180mm/ω/% ≥

75.0

70.0

65.0

60.0

1.18mm/ω/% ≤

2.0

—

—

—

a. For the content at the time of packaging, the value obtained by multiplying the total alkali content in the product at the time of delivery by the mass of the delivered product and then dividing by the mass of the product listed on the delivery sheet should not be lower than this numerical value.
b. It is a project for controlling heavy-quality soda ash.