Production process and product standard of 2-naphthylamine-4,8-disulfonic acid

6.
Production process

Add 500kg of 20% fuming sulfuric acid into the sulfonation reactor, slowly add fine naphthalene powder within 1.
5h under stirring, and control the temperature at 25-30°C
.

Press all the carbides into the nitrification pot, and add 111kg≥96% concentrated nitric acid uniformly within 8 hours under stirring.
The temperature is strictly controlled at 25-30°C.
After the addition, the temperature is kept and stirred for 10 hours
.

Add 2200L of water into the salt-forming reactor, cool to 0°C, slowly add the nitrate, and the temperature is lower than 70°C, and the addition is completed in about 3.
2h
.

Take 1/2 of the above filter cake, add 400L of water, and beat for 2h
.

Add water to the reduction pot, stir and raise the temperature to 30-50°C, add 100kg iron filings and 10kg 92.
5% sulfuric acid
.

7.
Product Standard

8.

Content determination: Weigh about 10g of the slurry sample (accurate to 0.
0005g), place it in a 500mL beaker, and add 200mL of distilled water
.

Where: V——The volume of sodium nitrite standard solution consumed by the sample, mL;

c——The molar concentration of sodium nitrite standard solution, mol/L;

G——The mass of the sample, g
.

9.
Product use

This product is a dye intermediate, used to synthesize reactive dyes and direct dyes, such as reactive yellow, reactive yellow, reactive brown, and direct light fast blue B2RL
.

10.
Security measures

(1) Strong corrosive materials such as fuming sulfuric acid and concentrated nitric acid are used in production and the product is poisonous.
Therefore, the equipment should be sealed to prevent leakage.
The operator should wear labor protection equipment and maintain good ventilation in the workshop
.

(2) Packed in plastic drums or iron drums, and stored in a cool, dry and ventilated place
.

Related links: Production principle and process flow of 2-naphthylamine-4,8-disulfonic acid