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NITRO DERIVATIVES OF NAPHTHALENE^445

TABLE 98

MATERIAL CONSUMPTION FOR 1000 kg OF DINITRONAPHTHALENE

Material

Naphthalene

HNO 3 (100%)

H 2 SO 4 (100%)

One-stage

nitration, kg

625

739

732

Two-stage

nitration, kg

612

637

684

Calculated

theoretical

quantity, kg

587

579

The possibility of recovering nitric acid from vapours carried away through

the ventilator has not been taken into account.

According to Gorst [31] three grades of DNN are specified in the U.S.S.R. (OST

2940. (Table 99).

TABLE 99

General appearance

Setting point, °C

Moisture and volatile matters, max.

insoluble in acetone-xylene mixture, max.

Ash total, max.

containing: SiO 2 max.

Pb

Fe

Acidity (% H 2 SO 4 )

Grade I Grade II Grade III

DNN should be a uniform powdery

or granular material free from foreign

inclusions

150 150 150

0.5% 0.5% 0.5%

0.2% 0.3% 0.5%

0.2% 0.2% 0.3%

0.05% 0.05% 0.05%

• traces 0.03%
  traces traces
  0.1% 0.1% 0.2%

NITRATION OF NITRONAPHTHALENE TO TRINITRONAPHTHALENE

French method [31a]

At the St. Chamas plant, the nitrator is of 4 m^3 capacity, equipped with a pro-

peller stirrer (100 r. p. m.) and with a jacket for cooling or heating. There is an outlet

80 mm in diameter at the bottom of the nitrator for discharging the contents.

The nitrator is charged with 800 kg of the spent acid from trinitration and

1330 kg of a mixture:

HNO 3 40%

H 2 SO 4 55%

H 2 O 5%

This mixture has an exceptionally high content of nitric acid, which is of great

importance to obtain the required high degree of nitration.