Purification of nitroglycerine

The greater part of the add absorbed in the nitroglycerine is removed in the primary washing, which is carried out with cold water of about 15°C, usually in the same room as the nitrator. This primary washing is insufficient to remove the last traces of absorbed add which are very difficult to eliminate. The product is therefore washed again first with hot water, then with a dilute solution of sodium carbonate (2-4%), again with hot water and finally by a cold water wash. The temperature of the hot water and sodium carbonate solution should be held at such a level, e.g. 60-70°C, that the whole contents of the washing tank can be kept at a temperature of e.g. 45-50°C. The last cold wash, referred to as stabilization, is carried out in a separate room, into which acid vapour from the nitration room should not be allowed to penetrate. 

The design of the most widely used type of nitroglycerine washing tank is illustrated in Fig. 18. The tank of a cylindrical shape is constructed of sheet lead 

The lower layer, i.e. nitroglycerine, is discharged from the tank through the rubber hose (7) which is normally kept raised in a higher position by means of a hook 

The amount of water or solution to be used equals 2.5 parts by weight to 1 part of nitroglycerine. 

Afterwards, washing with a 2-3% sodium carbonate solution heated to about 70°C takes place. After the solution is poured into the tank with the nitroglycerine 

---

From experience gained over many years, special equipment and methods of nitration and purification of nitroglycerine have been developed and certain traditions established. Recently, however, changes have occurred in this field. Continuous methods of nitroglycerine manufacture have been introduced. In many cases they have revolutionized traditional techniques and led to new manufacturing processes. 

Separation of nitroglycerine from acid Purification of nitroglycerine Filtering nitroglycerine Transport of nitroglycerine Recovery of stabilizing water The spent acid... 

Nitroglycerine can detonate in pipes of diameter down to approximately 5 mm. In nitroglycerine manufacture there is, therefore, an inherent danger of transmission of detonation from one manufacturing house to another in the series. Even a pipe which has been emptied of nitroglycerine can have on it a skin of the product sufficient to enable transmission of detonation from one end of the pipe to the other. To prevent the spread of an accident it is now usual to transfer nitroglycerine as a non-explosive emulsion in an excess of water. Such emulsion transfer is particularly convenient with the NAB process, as the emulsion transfer lines can also carry out the necessary process of washing and purification. 

The transport of stabilized nitroglycerine to the rooms where it is to undergo final purification, e.g. filtration through a flannel, is now performed by means of a pipeline. In order to increase the safety of this operation, an emulsion of nitroglycerine in water or in an aqueous solution of sodium carbonate is produced by means of an injector and this emulsion is run through the pipeline. 

Tsuchida, S., Maki, T., Sato, K., Purification and characterization of glutathione transferases with an activity toward nitroglycerin from human aorta and heart. J. Biol. Chem. 265 (1990), p. 7150-7157... 

Description of Applicable Wastes Relatively stable high explosives such as high-melting explosive (HMX, or octahydro-l,3,5,7-tetranitro-1,3,5,7-tetrazocine), 2,4,6-tetranitro-N-methylaniline (tetryl), or TNT can be reliably reclaimed and reused. Propellants such as nitrocellulose (NC), dinitrotoluene (DNT), dibutyl phthalate (DBP), and nitroglycerine (NG) and oxidizers such as ammonium perchlorate (AP) are less stable and may require significant purification prior to reuse. 

---