Refined tnt by sulfuric acid crystallization

Abstract

An explosive refining technique, used for TNT refining. It is characterized in that: use sulfuric acid (SA) to dissolve crude TNT at 100-120°C, the ratio of SA to TNT is 2-3.5:1 (V/V), stir while cooling down to 70-80°C, add a little TNT seed crystals are crystallized, and when the temperature is lowered to 20-40° C., vacuum filtration is performed to remove acid, and then 10% SA (equivalent to the proportion of SA used in crystallization) is taken and washed 1-2 times. Then, wash with hot water until the acidity is qualified, and dry to make tablets; the SA mother liquor that cannot be recycled is diluted to 60-70% with water, and various nitrate impurities are precipitated, that is, TNT oil. The diluted SA after filtration is concentrated and reused. Refined in crystallization. The recovery rate of the refined Bisulfite method by this method is high, and the recovered TNT oil can be used as civil explosives, which can increase the profit equivalent to 10% of the output value. There is no red waste water, so there is no need to incinerate and do not pollute the environment. It can be seen that this method has obvious advantages; it is also simpler and more environmentally friendly than the refining of dilute nitric acid in the United States. Therefore, it is a perfect green process to use pure o--MNT or (and) pure p--MNT to nitrate TNT, and then refine it with SA crystallization.

Description

technical field [0001] The invention relates to a technology for refining explosives, which is used for refining TNT. Background technique [0002] TNT (scientific name 2.4.6TNT, also known as symmetrical TNT), it has always been the explosive with the largest output and the best comprehensive performance in the world. Since toluene and nitric acid mixed acid are nitrated into crude TNT, it also contains 4.5% asymmetric TNT and other low-level nitrates and other impurities. Fried, very unsafe. Therefore, crude TNT must be refined. There are only two refining methods that have been industrialized, namely sodium sulfite (Na 2 so 3 ) method and dilute nitric acid (NA) crystallization method (see "High Explosive Chemistry and Technology" written by "Su" Orlova and translated by Ye Qingtang, published by National Defense Industry Press in 1965 and edited by China North Chemical Industry Company, 2001 The two books "Theory and Practice of Explosives" published in 2010), the f...

AI Technical Summary

Problems solved by technology

Its serious disadvantage is: at 80 ~ 82 ℃, Na 2 SO 3 It will react with symmetrical TNT and dissolve into wastewater, reducing the yield of finished products by about 7%. Based on an annual output of 10,000 tons of TNT (priced at 13,000 yuan per ton), the loss is about 9 million yuan; it also produces high-concentration red wastewater If it is not treated, it will seriously pollute the environment. The current wastewater treatment method is to heat and concentrate it, and then incinerate it with heavy oil. If one ton of TNT is produced to produce one ton of wastewater, the incineration fee for each ton of red water is about 400 yuan. It costs 4 million yuan more, and the sum of the two items is 13 million yuan, which is equivalent to 10% of the annual output value, which is a big loss! After incineration, a large amount of harmful gases such as sulfur dioxide, nitrogen oxides and PM2.5 are generated, causing air pollution, which is a problem that is not easy to solve! Refining with dilute NA crystallization is a non-chemical reaction physical method, it does not react with symmetrical TNT, the yield is higher than the previous method, and recovers a variety of nitrated impurities, the so-called TNT oil, which can be used as civilian explosives and increase economics Benefits; In addition, the dilute NA method does not produce red wastewater, which is conducive to environmental protection

However, TNT is a kind of strong explosive, and huge high-pressure equipment is used in production, which is very unsafe; and during the high-pressure extraction process, NA gas may escape into the air, and the boiling point of NA is only 86°C, and it dissolves at 85°C During the production process of TNT, leakage due to poor sealing of equipment caused environmental pollution

Therefore, the refining of dilute NA is not a perfect green TNT production process