RU2555490C2 - Method of potassium nitrate regeneration - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of smoke black powder and can be used for the regeneration of potassium nitrate from sweepings of the gunpowder production with an expired storage term. The method includes mixing the smoke black powder to be utilised with water in a tank, heating the mixture to 90-100°C, filtration of a solution of a sulphur-coal mixture and potassium nitrate, crystallisation of the latter with constant cooling of the crystalliser, collection of potassium nitrate crystals, its centrifuging to remove the solution and drying, with the filtration being realised with a working mixer in a heated filter; crystallisation is carried out with mixing the solution by the supply of compressed air; mother liquor, which is formed in the crystalliser is pumped into a tank, heated to a temperature of 90-100°C and used to wash the residue on the heated filter, the obtained solution is re-supplied into the crystalliser and subjected to crystallisation, the precipitated sediment of potassium nitrate is removed, the solution, remaining in the crystalliser, is re-supplied for mixing with the smoke black powder to be utilised. The technical result of the invention consists in an increased output of potassium nitrate, extracted from smoke black powder.

EFFECT: method is simple and makes it possible to use industrial equipment.

1 dwg, 2 ex

Description

The invention relates to the technology of smoky black powder (PP) and can be used for the regeneration of potassium nitrate from recyclable smoke powders and powders with expired shelf life. In the future, potassium nitrate can be used in the production of CP or as a mineral fertilizer.

From the literature, methods for the extraction of soluble substances by extraction followed by crystallization are known [1-3]. The main disadvantage of the known methods is the small amount of recovered nitrate (less than 30%).

Thus, the method [2] describes the extraction of soluble substances by extraction and then crystallization of the soluble substance. In this case, 25-30% of the substance is extracted, since when passing through the filter there are large losses.

The closest in technical essence to the claimed invention is a method of regeneration of potassium nitrate from production estimates [4], which consists in mixing utilized smoke powder with water, heating with constant stirring, settling the mixture to precipitate solid particles, passing a solution of potassium nitrate through a filter and precipitating crystals in a cooled mold. As a disadvantage, not more than 30% of potassium nitrate is recovered from all contained in the PP.

The technical result of the present invention is to increase the yield of potassium nitrate recoverable from DCP.

The technical result is achieved by the fact that in the method of regenerating potassium nitrate, which includes mixing the utilized smoke powder with water, heating the mixture to 90-100 ° C, filtering the solution, crystallizing potassium nitrate with constant cooling of the mold, collecting crystals of potassium nitrate, centrifuging it for removal of the solution and drying, and the sulfur-coal mixture and the solution of potassium nitrate pass through a heated filter with the stirrer working, crystallization is carried out with stirring of the solution by supplying a compressed air, and the mother liquor formed in the crystallizer is heated to a temperature of 90-100 ° C and washed with the precipitate on a heated filter, and the resulting solution is fed into the crystallizer and again subjected to crystallization, the precipitate formed is removed, and the remaining solution in the crystallizer is again sent for mixing with the recyclable black powder.

Examples of specific performance.

Example 1. For the regeneration of potassium nitrate from estimates of the production of PPP, the technological scheme shown in Fig. 1 was used.

Up to half of the tank is poured into the tank 1 with the mixer, the mixer is turned on, the utilized smoke powder is loaded by weight not more than half the weight of the water and the steam is let into the steam jacket. When the temperature in the tank reaches 100 ° C, open the valve 2 and filter the suspension through a heated filter 3, which has a temperature of 95 ° C. The filtrate enters the crystallizer with jacket 4. Cold water is allowed into the jacket, the solution is mixed with a stream of compressed air. The process is continued until the solution temperature drops to 25 ° C. The precipitate of nitrate is loaded into a tissue bag and squeezed in a centrifuge 5 until the solution is stopped.

The resulting mother liquor from the crystallizer 4 is pumped into the tank 1, heated to 95 ° C and washed with the precipitate on the filter 3, after which the resulting solution is poured into the crystallizer 4 and again subjected to crystallization as described above. In this case, 82% of nitrate is recovered.

Drying of nitrate is carried out in an oven 6, heated by steam at a temperature of not more than 120 ° C to a moisture content of 0.08%.

Example 2. For the regeneration of potassium nitrate from estimates for the production of PPP, the technological scheme shown in Fig. 1 was used, but not water was poured into tank 1, but the mother liquor of nitrate from crystallizer 4 formed after the crystallization of nitrate. In this case, this method allows you to extract 85% nitrate.

In any case, the use of the proposed method can significantly increase the amount of recovered nitrate.

The method is simple and allows the use of industrial equipment.

INFORMATION SOURCES

1. Kasatkin A.G. Basic processes and apparatuses of chemical technology. 9th ed., Trans. M .: Chemistry, 1973

2. Pavlov K.F., Romankov P.G., Noskov A.A. Examples and tasks on the course of processes and apparatuses of chemical technology. 9th ed., Trans. and add. L .: Chemistry, 1981

3. Zhuzhikov V.A. Filtration. Theory and practice of separation of suspensions. 4th ed., Trans. and add. M .: Chemistry, 1980

4. Application for invention RU No. 2008109343 from 09.20.09. g.

Claims (1)

       A method for regenerating potassium nitrate, including mixing the utilized smoke powder with water in a tank, heating the mixture to 90-100 ° C, filtering a solution of a sulfur-carbon mixture and potassium nitrate, crystallizing the latter with constant cooling of the crystallizer, collecting crystals of potassium nitrate, centrifuging it to remove the solution and drying, characterized in that the filtration is carried out with the stirrer operating in a heated filter, crystallization is carried out with stirring of the solution by supplying compressed air formed in cr In the crystallizer, the mother liquor is pumped into the tank, heated to a temperature of 90-100 ° C and washed with the precipitate on a heated filter, the resulting solution is again fed into the crystallizer and subjected to crystallization, the precipitated nitrate precipitate is removed, and the remaining solution in the crystallizer is again sent for mixing with the utilized smoky gunpowder.

Images