PL16975B1 - Method for the production of sodium nitrate. - Google Patents

Description

Soda and nitric acid are usually used as starting materials for the production of sodium nitrate. Soda is produced in a separate factory from cooking salt, which makes it an expensive raw material. Production of sodium nitrate directly from cooking salt. and nitric acid is inexpensive and heretofore without practical significance. Although various methods have been proposed for the de-distillation of the hydrochloric acid formed, the separation of the resulting mixture of hydrochloric acid, nitric acid and the reaction products of these acids presents considerable difficulties. and calcium nitrate it is possible to obtain sodium nitrate in solution and gypsum as a precipitate.Moreover, it is known that gypsum can be converted with ammonium carbonate into ammonium sulphate and calcium carbonate. Using both of the mentioned reactions it is prepared, according to the present invention, from NaCl, HNO3 and NH3, as raw materials, in the closed circular process of NaNOs and NH4Cl. In the above circular process, the circulation of CaO, SO3 and CO2 as auxiliary means The process is carried out as follows. The solution obtained in the process, containing (NHJ2SO4, NHJ21 and NaCl, is mixed with NaCl in an amount equivalent to (NH4) 2SO ± and NH3 is introduced. The formation of SO2 as a precipitate which separates and is treated with nitric acid together with calcium carbonate which is chilled in the wheel process, resulting in the formation of gypsum and a NaNO3 solution, while the CO2 escapes. The gypsum is separated by decalcification and oozing from the NaNO3 moiety which is evaporated to give solid NaNO3. Instead of evaporating the NaNO 3 solution, it can be cooled to separate some of the NaNO 3 and the mother liquor used to dissolve further amounts of Na 2 SO 4. The lug, containing the Na 2 O.sub.3 moons obtained in the first run, cooled the sieve to separate some NH.sub.4 Cl. To facilitate the release of NH4Cl, NaCl can already be added here, used as a raw material. After separation from NH4Cl, the slurry is saturated with CO2 to produce (NHJ2CO3. The necessary carbonic acid is obtained by the treatment of Na2SO4 and CO3 already described with HNO3. The solution of (NH4) 2CO3, NH4Cl, NaCl thus obtained is mixed with gypsum, obtained in the preparation of NaNO3, while gypsum forms (NH4) 2SO4 and CaCO3. This transformation takes place smoothly, due to the increased solubility of the gypsum in the NH4Cl solution. The solution obtained in this way is the solution mentioned in the introduction (NHJ2SO4) NaCl, NaCl is added to which NaCl is added and NH3 is introduced, resulting in new amounts of Na2SO4 and so on. For better NaJiOi yield, an excess of NaCl, which remains in the circular circulation in the solution, is preferred. Instead of introducing NH3 after conversion of CaSO4 a (NHJ2CO3, NH3 can also be added before the above reaction. This has the advantage that the cold solution, after being separated by NH4Cl cooling, is heated without any more favorable heat for the reaction, because Na2SO4 and CaCOs are treated that you are using HNO3 together, you don't need to sip them separately. On the contrary, common desiccation gives a great practical advantage, because, as is known, the chemically separated CaCO 3 is soaked in its fineness with great difficulty. Of course, high ammonium chloride is recovered and reintroduced into the process before the regeneration of ammonium chloride. PL

Claims (6)

Claims, 1. The method for the preparation of sodium nitrate, characterized by the fact that the lye obtained by mixing a carbonate solution and ammonium chloride obtained in the process with the gypsum obtained in this process and with calcium carbonate is treated with sodium chloride and ammonium chloride. As such, the mixture of solid sodium sulphate and calcium carbonate produced is then treated with nitric acid to keep gypsum, sodium nitrate solution and carbonic acid returning to the process separated from the mixture of sodium sulfate and calcium carbonate The ammonium chloride ammonium chloride solution is cooled to remove some of the ammonium chloride and treated with carbonic acid to form ammonium carbonate, the black ammonium carbonate and ammonium chloride solution is mixed with the plaster obtained previously. 2. Method according to andastrz. A method as claimed in claim 1, characterized in that most of the sodium nitrate is released solid from the sodium nitrate solution by cooling, and the mother liquor is used to dissolve further amounts of sodium sulfate for conversion with nitric acid and calcium carbonate, 3. The method according to claim 1, characterized by the fact that the calcium carbonate obtained by mixing gypsum with a solution of carbonate and ammonium chloride is not separated before mixing with sodium chloride. 4. A method according to claim 1, characterized in that sodium chloride is introduced before the separation of the anion adsorption by cooling for better separation of the latter. 5. Way according to zastiriz. The method of claim 1, wherein the total amount of ammonium required in the process is introduced before the gypsum is mixed with the carbonate and ammonium chloride solution to heat the slurry without externally applying heat to a temperature more favorable to the reaction. 6. The method according to isastrz, characterized by the fact that an excess of sodium chloride is constantly dissolved in the liquor, so that the separation of sodium sulphate is complete, Chemieverfahren Gesellschaft mb H. Deputy: Dr, Eng. M Kryzan, patent attorney. pavement of L. Boguslawski I Skl, Warsitwa. PL