DE340595C - Process for the production of a fertilizer - Google Patents

Description

Process for the production of a fertilizer. The purpose of the procedure is the sodium bisulphate residues, which are produced from nitric acid during the manufacture of nitric acid waste, to make them usable for digesting rock phosphates and in this way to save the corresponding amounts of sulfuric acid.

Aqueous bisulfate solutions only give poor digestion results. Therefore an attempt was made to digest the digestion by melting it together with sodium bisulfate to accomplish. . The easily melting bisulfate is transformed into the neutral sulphate, which has a very high melting point the temperature is gradually increased to a very high level in order to keep the digestion mass in the molten liquid To maintain conditions. Due to the high digestion temperature, however, the unlocked Phosphoric acid is partly insoluble again, so that no superphosphate is obtained in this way can produce.

Experiments have now shown that when melting rock phosphates Good digestion results are achieved with bisulphate when using easily melting salts is added, whereby the melting temperature is kept so low that it becomes re-insoluble of the digested phosphate does not take place.

Ammonium sulfate has proven to be particularly suitable for this purpose.

Now, however, class 16 is already in patent specification 27076 has been proposed that the digestion of rock phosphates by means of acidic, sulfuric acid To accomplish ammonia to make ammonia-containing superphosphates. from This method differs the present invention on the one hand by the Use of neutral ammonium sulphate, which is only partially produced by reaction with the sodium bisulfate passes into acidic ammonium sulfate and the fact that not the The amount of ammonium salt equivalent to the rock phosphate, but considerably less used is, namely only as much as the required lowering of the melting temperature necessary is.

For example, 100 parts of phosphate, 23o parts of sodium bisulphate and 100 parts of neutral ammonium sulphate are melted together. A honey-thick melt is then obtained at 50 to 16 °, which solidifies to a solid glass when it cools and contains 96 percent water-soluble phosphoric acid.

With the new method, the falling in large quantities and Sodium bisulphate, which is otherwise difficult to use, to produce a high-quality fertilizer made usable.

Claims (1)

PATENT CLAIM: Process for the production of a fertilizer, characterized in that rock phosphates are melted together with sodium bisulfate and an amount of a neutral ammonium salt, in particular ammonium sulfate, which is considerably less than the equivalent of the sodium bisulfate or rock phosphate used, but which is sufficient to maintain the melting temperature of the mixture to be reduced so far that the digested phosphate does not become insoluble again.