Study of The Physicochemical and Commercial Properties of NPK Fertilizers

Kyzylkum phosphate rock was studied with a nitric acid content of 50 and 75 and 100%, as well as in fertilizers obtained from the ratio of R2O5: K2O = 1:1. The gyroscopic points of the fertilizer size of 2-3 mm were determined at 250 ° C by the desiccator method of N.Ye. Pestov. The points of hygroscopicity of fertilizer samples with an initial moisture content of 1.0% were No. 1 - 46.5%, No. 2 - 38.0% and No. 3 - 32.4%.

Monitoring Hydrofluoric Acid Activity by Vapor-Phase Infrared Spectroscopy

Infrared spectra of the vapor phase over solutions approximating those used in the dissolution of plutonium, typically 10 M in nitric acid and 0.2 M in hydrofluoric acid, reveal that the hydrofluoric acid (HF) activity can be monitored in a facile and noninvasive manner. The amount of vaporized HF is strongly dependent upon the nitric acid content; the vapor-phase HF content over a series of solutions in which the HF concentration is held constant at 0.5 M increases by a factor of nearly 25 as the HNO3 concentration is increased from 0 to 14 M. This effect is due to changes in the HF activity and is not a result of changes in the heat of vaporization, which was measured (by van't Hoff plots) to be 9.4 ± 0.6 kcal/mole for 16 mock process solutions ranging from 0.01 to 0.1 M HF and 8 to 14 M HNO3. This result demonstrates that spectroscopic methods can use the vaporization of an analyte to measure the activity rather than the concentration.