CC BY
12
n the solid phase [2].
To determine the phase composition of phosphorite and products of its processing, X-ray phase analysis was carried out. The phase composition of the initial and processed sample of phosphorite raw materials was studied using a Bruker AXS X-ray diffractometer (Germany). The diffraction patterns were interpreted automatically using the EVA software package of a Bruker AXS X-ray diffractometer. Diffractograms of the original and processed sample of phosphorite raw materials are shown in Figures 3,4 and 5.
Figure 3 shows a diffraction pattern of a sample of the original LPh; the diffraction pattern contains lines of quartz and dolomite, characterized by 2 9 angles of reflections of diffraction lines (angular degrees). Quartz: 29.38; 20.82; 2.62; 50.2. Dolomite: 31.98; 33.18; 39.39; 41.2; 50.4; 51.3.
Rice 3. X-ray diffraction pattern of the original LPh (Fosmuka 1-layer)
Figure 4 shows the X-ray diffraction pattern of LPh processing (Fosmuka 1-layer) with 10% HNO3 solution. Quartz is present as impurities in the fluorocarbonate apatite phase (29 are the angles of diffraction reflections, angular degrees: 20.9; 20.47; 26.7; 49.68; 49.61; 60.72), perixiglas (magnesium oxide) (29 - angles of diffraction
reflections, angular degrees: 35.94; 42.9; 62.3; 78.5), calcium oxide (2 9 - angles of diffraction reflections, angular degrees: 25.9; 25.88; 26.73; 28 .18; 29.87; 30.34; 48.43; 47.07), silicon oxide (29 - angles of diffraction reflections, angular degrees: 57.47; 64.73; 72.99; 23.02).
Figure 4. X-ray diffraction pattern of the LPh processing product (Plast I) with 10% HNO3 solution
A comparison of the diffraction patterns shows that in Fig. 5 there are no most intense peaks characteristic of dolomitic carbonate components, and in Fig. 4 there are only weak reflections at 50.4; 51.3. This corresponds
to the fact that carbonates are not completely decomposed in the IR spectrum of the nitric acid-treated sample, while complete decarbonization occurs in the hydrochloric acid-treated sample [5].
Figure 5. X-ray diffraction pattern of the LPh processing product (Plast I) with 20% HCl solution
Another feature of the conducted acid processing of phosphorites is that, theoretically, with this method of processing, the silicate components should not be subjected to decomposition. However, the results of the analysis of the liquid phase indicate a sufficient content of SiO2 in the solution. In addition, a comparison of the diffraction patterns indicates a significant decrease in the intensity of the main reflection of quartz at 29.84 (1430, Fig. 4.), 29.84 (5900, Fig. 5) relative to a similar reflection of 29.38 (~14500, Fig. 3) in the diffraction pattern original sample of phosphorite.
The reason for the facts is the presence of up to 2.0% F in the original phosphorite. In our opinion, due to the presence of fluorine in the original phosphorite during acid processing, the decomposition of fluoride salts occurs with the formation of HF. Further, under the action of HF, the silicates are converted into [SiF6]-2,
which contributes to their transition into solution. Following this, in the diffraction patterns of acid-processed products, the intensities of the peaks characteristic of quartz constituents of phosphorite are reduced.
Conclusion
Based on the results of the studies carried out, it can be concluded that low-grade phosphorites (< 15% P2O5) can be processed under the action of strong acids, with the production of liquid and solid phases. The liquid phase is dominated by phosphate, chloride, and nitrate ions, respectively, depending on the acid used, as well as metal cations. The solid phases mainly consist of activated aluminosilicates and phosphates. Depending on the composition, both phases formed can be used in the future to obtain inorganic materials for special purposes, to which the results of our next studies will be devoted.
References:
1. Patent of the Republic of Uzbekistan No. IAP 05945. Composition for fire-retardant treatment of cellulose materials. / Tursunova I.N., Mardonov U.M., Erkaev A.U., Muratova M.N., Umirov F.E., Umarova A.T. // Appl.04.03.2014., Bulletin No. 9 (173). -Tashkent, 2015b publ.28.08.2019.
2. Nakamoto K. Infrared spectra of inorganic and coordination compounds. - M.: Mir, 1966. -216s.
3. Plyusina I.I. Infrared spectra of minerals.-M. Publishing House of Moscow State University, 1977, -175 p.
4. Korovin M.V., Anan'eva L.G. Infrared spectroscopy of carbonate rocks and minerals. Uch. allowance, Publishing House of the Tomsk Polytechnic. University, 2016, - 71s.
5. Gotto Z.A., Shevchuk V.V., Mozheiko F.F., Ostrovsky L.K. Activation of phosphate rock by partial decomposition with mineral acids.// Vesti National Academy of Sciences of Belarus. Gray chemical sciences. , 2014, No. 3. pp. 110-116.
