Determination of Uranium Concentration in Uranium Ore

Determination of Uranium Concentration in Uranium OreInvestigation of effective Parameters on ratiocination of uracil submerging in uracil ore by X-ray fluorescence spectrographic analysisA. AliValiOllahi*, Gh. Alahyarizadeh, S. A. Ahmadi, A. Minuchehr, A. ZolfaghariAbstractUranium concentration in four variant sample solutions (A, B, C and D) of uracil ore was determined by X-Ray Fluorescence spectroscopy (XRF) and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The effect of several different parameters on the XRF results including types of acid digestion, sample amount and standardisation orders were overly investigated. Regarding to absent of uranium ore standard, the samples were wide-awake as solutions. Three different microwave acid digestions, (HNO3 HCl HF-622), (H3PO4 H2SO4 HF-333), (HNO3 H2O2 HF-422), were utilize. The highest uranium concentrations for trio samples (A, C and D) were obtained by third acid digestion rule and another sample (B), was obtained by second acid digestion, which were 10.8, 4.8, 9.8 and 12.5 ppm, respectively. To study the matrix effect, different standard calibrations such as external calibration, internal do-gooder were applied. The results were also confirmed by the measuring sticks which were performed by ICP-OES.Keywords Uranium ore, X-Ray Fluorescence spectroscopy, ICP-OES, Microwave acid digestion, internal additionIntroductionUranium is the famous element from the actinide series in the periodic instrument panel which has an atomic number of 92. it is silver color, ductile, flexible and slightly paramagnetic metal which has high density. Uranium is the material of vast technological importance because of its use as the main fuel in nuclear reactors. The usual source for uranium production is uranium ores which are too limited. Therefore, aspiration of uranium concentration in the uranium ores has very high importance 1, 2.Several techniques have been developed for determinatio n of uranium. Including inductively coupled germ plasm-mass spectrometry (ICP-MS) 3, 4, inductively coupled germ plasm atomic emission spectrometry (ICP-AES) 5, inductively coupled plasma optic emission spectrometry (ICP-OES) 6, 7, flame atomic acculturation spectrometry (FAAS) 8, graphite furnace atomic absorption spectrometry (GFAAS) 9, X-Ray fluorescence spectrometry (XRF) 10, 11. Geological samples which contain uranium are most commonly analyzed by XRF method. Many studies have been carried out on the use of XRF for determination of uranium concentration in ore samples. P. Arikan et al studied quantitative analysis of uranium in ore deposit by XRF their experiments clearly yield the capability of XRF method for analysis of uranium in uranium bearing ores 12. M. A. Al-Eshaikh determined uranium content in phosphate ores employ different measurement techniques they concluded that XRF provides the accurate results for heavy elements such as uranium 15. Furthermore, many resea rches have been issued on the use of ICP-OES for the determination of uranium in uranium matrices. P. Murugesan et al studied determination of total concentration of uranium in borehole core samples by ICP-OES they concluded that the ICP-OES results obtained compare favorably by using differential technique in laser-induced fluorimetry, which they employ as a reference measurement procedure 13 and J. S. Santos et al studied operating condition for determination of uranium by ICP-OES their results concur with the results achieved using ICP-MS 14.In the present study, XRF spectrometry was utilize to determine the concentration of uranium in four different uranium ore samples which was watchful by three various acid digestion strategies. The effect of different acid digestions and also different addition methods were studied on the results. ICP-OES method was also used for the results validation.Materials and methodsInstrumentationThe analytic determination of uranium was carried out with ICP-OES spectrometer Spectra Genesis and XRF spectrometer Spectra Xepos.A Spectra Xepos XRF spectrometer that uses a 50 watt end-window X-ray tube to excite samples was used for XRF measurements. The target changer, with up to 8 polarization and secondary targets, offers many different excitation conditions ensuring optimum determination of all elements from Na to U. The detector is a state-of-the-art silicon drift detector and measurements can be conducted in a He gas.And also a Spectro Genesis spectrometer that is equipped with powerful automation functions for the safe unattended analysis of a large number of samples with an optional autosampler, several hundred samples can be processed without operator intervention. An extensive mail boat Such as a wide range of sample introduction systems, autosamplers, an autodilutor, an ultrasonic nebulizer and hydride generator accessories is available for the Spectro Genesis and it covers the entire relevant wavelength range fro m one hundred seventy-five to 777nm. A free-running generator with a frequency of 27.12 MHz and a power output of 0.7 to 1.7 kW is utilized. It includes automatic plasma ignition as well as an energy and argon-saving standby mode. The software uses for the Spectro Genesis is The Smart Analyzer Vision software. circuit card 1 shows some operating conditions and basic information about the devices used in this study. knock back 1 Operating parameters of ICP-OES and XRFThe sample digestions were arranged using the Multiwave 3000 Anton Paar Microwave Digestion System with eight digestion vessels was used for microwave assisted acid digestion procedures. delay 2 shows operating conditions used for the acid digestion procedures. duck 2 Operating programs of microwave acid digestionsFanHold(min)Ramp(min)P-Rate( bar/sec)Power WattProgram131515500.56000Cleaning124520500.57000 important122020000.56000ComplexingReagents and solutionsThe acids were used hydrochloric acid (37% w/v), nitric aci d (67% w/v), hydrofluoric acid (40% w/v), sulfuric acid (95% w/v), phosphoric acid (424% w/v) and hydrogen peroxide (521% w/v) were suprapure reagents (Suprapure, Merck). Boric acid (2% w/v) was analytical-reagent grade (AnalaR BDH, Chemical Poole, England). High-purity wet (electrical resistivity 18Mcm) was produced with a Milli-Q system (Millipore, MA, USA).Calibration was obtained with external standards. Standard solutions were prepared by diluting a 1000ppm uranium standard solution (ICP Multielement Standard IV, Merck, Darmstadt, FRG).Sample trainingFour different uranium ore samples were collected from various regions of Iran that named A, B, C and D.To prepare the liquid sample for examination with XRF and ICP-OES spectrometers, the ore samples should be completely digested using acid combinations. imputable to the silica in the samples, HF acid had to be used to achieve complete digestion. Three different acid combinations were used, first 6ml of hydrochloric acid, 2ml of nitric acid confident(p) 2ml of hydrofluoric acid (HNO3HClHF-622) 16, second 3ml of phosphoric acid, 3ml of sulfuric acid and 3ml of hydrofluoric acid (H3PO4 H2SO4 HF-333) 17 and third 4ml of nitric acid, 2ml of hydrogen peroxide and 2ml of hydrofluoric acid (HNO3 H2O2 HF-422) 18, 19.0.4g of apiece ore sample (Results and discussionsCalibration of XRF methodStandard 1000ppm uranium solutions were available five solutions (100ppm, 20ppm, 5ppm, 2ppm and blank) were prepared, 3.5ml of each solution was analyzed in the XRF and the uranium method was created. For deter archeological site different elements in XRF method usually K or L is used, since uranium is a heavy element, L was measured 21, 22, 23. Intensities of uranium peaks and calculated concentration of uranium in standard solutions is summarized in table 3 and the calibration curve is plotted in figure 1.Table 3 Normal impulses and calculated conc. of U in StandardsFigure 1 Calibration plot of standards using X-Rays square up of different acid digestions on uranium measurementThe uranium ore samples (A, B, C and D) were digested using three different acid digestion strategies. Using the uranium method obtained from calibration 3.5ml samples were prepared and analyzed in the XRF and their uranium concentrations were measured, results are summarized in table 4.Table 4 Uranium concentration (ppm) of U-ore samples by XRFknead of the volume of samples on uranium measurementTo check the influence of the volume of samples on measurements, 2ml, 3ml, 3.5ml and 4ml samples were also prepared using sample B 333 and analyzed in the XRF and their uranium concentrations were measured using the uranium method previously obtained. Table 5 shows the results and it can be seen, the volume of samples has insignificant effect on the results.Table 5 Uranium concentration (ppm) for different amount of sampleInfluence of addition on sample matrices in XRF measurementSince the matrix structure of samples has a significant i nfluence on XRF measurements, the influence was studied using the addition method. One of the uranium ore samples (sample B) was used 2.5ml of this sample was added by 1ml of the addition solution. Addition solutions were 200ppm, 100ppm, 50ppm and blank. The final solutions were analyzed by XRF using uranium method. The results are summarized in table 6 and figure 2.Table 6 Uranium concentration (ppm) for various additionsFigure 2 Uranium concentration for various additionsAnother addition method was also used, in this method 3ml, 2.5ml, 2ml, 1.5ml, 1ml and 0.5ml samples were added by respectively 0.5ml, 1ml, 1.5ml, 2ml, 2.5ml and 3ml of standard 100ppm solution, the results are summarized in table 7 and figure 3.Table 7 uranium concentration (ppm) of various additionsFigure 3 Concentration of various additionsICP-OES method results compared to XRFDue to its high accuracy, rapid analysis and simplicity, ICP-OES method was used for result validation. Similar to the XRF method, cali bration is achieved using standard solutions. Eight standard solutions were used, and the results are summarized in table 7 and the calibration curve is plotted in figure 3Table 8 Insenties of U peaks and calculated conc. of U in standard solutionsFigure 4 Calibration plot of standards using ICP-OES. The uranium ore samples (A, B, C and D) were digested using resembling acid digestion strategies used in XRF method. Uranium concentrations were measured in the samples (table 9).Table 9 Uranium concentration (ppm) of U-ore samples by ICP-OESAs it can be seen the results of uranium concentration from ICP-OES are conformity with the results of XRF.ConclusionUranium is a material of vast technological importance because of its use as a main fuel in nuclear reactors. Determination of uranium concentration in uranium ores has very high importance. Uranium concentration in four different ore samples of Iran uranium ores was determined by XRF and ICP-OES spectrometry methods. Three different microwave acid digestions were used. After sample preparation, calibration was done using standard solutions. Five samples were used for the XRF method and eight were used for ICP-OES. The uranium concentration was measured in these samples.References1 N. L. Misra, S. Dhara, A. Das, G. S. Lodha, S. K. Aggarwal And I. Varga, Trace determination of uranium in fertilizer samples by total reflectance X-ray fluorescence, Pramana J. Phys., Vol. 76, No. 2, February 20112 J. S. Santos, L. S. G. Teixeira, W. N. L. dos Santos, V. A. Lemos, J. M. Godoy and S. L.C. Ferreira, Uranium determination using atomic spectrometric techniques An overview, Analytica Chimica Acta 674 (2010) 1431563 A. Sasmaz M. Yaman, Determination of Uranium and Thorium in Soil and Plant separate around Abandoned LeadZincCopper Mining Area, Communications in Soil Science and Plant Analysis, (2008), 3917-18, 2568-25834 C. Charalambous, M. Aletrari, P. Piera, P. Nicolaidou-Kanari, M. Efstathiou, I. Pashalidis, Uranium levels in woman of the street ground water samples determined by ICP- M S and alpha-spectroscopy, diary of Environmental Radioactivity 116 (2013) 187e1925 A. Premadas, P. K. Srivastava, Inductively coupled plasma atomic emission spectrometric determination of lanthanides and Y in various uranium hydrometallurgical products, Journal of Radioanalytical and Nuclear Chemistry, Vol. 251, No. 2 (2002) 2332396 K. Satyanarayana and S. Durani, Separation and inductively coupled plasma optical emission, spectrometric (ICP-OES) determination of eviscerate impurities in nuclear grade uranium oxide, J Radioanal Nucl Chem (2010) 2856596657 M. Bettinelli, G.M. Beone, S. Spezia and C. Baffi, Determination of heavy metals in soils and sediments by microwave-assisted digestion and inductively coupled plasma optical emission spectrometry analysis, Analytica Chimica Acta 424 (2000) 2892968 B. P. Li, M. B. Luo, J. Q. Li, W. Liu, Y.Z. sunbathe and G.L. Guo, Determination of cadmium and lead in high p urity uranium compounds by flame atomic absorption spectrometry with on-line micro-column preconcentration by CL-7301 resin, Journal of Radioanalytical and Nuclear Chemistry, Vol. 278, No.1 (2008) 389 T. Inui, A. Kosuge, A. Ohbuchi, K. Fujita, Y. Koike, M. Kitano and T. Nakamura, Determination of heavy metals at sub-ppb levels in water by graphite furnace atomic absorption spectrometry using a direct introduction technique after preconcentration with an iminodiacetate blood disk, American Journal of Analytical Chemistry, (2012) 3, 683-69210 Y. B. Rao, B. V. V. Ramana, P. G. Raghavan and R. B. Yadav, Determination of uranium in process stream solutions from uranium extraction plant employing energy dispersive X-ray fluorescence spectrometry, J Radioanal Nucl Chem (2012) 29437137611 S. Dhara, N. L. Misra, S. K. Aggarwal and V. Venugopal, Energy dispersive X-ray fluorescence determination of cadmium in uranium matrix using Cd K line excited by continuum, Spectrochimica Acta Part B 65 (2010) 461 46512 P. Arikan and A. Ozmen, Quantitative analysis of uranium in ore deposit by calibration normalization of XRF, Commun. Fac. Sci. Univ. Ank. Series A2, A3, (1987) V. 36, pp 35-4013 P. Murugesan1, S. K. Jain1, M. Kumar, P. K. Tarafder and D. P. S. Rathore, Determination of total concentration of uranium in borehole core samples comparative studies using differential technique in laser-induced fluorimetry and ICP-OES, Exploration and Research for atomic Minerals, Vol. 23, 2013, pp. 137-14414 J. S. Santos, L. S. G. Texeira, R. G. O. Araujo, A. P. Fernandes, M. G. A. Korn and S. L. C. Ferreira, Optimization of the operating conditions using factorial designs for determination of uranium by inductively coupled plasma optical emission spectrometry, Micro chemical Journal 97 (2011) 113-11715 M. A. Al-Eshaikh, A. N. Kadachi, M. M. Sarfraz, Determination of uranium content in phosphate ores using different measurement techniques, Journal of King Saud University Engineering Sc iences (2013)16 M. Chen and L. Q. Ma, Comparison of Three aqua Regia Digestion Methods for Twenty Florida Soils, Soil Sci. Soc. Am. (2001) J. 6549149917 S. V. D. Sluis, Y. Meszaros, W. G. J. Marchee, H. A. Wesselingh and G. M. V. Rosmalen, The digestion of phosphate ore in phosphoric acid, Ind. Eng. Chem. Res. 1987, 26, 2501-250518 F. L. Pantuzzo, J. C. J. Silva, V. S.T. Ciminelli, A fast and accurate microwave-assisted digestion method for arsenic determination in complex mining residues by flame atomic absorption spectrometry, Journal of Hazardous Materials 168 (2009) 1636163819 J. Ivanova, R. Djingova, S. Korhammer and B. Markert , On the microwave digestion of soils and sediments for determination of lanthanides and some toxic and essential elements by inductively coupled plasma source mass spectrometry, Talanta 54 (2001) 56757420 Brian Lee Francom, X-ray fluorescence instrument calibration, Theory and Application, Department of Physics Brigham Young University-Idaho, December 200821 R. M. Conrey, J. A. Wolff, A. Seyfarth, A. VanHoose, M. Goodman-Elgar, N. Bettencourt, D. Boschmann and K.Werling, Portable XRF Calibration Using Influence Coefficients22 D. F. Siems, the Determination of 30 Elements in Geological Materials by Energy-Dispersive X-ray Fluorescence Spectrometry, (2000) Open-File Report 00-475